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MORBID OBESITY (CLASS III OBESITY)

Obesity is an increase in body weight beyond the limitation of skeletal and physical requirements caused by an excessive accumulation of fat in the body. Morbid obesity, also referred to as clinically severe obesity and class III obesity, refers to an individual with a body mass index (BMI) of 40 or greater.

Morbid obesity (class III) is also categorized based on BMI with terms such as super-obese (BMI >50) and super-super obese (BMI >60). BMI is a measurement of excess adipose tissue in the body according to height and weight that is used to quantify body fat.

The immediate cause of obesity is a caloric intake that is persistently higher than caloric output. Obesity may also be caused by illnesses such as hypothyroidism, Cushing disease, and hypothalamic lesions.

Morbid obesity (class III) has been associated with cardiac disease, type 2 diabetes mellitus (T2DM), obstructive sleep apnea (OSA), and various cancers. The initial treatment for morbid obesity (class III) is usually medical management using conservative measures. Medical management to induce weight loss includes caloric restriction, increased physical activity, US Food and Drug Administration (FDA)–approved weight-loss agents, and behavioral modification.

Another method used for weight loss is supplemented fasting, which combines a low-calorie intake with a supplemented mixture of protein, carbohydrates, vitamins, and minerals. However, prolonged adherence to this diet (≥2 months) has resulted in undesirable results such as loss of body protein, cardiopathology, or, in some cases, sudden death. Therefore, supplemental fasting is not a standard treatment for morbid obesity.

When attempts to induce weight loss through the medical management methods described above have failed, bariatric surgery is often considered as an intervention to treat morbid obesity. Current surgical procedures used for weight loss in morbidly obese (class III) individuals have been noted to reduce medication use and, in some cases, eliminate T2DM altogether in morbidly obese individuals. The same procedures have been proposed to treat T2DM in individuals who are not morbidly obese. Refer to Attachment A in this policy for BMI charts.

Bariatric surgical procedures reduce caloric intake by modifying the anatomy of the gastrointestinal tract. These procedures are classified as follows:

• Restrictive procedures
• Gastric restriction combined with a diversionary procedure
• Diversionary malabsorptive procedures (regulatory metabolic)

Restrictive procedures, such as adjustable gastric banding and vertical banded gastroplasty (VGB), cause weight loss by limiting the capacity of the stomach for food and by slowing the flow of ingested nutrients. Diversionary (alone or combined with a restrictive procedure) and malabsorptive procedures bypass or resect the stomach and also bypass long segments of the small intestine in order to reduce the area of mucosa available for nutrient absorption.

With restrictive procedures, expected weight loss is approximately 50% of an individual's presurgery body weight. Diversionary procedures provide for a weight loss of as much as 60% to 70% of body weight. In general, weight loss with malabsorptive procedures tends to be greater than weight loss with solely restrictive procedures. Studies show that individuals reach their maximum expected weight loss within 2 years of the procedure. Within this 2-year time frame, a normal stretching of the gastric pouch occurs; therefore, unless the individual continues with dietary restrictions and exercise, weight loss will plateau, or the individual may regain weight. A dedicated and experienced team is needed to assess, educate, and manage the individual before and after surgery. Studies have shown that bariatric surgery performed at hospitals with more than 100 cases performed annually is associated with fewer complications and a greater degree of success.

Epidemiologic data have shown that lower BMI values are correlated with risk of T2DM, cardiometabolic risk factors, and increased risk of mortality in South Asian, Southeast Asian, and East Asian populations when compared to other ethnic groups (Ntuk et al., 2014; Razak et al., 2007; Zhou, 2002). In 2000, the World Health Organization proposed the following weight classification in adult Asians: BMI less than 18.5 kg/m² indicates underweight; 18.5 to 22.9 kg/m² is healthy weight; 23 to 24.9 kg/m² is overweight, 25 to 29.9 kg/m² is obese class I, and 30 kg/m² or higher is obese class II. The United States Census Bureau collects race data according to US Office of Management and Budget guidelines, and these data are based on self-identification. According to the US Census Bureau, Asian is defined as a person with origins from the Far East (China, Japan, Korea, and Mongolia), Southeast Asia (Cambodia, Malaysia, the Philippine Islands, Thailand, Vietnam, Indonesia, Singapore, Laos, etc.), or the Indian subcontinent (India, Pakistan, Bangladesh, Bhutan, Sri Lanka, and Nepal) (2010). The National Center for Health Statistics, a division of the Centers for Disease Control and Prevention (CDC), also collects data on race; they state that race is based on a respondent's description of their own racial background, regardless of Hispanic or Latino origin (2019).

MEDICALLY NECESSARY BARIATRIC SURGICAL PROCEDURES

Bariatric surgery is performed to treat class III (clinically severe) obesity. Class III obesity, formerly referred to as morbid obesity, is defined as a BMI greater than 40 kg/m² or a BMI greater than 35 kg/m² with associated complications including, but not limited to, T2DM, hypertension, or OSA. Class III obesity results in a very high risk for weight-related complications, such as T2DM, hypertension, OSA, and various types of cancers (for men: colon, rectal, prostate; for women: breast, uterine, ovarian), and a shortened lifespan. A man with class III obesity at age 20 can expect to live 13 fewer years than his counterpart with a normal BMI, which equates to a 22% reduction in life expectancy.

According to the CDC, obesity is also frequently classified into the following categories: class I: BMI of 30 to less than 35 kg/m²; class II: BMI of 35 to less than 40 kg/m²; and class III: BMI of 40 kg/m² or higher. Class III obesity is sometimes categorized as “severe" obesity.

The first treatment of class III obesity is dietary and lifestyle changes. Although this strategy may be effective in some individuals, only a few individuals with class III obesity can reduce and control weight through diet and exercise. Most individual​s find it difficult to comply with these lifestyle modifications on a long-term basis. When conservative measures fail, some individuals may consider surgical approaches.

Resolution (cure) or improvement of T2DM after bariatric surgery and observations that glycemic control may improve immediately after surgery before a significant amount of weight is lost have promoted interest in a surgical approach to the treatment of T2DM. The various surgical procedures have different effects, and gastrointestinal rearrangement seems to confer additional antidiabetic benefits independent of weight loss and caloric restriction. The precise mechanisms are not clear, and multiple mechanisms may be involved. Gastrointestinal peptides, e.g., glucagon-like peptide-1, glucose-dependent insulinotropic peptide, and peptide YY, are secreted in response to contact with unabsorbed nutrients and by vagally mediated parasympathetic neural mechanisms. Glucagon-like peptide-1 is secreted by the L cells of the distal ileum in response to ingested nutrients and acts on pancreatic islets to augment glucose-dependent insulin secretion. It also slows gastric emptying, which delays digestion, blunts postprandial glycemia, and acts on the central nervous system to induce satiety and decrease food intake. Other effects may improve insulin sensitivity. Glucose-dependent insulinotropic peptide acts on pancreatic beta cells to increase insulin secretion through the same mechanisms as glucagon-like peptide-1, although it is less potent. Peptide YY is also secreted by the L cells of the distal intestine and increases satiety and delays gastric emptying.

ADJUSTABLE GASTRIC BANDING (AGB), LAPAROSCOPIC

Recent advances in laparoscopy have renewed the interest in gastric banding techniques for the control of severe obesity. Laparoscopic adjustable silicone gastric banding (LASGB) has become an attractive method because it is minimally invasive and allows modulation of weight loss. Available brands of LASGB include the Lap-Band System (Allergan, Inc., Irvine, CA) and the Realize Adjustable Gastric Band (Ethicon Endo-Surgery, Cincinnati, OH). The claimed advantage of LASGB is the adjustability of the band, which can be inflated or deflated percutaneously according to weight loss without altering the anatomy of the stomach. This method entails encircling the upper part of the stomach using bands made of synthetic materials, creating a small upper pouch that empties into the lower stomach through a narrow, nonstretchable stoma. The reduced capacity of the pouch and the restriction caused by the band diminish caloric intake, depending on important technical details, thus producing weight loss comparable to vertical gastroplasties, without the possibility of staple-line disruption and lesser incidence of infectious complications. However, distension of the pouch, slippage of the band, and entrapment of the foreign material by the stomach have been described and are worrisome.

AGB was designed to mimic the VBG but is a less-invasive procedure. Adjustable banding allows the size of the gastric pouch to be altered with the positioning of the band. This adjustable, inflatable band is placed around the exterior of the stomach to narrow the upper stomach and create a small gastric pouch with a rate-limiting stoma. The band has a balloon that is adjusted by injecting or removing saline from an access port, which is placed under the skin in the abdomen. The band is either initially empty or only partially inflated, allowing the individual to get acquainted with the band while healing from the surgery. A band adjustment is usually made 4 to 6 weeks after surgery, depending on the amount of weight that is lost, the amount of food the individual is able to comfortably consume, the amount of exercise in which the individual is participating, and how much fluid was initially placed in the band. Adjustments are done either in the hospital or in a doctor's office. Use of X-ray equipment (fluoroscopy) may be needed to guide the needle into the access port and/or to evaluate the pouch size and the stoma size. Subsequent adjustments may be made based on the needs of the individual. AGB devices are not FDA-approved for individuals under 18 years of age.

A decision memorandum from the Centers for Medicare & Medicaid (CMS; 2006) found that there was sufficient evidence to support LASGB as reasonable and necessary for Medicare beneficiaries with a BMI greater than 35 and comorbid medical conditions. Sustained weight loss was well documented, ranging from an approximate mean of 30% to 50% excess weight loss in LASGB, compared to an approximate mean of 50% excess weight loss in Roux-en-Y gastric bypass (RYGBP). The CMS decision memorandum found that short- and long-term mortality associated with both LASGB and RYGBP were low (<2%) in this younger age group.

Peer-Reviewed Literature

In a randomized controlled trial (RCT), Dixon et al. (2008) evaluated the safety and effectiveness of laparoscopic AGB (LAGB) compared to conventional therapy in controlling T2DM. Sixty individuals with recently diagnosed (<2 years) T2DM and a BMI between 30 and 40 were enrolled. Of the 60 individuals enrolled, 92% (n=55) completed 2-year follow-up. Outcome measurements included remission of T2DM (fasting glucose <126 mg/dL and hemoglobin A1c [HbA1c] <6.2% while taking no glycemic therapy) and weight loss. Remission of T2DM was achieved by 73% of the LAGB group (n=22) and 13% of the conventional therapy group (n=4), representing a statistically significant difference. Surgical and conventional therapy groups had a statistically significant reduction of 20.7% and 1.7% of mean weight, respectively, at 2-year follow-up (P<0.001). There were no serious complications in either group. The authors concluded that individuals undergoing LAGB were more likely to achieve T2DM remission through greater weight loss. The study is limited in its relatively small sample size and midterm follow-up.

In a prospective RCT, Nguyen et al. (2009) compared the outcomes of laparoscopic RYGBP and LAGB for the treatment of morbid obesity. A total of 250 individuals with a BMI between 35 and 60 were randomly assigned to RYGBP or LAGB. Ultimately, 111 individuals underwent RYGBP and 86 individuals underwent LAGB. Outcome measurements included weight loss, changes in quality of life (QOL), length of hospital stay, and reoperation rates. Treatment failure was defined as less than 20% of excess weight loss (EWL) or conversion to another bariatric operation for failure of weight loss. The mean BMI was statistically significantly higher in the RYGBP group (P<0.01), while the mean age was higher in the LAGB group (P<0.01). Compared with LAGB, operative blood loss was higher and the mean operative time and length of stay (LOS) were longer in the RYGBP group. The 30-day complication rate was higher after RYGBP (21.6% vs. 7.0%). However, there were no life-threatening conditions. The EWL percentage at 4-year follow-up was higher in the RYGBP group (68% vs. 45%; P<0.05). Treatment failure occurred in 16.7% of individuals undergoing LAGB and in 0% of those undergoing RYGBP. The authors concluded that LAGB and RYGBP are both safe and effective approaches for the treatment of morbid obesity. RYGBP resulted in better weight loss at mid- and long-term follow-up, although it may be associated with more perioperative and late complications.

In a multicenter, prospective, open-label study, Shayani et al. (2012) reported on the 2-year results of the LAP-BAND AP® trial. A total of 517 morbidly obese individuals at 50 clinical centers were followed up for 2 years after undergoing LAGB. The mean age was 42.5 years and the mean BMI was 44.0. Outcome measurements included percent weight loss and BMI. At 2-year follow-up, the mean BMI change was −8.5 and the mean percent weight loss was −19.3%. Obesity-related comorbid conditions were remitted or improved in the majority of study participants at 2 years, including T2DM (96), hypertension (91%), gastroesophageal reflux disease (GERD) (91%), hyperlipidemia (77%), OSA (86), depression (75%), and osteoarthritis (93%). LAGB was relatively well tolerated, with 19.1% and 6.0% of individuals reporting device-related adverse events (AEs) or serious device-related AEs, respectively. The authors concluded that LAGB was a safe and effective procedure, with clinically meaningful improvements in QOL and obesity-related comorbidities. The study is limited in its lack of a comparative control group.

In a prospective longitudinal cohort study, O'Brien et al. (2013) evaluated the long-term outcomes associated with LAGB. A total of 3227 individuals, with a mean age of 47 years and a mean BMI of 43.8, were treated with LAGB. Follow-up was intact for 81% of study participants overall and 78% for those beyond 10 years. There was no perioperative mortality for the primary placement or any revisional procedures. Study participants demonstrated a mean of 47.1% EWL at 15 years and 62% EWL at 16 years. There was a mean of 47% EWL for all individuals who were followed up for at least 10 years. Revisional procedures were performed for proximal enlargement (26%), port and tubing problems (21%), and erosion (3.4%). The need for revision has decreased as the technique evolved, with a 40% revision rate for proximal gastric enlargements in the first 10 years. The revision rate decreased to 6.4% in the last 5 years. The authors concluded that LAGB demonstrates a durable weight loss that is maintained to 15 years. The study is limited in its lack of a comparative control group.

SLEEVE GASTRECTOMY, LAPAROSCOPIC OR OPEN

Sleeve gastrectomy (SG) is a surgical weight loss procedure in which the stomach is reduced to about 35% of its original size by surgical removal of a large portion of the stomach, following the major curve. The open edges are then attached together (often with surgical staples) to form a sleeve or tube with a banana shape. The procedure permanently reduces the size of the stomach. The SG was originally developed as the first stage in a two-stage procedure in high-risk individuals with a BMI of more than 60; however, it was later proposed as a stand-alone procedure.

In 2009, the American Society for Metabolic and Bariatric Surgery (ASMBS) issued their Position Statement on Sleeve Gastrectomy as a Bariatric Procedure, stating that the concept of staged bariatric surgery using lower risk procedures as initial treatment appears to have value as a risk-reduction strategy for high-risk individuals, and that, because a significant proportion of individuals have demonstrated durable weight loss after SG and might not require conversion to another procedure, it is justifiable to recommend SG as an ASMBS-approved bariatric procedure. In 2011, the ASMBS noted that SG was considered an acceptable option both as a primary bariatric procedure (stand-alone) and as a first-stage procedure in high-risk individuals as part of a planned two-stage procedure.

A decision memorandum from the CMS (2012) found that open or LSG may be reasonable and necessary for beneficiaries with a BMI greater than or equal to 35 with comorbidities.

An assessment by the California Technology Assessment Forum (CTAF) (Walsh, 2010) concluded that SG does not meet CTAF technology assessment criteria for improvement in health outcomes for the treatment of obesity. The CTAF assessment reported that the results of multiple case series and retrospective studies have suggested that SG as a primary procedure is associated with a significant reduction in excess weight loss. The CTAF assessment reported that the complication rate from SG ranged from 0% to 4.1% and complications included leaks, bleeding, strictures and mortality. The CTAF assessment found few comparative studies of SG. CTAF identified only two RCTs that have compared SG to another surgical procedure (citing Himpens et al., 2006; Karamanakos et al., 2008). These trials included 112 participants who were followed from 1 to 3 years. Among the 80 subjects followed for 3 years, there were a similar number of complications in the SG and the RYGBP groups, although the complications in the SG group were more severe. The CTAF assessment stated that, "[t]o date, long term outcomes from registry studies are relatively limited, but longer term follow-up will provide additional important information."

An assessment of surgical treatment for obesity from the Canadian Agency for Drugs and Technologies in Health (CADTH) (Klarenbach et al., 2010) also concluded that the evidence base for SG is limited.

Peer-Reviewed Literature

A systematic evidence review prepared for the British Medical Journal's Clinical Evidence concluded that the effectiveness of SG for morbid obesity is unknown (DeLaet and Schauer, 2009). The evidence review found no clinically important results from randomized controlled clinical trials about SG compared with nonsurgical treatment, or compared with VGB or biliopancreatic diversion (BPD). They found low-quality evidence that SG may be more effective than gastric banding at increasing weight loss at 1 and 3 years, and moderate-quality evidence that SG seems more effective than gastric bypass at increasing mean EWL at 1 to 2 years.

A systematic evidence review of SG by the Australia and New Zealand Horizon Scanning Network (ANZHSN) (Lee, 2007) found that the evidence showed that LSG can induce substantial EWL at least as effectively as LASGB (in one study up to 3 years postsurgery) but less effectively than gastric bypass and duodenal switch (DS) in the short term. The report noted, however, that these results should be viewed in light of the ease and simplicity of LSG relative to the other more invasive procedures. The report found a comparable reduction in comorbidities in individuals who underwent LSG or RYGBP, most notably in resolution rates of diabetes within 4 months after surgery despite laparoscopic gastric banding individuals being significantly more obese than the RYGBP individuals in the study. Evidence suggested that, compared to LASGB, LSG had lower complication rates but more severe complications. The report found LSG safer than laparoscopic RYGBP or intragastric balloon implantation. The report stated that evidence of the safety of LSG compared with DS is conflicting possibly because of differences in baseline individual characteristics. The report stated that the incidence of gastric sleeve dilatation appears to be an uncommon event, but the evidence is far from conclusive at this point. The report noted that one study found that LSG and LASGB had significantly shorter operative times compared to RYGBP and DS. LSG had a significantly longer LOS compared to LASGB, but a significantly shorter LOS compared to RYGBP and DS. The report found that knowledge gaps include comparing the effectiveness of LSG to established bariatric procedures in super-obese individuals (BMI ≥50) as a stand-alone procedure; long-term (>5 years) safety, durability of weight loss and comorbidity data for LSG relative to existing bariatric procedures; and effects of LSG on plasma ghrelin levels and subsequent effect on appetite. More recently, a review of the literature by the Veterans Health Administration Technology Assessment Program (Adams, 2008) found no new literature that would not alter the conclusions of the ANZHSN review.

A randomized controlled clinical trial comparing short-term (1-year) outcomes of LSG to laparoscopic RYGBP found comparable reductions in body weight and BMI (Karamanakos et al., 2008). However, power calculations were not reported, and the study (n = 32) was likely under-powered to detect clinically significant differences in effectiveness between the two procedures. This study was poorly reported, failing to discuss inclusion criteria for the trial and AEs associated with the procedures.

An earlier retrospective study by Lee et al. (2007) (n = 846) found similar rates of short-term weight loss in persons who elected SG and persons who elected RYGBP or DS procedures. However, the lack of randomization and retrospective nature of the study results in a substantial risk of bias.

The strongest arguments for SG relate to the comparatively poor outcomes of LASGB, which is the competing option for persons wishing to undergo a restrictive (nonmalabsorptive) procedure. A randomized clinical study by Himpens et al. (2006) compared LSG to LASGB (n = 80). Although median weight loss was significantly greater after 1 and 3 years with SG (65 lbs.) than with LASGB (37.5 lbs.), the total weight loss with either procedure was insufficient for most potential candidates. The study also found that SG was associated with more severe complications than LASGB. The study was also poorly reported, including failure to discuss randomization and blinding procedures, and whether any subjects did not comply with randomization or were lost to follow-up. Clinical studies have reported long-term reoperation rates with LASGB of up to 60% (e.g., Scozzari et al., 2009; Camerini et al., 2004; Tweddle et al., 2004; Morino et al., 2002). Australia has reported that the costs of band adjustments with LASGB has exceeded the costs of the primary LASGB procedure.

Colquitt et al. (2009), in the Cochrane Database of Systematic Reviews, reviewed evidence for bariatric surgical procedures. They found that although the effects of the available bariatric procedures compared with medical management  and with each other are uncertain, "limited" evidence suggests that SG results in weight loss similar to RYGBP and greater than with LASGB. The assessment stated that information from the included trials did not allow the authors to reach any conclusions about the safety of these procedures compared with each other. The assessment noted that due to limited evidence and poor quality of the trials comparing each pair of procedures, these conclusions should be viewed with caution.

In an RCT, Kehagias et al. (2011) evaluated the safety and effectiveness of LSG compared to gold standard laparoscopic RYGBP for the management of obesity in individuals with a BMI less than 50. Sixty study participants were randomly assigned to RYGBP or LSG and were monitored for 3 years postoperatively. Outcome measurements included percent EWL, early and late complications, improvement of obesity-related comorbidities, and nutritional deficiencies. There was no statistically significant difference in early and late morbidity in either group and there were no mortalities. Weight loss was statistically significantly better after LSG in the first year of follow-up. At 3-year follow-up, percent EWL reached 62% after RYGBP and 68% after LSG, although this did not represent a statistically significant difference (P=0.13). There was no statistically significant difference in the overall improvement of comorbidities, and nutritional deficiencies occurred at the same rate in both groups, with the exception of vitamin B₁₂ deficiency, which was more common after RYGBP. The authors concluded that both LSG and RYGBP were safe and effective in the reduction of comorbidities, while LSG is associated with fewer postoperative metabolic deficiencies. The study is limited in its relatively small sample size and mid-term follow-up period.

In a double-blind RCT, Lee et al. (2011) evaluated the safety and effectiveness of LSG compared to gold standard RYGBP in moderately obese individuals. Sixty study participants with poorly controlled T2DM after conventional treatment of at least 6 months and a BMI between 25 and 35 were randomly assigned into two groups. The primary outcome measurements was remission of T2DM, defined as fasting glucose less than 126 mg/dL and HbA1c less than 6.5% without glycemic therapy. Secondary outcome measurements included weight and metabolic syndrome. At 12-month follow-up, remission of T2DM was achieved by 93% (n=28) in the RYGBP group and 47% (n=14) of the LSG group, representing a statistically significant difference (P=0.02). Participants enrolled in the RYGBP group lost more weight, achieved a lower waist circumference, and had lower glucose, HbA1c, and blood lipid levels compared to LSG. No serious complications occurred in either group. The authors concluded that individuals undergoing RYGBP were more likely to achieve remission of T2DM compared to individuals undergoing LSG. The study is limited in its relatively small sample size and short-term follow-up period.

ROUX-EN-Y GASTRIC BYPASS WITH LONG LIMB (DISTAL) (>150 CM), LAPAROSCOPIC OR OPEN
RYGBP with long limb (combination restrictive and malabsorption) consists primarily of long-limb RYGBP procedures, which vary in the length of the alimentary and common limbs. The stomach may be bypassed in a variety of ways, involving either resection or stapling along the horizontal or vertical axis. An example of this is to divide the stomach with a long segment of the jejunum (instead of ileum) anastomosed to the proximal gastric stump, creating the alimentary limb. The remaining pancreaticobiliary limb (consisting of stomach remnant), duodenum, and length of proximal jejunum are then anastomosed to the ileum, creating a common limb varying in length, where the ingested food mixes with the pancreaticobiliary juices. The long alimentary limb permits absorption of most nutrients. The short common limb primarily limits fat absorption.

ROUX-EN-Y GASTRIC BYPASS WITH SHORT LIMB (PROXIMAL) (≤150 CM), LAPAROSCOPIC OR OPEN
RYGBP with short limb (combination restrictive and malabsorption), also referred to as the traditional gastric bypass, combines a partition of the stomach with a Roux-en-Y tract less than 150 cm, causing the flow of food to bypass the duodenum and proximal small bowel and to be delivered directly to the jejunum, creating a gastroenterostomy.

Peer-Reviewed Literature

RYGBP combines restriction and malabsorption principles, and combines gastric segmentation along its vertical axis with a Roux-en-Y procedure, such that the food bypasses the duodenum and proximal small bowel. Long-limb RYGBP is similar to standard RYGBP, except that the limb through which food passes is longer and is often used to treat super obese individuals. Because the normal flow of food is disrupted, available literature indicates that there is a greater potential for metabolic complications compared to gastric restrictive surgeries, including iron deficiency anemia, vitamin B₁₂ deficiency, and hypocalcemia, all of which can be corrected by oral supplementation. Several studies have suggested that RYGBP is a more effective weight loss procedure than VBG, offering the best combination of maximum weight control and minimum nutritional risk (Sugerman et al., 1989; Howard et al., 1995). Pories et al. (1995) reported 57.7%, 54.7%, and 49.2% EWL with RYGBP at 5, 10, and 14 years, respectively, in a large series with 95% follow-up. Thus, the RYGB is "the current procedure of choice for patients requiring surgery for morbid obesity" (Barrow, 2002). An assessment conducted by the L'Agence Nationale d'Accreditation d'Evaluation en Sante (French National Technology Assessment Agency [ANAES], 2001; Msika, 2003) found that surgical mortality for RYGBP and VBG is about the same. However, RYGB is associated with significantly more weight loss and has become the procedure of choice for obesity surgery.

Gentileschi et al. (2002) systematically reviewed the published literature on open and bariatric laparoscopic obesity surgery. The authors concluded that the available evidence indicated that laparoscopic VBG and laparoscopic RYGBP are as effective as their open counterparts.

An assessment of laparoscopic RYGBP by the Blue Cross and Blue Shield Association Technology Evaluation and Coverage Program (BCBSA, 2005) stated that among available bariatric surgical procedures, RYGBP appears to have the most favorable risk-to-benefit ratio, and that the overall risk-to-benefit ratio of laparoscopic RYGBP is similar to that of open RYGBP. The assessment found that open and laparoscopic RYGBP induces similar amounts of weight loss. However, the assessment found that the profile of AEs differs between the two approaches. Laparoscopic RYGBP is a less-invasive approach that results in a shorter hospital stay and earlier return to usual activities. The assessment found that the estimated mortality rate was low for both procedures, but somewhat lower for laparoscopic surgery than open surgery (0.3% vs. 1.1%). Laparoscopic RGBY had a higher rate of postoperative anastomotic leaks than open RGBY (3.7% vs. 1.9%), and a somewhat higher rate of bleeding (4.1% vs. 2.4%). The report found, on the other hand, that open surgery had higher rates of cardiopulmonary complications (2.6% vs. 1.0%) and wound infections (11.0% vs. 4.7%). Regarding long-term AEs, the rates of reoperation (9.9%) and anastomotic problems (8.0%) may be higher for laparoscopic RGBY than for open RGBY (6.0% and 2.0%, respectively), while the rate of incisional hernia is higher for open RGBY than laparoscopic RGBY (9.0% vs. 0%).

An assessment by the Institute for Clinical Systems Improvement (ICSI, 2005) found that large studies have shown that RYGBP may result in weight loss of 60% to 70% of excess weight. It also found that VBG shows substantial weight loss efficacy but less than that for RYGBP. In addition, VBG has a high rate of serious morbidity, including a reoperation rate of up to 30% due to stoma obstruction and staple-line disruption. Therefore, the evidence supports the overall superiority of RYGBP over VBG in safety and efficacy for bariatric surgery.

A decision memorandum from the CMS (2006) concluded that the evidence is sufficient that open and laparoscopic RYGBP is reasonable and necessary for Medicare beneficiaries who have a BMI greater than 35 and have at least one comorbidity related to obesity, and have been previously unsuccessful with medical treatment for obesity. The assessment concluded that the evidence is not adequate to conclude that open or laparoscopic VGB is reasonable and necessary and they are therefore noncovered for all Medicare beneficiaries.

A systematic evidence review by the CADTH (Klarenbach et al., 2010) found that although data from large, adequately powered, long-term RCTs are lacking, bariatric surgery seems to be more effective than standard care for the treatment of severe obesity in adults. Procedures that are mainly diversionary (e.g., BPD) result in the greatest amounts of weight loss, hybrid procedures are of intermediate effectiveness (e.g., RYGBP), and restrictive procedures (e.g., adjustable gastric banding) result in the least amounts of weight loss. RYGBP and adjustable gastric banding tended to lead to trade-offs between the risk of AEs and the need for procedure conversion or reversals.

In a controlled study, Karlsen et al. (2013) evaluated health-related QOL (HRQL) after RYGBP compared to intensive lifestyle intervention (ILI). A total of 139 morbidly obese individuals chose treatment with RYGBP (n=76) or ILI (n=63). ILI comprised four stays, each lasting 7 weeks, at a specialized rehabilitation center over the course of 1 year. The daily schedule was divided between physical activity, psychosocially oriented interventions, and motivational approaches. No special diet or weight-loss medications were prescribed. Outcome measurements included HRQL questionnaires before treatment and at 1-year follow-up. BMI, mental health, and emotional health outcomes were all statistically significantly better for individuals undergoing RYGBP compared to ILI. The authors concluded that morbidly obese individuals may benefit from both ILI and RYGBP, although individuals undergoing RYGBP may have better outcomes.

In a multicenter RCT, Ikramuddin et al. (2013) evaluated the safety and effectiveness of RYGBP compared to lifestyle and intensive medical management to achieve control of obesity-related comorbid factors. A total of 120 individuals with T2DM and a BMI between 30 and 39.9 were randomly assigned into an RYGBP or medical management ​group and were followed for 12 months. Medical management included medications for hyperglycemia, hypertension, and dyslipidemia. Successful outcomes were defined as HbA1c levels of less than 7%, low-density lipoprotein (LDL) cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg. After a 12-month follow-up, 49% of participants (n=28) in the RYGBP group and 19% of participants (n=11) in the medical management group achieved successful outcomes. Participants in the RYGBP group required 3.0 fewer medications and lost 26.1% of their initial body weight compared to only 7.9% of those in the medical management group. Regression analyses indicated that the achieved successful outcomes were primarily attributable to weight loss. There were 22 serious AEs in the RYGBP, including one cardiovascular event. There were 15 serious AEs in the medical management group. The authors concluded that in mild to moderately obese individuals with T2DM, adding RYGBP surgery to lifestyle and medical management was associated with a greater likelihood to lose weight and control obesity-related comorbid factors.

BILIOPANCREATIC DIVERSION, LAPAROSCOPIC OR OPEN
Biliopancreatic diversion, also known as the Scopinaro procedure, consists of a subtotal gastrectomy and diversion of the biliopancreatic juices into the distal ileum by a long Roux-en-Y procedure. The degree of malabsorption depends on the length of the common tract. Because of the high incidence of cholelithiasis (stone formation in the gallbladder) that results from BPD, cholecystectomy is commonly performed with this procedure. BPD consists of the following components:

• Distal gastrectomy to limit food intake by inducing a temporary early satiety and/or dumping syndrome in the early postoperative period
• 200-cm alimentary tract made from the ileum to connect the stomach to a common distal segment
• 300- to 400-cm biliary tract connecting the duodenum, jejunum, and remaining ileum to the common distal segment
• 50- to 100-cm common tract where food (from the alimentary tract) mixes with biliopancreatic juices (from the biliary tract)

The DS is a variant of the BPD procedure with a vertical subtotal gastrectomy and pylorus preservation, which eliminates the "dumping syndrome." The duodenum is divided just beyond the pylorus. The small bowel is then divided, and the end going to the cecum of the colon is connected to the short stump of the duodenum. This becomes the "enteral limb." The other end, leading from the gallbladder and pancreatic ducts, is connected onto the enteral limb at about 75 to 100 cm from the ileocecal valve. This limb is the "biliopancreatic limb." The last 75 to 100 cm then becomes the "common channel," measuring about 10% of the total small bowel length and is the only portion that can absorb fat. Some have advocated use of the DS procedure in super-obese individuals (i.e., persons with BMI >50) because of the substantial weight loss induced by this procedure. Individuals who have this operation must have lifelong medical follow-up, since the side effects can be subtle, and can appear months to years after the surgery.

Peer-Reviewed Literature

In a retrospective study, Scopinaro et al. (1996) evaluated the safety and effectiveness of 1968 obese individuals who underwent BPD since 1976. The last consecutive 1217 individuals underwent BPD with a 200-cm alimentary limb, a 50-cm common limb, and a gastric volume varying between 200 and 500 mL. Mean excess weight was 117% and mean age was 37. Individuals were followed for up to 115 months. Outcome measurements included mean percent EWL and complication rates. Mean percent initial EWL at 8 years was 77%. Specific late complications included protein malnutrition (7%), anemia (<5%), and stomal ulcer (2.8%). Surgical revision by common limb elongation or by restoration was performed in 1.7% of individuals. The authors concluded that BPD was a safe and effective procedure, but may be dangerous if performed incorrectly. The study is limited in its lack of a comparative control group, retrospective study design, and heterogeneous study population and treatment.

BILIOPANCREATIC BYPASS (SCOPINARO PROCEDURE) WITH DUODENAL SWITCH
A BPD-DS is a variant of the BPD procedure. It involves a partial gastrectomy, in which the pylorus and initial segment of the duodenum are preserved and anastomosed to a segment of the ileum to create the alimentary limb. The goal of this procedure is to limit food digestion and absorption to a shorter, common ileal segment.

Peer-Reviewed Literature

In an RCT, Hedberg and Sundom (2012) evaluated the safety and effectiveness RYGBP compared to BPD-DS, a modification of the Scopinaro BPD procedure. Forty-seven individuals with a mean BMI of 54.5 were randomly assigned to RYGBP (n=23) or BPD-DS (n=24). Outcome measurements included BMI and glycated hemoglobin levels. BPD-DS resulted in a statistically significantly greater weight loss than RYGBP (−23.2 vs. −16.2 or 80% vs. 51% EWL; P<0.001). BPD-DS also yielded lower glucose and glycated hemoglobin levels at 3-year follow-up. While more study participants listed troublesome diarrhea and malodorous flatus after BPD-DS, no statistically significant difference was seen. The authors concluded that BPD-DS produced superior weight results and lower glycated hemoglobin levels compared with RYGBP in individuals with a BMI greater than 48. The study is limited in its relatively small sample size and lack of long-term follow-up.

In a retrospective study, Pata et al. (2013) evaluated the safety and effectiveness of BPD-DS. A total of 874 individuals with a mean preoperative BMI of 52 underwent the DS procedure. Comorbidities present included hypertension (57%), hypercholesterolemia (87%), hypertriglyceridemia (53%), T2DM (35%), and OSA (9%). The mean follow-up was 11.9 years. The median BMI decreased to 33.9 after 1 year following the BPD-DS procedure, 31.1 after 2 to 5 years, 30.9 after 5 to 10 years, and 31.2 after 10 to 15 years. Sixty-seven percent of diabetic individuals were able to stop insulin and 97% were able to stop oral hypoglycemic medications within a year. Blood pressure, triglyceride, and cholesterol levels became normal in greater than 96% of individuals within a year. OSA was resolved within 8 months in all cases. There was no long-term mortality. The authors concluded that BPD-DS was a viable bariatric procedure with excellent long-term outcomes in terms of weight loss, improvement of obesity-related diseases, and QOL. The study is limited in its lack of a comparative control group.

SINGLE ANASTOMOSIS DUODENAL-ILEAL SWITCH (SADI-S)/SLEEVE GASTRECTOMY WITH SINGLE ANASTOMOSIS DUODENO-ILEAL BYPASS (SIPS)

SADI procedures are simplified versions of the BPD-DS procedures. Primarily, SADI only requires one anastomosis, while a BPD-DS requires two anastomoses, which potentially leads to increased peri- and postprocedural complications. The single anastomosis creates the common channel, which typically ranges from 250 to 300 cm, and the biliopancreatic limb.

Peer-Reviewed Literature

Zaveri et al. (2015) noted that the increase in the prevalence of obesity and GERD has paralleled one another. Laparoscopic fundoplication (LF) (Nissen or Toupet) is a minimally invasive form of anti​reflux surgery. The DS is a highly effective weight loss surgery with a proven record of long-term weight loss success. However, fundoplication alone does not give satisfactory results when used for GERD in morbidly obese individuals. These researchers presented a novel approach combining stomach intestinal pylorus-sparing surgery (SIPS) with LF for morbidly obese individuals with GERD. The data from individuals who underwent the SIPS procedure along with LF in the past year were​ retrospectively analyzed. The variables collected were age, sex, height, weight, intraoperative and postoperative complications, LOS, operative time, and estimated blood loss. All revisions were excluded. Descriptive statistics such as mean and standard deviation were used to analyze the data. The total sample size of the study was five individuals, with a mean age of 59.6 ± 16.4 years, a mean weight of 292.1 ± 73.6 pounds, and a mean BMI of 43.4 ± 6.3. Weight loss patterns were the same as those without LF. All five individuals had resolution or improvement in their GERD symptoms within 6 months. The authors concluded that SIPS with LF provided substantial and sustained weight loss and GERD resolution; however, long-term follow-ups and further study on this novel surgical technique are recommended.

This study had two main drawbacks: first, it was a small study including five individuals. Second, this study was not meant to provide definitive superiority to LF or LRYGBP alone in the setting of obesity but as a possibility in individuals in whom both LF and LRYGBP are not options for various reasons. Consequently, predicting its widespread applicability to all bariatric individuals with reflux is premature and awaits larger trials; these researchers could not evaluate endoscopy or pH testing postoperatively in their individuals, which is fundamental to evaluate the effect of antireflux surgery. Although they could get GERD-HRQL questionnaires for all their individuals, these investigators could not compare the data pre- and postsurgery.

Mitzman et al. (2016) stated that although the DS has been the most effective weight loss surgical procedure, it is performed in a small minority of the total bariatric surgical cases. Modifications that can make the operation technically simpler and reduce a long-term risk of short bowel syndrome would be of benefit. These investigators detailed their initial experience with a modified DS: the SIPS procedure. Data from individuals who underwent a primary SIPS procedure performed by two surgeons at two centers between January 2013 and August 2014 were retrospectively analyzed. All revisions of prior bariatric procedures were excluded. Regression analyses were performed for all follow-up weight loss data. A total of 123 individuals were available; 102 individuals were beyond 1 year postoperative, with data available for 64 (62% followed-up). The mean BMI was 49.4 kg/m²; two individuals had diarrhea (1.6%), four had abdominal hematoma (3.2%), and one had a stricture (0.8%) in the gastric sleeve; two individuals (1.6%) were re-admitted within 30 days; one individual (0.8%) underwent reoperation because of an early postoperative ulcer. At 1 year, individuals had an average change in BMI of 19 units (kg/m²), which was compared to an average of 38% of total weight loss (TWL) or 72% of EWL. The authors concluded that modification of the classic DS to one with a single anastomosis and a longer common channel had effective weight loss results. Morbidity appeared comparable to other stapling reconstructive procedures. Moreover, they stated that future analyses are needed to determine whether a SIPS procedure reduces the risk of future small bowel obstructions and micronutrient deficiencies.

Cottam et al. (2017) stated that in bariatric surgery, the procedure with the highest average weight loss is the BPD-DS. A new simplified DS called the SIPS surgery with less malabsorption and one fewer anastomosis claims to have similar outcomes when compared with the BPD-DS. These researchers performed a retrospective matched cohort analysis of SIPS versus BPD-DS individuals in a single private practice by matching every BPD-DS to a SIPS individual of the same gender and BMI. EWL percentage, BMI, and percentage TWL were compared. Additionally, comorbidity resolution, nutritional data, and complications were also compared. Data were analyzed using both descriptive and comparative statistics. Over 2 years, there was no statistical difference in weight loss between BPD-DS and SIPS. There also was no difference in nutritional data between the two procedures pre- and postoperatively. Complication rates were lower in SIPS; however, due to the small sample sizes, this is not statistically significant. The authors concluded that weight loss and nutritional results between SIPS and BPD-DS were similar at 2 years. However, there are fewer complications with SIPS. The main drawbacks of this study were its retrospective design and small sample size.

Shoar et al. (2018) noted that owing to the possibility of weight regain (WR) after the long-term follow-up of gastric bypass individuals and because of the high morbidity of BPD-DS, single-anastomosis duodeno-ileal switch (SADIS) has emerged as a rescue procedure in bariatric surgery. These researchers summarized the literature data on SADIS. They carried out a comprehensive literature review through October 2016 to identify English studies on SADIS performed in human subjects. Outcomes of interest were technical considerations, postoperative complications, weight loss outcome, comorbidity resolution rate, and nutritional deficiency after SADIS. Twelve studies, including 581 SADIS individuals (217 males and 364 females) were included. SADIS was a primary procedure in 508 individuals (87.4%) and a conversion procedure in 73 individuals (12.6%). The length of common limb was 300 cm in 54.2%, 250 cm in 23%, and 200 cm in 13.4% of individuals. Anastomosis technique was a linear stapler in 26.7% and a hand-sewn suture technique in 73.3% of individuals. Diarrhea was the most common complication (1.2%). The average percentage EWL was 30% at 3 months, 55% at 6 months, 70% at 1 year, and 85% at 2 years. Comorbidity resolution rate was 74.1% for T2DM, 96.3% for hypertension, 68.3% for dyslipidemia, 63.3% for OSA, and 87.5% for GERD. Overall, vitamin A, selenium, and iron deficiency were the most common nutritional deficiencies with the possibility of the protein malnutrition in up to 34% of the individuals when measured. The authors concluded that as a modified bariatric procedure, SADIS has promising outcomes for weight loss and comorbidity resolution in morbidly obese individuals. When measured, there was a high prevalence of macronutrient deficiencies following SADIS. There is a high technical variability, and long-term data are needed before any meaningful conclusion can be made.

In a systematic review and meta-analysis, Lee et al. (2019) compared the safety and efficacy between SADI or BPD-DS versus RYGBP as a revisional procedure for SG. Medline, Embase, Cochrane Central Register of Controlled Trials, and PubMed were searched up to August 2018. Studies were eligible for inclusion if they compared SADI or BPD-DS with RYGBP as a revisional bariatric procedure for SG. Primary outcome was absolute percentage TWL. Secondary outcomes were LOS, AEs, and improvement or resolution of comorbidities (diabetes, hypertension, or hypercholesterolemia). Pooled mean differences (MDs) were calculated using random effects meta-analysis. Six retrospective cohort studies involving 377 individuals met the inclusion criteria. The SADI/BPD-DS group achieved a significantly higher percentage TWL compared with RYGBP by 10.22% (95% confidence interval [CI], −17.46 to −2.97; P=0.006). However, there was significant baseline equivalence bias, with four studies reporting higher initial BMI in the SADI/BPD-DS group. There were no significant differences in LOS, AEs, or improvement of comorbidities between the two groups. The authors concluded that SADI, BPD-DS, and RYGBP were safe and effective revisional surgeries for SG. Both SADI and RYGBP were effective in lowering initial BMI, but there is more evidence for excellent weight loss outcomes with the conversion to BPD-DS when the starting BMI was high. Moreover, these researchers stated that further RCTs are needed for definitive conclusions.

In a retrospective, 3-year trial, Ozmen et al. (2020) examined the early effects of single-anastomosis duodenal switch–proximal approach (SADS-p) and one-anastomosis gastric bypass–mini gastric bypass (OAGB-MGB) on the homeostasis model assessment of insulin resistance (HOMA-IR) index levels in morbidly obese individuals with T2DM. Outcomes of individuals undergoing SADS-p and OAGB-MGB were compared considering the changes in HOMA-IR index levels. All bariatric procedures were performed by a single primary surgeon recognized as a surgeon of excellence by the International Federation for the Surgery and Other Therapies of Obesity–European Chapter​ (IFSO-EC) with the assistance of one or two additional attending surgeons. SADS-p was performed on 60 (10 males) individuals, and 200 (27 males) individuals underwent OAGB-MGB; 46 individuals (78%) in the SADS-p group and 125 (63%) in the OAGB-MGB group had T2DM.  Individuals were evaluated before surgery and 1, 3, 9, and 12 months after surgery. In both groups, the HOMA-IR index levels decreased significantly after surgery (P<0.05), and both procedures markedly improved glycemic control. In the SADS-p group, the HOMA-IR index levels significantly decreased from 6.2 to 1.4 after the twelfth month of surgery (P<0.05); in OAGB-MGB group, HOMA-IR index levels significantly decreased from 5.9 to 1.7 after the twelfth month of surgery (P<0.05). The authors concluded that both procedures are promising operations that offer excellent control on weight, HOMA-IR index, and diabetes.

In a retrospective study, Finno et al. (2020) examined weight loss, comorbidity remission, complications, and nutritional deficits after DS and SADI-S. A total of 440 individuals underwent DS (n = 259) or SADI-S (n = 181). Mean preoperative BMI was 50.8 ± 6.4 kg/m². Mean follow-up was 56.1 ± 37.2 months for DS and 27.2 ± 18.9 months for SADI-S. Global mean EWL was 77.4% at 2 years, similar for SADI-S and DS, and 72.1% at 10 years after DS. Although early complications were similar in SADI-S and DS (13.3% vs. 18.9%; P=n.s.), long-term complications and vitamin and micronutrient deficiencies were superior after DS. Rate of comorbidities remission was 85.2% for diabetes, 63.9% for hypertension, 77.6% for dyslipidemia, and 82.1% for sleep apnea, with no differences between both techniques. In individuals with initial BMI of greater than 55 kg/m² (n = 91), DS achieved higher percentage of BMI of less than 35 kg/m² (80% vs. 50%; P=0.025) and higher rate of diabetes remission (100% vs. 75%; P=0050). The authors concluded that DS and SADI-S showed similar weight loss and comorbidity remission rates at 2 years. In individuals with initial BMI of greater than 55 kg/m², DS obtained better BMI control at 2 years and better diabetes remission, but more long-term complications and supplementation needs.

Cottam et al. (2020) noted that the SADS procedure has been suggested to be an effective bariatric procedure that offers excellent weight loss and, by lengthening the common channel, the potential to reduce micronutrient deficiencies. These researchers examined the weight loss, comorbidity resolution and the 1-year nutritional outcomes of the SADS procedure. Between October 2014 and January 2017, 120 individuals were enrolled at six sites across the United States and underwent the SADS procedure; weight loss, comorbidities, QOL, and AEs were followed postprocedure for 12 months. At 1, 6, and 12 months, 98.3%, 85.5%, and 77.1% of the individuals were available for assessment, respectively. At 12 months, individuals showed significantly reduced BMI when compared to baseline (46.8 ± 5.8 vs. 29.8 ± 4.4; P<0.001, respectively); 65 individuals had T2DM at baseline; however, 11 individuals were lost to follow-up. Of the available data (54 individuals), 96.3% of the individuals had a resolution of T2DM by 12 months with a mean A1c reduction from 7.8 ± 1.6 to 5.3 ± 0.7. Furthermore, there were reductions in hyperlipidemia, sleep apnea, and hypertension at 12 months. Individual GERD satisfaction and QOL (SF-36) scores were significantly higher at 12 months postprocedure (P<0.001 in all cases) while 12-month protein levels remained at normal values. There were abnormalities of parathyroid hormone (PTH) and vitamin D at 1 year with all other nutritional markers being not significantly different at 1 year from baseline. There were 10 III-b or greater complications according to the Clavien-Dindo scoring system during the study period, not all of which were related to the surgery. The authors concluded that SADS was a highly effective weight loss procedure with significant comorbidity reduction at 1 year. At 1 year, complications and vitamin and mineral deficits appeared to be consistent with other malabsorption operations. The authors concluded that long-term follow-up is needed, especially around complications and vitamin deficiencies.

Surve et al. (2020a) noted that the long-term outcomes of primary SADI-S have never been reported in the literature. In a retrospective study, these researchers examined the long-term outcomes after primary laparoscopic SADI-S (LSADI-S). Data from 750 individuals who underwent a primary LSADI-S from June 2013 through November 2019 by three surgeons were analyzed. The mean age and preoperative BMI were 49.3 ± 13.1 years and 50 ± 12.6 kg/m², respectively. Follow-up was available on 109 individuals (61%) at 5 years and on 87 individuals (53%) at 6 years; six individuals did not have any follow-up. The average operative time and LOS were 67.6 ± 27.4 mins and 1.5 ± .8 days, respectively. The intraoperative short-term and long-term complication rates were 0%, 7.8%, 11.7%, respectively. The 30-day emergency room (ER) visit, readmission, and reoperation rates were 0.4%, 1.1%, and 1.1%, respectively. In total, there were 15 (2%) grade IIIb long-term complications unique to LSADI-S. Complete remission of T2DM was observed in 77% of the diabetic population. At 5 and 6 years, the mean change in BMI was 17.5 ± 6.9 and 17.6 ± 6.4 kg/m², respectively. The mortality rate was 0.5%. The authors concluded that LSADI-S was effective in this retrospective review in achieving good initial weight loss and weight maintenance. Surve et al. noted that although these findings showed acceptable nutritional complications, questions still remain because of the retrospective nature of the study; further long-term outcome studies with better follow-up rates are needed to confirm the long-term nutritional results of LSADI-S.

This study's main drawback was the follow-up percentage. The long-term follow-up rate was 61% at 5 years and 53% at 6 years. Because there are no long-term outcomes articles in the literature, and the mid-term data were limited, these researchers believed it is important to report the long-term outcomes even with what they would consider a limited individual follow-up. However, there were enough individuals past 5 years, so that the probability of the weight loss data changing would be minimal with the acquisition of more individuals. There also were enough patient-years that any common long-term complication should have been seen. In addition, as this was the authors' total experience with this procedure, it included their learning curve. The complication rate has fallen as these investigators have become more skilled at performing this procedure. This article was not and should not be the final word on SADI-S. Many issues are unresolved. For example, what is the optimal SG size and what is the optimal common channel lengthening (CCL) for BMI or coexisting conditions? The question has not been answered by this article, and they deserve to be. Furthermore, what is the optimal length of the common channel to avoid diarrhea postoperatively, and what level of postoperative revisions for diarrhea is acceptable? These researchers simply do not know. Further long-term studies are needed to confirm the safety and efficacy of this procedure.

Surve et al. (2020b) stated that the long-term effectiveness of RYGBP and SADI-S is unknown. These investigators compared the long-term outcomes. Data from 1254 individuals who underwent primary RYGB or SADI-S were used for a retrospective matched cohort. Data were obtained by matching every RYGB individual to a SADI-S individual of the same sex, BMI, and weight. Only individuals out 5 years and had at least one greater than 5-year follow-up visit were included. The matched cohort included 61 RYGB and 61 SADI-S individuals. There was no statistical, demographic difference between the two groups. At 5 years, a 100% follow-up was available in each group. The intraoperative outcomes were significantly better with SADI-S. The 30-day readmission, reoperation, emergency department (ED) visits, and complication rates were statistically similar between the two groups. The long-term complication rates, Clavien-Dindo grade IIIb complications, and number of individuals with more than one complication were significantly lower with SADI-S. Weight loss was significantly greater in the SADI-S group at 5 years. The long-term weight-loss failure rate was significantly higher in the RYGB group. The SADI-S procedure was associated with fewer reintervention through 6 years (14.7% individuals vs. 39.3% individuals; P=0.001). Conversion or reversal of the procedure was required only in the RYGBP group. There also was no significant difference in nutritional outcomes between the two procedures. The authors concluded that in this matched cohort comparison of long-term outcomes, the SADI-S procedure was superior to the RYGBP procedure with regard to operative outcomes, lethal long-term complications, number of individuals with more than one complication, reintervention rates, weight loss, weight-loss failure rates, and conversion rates. Moreover, these researchers stated that more such studies with a larger sample size are needed. They stated that the SADI-S may be considered one of the viable alternatives to RYGBP.

Surve et al. also noted that this study had several drawbacks. First, the small sample size of the cohort: 61 individuals in each group, with a 100% follow-up at 5 years. In the majority of bariatric practices, only 20% to 25% of the individual population followed up after 5 years. Moreover, getting labs after 5 years is even more difficult. These researchers were still able to compare their findings with other long-term outcome studies in the literature because most studies on the long-term outcome of RYGBP had less than 200 individuals, specifically at 5 years. Second was the lack of long-term comorbidity outcomes. These investigators had sufficient long-term comorbidity data for one of the two procedures; however, because this was a comparative study, they decided not to present them. Third, the number of available labs was insufficient to make any definite conclusion on the nutritional outcomes. Surgeons will rightly be skeptical of this paper showing SADI-S with fewer nutritional complications than RYGBP (especially calcium). Fourth was the retrospective nature of the study. Fifth was the learning curve of the SADI-S procedures. These investigators' practice began to perform the SADI-S procedure in 2013. Around 55% of the SADI-S individuals who were included in the study had been operated on in the first 2 years.

Enochs et al. (2020) noted that the SG, RYGBP, and SADI-S are recognized bariatric procedures. A comparison has never been made among these three procedures and especially in different BMI categories. These researchers analyzed a large cohort of individuals undergoing either laparoscopic (L) SG, LRYGB, or LSADI-S to examine and compare weight loss and glycosylated hemoglobin level. The secondary objective was to compare the nutritional outcomes between LRYGB and LSADI-S. This was a retrospective review of 878 individuals who underwent LSG, LRYGB, or LSADI-S from April 2014 through October 2015 by five surgeons in a single institution. For weight loss analysis, the individuals were categorized into four different categories as follows: individuals regardless of their preoperative BMI, individuals with preoperative BMI of less than 45 kg/m², individuals with preoperative BMI 45 to 55 kg/m², and individuals with preoperative BMI of greater than 55 kg/m². A total of 878 individuals were identified for analysis. Of 878 individuals, 448 individuals, 270 individuals, and 160 individuals underwent LSG, LRYGB, and LSADI-S, respectively. Overall, at 12 and 24 months, the weight loss was highest with LSADI-S, followed by LRYGB and LSG in all four categories. At 2 years, the individuals lost 19.5, 16.1, and 11.3 BMI points after LSADI-S, LRYGB, and LSG, respectively. Furthermore, the weight loss was highest in individuals with preoperative BMI of less than 45 kg/m² and lowest in individuals with preoperative BMI of greater than 55 kg/m² at 12 and 24 months. In addition, there were no statistically significant differences between the nutritional outcomes between LRYGB and LSADI-S. The LSADI-S had significantly lower rates of abnormal glycosylated hemoglobin than LRYGB and LSG at 12 months (P<0.001). The authors concluded that the weight loss outcomes and glycosylated hemoglobin rates were better with LSADI-S than LRYGB or LSG. The nutritional outcomes between LRYGB and LSADI-S were similar.

Enochs et al. reported several drawbacks with this study. First, it was retrospective rather than prospective. At 2 years, these researchers had a follow-up of 50% for the LSG group. The study did not include complication data and analysis of other obesity-related coexisting condition data in any of the groups. Moreover, they were unable to make a definite conclusion for individuals with BMI 0.55 kg/m², as the group had a small number of individuals. Another drawback was the lack of similarity among the three groups. In all four BMI categories, the individuals that underwent LSADI-S had highest preoperative weight and BMI. Despite these differences, LSADI-S had better weight loss than LSG and LRYGB. Moreover, the T2DM resolution rate was highest with LSADI-S. Also, the study did not include some of the nutritional data points like prealbumin, PTH, and vitamins B₁ and B₉.

Kallies and Rogers (2020) provided an updated statement on single-anastomosis DS by the ASMBS in response to numerous inquiries made to the Society by individuals, physicians, society members, hospitals, and others regarding single-anastomosis DS as a treatment for obesity and metabolic disease. This recommendation is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. With additional publications reporting outcomes of many more individuals who have undergone SADI-S since the previous ASMBS statement (amounting to a total of approximately 1500 currently reported individuals), the ASMBS has reached the conclusion that SADI-S provides for similar outcomes to those reported after classic DS and should therefore be endorsed, similar to the ASMBS' endorsement of the predicate procedure of BPD-DS. The conclusion from the current review is that the currently available peer-reviewed literature does not suggest outcomes will differ substantially from those seen with classic DS. The ASMBS will continue to monitor and evaluate emerging data on this procedure and, when appropriate, will issue an updated evidence-based position statement at a future time. The following recommendations are currently endorsed by the ASMBS regarding SADI-S for the primary treatment of obesity or metabolic disease:

SADI-S, a modification of classic Roux-en-Y DS, is therefore endorsed by ASMBS as an appropriate metabolic bariatric surgical procedure. Publication of long-term safety and efficacy outcomes is still needed and is strongly encouraged, particularly with published details on SG size and common channel length. Data for these procedures from accredited centers should be reported to the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database and separately recorded as single-anastomosis DS procedures to allow for accurate data collection.

There remain concerns about intestinal adaptation, nutritional issues, optimal limb lengths, and long-term weight loss/regain after this procedure. As such, ASMBS recommends a cautious approach to the adoption of this procedure, with attention to ASMBS-published guidelines on nutritional and metabolic support of bariatric individuals, in particular for the DS individual.

While the updated ASMBS statement (Kallies and Rogers, 2020) endorses SADI-S as an appropriate metabolic bariatric surgical procedure, it also points out that studies of long-term safety and efficacy are still needed—a view that is supported by the studies described above.

Furthermore, an UpToDate review on descriptions of bariatric procedures for the management of severe obesity (Lim, 2020) states that "Several other procedures, including one-anastomosis gastric bypass (OAGB) and single anastomosis duodeno-ileal bypass (SADI), are still considered investigational in terms of being a standard bariatric procedure."

Yashkov et al. (2021) stated that there are only a small number of studies providing a comparison between SADI-S and Hess-Marceau's BPD-DS (RY-DS) operations. These researchers compared 5-year results of SADI-S 250 (common limb 250 cm) with RY-DS. Data of individuals who underwent open SADI-S (n = 226) and RY-DS (n = 528) were retrospectively studied. Percentage EWL, percentage excess body mass index loss (EBMIL), percentage TWL, antidiabetic effect, complications, and revision rate were compared between the two groups. After the first 12 months, percentage EWL (77.0% vs. 73.3%) and percentage TWL (39.4% vs. 38.9%) were statistically significantly better after SADI-S (P<0.01 and P<0.05, respectively), but not percentage EBMIL (P>0.05). At nadir to 24 to 36 months, EWL, TBWL, and EBMIL after SADI-S was comparable to the RY-DS group. Up to the fourth and fifth year, better weight loss (TBWL, EBMIL, EWL) was observed after RY-DS than after SADI-S. Early complication rate was less (2.65%) in the SADI-S group than in the RY-DS (5.1%). Protein deficiency and small bowel obstruction rates were also lower after SADI-S; 93.4% of individuals achieved total remission of their diabetes; 7.5% of individuals in the SADI-S group had symptoms of bile reflux, which was a main indication for revisions. The authors concluded that SADI-S has many advantages over RY-DS; however, weight loss and antidiabetic effects after the third year were marginally lower after SADI-S compared to RY-DS. SADI-S was less dangerous in terms of malabsorption and appeared to be a reasonable alternative to RY-DS as a metabolic operation. RY-DS could be implemented for WR and/or bile reflux after SADI-S.

This study had several drawbacks. This was a retrospective analysis of two modifications of BPD-DS, one of which (RY-DS) had been performed between 2003 and 2015 and another one (SADI-S), since 2014. For this reason, these investigators compared more recent information regarding 5-year antidiabetic effects of SADI-S with their preliminary published data regarding 5-year results of RY-DS. There was no learning curve period in the SADI-S group, but there was in RY-DS group. Although the initial weight of the individuals in the SADI-S group was higher (P<0.01), they were also taller, so there was no statistically significant difference in the initial BMI between the two groups. More individuals from the SADI-S group suffered from T2D. In the period when the investigators used SADI-S, a significant number of "easier" individuals were suggested as candidates for a SG. In cases of T2D, SADI-S was preferable over a SG alone. Furthermore, the percentage of individuals with T2D has increased over the last 5 to 10 years because more individuals considered their diabetes to be a more significant health problem than obesity itself. Another limitation was that both RY-DS and SADI-S procedures were performed by the authors using an open technique. Although laparotomies are infrequently used in metabolic surgery, in their experience both open RY-DS and SADI-S procedures could be performed safely by laparotomy with a minimal 30-day morbidity (0.38% for RY-DS; 0.44% for SADI-S) with low early morbidity (5.1% and 2.65%, accordingly). In the recently published study from Brazil [​Kim, 2016] using a laparoscopic technique, the authors demonstrated 18.9% early complications after RY-DS and 13.3% after SADI-S.

Spinos et al. (2021) noted that single-anastomosis duodeno-ileal bypass with sleeve gastrectomy–one anastomosis DS (SADI-S/OADS) was developed as a bariatric operation with reduced overall morbidity and lasting weight loss results. These investigators carried out a systematic review of the literature, including 14 studies reporting on weight loss, comorbidity resolution, postoperative complications, and nutritional deficiencies following SADI-S. Twelve months after SADI-S, the mean total body weight lost ranged from 21.5% to 41.2%, with no WR observed after 24 months. The comorbidity resolution rate was 72.6% for diabetes, 77.2% for dyslipidemia, and 59.0% for hypertension cases. The need for reoperation was the most common postoperative complication. While several individuals developed nutrient deficiencies, SADI-S appeared to be an overall safe and effective bariatric operation. The authors concluded that since the initial conception, the popularity of SADI-S has increased. SADI-S offers the benefits of a combined malabsorptive and restrictive bariatric operation, with fewer postoperative complications than the traditional DS and has drawn the interest of several different investigators to study it further. The next step for the scientific community now will be to organize RCTs with long-term follow-ups to ensure the consistency of high-quality outcomes reported so far.

The authors stated that the findings of this systematic review warrant careful interpretation because of its inherent limitations. Due to the heterogeneity in the technical aspects of these operations, as well as the reported outcomes, these researchers were unable to perform a comparative study or meta-analysis on the outcomes of SADI-S. All studies included in this systematic review were either cohort studies or case series, and retrospective in nature; therefore, the overall level of evidence presented was low. There was significant heterogeneity in the reported outcomes, their definitions, and their categorization. Finally, the follow-up of most studies was rather short, which could be explained by the novelty of the technique; most studies were published in or after 2018.

Chen et al. (2021) noted that SG and RYGBP are the most commonly performed bariatric procedures globally, but both techniques have shortcomings. Several modifications of SG (SG-plus procedures) have been developed; however, the effectiveness of the different procedures has not been completely elucidated. In a meta-analysis, these investigators examined the safety and effectiveness of SG plus procedures. Out of the initially identified 2357 studies, 13 were selected for this meta-analysis: two studies on banded sleeve gastrectomy (BSG), four studies on SG plus duodenal-jejunal bypass (SG + DJB) or sleeve gastrectomy with loop duodenal-jejunal bypass (SADJB), two studies on sleeve gastrectomy with jejunal-jejunal bypass (SG + JJB), four studies on single anastomosis duodenal-ileal switch (SADI-S), and one study on stomach intestinal pylorus-sparing surgery (SIPS). The SADI-S procedure was found to achieve significantly greater percentage of excess weight loss than the RYGBP. SG + DJB and SADJB achieved greater weight loss than the RYGBP. Major complications were fewer with SG + JJB than with RYGBP, but the difference was not significant. Overall, SG-plus procedures appeared to achieve better weight loss and cause fewer complications than RYGBP.

Andalib et al. (2021) noted that SADI-S is a modification of the classic DS. These modifications are intended to address concerns about DS, including malnutrition, longer operative times, and technical challenges, while preserving the benefits. In a prospective, single-center, cohort study, these investigators examined safety and outcomes of SADI-S as compared to the classic DS procedure. Data were depicted as count (percentage) or median (inter-quartile range [IQR]). Forty-two individuals underwent SADI-S, of whom 11 had it as a second-stage procedure (26%). Twenty individuals underwent DS, of whom 12 had it as second-stage procedures (60%). Both groups were similar at baseline. The median age was 45 (14) years, 39 (63%) were female, the median BMI was 48.2 (7.7) kg/m², and 29 (47%) individuals had diabetes. The operative time was shorter for one-stage SADI-S versus DS surgery (211 [70] vs. 250 [60] minutes, respectively; P=0.05) but was similar for second-stage procedures (P=0.06). The 90-day complication rates were 11.9% (n = 5/42) after SADI-S and 5.0% (n=1/20) after DS surgery (P=0.64). There were no mortalities. Median follow-ups for one-stage SADI-S and DS were 17 (11) and 12 (24) months, respectively (P=0.65). Similar BMI changes were observed after one-stage SADI-S (17.9 kg/m² [8.7]) and DS (17.5 kg/m² [16]; P=0.65). At median follow-ups of 10 (20) and 14 (16) months after second-stage SADI-S and DS, respectively (P=0.53), surgical procedures yielded added 5.0 kg/m² (5.8) and 6.5 kg/m² (7.1) changes in BMI, respectively (P=0.26). Complete remission rates for diabetes were 91% after SADI-S (n=21/23) and 50% after DS (n=3/6). Compared with the SADI-S procedure, DS surgery was associated with higher frequencies of deficiencies in some fat-soluble vitamins, especially vitamin D. The authors concluded that SADI-S procedure was safe, and its short-term outcomes, including weight loss and the resolution of comorbidities, were similar to those of DS.

Kermansaravi et al. (2021) stated that morbid obesity is a global chronic disease, and bariatric procedures have been approved as the best method to control obesity. RYGBP is one of the most common bariatric surgeries in the world and has become the gold standard procedure for many years. However, some individuals experience WR or weight loss failure after the initial bypass surgery and require revisional or conversional interventions. International databases including PubMed, International Scientific Indexing (ISI), and Scopus were considered for a systematic search of articles that were published up through May 5, 2020. Forty-one published studies, which reported revision procedure on 1403 individuals, were selected and analyzed for this review. The selected studies were categorized into six groups of revision procedures, including laparoscopic pouch resizing and/or revision of GJA, adjustable or nonadjustable gastric band over pouch ± pouch/GJA resizing, endoscopic revision of gastric GJA ± pouch, distal Roux-en-Y gastric bypass (DRGB), BPD-DS or SADI-S, DRGB + band or pouch/GJA re-sizing. Revision procedures result in more weight loss after the initial weight loss procedures. In the 1-year follow-up, DRGB by itself with standardized mean difference (SMD) of −1.24 presented a greater decrease in BMI. DRGB plus band or pouch/GJA resizing, BPD-DS or SADI, adjustable or nonadjustable gastric banding over pouch ± pouch/GJA resizing, endoscopic pouch and/or GJA revision and laparoscopic pouch or/and GJA resizing revealed a lower decrease in BMI in order, respectively. In the 3-year follow-up, BPD-DS or SADI-S method with SMD of −1.40 presented the highest decrease in BMI. In follow up, DRGB alone, adjustable or nonadjustable gastric banding over gastric pouch ± pouch/GJA resizing, DRGB + band or gastric pouch/GJA resizing, laparoscopic pouch and/or GJA resizing and endoscopic revision of pouch and/or GJA revealed less reduction in BMI, respectively. In the 5-year follow-up, DRGB alone procedures with SMD of −2.17 presented the greatest reduction in BMI. Subsequently, BPD-DS or SADI-S, laparoscopic pouch and/or GJA size revision, and endoscopic revision of GJA/pouch revealed less overall decrease in BMI in order. The authors concluded that all methods of revision procedures after the initial RYGBP have been effective in the resolution of WR. However, based on the findings in this systematic review, it appeared DRGB or BPD-DS/SADI-S is the most effective procedure in the long-term follow-up outcome.

Vilallonga et al. (2021) noted that individuals with LSGs can experience weight-loss failure and must undergo conversion to another bariatric procedure. An analysis of the bariatric literature concerning the SADI-S as revisional surgery after LSG in terms of safety and effectiveness identified 607 studies; 59 studies were analyzed for full-content review and nine primary studies (398 individuals) were included. Revisional SADI was carried out in 294 individuals at a mean interval of 37.7 months (range, 11–179); percentage TWL varied from 20.5% to 46.2%. Early complications following surgery occurred in 4.1% of surgeries, including leak in seven cases (1.9%); mortality was nil. The authors concluded that SADI after LSG, after failed SG or as a sequential procedure, offered a satisfactory weight loss result. Both early- and late-term complications were acceptable.

In recent years, the robot surgical system has been employed in SADI-S; however, only a few studies with very small sample size exist regarding robotic SADI-S. In a retrospective study, Wang et al. (2022) estimated the outcomes of totally robotic SADI-S. A total of 102 consecutive individuals undergoing totally robotic SADI-S between March 2020 and December 2021 were included. Individual demographics, operative time, postoperative hospital LOS, complications, conversion to laparotomy, reoperation, readmission, mortality, and postoperative weight loss were recorded to analyze the safety, effectiveness, and learning curve of totally robotic SADI-S. Based on the operative time, these investigators evaluated the learning curve of robotic SADI-S by the cumulative sum (CUSUM) method. The overall follow-up rate was 100%. The mean operative time was 186.13 ± 36.91 minutes. Short-term (≤30 days) complication was present in 6.9% (n = 7), of which major complications were identified in 2.9% (n = 3), including two gastric leakages and one postoperative acute respiratory failure. None of the individuals experienced a long-term (>30 days) complication. No conversion to laparotomy or deaths occurred during the study period. The mean percentage TWL at 3, 6, 12, and 24 months was 21.87 ± 4.44%, 32.49 ± 5.31%, 40.86 ± 7.84%, and 44.64 ± 5.88%, respectively. The mean percentage EWL at 3, 6, 12, and 24 months was 52.78 ± 16.99%,76.53 ± 17.99%, 95.22 ± 18.59%, and 113.74 ± 23.30%, respectively. The CUSUM of operative time reached the first peak when the number of cases accumulated to the 16th case, then reached the second peak and continued to decline when the number of cases accumulated to the 27th case. Subsequently, all the individuals were classified into the learning stage group (the first 27 individuals) and the mastery stage group (the last 75 individuals). Except for operative time, proportion of abdominal drainage tubes, and postoperative hospital LOS, there was no significant difference between the learning stage and mastery stage groups. The authors concluded that totally robotic SADI-S appeared to be feasible and effective in the treatment of morbid obesity, just like laparoscopic SADI-S. The learning curve of robotic SADI-S was 27 cases.

Portela et al. (2022) stated that SADI-S is a novel bariatric surgery modified from the classic BPD-DS. These surgical modifications address most BPD-DS hurdles; however, the risk of bile reflux may hinder SADI-S acceptance. In a meta-analysis, these researchers examined the event rate of bile reflux after SADI-S. PubMed, ScienceDirect, Cochrane, Web of Science, and Google Scholar were used to search English articles between 2008 and 2021 by two independent reviewers using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). The risk of bias was assessed using Newcastle-Ottawa Scale and the JBI tool. Event rates were meta-analyzed using Comprehensive Meta-Analysis (CME) V3. Of 3027 studies analyzed, seven were included. Studies were published between 2010 and 2020; six of seven studies were retrospective: three studies had a low risk of bias, three studies had a moderate risk of bias, and one had a high risk of bias. The mean follow-up was 10.3 months. The total number of individuals was 2029, with 25 reports of bile reflux, resulting in an incidence of 1.23%, with an event rate of 0.016 (95% CI, 0.004–0.055). The authors concluded that bile reflux has not been demonstrated to be problematic following SADI-S in this meta-analysis.

In a systematic review of SADI-S, Verhoeff et al. (2022) examined observational and comparative studies evaluating the procedure, with meta-analysis comparing outcomes to other malabsorptive procedures. They carried out a systematic search of Medline, Embase, Scopus, and Web of Science in March 2021. The study followed PRISMA guidelines. Studies evaluating SADI-S with “n" greater than five were included. The primary outcome was diabetes remission, and secondary outcomes included perioperative outcomes, comorbidity resolution, and weight loss. These investigators reviewed 2285 studies with 16 included examining 3319 individuals and 1704 (51.3%) undergoing SADI-S. Individuals undergoing SADI-S had increased BMI (49.6 kg/m² vs. 48.8 kg/m²) and weight (139.7 kg vs. 137.1 kg), and were more likely to have diabetes (46.3% vs. 42.1%) and dyslipidemia (36.6% SADI-S vs. 32.7%). SADI-S had a shorter operative duration than malabsorptive procedures (MD, 36.74; P<0.001), 0.85-day shorter postoperative stay (P<0.001), and trended toward fewer complications (OR, 0.69; P=0.06). Rate of reoperation (OR, 0.83; P=0.59) was similar and diabetes mellitus remission was similar (OR, 0.07; P=0.1). Subgroup analysis suggested greater diabetes mellitus remission than RYGBP (OR, 4.42; P=0.04). SADI-S had fewer malabsorptive complications, although follow-up was shorter. Weight loss was 37.3% compared to 35.6% TWL after SADI-S and malabsorptive procedures, respectively. The authors concluded that SADI-S demonstrated improved metabolic and weight loss outcomes with lower perioperative risks. These investigators stated that SADI-S represents a promising bariatric procedure; however, long-term outcomes are needed to guide future uptake.

Furthermore, an UpToDate review on “Bariatric procedures for the management of severe obesity: Descriptions" (Lim, 2022) states that “Single-anastomosis duodenoileal bypass with sleeve gastrectomy (SADI-S) is fundamentally a variant of the BPD/DS operation, in which the transected duodenum is anastomosed to a loop of distal small bowel as opposed to the Roux-en-Y configuration used in classic BPD/DS. Thus, there is only one anastomosis. The SADI-S procedure was developed in part to reduce the complexity and therefore the risks of performing a Roux-en-Y configuration with small-diameter distal bowel and a need for two anastomoses. SADI-S has been endorsed by the ASMBS as an appropriate primary metabolic bariatric procedure. Additionally, it has been used as a conversional procedure for inadequate weight loss after either RYGBP or SG."

In 2024, Palmieri et al. conducted a systematic review of SADI-S. Seventeen studies were included. The analysis concluded that SADI-S resulted in a mean TWL of greater than 25% at 12 months and greater than 44% at 24 months, comparable to that of BPD-DS. Additionally, comorbidity remission rates for T2DM, hypertension, and dyslipidemia were of 75.8%, 61.2%, and 60.4%, respectively. 

In 2024, Ponce de Leon-Ballesteros published the 2023 update to IFSO's position statement on SADI-S/single anastomosis DS (SADS). Ninety-three studies were included in the task force's systematic review. The authors note that the procedures demonstrated efficacy in weight loss and control of T2DM, hypertension, and hyperlipidemia. However, the authors also note that high-quality evidence is lacking; they will reconsider its position in 2 years.

Axer et al. (2024) published the perioperative safety outcomes from an RCT comparing SADI-S to BPD-DS. Fifty-six individuals were randomly assigned to SADI-S or BPD-DS. The SADI-S group had a shorter operative time, while early complications and hospital LOS were similar between groups. EWL and TWL were also similar between groups at 1-year follow up.

Pereira et al. (2025) published a comparative cohort study from a single bariatric center. A total of 114 individuals underwent SADI-S or BPD-DS. Individuals were required to have a BMI greater than 45 to be eligible for the study. The percentage of TWL was the primary outcome, and after propensity score matching, was greater among those who received BPD-DS compared to those who received SADI-S. However, there were no significant differences in remission rates of various obesity-related comorbidities and no difference in complications or nutritional deficiencies. This study is limited by its study design, single center, and small sample size.

In 2025, Robert et al. published 2-year results of an open-label RCT comparing the safety and efficacy of SADI-S to RYGB. The trial was conducted in bariatric centers across France among individuals with a BMI greater than 40, or 35 with a comorbidity. Individuals undergoing a revisional procedure were also eligible. The primary outcome was the percentage of EWL at 2 years, analyzed with an intent-to-treat analysis. A total of 381 participants were randomly assigned, but 144 in the SADI-S group and 159 in the RYGB group were followed through 2 years. At 2 years, the percentage of EWL was 6.71% greater among individuals who received SADI-S compared with those who received RYGB. The interventions had similar effects on diabetes remission, dyslipidemia remission, and hypertension remission. Nutritional deficiencies varied across interventions. Early surgical complications occurred more frequently among the SADI-S group, but late complications occurred less. GERD was more common among those who received SADI-S, but dumping syndrome was more common among those who received RYGB. There appears to be a tradeoff between these procedures, although they are not the most comparable. SADI-S more closely resembles a BPD-DS.

In 2025, Sanchez-Cordero et al. conducted a systematic review of the long-term outcomes of SADI-S. Four studies, totaling 1088 participants, with 5-year follow-up, were included in the analysis. However, at 5 years only 326 participants had data available. The average TWL was 33.67% and average EWL was 77.88%. Complications ranged from 5.4% to 17.9% in the short and long terms, while mortality rates remained low. The authors conclude that SADI-S has a comparable safety and efficacy profile as other bariatric surgeries, but additional prospective studies are needed to validate these findings.

Sabatella et al. (2025) conducted a systematic review and meta-analysis comparing SADI-S to RYGB. Eight studies, totaling 4249 individuals, were included in the analysis. According to this analysis, SADI-S resulted in greater TWL, EWL, and diabetes remission. Additionally, long-term complications were less frequent among the SADI-S group, but the frequency of short-term complications, particularly among those with a BMI less than 50, were greater among the SADI-S group.

BARIATRIC SURGERY FOR TYPE 2 DIABETES WITH A BMI GREATER THAN 30

Zechmeister-Koss et al. (2014) applied the GRADE approach to evaluate the safety and effectiveness of the duodenal-jejunal bypass liner (DJBL) for the treatment of individuals with obesity greater than or equal to grade II (with comorbidities) and individuals with T2D and obesity greater than or equal to grade I. These researchers included 10 studies with a total of 342 individuals that primarily investigated a prototype of the DJBL. In individuals with high-grade obesity, short-term EWL was observed. For the remaining individual-relevant endpoints and individual populations, evidence was either not available or ambiguous. Complications (mostly minor) occurred in 64% to 100% of DJBL individuals compared to 0% to 27% in the control groups. Gastrointestinal bleeding was observed in 4% of individuals. The authors do not yet recommend the device for routine use.

Parikh et al. (2014) compared bariatric surgery versus intensive medical weight management (MWM) in individuals with T2DM who do not meet current National Institutes of Health criteria for bariatric surgery. The investigators examined whether the soluble form of receptor for advanced glycation end products (sRAGE) is a biomarker to identify individuals most likely to benefit from surgery. Fifty-seven individuals with T2DM and BMI between 30 and 35, who otherwise met the criteria for bariatric surgery, were randomly assigned to MWM versus surgery (bypass, sleeve or band, based on individual preference). The primary outcomes assessed at 6 months were change in HOMA-IR and diabetes remission. Secondary outcomes included changes in HbA1c, weight, and sRAGE. The surgery group had improved HOMA-IR (−4.6 vs. +1.6; P=0.0004) and higher diabetes remission (65% vs. 0%; P<0.0001) than the MWM group at 6 months. Compared to MWM, the surgery group had lower HbA1c (6.2 vs. 7.8; P=0.002), lower fasting glucose (99.5 vs.157; P=0.0068), and fewer T2DM medication requirements (20% vs. 88%; P<0.0001) at 6 months. The surgery group lost more weight (7.0 vs. 1.0 BMI decrease; P<0.0001). Higher baseline sRAGE was associated with better weight loss outcomes (r= −0.641; P=0.046). There were no mortalities. The authors concluded that surgery was very effective short-term in individuals with T2DM and BMI between 30 and 35. Baseline sRAGE may predict individuals most likely to benefit from surgery. However, they stated that these findings need to be confirmed with larger studies.

Sjöström et al. (2014) noted that short-term studies showed that bariatric surgery causes remission of diabetes. The long-term outcomes for remission and diabetes-related complications are not known. These researchers determined the long-term diabetes remission rates and the cumulative incidence of microvascular and macrovascular diabetes complications after bariatric surgery. The Swedish Obese Subjects (SOS) is a prospective matched cohort study conducted at 25 surgical departments and 480 primary health care centers in Sweden. Of individuals recruited between September 1, 1987, and January 31, 2001, 260 of 2037 control individuals and 343 of 2010 surgery individuals had T2DM at baseline. For the current analysis, diabetes status was determined at SOS health examinations until May 22, 2013. Information on diabetes complications was obtained from national health registers until December 31, 2012. Participation rates at the 2-, 10-, and 15-year examinations were 81%, 58%, and 41% in the control group and 90%, 76%, and 47% in the surgery group. For diabetes assessment, the median follow-up time was 10 years (interquartile range [IQR], 2–15) and 10 years (IQR, 10–15) in the control and surgery groups, respectively. For diabetes complications, the median follow-up time was 17.6 years (IQR, 14.2–19.8) and 18.1 years (IQR, 15.2–21.1) in the control and surgery groups, respectively. Adjustable or nonadjustable banding (n = 61), VGB (n = 227), or gastric bypass (n = 55) procedures were performed in the surgery group, and usual obesity and diabetes care was provided to the control group. Main outcome measures were diabetes remission, relapse, and diabetes complications. Remission was defined as blood glucose less than 110 mg/dL and no diabetes medication. The diabetes remission rate 2 years after surgery was 16.4% (95% CI, 11.7%–22.2%; 34/207) for control individuals and 72.3% (95% CI, 66.9%–77.2%; 219/303) for bariatric surgery individuals (odds ratio [OR], 13.3; 95% CI, 8.5–20.7; P<0.001). At 15 years, the diabetes remission rates decreased to 6.5% (4/62) for control individuals and to 30.4% (35/115) for bariatric surgery individuals (OR, 6.3; 95% CI, 2.1–18.9; P<0.001). With long-term follow-up, the cumulative incidence of microvascular complications was 41.8 per 1000 person-years (95% CI, 35.3–49.5) for control individuals and 20.6 per 1000 person-years (95% CI, 17.0–24.9) in the surgery group (hazard ratio [HR], 0.44; 95% CI, 0.34–0.56; P<0.001). Macrovascular complications were observed in 44.2 per 1000 person-years (95% CI, 37.5–52.1) in control individuals and 31.7 per 1000 person-years (95% CI, 27.0–37.2) for the surgical group (HR, 0.68; 95% CI, 0.54–​0.85; P=0.001). The authors concluded that in this very-long-term follow-up observational study of obese individuals with T2DM, bariatric surgery was associated with more frequent diabetes remission and fewer complications than usual care. Moreover, they stated that these findings require confirmation in randomized trials.

Yu et al. (2015) evaluated the long-term effects of bariatric surgery on individuals with T2DM. These investigators searched Cochrane, PubMed, and EMbase up to Dec 2013; RCTs and cohort studies of bariatric surgery for diabetes individuals that reported data with more than 2 years of follow-up were included. They used rigorous methods to screen studies for eligibility and collected data using standardized forms. Where applicable, these investigators pooled data by meta-analyses. Twenty-six studies, including two RCTs and 24 cohort studies that enrolled 7883 individuals, proved eligible. Despite the differences in the design, those studies consistently showed that bariatric surgery offered better treatment outcomes than nonsurgical options. Pooling of cohort studies showed that BMI decreased by 13.4 kg/m² (95% CI, −17.7 to −9.1), fasting blood glucose by 59.7 mg/dL (95% CI, −74.6 to −44.9), and glycated hemoglobin by 1.8% (95% CI, −2.4 to −1.3). Diabetes was improved or in remission in 89.2% of individuals, and 64.7% of individuals were in remission. Weight loss and diabetes remission were greatest in individuals undergoing BPD-DS, followed by gastric bypass, SG, and adjustable gastric banding. The authors noted that bariatric surgery may achieve sustained weight loss, glucose control, and diabetes remission. Moreover, they stated that large randomized trials with long-term follow-up are warranted to demonstrate the effect on outcomes important to individuals (e.g., cardiovascular events).

Furthermore, an UpToDate review on "Management of persistent hyperglycemia in type 2 diabetes mellitus" (McCullock, 2014) states that "Surgical treatment of obese individuals with diabetes results in the largest degree of sustained weight loss (20 to 30 percent after one to two years) and, in parallel, the largest improvements in blood glucose control. There are a growing number of unblinded trials comparing bariatric surgery with medical therapy for the treatment of type 2 diabetes …. Despite these impressive metabolic results, concerns remain about acute post-operative complications including need for re-operations and re-hospitalizations and rare, but potentially severe, AEs; the long-term success rates in maintaining weight loss; and the reproducibility of the results in individuals with an extensive history of diabetes or with a different surgical team. Some WR is typical within 2 to 3 years after bariatric procedures, and different bariatric procedures result in different levels of weight loss and corresponding reductions in glycemia. Longer-term follow-up of clinically important endpoints, such as effects on microvascular and macrovascular complications and mortality, are required before laparoscopic banding or other bariatric surgery procedures can be routinely recommended for the treatment of persistent hyperglycemia, resistant to multiple medications, in obesity-related type 2 diabetes."

Global usage of bariatric surgery has been dictated for the past quarter century by National Institutes of Health (NIH) recommendations restricting these operations to individuals with a BMI 35 kg/m² or greater (Cummings and Cohen, 2016). Strong evidence now demonstrates that bariatric procedures markedly improve or cause remission of T2DM, in part through weight-independent mechanisms, and that baseline BMI does not predict surgical benefits on glycemic or cardiovascular outcomes. This impels consideration of such operations as "metabolic surgery," which is used expressly to treat T2DM, including among individuals with a BMI less than 35 kg/m² who constitute the majority of people with diabetes worldwide. These investigators reviewed available evidence to inform that consideration. A meta-analysis of the 11 published RCTs, directly comparing bariatric/metabolic surgery versus a variety of medical/lifestyle interventions for T2DM, provided level 1A evidence that surgery is superior for T2DM remission, glycemic control, and HbA1c lowering. Importantly, this is equally true for individuals whose baseline BMI is below or above 35 kg/m². Similar conclusions were derived from meta-analyses of high-quality nonrandomized prospective comparisons. Meta-analysis of all pertinent published studies indicated that T2DM remission rates following bariatric/metabolic surgery are comparable above and below the 35 kg/m² BMI threshold. The safety, antidiabetes durability, and benefits on other cardiovascular risk factors from bariatric/metabolic surgery appeared roughly comparable among individuals with a BMI below or above 35 kg/m². Cummings and Cohen noted that further studies are needed to extend long-term findings and measure "hard" macrovascular/microvascular outcomes and mortality in RCTs. The authors concluded that available data, including level 1A evidence from numerous RCTs, support new guidelines from the 2nd Diabetes Surgery Summit that advocate for the consideration of bariatric/metabolic surgery as one option, along with lifestyle and medical therapy, to treat T2DM among individuals with a BMI less than 35 kg/m².

The authors also noted that "long-term data regarding bariatric surgery in lower-BMI patient​s is relatively limited … long-term results from RCTs of lower-BMI patients are still pending. Another understudied area is the relative cost-effectiveness of bariatric/metabolic surgery compared with conventional care among less obese patients with T2DM, and RCTs powered to observe "hard" outcomes such as cardiovascular events, cancer, and death are needed among patients of any BMI level."

Rubino et al. (2016) stated that despite growing evidence that bariatric/metabolic surgery powerfully improves T2DM, existing diabetes treatment algorithms do not include surgical options. The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2DM. A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal on Medline (January 1, 2005 to September 30, 2015), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., September 28 to 30, 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee. Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2DM. Numerous randomized clinical trials, albeit mostly short/mid-term, demonstrated that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2DM in individuals with class III obesity (BMI ≥ 40 kg/m²) and in those with class II obesity (BMI, 35.0 to 39.9 kg/m²) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for individuals with T2DM and BMI 30.0 to 34.9 kg/m² if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m² for Asian individuals. The authors concluded that although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2DM and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.

Yan et al. (2016) compared RYGBP surgery versus medical treatment for T2DM in obese individuals. Bariatric surgery can achieve remission of T2DM in obese individuals. RYGBP surgery has been performed as one of the most common surgical treatment options for obese individuals with T2DM, but the efficacy of RYGBP surgery comparing with medical treatment alone has not been conclusively determined. These investigators performed a systematic literature search and identified RCTs evaluating RYGBP surgery versus medical treatment for T2DM in obese individuals in PubMed, Embase, Cochrane database, and Cochrane Clinical Trials Registry. This systematic review and meta-analysis were performed according to PRISMA guidelines. The primary outcome was T2DM remission. Additional analyses comprised hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), BMI, waist circumference, serum lipid level, blood pressure, medication use, and AEs. Random-effects meta-analyses were calculated and presented as weighted OR or MD with 95% CIs. A total of six RCTs concerning 410 total obese individuals with T2DM were included. Follow-up ranged from 12 to 60 months. RYGBP surgery was associated with a higher T2DM remission rate (OR, 76.37; 95% CI, 20.70–281.73; P < 0.001) and serum level of high-density lipoprotein cholesterol (MD, 0.24  mmol/L; 95% CI, 0.18–0.30  mmol/L; 

P< 0.001) than medical treatment alone. HbA1c (MD, −1.25%, 95% CI, −1.88% to −0.63%; P < 0.001), BMI (MD, −6.54 kg/m; 95% CI, −9.28 to −3.80 kg/m²; P< 0.001), waist circumference (MD, −15.60  cm, 95% CI, −18.21 to −13.00  cm; 

P < 0.001), triglyceride (MD, −0.87  mmol/L; 95% CI, −1.17 to −0.57 mmol/L; P< 0.001), LDL cholesterol (MD, −0.32 mmol/L; 95% CI, −0.62 to −0.02 mmol/L; P=0.04), systolic blood pressure (MD, −2.83 mm Hg; 95% CI, −4.88 to −0.78 mm Hg, P< 0.01) were lower after RYGBP surgery. However, FPG (MD, −1.58  mmol/L; 95% CI, −3.58 to 0.41  mmol/L; P = 0.12), total cholesterol (MD, −0.40 mmol/L; 95% CI, −0.92 to 0.12  mmol/L; P= 0.13), and diastolic blood pressure (MD, 0.28 mm Hg; 95% CI, −​1.89 to 2.45  mm Hg; P= 0.80) were not significantly different between the two treatment groups. The medicine use and QOL were solely improved in the surgical group. Nutritional deficiencies and anemia were noted more frequently in the RYGBP group. The authors concluded that RYGBP surgery was superior to medical treatment for short- to medium-term remission of T2DM, improvement of metabolic condition, and cardiovascular risk factors. Moreover, they stated that further RCTs should address the safety and long-term benefits of RYGBP surgery on obese individuals with T2DM.

Friedman and Wolfe (2016) stated that a number of important questions need to be addressed before recommending bariatric surgery as a treatment for type II diabetic kidney disease (DKD). First, does bariatric surgery actually slow progression of DKD? If so, which individuals with DKD should be targeted for such an approach? Which bariatric procedure offers the best renoprotective effects? Are kidney-related benefits proportional to the weight lost? What effect does weight re-accumulation have on remission of DKD? Is actual remission required to treat DKD, or can more modest improvements suffice? What are the rates of complications and mortality after bariatric surgery in individuals with DKD, and are these risks outweighed by the kidney-related and other benefits? What additional benefits, such as improvements in dialysis access placement or transplantation wait-listing rates, can bariatric surgery offer?

These researchers noted that answering these questions will be challenging. A recent NIH symposium on long-term outcomes in bariatric surgery reviewed, in detail, the major hurdles in conducting well-powered, randomized, controlled bariatric surgery trials, specifically with regard to recruitment, sample size, and length of follow-up. Given the current funding environment, it was believed that alternative research strategies, including large observational studies using existing or prospective databases, should be considered. This may be especially relevant when considering the extended length of time that it could take to reverse DKD. These investigators and associated collaborators are currently working on just such a strategy.

The authors concluded that DKD is devastating to individuals and society. By inducing regression or remission of T2DM, bariatric surgery may also have the capability to effectively treat DKD. Small, short-term studies of bariatric surgery in individuals with T2DM and DKD suggest a renoprotective effect primarily as reflected by a reduction in albuminuria, but effects on harder, more clinically relevant outcomes are lacking. The field is, therefore, ripe for clinical studies designed to elucidate the kidney-related benefits of bariatric surgery.

Panosian et al. (2017) compared effects of RYGBP versus a multidisciplinary, group-based medical diabetes and weight management program on physical fitness and behaviors. Physical behavior and fitness were assessed in participants of the study Surgery or Lifestyle With Intensive Medical Management in the Treatment of Type 2 Diabetes (SLIMM-T2D) (NCT01073020), a randomized, parallel-group trial conducted at a US academic hospital and diabetes clinic with 18- to 24-month follow-up. Thirty-eight individuals with T2DM and hemoglobin A1c at 6.5% or higher and BMI of 30 to 42 kg/m² were randomly assigned to RYGBP or the medical program. A 6-minute walk test to evaluate fitness, self-reported physical activity, standardized physical surveys, and cardiometabolic risk assessment were performed at baseline and after intervention. Both groups similarly improved 6-minute walk test distance, with greater improvements in oxygen saturation and reduced heart rate after surgery. Self-reported physical activity improved similarly at 18 to 24 months after interventions, although exercise increased gradually after surgery, whereas early substantial increases in the medical group were not fully sustained. Self-reported total and physical health were similar by Short Form-36 but improved more in the Impact of Weight on Quality of Life survey after surgery. Improvement in cardiovascular risk scores, HbA1c, and BMI were greater after surgery. The authors concluded that in this small, randomized study, both interventions led to therapeutic lifestyle changes and improved objective and self-reported physical fitness. Greater improvements in heart rate, oxygen saturation, and perceived impact of weight on health were seen after surgery, which could be attributable to greater weight loss. They stated that the clinical importance of these improvements with greater weight loss warrants further investigation.

Ikramuddin et al. (2018) compared durability of RNYGB added to intensive lifestyle and medical management in achieving diabetes control targets. Observational follow-up of a randomized clinical trial at four sites in the United States and Taiwan, involving 120 participants who had an HbA1c level of 8.0% or higher and a BMI between 30.0 and 39.9 (enrolled between April 2008 and December 2011) were followed-up for 5 years, ending in November 2016. Lifestyle-intensive medical management intervention based on the Diabetes Prevention Program and LookAHEAD trials for 2 years, with and without (60 participants each) RNYBP followed by observation to year 5. Main outcome measures were the American Diabetes Association composite triple end-point of HbA1c less than 7.0%, LDL cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg at 5 years. Of 120 participants who were initially randomly assigned (mean age, 49 years [SD, 8 years], 72 women [60%]), 98 (82%) completed 5 years of follow-up. Baseline characteristics were similar between groups: mean (SD) BMI 34.4 (3.2) for the lifestyle-medical management group and 34.9 (3.0) for the gastric bypass group and had HbA1c levels of 9.6% (1.2) and 9.6% (1.0), respectively. At 5 years, 13 participants (23%) in the gastric bypass group and 2 (4%) in the lifestyle-intensive MM group had achieved the composite triple end-point (difference, 19%; 95% CI: 4% to 34%; P= 0.01). In the fifth year, 31 individuals (55%) in the gastric bypass group versus eight (14%) in the lifestyle-medical management group achieved an HbA1c level of less than 7.0% (difference, 41%; 95% CI, 19%–63%; P=0.002). Gastric bypass had more serious AEs than did the lifestyle-medical management intervention, 66 events versus 38 events, most frequently GIl events and surgical complications such as strictures, small bowel obstructions, and leaks. Gastric bypass had more PTH elevation but no difference in B₁₂ deficiency. The authors concluded that in extended follow-up of obese adults with T2DM randomly assigned to adding gastric bypass compared with lifestyle-medical management and intensive medical management alone, there remained a significantly better composite triple endpoint in the surgical group at 5 years. However, because the effect size diminished over 5 years, further follow-up is needed to understand the durability of the improvement.

The authors stated that this study had several drawbacks. The mean baseline HbA1c concentration of 9.6% indicated that this was a group of participants with relatively poorly controlled glycemia, so whether the results would be different with better controlled glycemia at baseline could not be determined. Similarly, the participants had diabetes for a mean of 9 years at study entry, so treatment effect on diabetes of lesser duration could be different. Conversely, blood pressure and LDL cholesterol levels were relatively well controlled among the study participants, so it was possible that individuals with less control might receive greater treatment benefit. Follow-up was incomplete (82% at 5 years), creating an opportunity for bias. Statistical analyses assumed missing data were missing at random, which may not have been true. Cross-overs, which were analyzed on an intention-to-treat basis, may have reduced observed treatment differences. The study tested a single type of bariatric surgery, the gastric bypass procedure which was most common at study initiation, so whether these conclusions apply to other surgical approaches will have to be assessed.

In a retrospective, matched cohort study, Fisher et al. (2018) examined the relationship between bariatric surgery and incident macrovascular (coronary artery disease and cerebrovascular diseases) events in individuals with severe obesity and T2DM. Individuals with severe obesity (BMI ≥35) aged 19 to 79 years with diabetes who underwent bariatric surgery between 2005 and 2011 in four integrated health systems in the United States (n = 5301) were matched to 14,934 control individuals on site, age, sex, BMI, HbA1c, insulin use, observed diabetes duration, and prior health care utilization, with follow-up through September 2015. Bariatric procedures (76% RYGBP, 17% SG, and 7% adjustable gastric banding) were compared with usual care for diabetes. Multivariable-adjusted Cox regression analysis investigated time to incident macrovascular disease (defined as first occurrence of coronary artery disease [acute myocardial infarction, unstable angina, percutaneous coronary intervention, or coronary artery bypass grafting] or cerebrovascular events [ischemic stroke, hemorrhagic stroke, carotid stenting, or carotid endarterectomy]). Secondary outcomes included coronary artery disease and cerebrovascular outcomes separately. Among a combined 20,235 surgical and nonsurgical cases, the mean (SD) age was 50 (10) years; 76% of the surgical and 75% of the nonsurgical cases were women; and the baseline mean (SD) BMI was 44.7 (6.9) and 43.8 (6.7) in the surgical and nonsurgical groups, respectively. At the end of the study period, there were 106 macrovascular events in surgical individuals (including 37 cerebrovascular and 78 coronary artery events over a median of 4.7 years; IQR, 3.2–6.2 years) and 596 events in the matched control individuals (including 227 cerebrovascular and 398 coronary artery events over a median of 4.6 years; IQR, 3.1–6.1 years). Bariatric surgery was associated with a lower composite incidence of macrovascular events at 5 years (2.1% in the surgical group vs 4.3% in the nonsurgical group; HR, 0.60 [95% CI, 0.42–0.86]), as well as a lower incidence of coronary artery disease (1.6% in the surgical group versus 2.8% in the nonsurgical group; HR, 0.64 [95% CI, 0.42–0.99]). The incidence of cerebrovascular disease was not significantly different between groups at 5 years (0.7% in the surgical group vs. 1.7% in the nonsurgical group; HR, 0.69 [95% CI, 0.38–1.25]). The authors concluded that in this observational study of individuals with T2DM and severe obesity who underwent surgery, compared with those who did not undergo surgery, bariatric surgery was associated with a lower risk of macrovascular outcomes. Moreover, they stated that these findings need confirmation in randomized clinical trials. Healthcare professionals should engage individuals with severe obesity and T2DM in a shared decision-making conversation regarding the potential role of bariatric surgery in the prevention of macrovascular events.

Fisher et al.'s study had several drawbacks. First, the observational design precluded causal inference, and unmeasured confounding may have persisted despite model adjustment for all major cardiovascular risk factors. However, the sensitivity analysis using E-value methodology (relative risk) indicated that the observed 5-year HR of 0.60 for incident macrovascular disease could only be explained by an unmeasured confounder that was associated with both receipt of bariatric surgery and risk of macrovascular disease by a risk ratio of more than 2.72 above and beyond that of the confounders that were measured in this study (upper confidence bound, 1.60). Given that this risk ratio was much greater than any observed for known macrovascular disease risk factors examined in the current study, such as hypertension, diabetes, or hyperlipidemia, it was implausible that an unmeasured confounder existed that could overcome the effect of bariatric surgery observed in the current analysis study. Second, baseline health characteristics and outcomes were established using data collected during routine medical care and billing, which meant that some information was missing and some comorbid conditions could be misclassified (e.g., ICD-9 diagnosis codes could be misapplied); however, major cardiac and cerebrovascular outcomes were more likely to be accurately captured claims for all diagnoses and procedures associated with ED and hospital admissions. Third, cause-specific mortality was not examined because cause of death data were not extracted a priori. Fourth, loss to follow-up could bias the result if individuals who underwent bariatric surgery and left the integrated healthcare systems in this study had very different macrovascular outcomes than the nonsurgical individuals who left these systems. Fifth, the sample size was insufficient to compare the effectiveness of alternative bariatric procedures for these outcomes. There has been a shift toward increased use of the SG procedure in recent years in the United States, and although this study included 17% SG, it was unclear whether the benefits observed in a primarily RYGBP population would be seen with SG. Sixth, given sample size and statistical constraints related to the number of variables that could be accommodated in the matching process, the authors could not match on every available characteristic. This left some imbalances in other variables that were not part of the matching algorithm. To further address confounding, all variables were adjusted for in their multivariable Cox models.

Courcoulas et al. published results from an RCT comparing RYGB to LAGB to intensive lifestyle weight loss (2015). Individuals with a BMI between 30 and 40 with a diagnosis of T2DM were eligible to enroll. Sixty-one individuals were enrolled and 52 were evaluated at 3 years. Partial or complete remission of T2DM was the primary outcome, which occurred most frequently among those randomly assigned to RYGB, followed by LAGB, then intensive lifestyle modifications. At 3 years, the RYGB group had the largest percentage of individuals not requiring medications to manage their diabetes. Total weight lost follows the same trend to that of partial or complete remission of diabetes. Approximately one third of individuals had a baseline BMI between 30 and 35.

Ikramuddin et al. conducted an RCT among individuals with uncontrolled T2DM and BMI between 30 and 40 (2016). A total of 120 participants were randomly assigned to medical management or RYGB, and were analyzed out to 36 months. The average BMI of both groups was 34, and over 50% in both groups had a BMI between 30 and 35. The primary outcome was HbA1c less than 7%, LDL cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg, which was assessed at 36 months. The odds of achieving this triple endpoint were four times greater among those who received RYGB compared to controls. Full remission of diabetes did not occur among any individuals in the control group, but occurred in 17% of RYGB participants. Weight loss differed by a mean 14.88% between the groups.

Schauer et al. in 2017 published 5-year outcomes of an RCT of RYGB or sleeve gastrectomy to medical therapy. The study included individuals with an HbA1c greater than 7% and a BMI between 27 and 43. The individuals were randomly assigned 1:1:1, and the primary outcome was an HbA1c below 6% regardless of medication usage. Overall, 134 of the 150 individuals were included in the 5-year analysis. After adjusting for multiple comparisons, it was found that a greater number of individuals randomly assigned to RYGB achieved the primary outcome compared to sleeve gastrectomy and medical therapy. Reductions in body weight were significantly greater among those in the surgical groups compared to medical therapy, and RYGB performed better than sleeve gastrectomy. When stratifying by baseline BMI, there was no difference in glycemic control between those with a BMI greater than 35 and those with a BMI below 35 (36% of the trial population).

In 2020, Horwitz et al. published the long-term outcomes of a previously conducted RCT. At the start of the trial, 57 individuals with a BMI between 30 and 35 with T2DM were randomly assigned to bariatric surgery or MWM. Five-year follow-up data were available in 75% of the participants. Compared to the controls, the individuals who had bariatric surgery had a lower prevalence of T2DM, use of insulin to lower BMI, and greater weight loss. While the trial was not originally designed for long-term follow-up, this does provide some evidence that bariatric surgery is effective at treating T2DM, even among those with a BMI between 30 and 35.

Zhou and Zeng (2023) published a systematic review and meta-analysis of studies that enrolled individuals with T2DM and a BMI less than 35. Seven articles were included, which varied in study design, intervention arm, and control arm. Five studies reported on diabetes remission, and in total, 64% of those who had bariatric surgery achieved diabetes remission, whereas only 2.8% of those who had nonsurgical management achieved diabetes remission. As expected, the reduction in BMI was significantly greater among those who had surgery compared with controls. This review is limited by the heterogeneity of interventions, controls, and study designs, but nevertheless provides some insight into understanding the effect of bariatric surgery on individuals with T2DM and a BMI less than 35.

BARIATRIC SURGERY FOR THE TREATMENT OF PSEUDOTUMOR CEREBRI/IDIOPATHIC INTRACRANIAL HYPERTENSION

Fridley et al. (2011) reviewed the literature on the effectiveness of bariatric surgery for obese individuals with idiopathic intracranial hypertension (IIH) with regard to both symptom resolution and resolution of visual deficits. The published literature was reviewed using manual and electronic search techniques. Data from each relevant manuscript were gathered, analyzed, and compared. These included demographic data, pre- and postoperative symptoms, pre- and postoperative visual field deficits, bariatric procedure type, absolute weight loss, changes in BMI, and changes in cerebrospinal fluid (CSF) opening pressure. Eleven relevant publications (including six individual case reports) were found, reporting on a total of 62 individuals. The RYGP was the most common bariatric procedure performed. Fifty-six (92%) of 61 individuals with recorded postoperative clinical history had resolution of their presenting IIH symptoms following bariatric surgery. Thirty-four (97%) of 35 individuals who had undergone pre- and postoperative fundoscopy were found to have resolution of papilledema postoperatively. Eleven (92%) of 12 individuals who had undergone pre- and postoperative formal visual field testing had complete or nearly complete resolution of visual field deficits, and the remaining individual had stabilization of previously progressive vision loss. In 13 individuals both pre- and postoperative CSF pressures were recorded, with an average postoperative pressure decrease of 254 mm H₂O. Changes in weight loss and BMI varied depending on the reported postoperative follow-up interval. The authors concluded that the published class IV evidence suggested that bariatric surgery may be an effective treatment for IIH in obese individuals, both in terms of symptom resolution and visual outcome. They stated that prospective, controlled studies are needed for better elucidation of its role.

Levin et al. stated that IIH occurs most frequently in young, obese women (2015). Gastric bypass surgery has been used to treat morbid obesity and its comorbidities, and IIH has recently been considered among these indications. These investigators presented a case report of a 29-year-old female individual with a maximum BMI of 50.3 and a 5-year history of severe headaches and moderate papilledema due to IIH. She also developed migraine headaches. After a waxing and waning course and various medical treatments, the individual underwent laparoscopic RYGP surgery with anterior repair of hiatal hernia. Dramatic improvement in IIH headaches occurred by 4 months postprocedure and was maintained at 1 year, when she reached her weight plateau with a BMI of 35. Presurgery migraines persisted. This added to the small number of case reports and retrospective analyses of the successful treatment of IIH with gastric bypass surgery, and brought these data from the surgical literature into the neurological domain. It offered insight into an early time course for symptom resolution, and explored the impact of weight-loss surgery on migraine headaches. The authors concluded that this treatment modality should be further investigated prospectively to analyze the rate of headache improvement with weight loss, the amount of weight loss needed for clinical improvement, and the possible correlation with improvement in papilledema.

Handley et al. (2015) systematically reviewed the effect of bariatric weight reduction surgery as a treatment for IIH. These investigators performed a comprehensive literature search using the following databases: Medline, Embase, PubMed, Scopus, Web of Sciences, and the Cochrane Library. No restrictions were placed on these searches, including the date of publication. Eighty-five publications were identified, and after initial appraisal, 17 were included in the final review. Overall improvement in symptoms of IIH after bariatric surgery was observed in 60 of the 65 individuals observed (92%). Postoperative lumbar puncture opening pressure was shown to decrease by an average of 18.9 cm H₂O in the 12 individuals in whom this was recorded. The authors concluded that bariatric surgery for weight loss is associated with alleviation of IIH symptoms and a reduction in intracranial pressure. Furthermore, an improvement was observed in individual​s in whom conventional treatments, including neurosurgery, were ineffective. They stated that further prospective randomized studies with control groups and a larger number of participants are lacking within the published studies to date.

SUBSEQUENT BARIATRIC SURGERIES

For individuals who are adults with class III obesity and failed bariatric surgery who receive revision bariatric surgery, the evidence includes systematic reviews, case series, and registry data. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Systematic reviews and case series have shown that individuals receiving revision bariatric surgery experienced satisfactory weight loss. Data from a multinational bariatric surgery database has found that corrective procedures following primary bariatric surgery are relatively uncommon but generally safe and efficacious. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

CONVERSION OF SLEEVE GASTRECTOMY TO ROUX-EN-Y GASTRIC BYPASS AS A TREATMENT OF GASTROESOPHAGEAL REFLUX DISEASE

LSG as a primary bariatric procedure has gained significant popularity (Abdemur et al., 2016). Conversion to RYGBP or Roux-en-Y esophagojejunostomy (LRYEJ) has been described as a therapeutic option for inadequate weight loss after LSG and unresolved comorbidities or complications such as leak, stricture, and severe GERD. These researchers determined reasons and outcomes of conversions of LSG to RYGBP. Between January 2004 and August 2014, 1118 individuals underwent primary LSG for morbid obesity. A retrospective review of a prospectively collected database was conducted for laparoscopic conversions of LSG to RYGBP or LRYEJ, describing reasons and outcomes. Conversion to RYGBP was identified in 30 (2.7%) individuals, of whom only nine (0.8%) were originally from the authors' institution. Of the entire cohort of revisions, nine (0.8%) had intractable GERD; only four (0.4% of total LSGs reviewed) were originally from the authors' institution; seven (0.6%) individuals underwent revision for inadequate weight loss: five (0.4%) originally from the authors' institution, two (0.2%) for stricture, and 12 (1.1%) for leak. Both the stricture and the leak cases were referred from outside institutions. All procedures were performed laparoscopically. The additional mean EWL after conversion to RYGBP was 30.9% with no mortalities. The authors concluded that the most common reason for conversion was chronic leak. The conversion rate of LSG to RYGBP due to inadequate weight loss, GERD, and stricture was 1.6% for the entire group, with 0.8% from the authors' institution. They stated that additional follow-up and studies are needed to define the real incidence of GERD after LSG.

El Chaar et al. (2017) noted that bariatric surgery is the only proven and effective long-term treatment for morbid obesity, with LSG being the most commonly performed weight loss procedure in the United States. Despite its safety and effectiveness, the association of LSG with both de novo and pre-existing GERD remains controversial. Therefore, this retrospective study determined the incidence, indications, and outcomes of revisional surgery following LSG in adult individuals at the authors' institution from 2010 to 2014. Descriptive outcomes were reported due to the small sample size. Of the 630 LSGs performed, 481 individuals were included in the analysis (mean age and BMI, 46.2 and 44.3, respectively; 79.5% female; 82.3% white). Twelve of 481 individuals underwent conversion to a different bariatric procedure due to inadequate weight loss, GERD, or both. The six of 12 individuals with GERD-related symptoms and failed medical management underwent conversion to RYGBP following preoperative wireless Bravo pH monitoring (Given Imaging) to confirm the diagnosis objectively. The other six of 12 individuals with inadequate weight loss received either RYGBP or BPD-DS based on personal choice. Overall, nine of 12 individuals underwent conversion to RYGBP, and three of 12 underwent conversion to BPD-DS. Median time from the initial surgery to conversion was 27 months (range, 17–41). Median operating room time was 168 minutes (range, 130–268). Median LOS was 48 hours (range, 24–72). The follow-up rate at 3 months was 100% (12/12 individuals). The authors concluded that some individuals may present following LSG with refractory GERD or inadequate weight loss, but that conversion to RYGBP or BPD-DS may be done safely and effectively.

Langer et al. (2010) noted that due to excellent weight loss success in the short-time follow-up, SG has gained popularity as the sole and definitive bariatric procedure. In the long-term follow-up, weight loss failure and intractable severe reflux can necessitate further surgical intervention. These investigators carried out a retrospective analysis of laparoscopic conversions from SG to RYGBP to assess the efficacy for reflux relief and weight loss success; eight of 73 individuals (11%) underwent conversion to RYGB for severe reflux (n = 3) or WR (n = 5) after a median interval of 33 months following LSG. In one individual, a banded gastric bypass was performed. In both groups, conversion to RYGBP was successful, as proton pump inhibitor (PPI) medication could be discontinued in all individuals presenting with severe reflux, and a significant weight loss could be achieved in the individuals with WR within a median follow-up of 33 months. Postoperative complications were observed in only one individual as leakage at the GJA was successfully treated by temporary stent placement. The authors concluded that conversion to RYGBP was an effective treatment for WR or intractable reflux symptoms following SG. Therefore, SG could be performed, intended as the sole and definitive bariatric intervention, with conversion from SG to RYGBP as an exit strategy for these complications.

Iannelli et al. (2016) reported their preliminary results within the two main indications for laparoscopic conversion of SG to RYGBP. Data from all individuals who underwent laparoscopic conversion from SG to RYGBP were retrospectively analyzed as to indications for revisional surgery, weight loss, and complications. Forty individuals underwent conversion—29 cases (72.5%) for weight loss failure and 11 cases for refractory GERD (27.5%). The mean interval from SG to RYGBP was 32.6 months (range, 8–113). Revisional surgery was attempted by laparoscopy in all cases, and conversion to laparotomy was necessary in three individuals (7.5%). Mean length of follow-up was 18.6 months (range, 9–60) after conversion. Follow-up rate was 100%. Mean percent TWL and percent EWL were 34.7% and 64%, respectively, when calculated from weight before SG. Remission rate for GERD was 100%; improvement was observed for all comorbidities after conversion. There was no immediate postoperative mortality. The postoperative complication rate was 16.7%. According to the Clavien-Dindo classification, there were five grade II and two grade IIIa complications. The authors concluded that laparoscopic conversion of SG to RYGBP was safe and feasible. In the short term, it appeared to be effective in treating GERD and inducing significant additional weight loss and improvement of comorbidities.

Casillas et al. (2016) evaluated the indications and outcomes of revision of SG to laparoscopic RYGBP (LRYGB) at a single community hospital. These researchers carried out a retrospective review of a prospectively collected database identifying SG operations done between February 2009 and June 2014. All individuals who underwent revision from SG to RYGBP were studied. Forty-eight individuals underwent revision of SG to RYGBP. Mean time to revision was 26 months (range, 2–60 months) and mean follow-up after RYGBP was 20 months (range, 4–​48 months). Indications for revision were reflux (n = 14), inadequate weight loss (IWL; n = 11), reflux and IWL (n = 16), stricture (n = 4), chronic leak (n = 1), and recurrent diabetes and reflux (n = 2). Reflux symptoms resolved in 96% of individuals after revision, and hiatal hernias were repaired in 50% of individuals. The percent TWL at 3, 6, 12, 24, and 36 months was 9.0%, 12.9%, 15.7%, 13.3%, and 6.5%, respectively. The overall rate of complication was 31%; there were no mortalities. The authors concluded that revision of SG to RYGB was a potentially effective means of treating SG complications, particularly reflux. Reflux was the most common indication for revision and was often associated with a hiatal hernia. These researchers stated that further studies are needed to evaluate the long-term maintenance of additional weight loss after revision of SG to RYGB.

Quezada et al. (2016) reported their results in converting SG to revisional LRYGB (R-LRYGB). Individuals who underwent R-LRYGBP after SG between June 2005 and April 2015 were identified. Demographic characteristics, anthropometrics, preoperative workup, and perioperative data were retrieved; TWL, EWL, and clinical progression over 3 years were registered. Fifty individuals were identified: mean age of 39 ± 8.4 years, 42 (84%) women; median BMI prior to R-LRYGB was 33.8 (31–36) kg/m². Indications for revision were WR (n = 28, 56%), GERD (n = 16, 32%), and gastric stenosis (n = 6, 12%). In WR individuals, mean follow-up at 3 years was 72.2% and median percentage of TWL at 12 and 36 months was 18.5 (12–24) and 19.3 (8–23), respectively; percentage of EWL at 12 and 36 months was 60.7 (37–82) and 66.9 (26–90), respectively. Over 90% of GERD individuals resolved or improved symptoms. All individuals with gastric stenosis resolved symptoms after conversion; there were no major complications. The authors concluded that R-LRYGB was a feasible, effective, and well-tolerated alternative in selected individuals with failed SG in which other therapies have been insufficient to either maintain weight loss or resolve complications. However, long-term follow-up is still needed.

Parmar et al. (2017) noted that IWL/WR and GERD unresponsive to medical management are two most common indications for conversion of SG to RYGBP. These investigators reported detailed outcomes of conversion of SG to RYGBP for these two indications separately. They examined prospectively maintained databases to identify individuals who underwent a conversion of their SG to RYGBP in their unit. Outcomes in individuals undergoing conversion for IWL/WR and those undergoing conversion for GERD were evaluated separately. These researchers performed 22 SG to RYGBP in their unit between August 2012 and April 2015 with a mean follow-up of 16 months. Indication for conversion was GERD in 10 of 22 (45.5%) individuals and IWL/WR in 11 of 22 (50.0%) individuals. Individuals undergoing conversion for GERD were significantly lighter (BMI 30.5) than those converted for IWL/WR (BMI 43.3) at the time of conversion. The conversion was very effective for GERD, with 100% of individuals reporting improvement in symptoms, and 80% of individuals were able to stop their antacid medications; the IWL/WR group achieved a further BMI drop of 2.5 points 2 years after surgery (final BMI, 40.8) in comparison with a 2.0-point BMI drop achieved by the GERD group (final BMI, 28.5). The authors concluded that conversion of SG to RYGBP was effective for GERD symptoms, but not for further weight loss, which was modest in both groups. These researchers stated that future studies are needed to examine the best revisional procedure for IWL/WR after SG.

Chang et al. (2018) stated that LSG has been validated as a safe and effective treatment for morbid obesity. However, data on the long-term outcome remain lacking. A total of 1759 LSGs were performed as primary bariatric procedures between 2005 and 2017, with mean age of individuals 35.2 ± 10.3 years (14–71), female 69.7%, mean BMI 37.9 ± 7.7 kg/m², and mean waist width 113.7 ± 17.9 cm. All individuals were evaluated and managed under a strict multidisciplinary team approach. These researchers carried out a retrospective analysis of a prospective bariatric database and telephone interview of individuals who defaulted clinic follow-up at 10 years. The mean operating time, intraoperative blood, and hospital LOS of LSG were 121.5 ± 36.5 minutes, 40.8 ± 69.7 mL, and 2.8 ± 2.7 days, respectively. The 30-day postoperative major complication occurred in 25 (1.4%) individuals. The major complication rate was 15% at the first year and 0% at the last year. The follow-up rate at 1, 5, and 10 years was 89.3%, 52.1%, and 64.4%, respectively. At postoperative year 1, 5, and 10, the mean percentage TWL and percentage EWL of LSG individuals were 33.4%, 28.3%, and 26.6% and 92.2, 80.1, and 70.5%, respectively. The mean BMI became 27, 26.2, and 27.1 kg/m² at postoperative 1, 5, and 10 years. At follow-up, 69 individuals needed surgical revision due to reflux disease (n = 45), WR (n = 19), persistent diabetes (n = 2), and chronic fistula (n = 3). The type of revision procedures were hiatal repair and gastropexy (n = 29), RYGBP (n = 23), and single anastomosis bypass (n = 17) with median time to revision of 33 months (range, 3–62). At 10 years, the overall revision rate was 21.5% (14/65) and 11 (16.9%) of 65 individuals underwent conversion to RYGBP. The other 54 individuals remained at LSG anatomy, but 45% of them required PPI for reflux symptoms. The authors concluded that primary LSG was a durable primary bariatric procedure with sustained weight loss and a high resolution of comorbidities at 10 years, but about 50% of the individuals had de novo GERD; the need for conversion to RYGBP was 16.9% at 10 years.

Boru et al. (2018) evaluated incidence, indications, and short-term outcomes of LSG conversion to LRYGB in three bariatric centers. Individuals operated on between January 2012 and December 2016 by primary LSG, with mean follow-up of 24 months and undergoing conversion to LRYGB for IWL, WR, and/or GERD, were retrospectively analyzed for demographics, operative details, perioperative complications, comorbidities evolution, and further weight loss. Thirty individuals (2.76%; seven males, 23 females, mean age of 41 ± 10.1 years, initial mean BMI of 46.9 ± 6.3 kg/m²) underwent successful conversion after a mean period of 33 ± 27.8 months for severe GERD (15 individuals; 50%), GERD and IWL/WR (three individuals, 10%), and IWL/WR (12 individuals, 40%). Surgical complications occurred in three individuals (10%). Mean BMI at revision time was 36 ± 9 kg/m², and 30.8 ± 5.2 kg/m², 28 ± 4.9 kg/m², and 28 ± 4.3 kg/m² after 6, 12, and 24 months, respectively. Resolution of GERD was achieved in 83% of cases. Overall, postoperative satisfaction was reported by 96% of the individuals, after mean follow-up of 24 ± 8.9 months. The authors concluded that in high-volume centers, where strict criteria for individuals' selection for LSG were applied, the expected incidence of reoperations for "non-responder" (IWL/WR) or de novo or persistent severe GERD nonresponder to medical treatment was low (<3%). These researchers stated that conversion of "non-responder" LSG to LRYGB was effective for further weight loss and GERD remission in the short term (2 years follow-up); however, a high postoperative complication rate was observed; long-term multidisciplinary follow-up is mandatory to confirm data on weight loss durability and comorbidity control.

The development of GERD following LSG is a major concern as it affects the QOL of the individuals and potentially exposes them to the complications of GERD (Raj et al., 2019). Raj et al. stated that the reported incidence of GERD after LSG was up to 35%. LRYGB is considered the procedure of choice for individuals with morbid obesity with GERD, but objective evidence based on physiologic studies for the same are limited. These researchers determined the physiologic changes related to gastroesophageal reflux based on symptoms index, 24-hour pH study, impedance, and manometry following LSG and LRYGB. This registered study is a prospective, nonrandomized, open-label clinical trial comparing the incidence of GERD after LSG and LRYGB. In this study, individuals without GERD were evaluated for GERD based on clinical questionnaires, 24-hour pH study, and impedance manometry preoperatively and 6 months postoperatively. Thirty individuals underwent LSG and 16 individuals underwent LRYGB. The mean DeMeester score increased from 10.9 ± 11.8 to 40.2 ± 38.6 (P=0.006) after LSG. The incidence of GERD after LSG was 66.6%. The increase in DeMeester score from 9.5 ± 4.6 to 12.2 ± 17.2 after LRYGB was not significant (P=0.7). There was a significant increase in non-acid reflux both following LSG and LRYGB. The authors concluded that the incidence of GERD following LSG was high, making it a contraindication for LSG. These researchers stated that LRYGB remains the preferred procedure for individuals with GERD; however, more studies are needed to understand the physiologic changes in individuals with pre-existing GERD.

An UpToDate review on "Late complications of bariatric surgical operations" (Ellsmere, 2019) states that "Gastroesophageal reflux after SG presents with classic symptoms such as burning pain, heartburn, and regurgitation. It can occur as an early and late complication. The first-line treatment is anti-reflux medical therapy. GERD unresponsive to anti-reflux medical therapy with no clear anatomic abnormalities, such as stoma stenosis or a hiatal hernia, can be effectively treated by conversion to RYGB."

TWO-STAGE PROCEDURE(S)
Two-stage procedure(s) have been proposed for extremely overweight individuals who are super or super-super obese (BMI of 50 to 60 or greater). The theory behind two-stage procedures is that by first performing a procedure such as a LSG in high-risk, morbidly obese individuals, followed by a second procedure such as a gastric bypass or a BPD-DS, complications and mortality can be reduced as a result of the significant weight loss resulting from the earlier procedure.

As a risk-reduction strategy/tool, the two-stage procedure(s) have been shown to be effective in very carefully selected individuals who require short-term weight loss and minimization or reduction of obesity-related comorbidities before undergoing a more complex bariatric procedure.

In a retrospective study, Cottam et al. (2006) evaluated the safety and effectiveness of LSG as an initial weight loss procedure for high-risk individuals with morbid obesity. A total of 126 participants underwent LSG, with a mean BMI of 65.3 [range, 45–91]. The mean number of comorbid conditions was 9.3, with a median of 10 [range, 3–17]. The incidence of major complications was 13%, with a mean of 46% EWL. Of the initial participants, 36 individuals with a mean post-LSG BMI of 49.1 (38% EWL) had a second-stage RYGBP. The mean number of comorbidities in this post-LSG group was 6.4 (reduced from 9). The mean time interval between the first and second stages was 12.6, with an incidence of major complications of 8%. The mean BMI after the second-stage RYGBP was 39 (reduced from 49.1), representing a statistically significant reduction (P<0.05). The mean number of comorbidities was reduced to two. The authors concluded that two-stage LSG followed by RYGBP was a safe and effective approach for high-risk individuals with morbid obesity. The study is limited in its retrospective study design and lack of a comparative control group.

In a retrospective study, Alexandrou et al. (2012) evaluated the long-term results of LSG as an initial weight loss procedure in super-morbid obese individuals. Forty-one individuals with a mean BMI of 59.5 underwent LSG. Of these, 29.3% (n=12) achieved a BMI of less than 35 with only LSG and lost 78.7% EWL. The remaining 28 individuals lost 48.1% EWL and achieved a mean BMI of 44.2, requiring a second-stage laparoscopic RYGBP. Of these 28 individuals, 10 underwent the second-stage procedure. The mean BMI after second-stage RYGBP was 33.6. The authors concluded that two-stage LSG followed by RYGBP was an effective treatment plan for individuals with super-morbid obesity. The study is limited in its relatively small sample size, retrospective study design, and lack of a comparative control group.

ADOLESCENT CONSIDERATION

The 1998 National Institutes of Health (NIH) Consensus Panel stated that bariatric surgery is an acceptable alternative to achieve sustained weight loss in adults but did not address its use in the adolescent population. However, published literature by Inge et al. (2004) addressed morbid obesity in adolescents and provided guidelines for selecting individuals for bariatric surgery. According to these investigators, the optimal timing of bariatric surgery for adolescents depends on variable components, such as skeletal development, psychosocial maturation, decisional capacity, and the support systems available to them.

Girls usually attain skeletal maturity at 13 years of age or older, and boys attain skeletal maturity at 15 years of age or older. These ages represent conservative estimates of skeletal maturity because overweight children often experience an early onset of puberty. Morbidly obese children are likely to achieve skeletal maturity (i.e., adult stature) earlier in adolescence, compared with age-matched, non-overweight children. When there is uncertainty regarding whether skeletal maturity has been attained, bone age can be objectively assessed with radiographs of the hand and wrist. If 95% or greater of adult stature (as confirmed by radiography) has been attained, there is little concern that a bariatric procedure may significantly impair linear growth. It is unknown if bariatric surgery may affect bone mineral density adversely and increase the risk of brittle bone fractures later in life. Additionally, several case reports suggest that adolescents may be disproportionately likely to develop thiamine deficiency. Nutritional complications of weight loss surgery are particularly important considerations for adolescents because of their long life expectancy and reproductive capacity.

Additionally, although these severely obese adolescents may be physiologically mature, psychological readiness for a bariatric surgery must be evaluated on an individual basis. An assessment of the individual's family environment with respect to postoperative-regimen adherence is also an important part of the evaluation. Compliance with medication, treatment protocols, and follow-up may be more problematic in adolescents.

In 2008, the Endocrine Society published clinical practice guidelines for the prevention and treatment of obesity in an adolescent population. The guidelines provided recommendations for bariatric surgery in adolescents with a BMI above 50 or above 40 with significant, severe comorbidities who have attained at least a Tanner IV pubertal development and final or near-final adult height. Psychological evaluation confirming stability and competence of the family unit and access to an experienced surgeon in a medical center employing a team capable of long-term follow-up was recommended as well. Bariatric surgery was not recommended for preadolescent children, pregnant or breast-feeding adolescents, or for those planning to become pregnant within 2 years of surgery.

In 2012, the ASMBS released best practice guidelines for the treatment of obese adolescents. The organization highlighted several comorbid factors related to obesity in adolescents including T2D, OSA, NASH, and pseudotumor cerebri. Because all adolescent boys and girls younger than 18 years of age with a BMI of 35 are considered to be greater than the 99th BMI percentile, the ASMBS indicated that BMI thresholds used for adult selection were appropriate in adolescents. It was recommended that bariatric surgery be considered for adolescents with a BMI between 35 and 40 with major comorbidities (e.g., T2D, moderate to severe OSA [based on an apnea-hypopnea index >15], pseudotumor cerebri, or severe NASH/metabolic dysfunction-associated steatohepatitis [MASH]). Bariatric surgery should also be considered for adolescents with a BMI greater than 40 and other less serious comorbidities (e.g., hypertension, insulin resistance, glucose intolerance, substantially impaired QOL, and clinically significant OSA. The ASMBS noted that the current evidence was not sufficiently robust to allow precise discrimination or recommendations for specific bariatric procedures. However, the ASMBS did recognize that substantial efforts should be made to achieve long-term follow-up to limit the associated risks of micronutrient and vitamin deficiencies. It was noted that in the United States, the use of AGB was considered off-label in the adolescent population. The number of sleeve gastrectomies being performed in the adolescent population has increased due to the low short-term complication rates reported in the adult population and the decreased risk of associated nutritional deficiencies.

Peer-Reviewed Literature

In a review of bariatric surgery in obese adolescents, Keidar et al. (2011) indicated that the literature was still lacking. The majority of the peer-reviewed literature consists of retrospective case series which demonstrate relative safety along with significant weight loss. In addition, the vast majority of obesity-related comorbidities were resolved following the procedure. The authors caution that precise individual selection criteria, choice of the procedure, and the extent of the multidisciplinary preoperative and postoperative care are yet to be defined.

In a retrospective cross-sectional study, Kelleher et al. (2013) determined the current rate of inpatient bariatric surgical procedures among adolescents and analyzed the national trends from 2000 to 2009. The primary outcome measurement was the national population based bariatric procedure rate. Secondary outcome measurements included trends in procedure rates and complication rates. The inpatient bariatric procedure rate increased from 0.8 per 100,000 individuals in 2000 to 2.3 per 100,000 in 2003. Since 2003, however, the rate has only increased to 2.4 per 100,000 individuals in 2009. The use of LAGB approached one-third (32.1%) of all procedures by 2009. The prevalence of comorbidities statistically significantly increased from 49.3% in 2003 to 58.6% in 2009 (P=0.002). The complication rate remained low. The authors concluded that despite the worsening childhood obesity epidemic, the rate of inpatient bariatric procedures among adolescents has plateaued since 2003. The predominant procedure types include RYGBP and LAGB. The study did not attempt to compare the safety and effectiveness between procedure types.

In a systematic review, Black et al. (2013) evaluated the current state of the peer-reviewed literature on the safety and effectiveness of bariatric surgery in obese adolescents. Outcome measurements included change in BMI 1-year post-surgery, complication rates, comorbidity resolution, and HRQL. In total, 637 individuals from 23 studies were included. There were statistically significant decreases in BMI at 1-year follow-up, though complications were inconsistently reported. There was some evidence of comorbidity resolution and improvements in HRQL. The authors concluded that bariatric surgery led to significant short-term weight loss in obese adolescents. However, the risk of complications is not well-defined and long-term, prospectively designed studies were needed to firmly establish the harms and benefits of bariatric surgery in an adolescent population. The study is limited in its heterogeneity and lack of comparisons between the various bariatric procedures.

ROUTINE LIVER BIPOSY FOR BARIATRIC SURGERY

Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), with input from the Clinical Issues Committee of the ASMBS, have issued the following guideline for liver biopsy as a part of preoperative medical evaluation bariatric surgery: "The liver may be assessed by hepatic profile and ultrasound. In cases of suspected cirrhosis, biopsy may be indicated."

The American Association of Clinical Endocrinologists, Obesity Society, and ASMBS clinical practice guidelines on "The perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient" (Mechanick et al., 2013) stated that "Consideration can be made for liver biopsy at the time of surgery to document steatohepatitis and/or cirrhosis that may otherwise be unknown due to normal appearance and/or liver function tests (Grade D)" (Grade D recommendation is based on expert opinion because of a lack of conclusive clinical evidence; if a two-thirds consensus cannot be reached, then the recommendation grade is D).

An UpToDate review on "Bariatric operations for management of obesity: Indications and preoperative preparation" (Lim, 2015) states that "For patients suspected to have nonalcoholic fatty liver disease (NAFLD) on the basis of hepatomegaly on the physical examination, liver function tests are obtained. In addition, radiographic imaging is obtained, such as an ultrasound or a computed tomography scan, or a biopsy may be required to evaluate for cirrhosis."

Cazzo et al. (2014) stated that NAFLD is common among individuals who undergo bariatric surgery; its postsurgical improvement has been reported. Their study aimed to determine the evolution of liver disease evaluated through NAFLD fibrosis score 12 months after surgery. This prospective cohort study evaluated individuals immediately before and 12 months following RYGBP. Mean score decreased from 1.142 to 0.066; surgery led to a resolution rate of advanced fibrosis of 55%. Resolution was statistically associated with female gender, percentage of excess weight loss, postsurgical BMI, postsurgical platelet count, and diabetes resolution. The authors concluded that as previously reported by studies in which postsurgical biopsies were performed, RYGBP leads to a great resolution rate of liver fibrosis. Because postsurgical biopsy is not widely available and has a significant risk, calculation of NAFLD fibrosis score is a simple tool to evaluate this evolution through a noninvasive approach.

Shalhub et al. (2004) noted that NASH commonly occurs in obese individuals and predisposes to cirrhosis. The prevalence of NASH in bariatric individuals is unknown. The aim of this study was to determine the role of routine liver biopsy in managing bariatric individuals. Prospective data on individuals undergoing RYGBP was analyzed. One pathologist graded all liver biopsies as mild, moderate, or severe steatohepatitis. NASH was defined as steatohepatitis without alcoholic or viral hepatitis. Consecutive liver biopsy specimens were compared to those liver biopsy specimens selected because of grossly fatty livers. A total of 242 individuals underwent open and laparoscopic RYGBP between 1998 and 2001. Routine liver biopsies (68 consecutive individuals) and selective liver biopsies (additional 86/174, 49%) were obtained. Findings of cirrhosis on frozen section changed the operation from a distal to a proximal RYGBP. The two groups were similar in age, gender, and BMI. The group with the routine liver biopsies showed a statistically significant larger preponderance of NASH (37% vs. 32%). Both groups had a similar prevalence of cirrhosis. Neither BMI nor liver enzyme levels predicted the presence or severity of NASH. The authors concluded that routine liver biopsy documented significant liver abnormalities in a larger group of individuals compared with selective liver biopsies, thereby suggesting that liver appearance is not predictive of NASH. Liver biopsy remains the gold standard for diagnosing NASH. The authors recommended routine liver biopsy during bariatric operations to determine the prevalence and natural history of NASH, which will have important implications in directing future therapeutics for obese individuals with NASH and for individuals undergoing bariatric procedures.

Oliveira et al. (2005) stated that pathogenesis of NAFLD remains incompletely known, and oxidative stress is one of the mechanisms incriminated. Their study evaluated the role of liver oxidative stress in NAFLD affecting morbidly obese individuals. Thirty-nine consecutive individuals with BMI greater than 40 kg/m² submitted to RYGBP were enrolled, and wedge liver biopsy was obtained during operation. Oxidative stress was measured by concentration of hydroperoxides (CEOOH) in liver tissue. Female gender was dominant (89.7%) and median age was 43.6 ± 11.1 years. Histology showed fatty liver in 92.3%, including 43.6% with NASH, 48.7% with isolated steatosis, and just 7.7% with normal liver. Liver cirrhosis was present in 11.7% of those with NASH. Concentration of CEOOH was increased in the liver of individuals with NASH when compared to isolated steatosis and normal liver (0.26 ± 0.17, 0.20 ± 0.01, and 0.14 ± 0.00 nmoL/mg protein, respectively) (P<0.01). Liver biochemical variables were normal in 92.3% of all cases, and no difference between NASH and isolated steatosis could be demonstrated. The authors concluded that non-alcoholic steatosis, steatohepatitis, and cirrhosis were identified in substantial numbers of morbidly obese individuals; concentration of hydroperoxides was increased in those with steatohepatitis, which is consistent with a pathogenetic role for oxidative stress in this condition.

Arun et al. (2007) stated that NAFLD is a chronic condition that can progress to cirrhosis and hepatocellular cancer. The most progressive form of NAFLD is NASH. Currently, the only method to diagnose NASH is with a liver biopsy; however, sampling error may limit diagnostic accuracy. These researchers investigated the discordance of paired liver biopsies in individuals undergoing gastric bypass. Two liver biopsies, composite size of 25 mm or greater and eight or more portal tracts (PTs), were obtained from the left lobe in 31 subjects. Group 1 included specimens at least 15 mm in length with at least four PTs compared with a second biopsy of at least 10 mm and at least four PTs (Group 2). The mean specimen size (number of PTs) for group 1 was 20.4 +/- 4.2 mm (11.7 +/- 5.5 PTs) and group 2 was 16.1 +/- 5.3 mm (8.2 +/- 4.1 PTs). Prevalence of NASH was 26% in Group 1 and 32% in Group 2. Sampling discordance was greatest for portal fibrosis (26%), followed by zone 3 fibrosis (13%) and ballooning degeneration (3%). The negative predictive values from Group 1 liver biopsies for NASH and portal fibrosis were only 83% and 67%, respectively. The authors concluded that significant sampling variability exists in class 2 and 3 obese individuals undergoing screening liver biopsies for NAFLD. The degree and histopathological discordance depends on zonal location and types of injury. Nevertheless, a 25-mm biopsy specimen without zone 3 cellular ballooning or fibrosis appears adequate to exclude the diagnosis of NASH.

EXPERIMENTAL/INVESTIGATIONAL AND NONCOVERED BARIATRIC SURGICAL PROCEDURES AND INDICATIONS

ADJUNCTIVE OMENTECTOMY TO BARIATRIC SURGERY

According to Fabbrini et al. (2010), visceral adipose tissue (VAT) is an important risk factor for the metabolic complications associated with obesity. Thus, a reduction in VAT is considered an important target of obesity therapy. These investigators examined if reducing VAT mass by surgical removal of the omentum would improve insulin sensitivity and metabolic function in obese individuals. They conducted a 12-month RCT to determine whether reducing VAT by omentectomy in 22 obese subjects increased their improvement following RYGBP surgery in hepatic and skeletal muscle sensitivity to insulin (study 1). Improvement was assessed by using the hyperinsulinemic-euglycemic clamp technique. These researchers also performed a 3-month, longitudinal, single-arm study to determine whether laparoscopic omentectomy alone, in seven obese subjects with T2DM, improved insulin sensitivity (study 2). Improvement was assessed by using the Frequently Sampled Intravenous Glucose Tolerance Test. The greater omentum, which weighed 0.82 kg (95% CI, 0.67–0.97), was removed from subjects who had omentectomy in both studies. In study 1, there was an approximate twofold increase in muscle insulin sensitivity (relative increase in glucose disposal during insulin infusion) and a fourfold increase in hepatic insulin sensitivity 12 months after RYGBP alone and RYGBP plus omentectomy, compared with baseline values (P<0.001). There were no significant differences between groups (P>0.87) or group x time interactions (P>0.36). In study 2, surgery had no effect on insulin sensitivity (P=0.844) or use of diabetes medications. The authors concluded that decreasing VAT through omentectomy, alone or in combination with RYGBP surgery, did not improve metabolic function in obese individuals.

In a double-blind RCT, Andersson et al. (2014) examined if removal of a large amount of visceral fat by omentectomy in conjunction with RYGBP would result in enhanced improvement of insulin sensitivity compared to gastric bypass surgery alone. Eighty-one obese women scheduled for RYGBP were included in the study. They were randomly assigned to RYGBP or RYGBP in conjunction with omentectomy. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp before operation and 62 women were also re-examined 2 years postoperatively. The primary outcome measure was insulin sensitivity; secondary outcome measures included cardiometabolic risk factors. Two-year weight loss was profound but unaffected by omentectomy. Before intervention, there were no clinical or metabolic differences between the two groups. The difference in primary outcome measure, insulin sensitivity, was not significant between the nonomentectomy (6.7 ± 1.6 mg/kg body weight/min) and omentectomy groups (6.6 ± 1.5 mg/kg body weight/min) after 2 years. Nor did any of the cardiometabolic risk factors that were secondary outcome measures differed significantly. The authors concluded that addition of omentectomy to gastric bypass operation did not result in an incremental effect on long-term insulin sensitivity or cardiometabolic risk factors. They stated that the clinical value of adjunctive omentectomy to gastric bypass operation is highly questionable.

VAT has been identified as an important risk factor for obesity-related comorbidities (Lee et al., 2018). Conflicting information exists on whether omentectomy added to bariatric surgery is beneficial to metabolic variables. These researchers evaluated the impact of omentectomy added to bariatric surgery on metabolic outcomes. Medline, Embase, and PubMed were searched up to May 2018. Studies were eligible for inclusion if they were RCTs comparing omentectomy added to bariatric surgery with bariatric surgery alone. Primary outcome measures were absolute change in metabolic variables (BMI, insulin, glucose, cholesterol, lipoproteins, and triglycerides); secondary outcomes were changes in adipocytokines. Pooled mean differences (mean deviation [MD]) were calculated using random effects meta-analyses, and heterogeneity was quantified using the I² statistic. Ten trials involving 366 individuals met the inclusion criteria with a median follow-up time of 1 year after surgery. Adding omentectomy to bariatric surgery demonstrated a minimal but statistically significant decrease in BMI compared with bariatric surgery alone (MD, 1.29; 95% CI, 0.35–2.23; P=0.007; I² = 0%; 10 trials). Conversely, individuals who underwent bariatric surgery alone had significant increases in high-density lipoprotein (MD, −2.12; 95% CI, −4.13 to −0.11; P=0.04; I² = 0%; six trials). Other metabolic outcomes and adipocytokines showed no significant difference between procedures. The authors concluded that the addition of omentectomy to bariatric surgery resulted in minimal reduction of BMI. They stated that considering no overall improvement in metabolic outcomes and the time and effort required, the therapeutic use of omentectomy added to bariatric surgery is not warranted.

ASPIREASSIST ASPIRATION THERAPY

In a pilot study, Sullivan et al. (2013) evaluated the use of endoscopic aspiration therapy for the treatment of obesity. This method entails endoscopic placement of a gastrostomy tube (A-Tube) and the AspireAssist siphon assembly (Aspire Bariatrics, King of Prussia, PA) to aspirate gastric contents 20 minutes after meal consumption. These researchers performed a study of 18 obese individuals who were randomly assigned (2:1) to groups that underwent aspiration therapy for 1 year plus lifestyle therapy (n = 11; mean BMI, 42.6 ± 1.4 kg/m²) or lifestyle therapy only (n = 7; mean BMI, 43.4 ± 2.0 kg/m²). Lifestyle intervention comprised a 15-session diet and behavioral education program; 10 of the 11 subjects who underwent aspiration therapy and four of the seven subjects who underwent lifestyle therapy completed the first year of the study. After 1 year, subjects in the aspiration therapy group lost 18.6% ± 2.3% of their body weight (49.0% ± 7.7% of EWL) and those in the lifestyle therapy group lost 5.9% ± 5.0% (14.9% ± 12.2% of EWL) (P<0.04); seven of the 10 individuals in the aspiration therapy group completed an additional year of therapy and maintained a 20.1% ± 3.5% body weight loss (54.6% ± 12.0% of EWL). There were no AEs of aspiration therapy on eating behavior and no evidence of compensation for aspirated calories with increased food intake. No episodes of binge eating in the aspiration therapy group or serious AEs were reported. The authors concluded that aspiration therapy appeared to be a safe and effective long-term weight loss therapy for obesity. These preliminary findings from a pilot study need to be validated by well-designed studies.

Forssell and Norén (2015) evaluated the effectiveness of a novel device, the AspireAssist aspiration therapy system, for the treatment of obesity. After 4 weeks taking a very-low-calorie diet, 25 obese men and women (BMI 39.8 ± 0.9 kg/m²) had the AspireAssist gastrostomy tube placed during a gastroscopy. A low-profile valve was installed 14 days later and aspiration of gastric contents was performed approximately 20 minutes after meals three times per day. Cognitive behavioral therapy was also started. At month 6, mean weight lost was 16.5 ± 7.8 kg in the 22 subjects who completed 26 weeks of therapy (P = 0.001). The mean percentage EWL was 40.8 ± 19.8 % (P= 0.001); two subjects were hospitalized for complications: one subject for pain after gastrostomy tube placement, which was treated with analgesics, and another because of an aseptic intra-abdominal fluid collection 1 day after gastrostomy tube placement. No clinically significant changes in serum potassium or other electrolytes occurred. The authors concluded that in this study, substantial weight loss was achieved with few complications using the AspireAssist system, suggesting its potential as an attractive therapeutic device for obese individuals.

In a prospective observational study, Norén and Forssell (2016) evaluated the safety and effectiveness of the novel AspireAssist Aspiration Therapy System for treatment of obesity, and its effect on the individual​'s QOL. Twenty-five obese subjects, mean age of 48 years (range, 33–​65) were included in this study. A custom gastrostomy tube (A-tube) was percutaneously inserted during a gastroscopy performed under conscious sedation. Drainage and irrigation of the stomach were performed three times daily, 20 minutes after each meal, for 1 to 2 years. Efficient aspiration was required thorough chewing of ingested food. Treatment included a cognitive behavioral weight loss program. Mean BMI at inclusion was 39.8 kg/m² (range, 35–49). After 1 year, mean (SD) BMI was 32.1 kg/m² (5.4), P<0.01, and EWL was 54.4% (28.8), P< 0.01. QOL, as measured with EQ-5D, improved from 0.73 (0.27) to 0.88 (0.13), P< 0.01. After 2 years, BMI was 31.0 kg/m² (5.1), P< 0.01, and EWL was 61.5% (28.5), P< 0.01. There were no serious AEs or electrolyte disorders. Compliance was 80% after 1 year and 60% after 2 years. The authors concluded that aspiration therapy is a safe and efficient treatment for obesity, and weight reduction improves QOL. Excess weight was approximately halved in a year, with weight stability if treatment was continued; and long-term results remain to be investigated.

This study by Noré​n and Forssell (2016; n = 25; 2-year follow-up) appeared to be an extension of their 2015 study (n = 25; 6-month follow-up). It is unclear whether firm conclusions can be drawn from a 25-person observational study. Furthermore, the authors noted that a "limitation of this study is the combination of aspiration therapy and CBT without any control group. This study only encompasses treatment during 1 to 2 years. Long-term patency is still unknown. It is our belief that once the desired weight goal is achieved, many, if not most, patients will need to continue aspiration therapy, albeit possibly at a reduced frequency, to maintain weight stability. In order to determine this, we have started a prospective study in which we will follow 50 patients with AspireAssist and 50 patients with laparoscopic gastric bypass procedure for 5 years."

Thompson et al. (2017) described AspireAssist as an endoscopic weight loss device comprising an endoscopically placed percutaneous gastrostomy tube and an external device to facilitate drainage of about 30% of the calories consumed in a meal, in conjunction with lifestyle (diet and exercise) counseling. In this 52-week clinical trial, 207 subjects with a BMI between 35.0 and 55.0 kg/m² were randomly assigned in a 2:1 ratio to treatment with AspireAssist plus lifestyle counseling (n = 137; mean BMI, 42.2 ± 5.1 kg/m²) or lifestyle counseling alone (n = 70; mean BMI, 40.9 ± 3.9 kg/m²). The coprimary endpoints were mean percent EWL and the proportion of participants who achieved at least a 25% EWL. At 52 weeks, participants in the AspireAssist group, on a modified intent-to-treat basis, had lost a mean (± SD) of 31.5 ± 26.7% of their excess body weight (12.1 ± 9.6% total body weight), whereas those in the lifestyle counseling group had lost a mean of 9.8 ± 15.5% of their excess body weight (3.5 ± 6.0% total body weight) (P<0.001). A total of 58.6% of participants in the AspireAssist group and 15.3% of participants in the lifestyle counseling group lost at least 25% of their excess body weight (P<0.001). The most frequently reported AEs were abdominal pain and discomfort in the perioperative period and peristomal granulation tissue and peristomal irritation in the postoperative period. Serious AEs were reported in 3.6% of participants in the AspireAssist group. The authors concluded that the weight loss efficacy and safety profile of AspireAssist may bridge the therapeutic gap between more conservative lifestyle modification and the established bariatric surgical procedures for people with class II and III obesity.

This study has several drawbacks: although this was an RCT, individuals could not be blinded as to treatment group because of the nature of the therapy. However, all other aspects of the study protocol, such as weight management counseling and study visits, were the same in the AspireAssist and lifestyle counseling groups to minimize any additional potential influences on the outcome measures. It was possible that bias was introduced into the study by the high number of pre-enrollment withdrawals (approximately 14% in each treatment group) and post-enrollment withdrawals (26% in the AspireAssist group and 48% in the Lifestyle Counseling group), which is a common problem in weight loss intervention studies. However, the baseline and demographic characteristics of the randomized, enrolled, and completer populations were analyzed for homogeneity and were not different in the AspireAssist and lifestyle counseling groups. The consistency of study results by using different statistical analyses further indicated that withdrawals did not bias the results, this report included only 1-year results, and hence did not provide longer term safety and effectiveness of the AspireAssist therapy. However, approximately 90% of the AEs associated with AspireAssist are related to the A-tube, with about 50% occurring within the first week of implantation. The placement and management of the A-tube was similar to percutaneous endoscopic gastrostomy tubes, which have been used in clinical practice for more than 35 years, so the short-term and long-term complications of this device are already well known, and the study population contained a high percentage of female participants, which is a common aspect of weight loss studies. Thus, these findings might not necessarily apply to men with obesity.

On June 14, 2016, the FDA approved the AspireAssist device to assist in weight loss in individuals aged 22 and older who are obese, with a BMI between 35 and 55, and who have failed to achieve and maintain weight loss through nonsurgical weight-loss therapy. Side effects related to use of the AspireAssist include occasional indigestion, nausea, vomiting, constipation, and diarrhea. The AspireAssist is contraindicated in those with certain conditions, including uncontrolled hypertension, diagnosed bulimia, diagnosed binge eating disorder, night eating syndrome, certain types of previous abdominal surgery, pregnancy or lactation, inflammatory bowel disease, or stomach ulcers. The AspireAssist is also contraindicated in individuals with a history of serious pulmonary or cardiovascular disease, coagulation disorders, chronic abdominal pain or those at a high risk of medical complications from an endoscopic procedure. Furthermore, the AspireAssist device is not indicated for use in short durations in those who are moderately overweight.

In a postmarket study, Nystrom et al. (2018) evaluated long-term safety and efficacy of aspiration therapy (AT) in a clinical setting in five European clinics. A total of 201 participants, with BMI between 35.0 and 70.0 kg/m², were enrolled in this study between June 2012 and December 2016. Mean baseline BMI was 43.6 ± 7.2 kg/m². Mean percent total weight loss at 1, 2, 3, and 4 years, respectively, was 18.2% ± 9.4% (n/N = 155/173), 19.8% ± 11.3% (n/N = 82/114), 21.3% ± 9.6% (n/N = 24/43), and 19.2% ± 13.1% (n/N = 12/30), where n is the number of measured participants and N is the number of participants in the absence of withdrawals or lost to follow-up. Clinically significant reductions in HbA1C, triglycerides, and blood pressure were observed. For participants with diabetes, HbA1C decreased by 1% (P< 0.0001) from 7.8% at baseline to 6.8% at 1 year. The only serious complications were buried bumpers, experienced by seven participants and resolved by removal/replacement of the A-Tube, and a single case of peritonitis, resolved with a 2-day course of intravenous antibiotics. The authors concluded that the findings of this study established that AT is a safe, effective, and durable weight loss therapy in people with class II and III obesity in a clinical setting. The high withdrawals/lost to follow-up rates were of concern: 10%, 18%, 44%, and 60% for years 1 to 4.

Weight management is increasingly incorporating endoscopic bariatric therapy (EBT; Kumar et al. [2017]). As the global burden of obesity and its comorbidities has increased, it is evident that novel therapeutic approaches will be necessary to address the obesity epidemic. EBTs offer greater efficacy than diet and lifestyle modification and lower invasiveness than bariatric surgery. The FDA has approved two intragastric balloons and AT for the treatment of obesity: Apollo Orbera is indicated for the treatment of class I and II obesity, Re Shape Integrated Dual Balloon system is indicated for the same range with a comorbidity, and Aspire Bariatrics AspireAssist is approved for individuals with a BMI between 35 and 55 kg/m². These devices have proven safe and effective in clinical trials and are gaining commercial acceptance in the United States; the Orbera has been used extensively outside the United States for over 20 years. These devices will need to be delivered in the context of a multidisciplinary weight loss program, integrating comprehensive care of obesity. Individual selection is important, and ensuring appropriate individual expectations and understanding of alternatives such as pharmacologic therapy and surgery is essential. With several EBTs on the horizon, individuals with obesity will have an even broader array of safe and effective options for weight management in the future. Kumar et al. note that AT addresses a broader BMI range and offers the potential for a significant and durable weight loss.

Pajot et al. (2017) reported that EBT is a rapidly developing area that has now seen FDA approval of six endoscopic bariatric devices and procedures; in addition, several other novel EBTs are progressing through various stages of development with newly published findings. These investigators aimed to assist readers in either selecting an appropriate therapy for the individual or deciding to incorporate these therapies into their practice. This paper provided an updated review of the available data on EBTs, both FDA approved and not, with a particular focus on safety and effectiveness, as well as guidance for discussing with individuals the decision to use endoscopic therapies. The authors of a large meta-analysis of Orbera concluded its ideal balloon volume to be 600 to 650 mL. AspireAssist has had favorable effectiveness and safety data published in a large RCT. A large study of endoscopic sleeve gastroplasty (ESG) has published findings at up to 24 months showing promising durability. Elipse, a swallowed intragastric balloon not requiring endoscopy for either insertion or removal, has had early favorable results published. A magnet-based system for creation of a GJA​ has published favorable findings from its pilot study. The authors concluded that EBTs are safe and effective therapies for weight loss when used in conjunction with lifestyle changes and fill an important gap in the management of obesity. There are now six FDA-approved EBTs available and several more in ongoing trials with favorable early findings. These researchers stated that more study is needed to understand the role of EBTs used in combination or in sequence with medications and bariatric surgery.

Christensen et al. (2017) noted that AT with AspireAssist is a novel endoscopic obesity treatment. Individuals aspirate approximately 30% of an ingested meal through a draining system connected to a percutaneous endoscopic gastrostomy tube. AspireAssist was recently approved by the FDA, and it induced weight loss comparable to the weight loss observed after bariatric surgery, but with a lower risk of complications. The authors stated that few clinical studies about the safety and efficacy of AspireAssist have been carried out and published. Thus, further intervention studies evaluating acute as well as long-term effects are needed. Moreover, an UpToDate review on "Bariatric procedures for the management of severe obesity: Descriptions" (Lim, 2018) lists aspiration therapy as an investigational procedure.

In a postmarket European registry study, Nystrom et al. (2018) evaluated the long-term safety and efficacy of the AspireAssist System in a clinical setting in five clinics. A total of 201 subjects, with BMI between 35.0 and 70.0 kg/m², were enrolled in this study between June 2012 and December 2016. Mean baseline BMI was 43.6 ± 7.2 kg/m². Mean percent total weight loss at 1, 2, 3, and 4 years, respectively, was 18.2% ± 9.4% (n/N = 155/173), 19.8% ± 11.3% (n/N = 82/114), 21.3% ± 9.6% (n/N = 24/43), and 19.2% ± 13.1% (n/N = 12/30), where n is the number of measured participants and N is the number of participants in the absence of withdrawals or lost to follow-up. Clinically significant reductions in HbA1C, triglycerides, and blood pressure were observed. For participants with diabetes, HbA1C decreased by 1% (P< 0.0001) from 7.8% at baseline to 6.8% at 1 year. The only serious complications were buried bumpers, experienced by seven participants and resolved by removal/replacement of the A-Tube, and a single case of peritonitis, resolved with a 2-day course of intravenous antibiotics. The authors concluded that the findings of this study established that aspiration therapy is a safe, effective, and durable weight loss therapy in people with classes II and III obesity in a clinical setting. Moreover, they noted that although the therapy required a substantial commitment on the part of the individual, the data suggested that a very large percentage of individual​s were willing and able to make the commitment to succeed with this therapy. Furthermore, the ability to perform the gastrostomy on an outpatient basis and the very low incidence of costly, serious complications suggested that aspiration therapy may be a lower cost alternative to bariatric surgery.

This study had several drawbacks. First, the report lacked a control group to provide a comparative base. Second, only two sites reported cardiometabolic data; however, the weight loss from these two sites was no greater than that of the sites not reporting cardiometabolic data, suggesting that it was unlikely that the results would differ substantially had there been data from all five clinics. Third, this report only provided results through 4 years of therapy and the number of participants in years 2 to 4 was less than in year 1; however, the durability of weight loss and relatively narrow band of 95% CIs suggested robustness of the data. With regard to safety, the excellent and consistent safety data between this report and the PATHWAY trial, coupled with the 30 years of widespread usage of the AspireAssist's nearest analog, the PEG tube, suggested that longer term safety results are not apt to substantially differ from the postprocedural results reported here.

On February 12, 2022, Aspire Bariatrics released a statement that AspireAssist would be withdrawn from the market on April 8, 2022.

BARIATRIC SURGERY AS A TREATMENT FOR IDIOPATHIC INTRACRANIAL HYPERTENSION IN PERSONS NOT MEETING MEDICAL NECESSITY CRITERIA FOR OBESITY SURGERY ABOVE

There is no of high-quality peer-reviewed evidence supporting the use of bariatric surgery for those not meeting the medical necessity criteria above (i.e., BMI < 35).

BARIATRIC SURGERY AS A TREATMENT FOR INFERTILITY IN PERSONS NOT MEETING MEDICAL NECESSITY CRITERIA FOR OBESITY SURGERY ABOVE

The American College of Obstetricians and Gynecologists' practice bulletin on bariatric surgery and pregnancy (ACOG, 2009) stated that bariatric surgery should not be considered a treatment for infertility.

In 2021, the American Society for Reproductive Medicine released a practice committee document for obesity and reproduction. The authors reported that obesity in women can disrupt the usual menstrual cycle, including a lack of ovulation entirely. Additionally, obesity in men can result in diminished semen and sperm quality. The authors note that there is limited data that firmly concludes the effectiveness of bariatric surgery on fertility, concluding that bariatric surgery is an “adjuvant to lifestyle modification."

BARIATRIC SURGERY FOR TYPE 2 DIABETES WITH A BMI LESS THAN 30

In 2018, the ASMBS released a position statement that is supported by the American Diabetes Association and the Society of American Gastrointestinal and Endoscopic Surgeons, that supports the use of bariatric surgery among individuals with a BMI greater than 30 and T2DM. There is no recommendation for the BMI threshold to be lower than 30. In 2022, the ASMBS reaffirmed its 2018 position.

In its 2024 edition of Diabetes Care: Standards of Care in Diabetes – 2024, The American Diabetes Association states the following: “Consider metabolic surgery as a weight and glycemic management approach in people with diabetes with BMI greater than or equal to 30 (or 27.5 in Asian American individuals) who are otherwise good surgical candidates."

There are no professional society recommendations that strongly endorse bariatric surgery among individuals with T2DM and a BMI less than 30.

In 2015, Baskota et al. published a systematic review and meta-analysis of studies that enrolled individuals with T2DM and a BMI less than 30. Ten studies from various countries and interventions were reviewed, totaling 290 participants. BMI and body weight loss were both statistically significant compared to baseline, as was HbA1c levels. In fact, HbA1c levels on average dropped 1.88%, which resulted in only 42% of individuals achieving an HbA1c level below 6%. The authors conclude that it is too early to suggest bariatric surgery for nonobese individuals with T2DM.

CONVERSION TO SLEEVE GASTRECTOMY FOR HYPOGLYCEMIA POST-RYGBP

Complications after RYGBP are well documented (Carter et al., 2016). Reversal of RYGBP is indicated in select cases but can lead to weight gain. Conversion from RYGBP to SG has been proposed for correction of complications of RYGB without associated weight gain. However, little is known about outcomes after this procedure. Carter et al. researchers performed a retrospective study of individuals who underwent RYGBP to SG conversion. Twelve individuals underwent RYGB to SG conversion for refractory marginal ulceration, stricture, dumping, gastrogastric fistula, hypoglycemia, and failed weight loss. No deaths occurred; four individuals experienced seven major complications, including portal vein thrombosis, bleeding, pancreatic leak, pulmonary embolus, seroma, anastomotic leak, and stricture; two required reoperation, and six were readmitted within 30 days; four required nasoenteric feeding postoperatively because of prolonged nausea. The complication of RYGBP resolved in 11 of 12 individuals. At 14.7 months, change in BMI for all individuals was a decrease of 2.2 kg/m². In five individuals with morbid obesity at conversion, the change in BMI was a decrease of 6.4 kg/m² at 19 months. The authors concluded that laparoscopic conversion from RYGBP to SG was successful in resolving certain complications of RYGBP and did not result in short-term weight gain. However, conversion had a high rate of major complications as well as a high rate of readmission and need for supplemental nutrition. They stated that although conversion to SG may be appropriate in carefully selected individuals, other options for individuals with severe chronic complications after RYGBP should be considered.

The 2017 ASMBS position statement on "Postprandial hyperinsulinemic hypoglycemia after bariatric surgery" (Eisenberg et al., 2017) stated that "Conversion of RYGBP to SG (primary or staged) has also been described in a few small series/case reports for complications related to RYGBP. Reversal of RYGBP with the addition of primary or staged SG specifically for treatment of refractory hyperinsulinemic hypoglycemia has been described in less than 10 individuals with resolution of hypoglycemia symptoms in the majority without findings of short-term weight gain. As with RYGBP reversal, these are technically challenging procedures with increased risk of complications, including a greater incidence of gastroesophageal reflux related to the addition of the SG. Currently, there is insufficient evidence to recommend this as treatment for hyperinsulinemic hypoglycemia."

An UpToDate review on "Late complications of bariatric surgical operations" (Ellsmere, 2018) states that "Based on the theory that severe, disabling hypoglycemia after gastric bypass surgery occurs in a subset of patients with loss of gastric restriction, with resultant rapid food passage and absorption, restoration of gastric restriction can result in symptom resolution. Gastric restriction can be restored by surgical placement of a silastic ring or an adjustable gastric band around the pouch. In one series, symptoms resolved in 11 of 12 patients with this approach."

GASTROPLASTY ("STOMACH STAPLING")

Gastroplasty, more commonly known as "stomach stapling" and not to be confused with VBG, is a technically simple operation, accomplished by stapling the upper stomach to create a small pouch into which food flows after it is swallowed. The outlet of this pouch is restricted by a band of synthetic mesh, which slows its emptying, so that the person having it feels full after only a few bites of food. According to the available literature, individuals who have this procedure seldom experience any satisfaction from eating, and tend to seek ways to get around the operation by eating more. This causes vomiting, which can tear out the staple line and destroy the operation. Overall, clinical studies have shown that about 40% of persons who have this operation do not achieve loss of more than half of their excess body weight. In the long-term, 5 or more years after surgery, only about 30% of individuals have maintained a successful weight loss. Studies have reported that many individuals must undergo another revisional operation to obtain the results they seek.

In January 2004, ASMBS, in their "Story of Obesity Surgery", the authors point out that stomach stapling “…resulted in very poor long-term weight loss and, after several attempted modifications, was abandoned eventually." Stomach stapling, in essence was replaced by VGB, which, of course, is also no longer utilized.

JEJUNOILEAL BYPASS (INTESTINAL BYPASS; MALABSORPTION)

Jejunoileal bypass (intestinal bypass; malabsorption) affects digestion by interrupting the absorption of food, which is accomplished by bypassing a portion of the bowel. Because food is unable to pass through the entire bowel, calories and nutrients are only partially absorbed, resulting in the reduction of body weight. Malabsorption surgeries (e.g., jejunoileal bypass, jejunocolic bypass) are associated with complications such as steatorrhea, electrolyte depletion, liver failure, arthralgia, hypoplasia of bone marrow, avitaminosis, and death. The available published peer-reviewed literature is insufficient to establish the safety and/or effectiveness of jejunoileal bypass for the treatment of obesity.

LAPAROSCOPIC GASTRIC PLICATION

Pujol Gebelli et al. (2011) stated that laparoscopic gastric plication (LGP) is a new technique derived from SG. Plication of the greater curvature produces a restrictive mechanism that causes weight loss. The results of the first cases where this technique has been applied in this hospital were presented. A review was made of individuals operated on in the authors' hospital between November 2009 and December 2010. Plication of the gastric greater curvature was performed under general anesthetic and by laparoscopy using three lines of sutures and with an orogastric probe as a guide. Results of the morbidity, mortality, and weight loss were presented. Thirteen individuals were operated on (seven women). The maximum BMI varied between 37.11 kg/m² and 51.22 kg/m² at the time of the operation. The most frequently found morbidity was nausea and vomiting. Two individuals required further surgery due intractable vomiting and total dysphagia; in one, the plication unfolded, and in the second it was converted into vertical gastrectomy. The authors concluded that LGP is a new surgical technique that gives equivalent short-term results to vertical gastrectomy. It is a reproducible and reversible technique with results and indications still to be validated.

Shen et al. described the surgical technique of laparoscopic greater curvature plication (LGCP) and validated the safety and effectiveness of LGCP for the treatment of obesity in Chinese individuals with a relatively low BMI. Twenty-two obese individuals (mean age, 33.8 ± 6.0 years; mean BMI, 37.0 ± 7.0 kg/m²) underwent LGCP between September 2011 and September 2012. After dissecting the greater omentum and short gastric vessels, the gastric greater curvature plication with two rows of nonabsorbable suture was performed under the guidance of a 32-F bougie. The data were collected during follow-up examinations performed at 1, 3, 6, and 12 months postoperatively. All procedures were performed laparoscopically. The mean operative time was 84.1 mins (50–120 mins), and the mean length of hospital stay was 3.8 days (2–10 days). There were no deaths or postoperative major complications that needed re-operation. The mean EWL% was 22.9% ± 6.9%, 38.6% ± 9.8%, 51.5% ± 13.5%, and 61.1% ± 15.9% at 1, 3, 6, and 12 months postoperatively. At 6 months, T2DM was in remission in two (50%) individuals, hypertension in one (33.3%) individual, and dyslipidemia in 11 (78.6%) individuals. Decreases in the index for homeostasis model assessment of insulin resistance (HOMA-IR) and in insulin and glucose concentrations were observed. The authors concluded that the early outcomes of LGCP as a novel treatment for obese Chinese individuals with a relatively low BMI were satisfactory with respect to the effectiveness and low incidence of major complications. They stated that additional long-term follow-up and prospective, comparative trials are still needed.

Brethauer et al. (2011) presented the results of a feasibility study using LGP for weight loss achieved without stapling or banding. After institutional review board approval, two methods were used to achieve laparoscopic gastric volume reduction. In the first group (anterior plication [AP]), the anterior gastric wall was folded inward from the fundus to the antrum using two rows of running sutures. The greater and lesser curvatures were approximated to create an intraluminal fold of the stomach. In the second group (greater curvature plication [GCP]), the short gastric vessels were divided, and the greater curvature was folded inward, with two suture lines to reduce the gastric capacity by a large intraluminal gastric fold. The average preoperative BMI was 43.3 kg/m² (range, 36.9–49.0), and three individuals were men. Of the 15 individuals, nine underwent AP. For the nine individuals who underwent AP, the 6- and 12-month endoscopic evaluations demonstrated comparable-size plications over time, except for in one individual, who had a partially disrupted fold. Of the six individuals who underwent GCP, the 6- and 12-month follow-up endoscopic examinations demonstrated a durable intraluminal fold, except for in one individual, with a partial disruption at the distal fold due to a broken suture. For individuals completing 1 year of follow-up, the percentage of excess weight loss was 23.3% ± 24.8% in the AP group (n = 5) and 53.4% ± 22.7% in the GCP group (n = 6). No bleeding or infectious complications developed. The first individual in the GCP group required reoperation and plication reduction due to gastric obstruction. The authors concluded that their initial experience has suggested that a reduction in gastric capacity can be achieved by way of plication of the anterior stomach and greater curvature. The early weight loss results have been encouraging, with better weight loss in individuals who underwent GCP. They stated that the use of laparoscopic GCP warrants additional investigation as a primary bariatric procedure.

Huang et al. (2012) noted that the laparoscopic adjustable gastric band has been widely accepted as one of the safest bariatric procedures to treat morbid obesity. However, because of variations in the results and the complications that tend to arise from port adjustment, alternative procedures are needed. These researchers have demonstrated, in a university hospital setting, the safety and feasibility of a novel technique—laparoscopic adjustable gastric banded plication—designed to improve the weight loss effect and decrease gastric band adjustment frequency. These investigators enrolled 26 individuals between May 2009 and August 2010. Laparoscopic adjustable gastric banded plication was performed using five-port surgery. They placed Swedish bands using the pars flaccida method, divided the greater omentum, and performed gastric plication below the band to 3 cm from the pylorus using a single-row continuous suture. The data were collected and analyzed pre- and postoperatively. The mean operative time was 87.3 minutes without any intraoperative complications. The average postoperative hospitalization was 1.33 days. The mean EWL at 1, 3, 6, 9, and 12 months after surgery was 21.9%, 31.9%, 41.3%, 55.2%, and 59.5%, respectively. The mean follow-up time was 8.1 months (range, 2–15), and the gastric band adjustment rate was 1.1 times per individual during this period. Two complications developed: 1) gastrogastric intussusception and 2) tube kinking at the subcutaneous layer.

Both complications were corrected by reoperation. No mortality was observed. The authors concluded that laparoscopic adjustable gastric banded plication provides both restrictive and reductive effects and is reversible. The technique is safe, feasible, and reproducible and can be used as an alternative bariatric procedure. Moreover, the authors stated that comparative studies and long-term follow-up are needed to confirm their findings.

Ji et al. (2014) conducted a systematic review of the currently available literature regarding the outcomes of LGP for the treatment of obesity. The authors' systematic review yielded 14 studies encompassing 1450 individuals undergoing LGP. Perioperative data were collected from each study and recorded. Mean preoperative BMI ranged between 31.2 and 44.5 kg/m², and 80.8% of the individuals were female. Operative time ranged from 50 to 117.9 minutes (average, 79.2 minutes). Hospital stay varied from 0.75 to 5 days (average, 2.4 days). The percentage EWL for LGP varied from 31.8% to 74.4% with follow-up from 6 months to 24 months. No mortality was reported in these studies and the rate of major complications requiring reoperation ranged between 0% and 15.4% (average, 3.7%). The authors concluded that early reports with LGP were promising with a favorable short-term safety profile. However, it remains unclear if weight loss following LGP is durable in the long-term. They stated that additional prospective comparative trials and long-term follow-up are needed to further define the role of LGP in the surgical management of obesity.

In a prospective study, Zeinoddini et al. (2014) evaluated the safety and effectiveness of LGP on adolescents. Measured parameters included percentage EWL, percentage BMI loss, obesity-related comorbidities, operative time, and length of hospitalization and complications. LGP was performed in 12 adolescents (nine females, three males). Mean (SD) age of the individuals was 13.8 ± 1 year. Mean preoperative weight and BMI were 112.4 ± 19.7 kg and 46.0 ± 4 kg/m², respectively. Mean (SD) percentages of EWL and BMI loss were 68.2 ± 9.9% and 79.0 ± 9.0%, respectively, after 2 years. All medical comorbidities were improved after LGP. There were no deaths. One individual required replication 4 days postoperatively due to obstruction at the site of the last knot. No other major complications were observed. No individual required rehospitalization. The authors concluded that LGP has the potential of being an ideal weight loss surgery for adolescents, resulting in excellent weight loss and minimal psychological disruption. It is associated with a minimal risk of leakage, bleeding, and nutritional deficiency. However, they stated that large well-designed studies with long-term follow-up are needed.

In 2021, Meyer et al. conducted a systematic review and meta-analysis of the effect of gastric plication on T2DM. Fourteen studies, including 2071 participants, were included in the analysis. While there was a short-term effect on weight loss, there was no effect on T2DM. Additionally, the authors note the need for medium- and long-term follow up, as only two studies had follow up beyond 3 years.

Ding et al. (2020) conducted a network meta-analysis of RCTs on the effect of bariatric surgeries on T2DM. Seventeen studies, totaling 1108 individuals, were included in the study. The analysis revealed that all routine bariatric surgeries except for gastric plication were effective in achieving diabetes remission. There were no RCTs of gastric plication with follow up beyond 3 years, but all other bariatric surgeries met this criteria.

In 2021, El Soueidy et al. conducted a systematic review of LGP. Fifty-three studies were included, totaling 3103 individuals. The mean percentage of EWL ranged from 35% to 77% at 12 months postoperation. One study had follow-up at 10 years, in which the mean excess weight lost was 42%. The authors note that gastric plication is acceptable for the treatment of obesity, but they also highlight that sleeve gastrectomy is superior.

In 2023, De Luca et al. reaffirmed the results of Ding et al.'s 2020 study. The authors also found that gastric plication was the only routinely used bariatric surgery that did not have a significant effect on diabetes remission.

LAPAROSCOPIC SINGLE-ANASTOMOSIS DUODENO-ILEAL BYPASS WITH GASTRIC PLICATION

Balint et al. (2022) noted that bariatric surgery is more effective in the management of morbid obesity and related comorbidities than is conservative therapy. Pylorus-preserving single-anastomosis duodenoileal bypass with sleeve gastrectomy (SADI-SG) is a modified DS technique; gastric plication (GP) is an alternate to SG. In a cohort study, morbidly obese (BMI >40, or >35 in the presence of diabetes or prediabetes) individuals were recruited and underwent SADI-GP. Complications related to surgery were recorded to assess the feasibility of the procedure. Weight loss outcomes were analyzed to determine effectiveness. Minnesota Multiphasic Personality Inventory 2 (MMPI-2) was recorded after 1 year of follow-up, and test scales were used to describe physiological phenomena. Seventeen middle-aged (mean age, 40 years) individuals were involved in this trial; 15 of them were women. The mean duration of surgery was 205 minutes. There were no complications of conversion, death, bleeding, venous thromboembolism (VTE) or 30-day re-admission to hospital. These researchers did experience CD4a (pulmonary insufficiency due to chronic lung disease) and a CD3b (anastomosis leakage treated laparoscopically) complications. Vomiting occurred in three individuals (CD1). Obesity-related comorbidities showed favorable resolution rates (77.8% for hypertension, 81.2% for dyslipidemia, 100% for diabetes at the 1-year follow-up). Weight loss outcomes were favorable (53.20 EWL percentage, and 35.58 TWL percentage at 1-year follow-up). Greater weight loss caused significantly higher levels of Depression (t[13.958] = −2.373; P=0.00; P<0.05) and Low Positive Emotions (t[13.301] = −2.954; P=0.00; P<0.05) and Introversion/Low Positive Emotionality (t[13.408] = −1.914; P=0.02; P<0.05) in MMPI-2 data. The authors concluded that according to this safety study, SADI-GP is a promising malabsorptive procedure, but a long-term, high-volume case series or an RCT is needed to examine complication rates and weight loss outcomes.

This study had limitations due to the small sample size (n = 17) and study design. These researchers did not reach the projected number of included cases because they experienced a higher than expected dropout rate, and the number of individuals with obesity applied for screening was too low considering the strict selection criteria. There was a huge selection bias in this cohort because 88% of the study population were women. It could skew these findings that there was no control endoscopic or radiologic examination scheduled for gastric-plicated individuals. Routine cholecystectomy was carried out in 15 cases that could bias operating time and occurrence of some complications. Finally, this study presented only short-term results; thus, the effectiveness of the procedure could not be determined at the time.

Osorio et al. (2021) stated that SADI-S is being proposed for obese individuals with insufficient weight loss or WR after SG; however, limited information is available. These researchers examined the safety and effectiveness of SADI-S as a revisional surgery after SG, compared with standard DS. This was a cohort, single-center study that entailed all individuals submitted to SADI-S and DS after failed SG in a high-volume institution, between 2008 and 2020. Forty-six individuals submitted to SADI-S and 55 to DS were included, 37.2 and 41.5 months after SG (P=0.447), with initial BMI of 56.2 versus 56.6 (P=0.777) and 39.2 versus 39.7 before revisional surgery (P=0.675). All surgeries were laparoscopic. Clavien-Dindo greater than II complication rate was 6.5% for SADI-S and 10.9% for DS (P=0.095), with no 90-day mortality. Follow-up at 2 years was available for 38 SADI-S and 38 DS individuals, with TWL of 35.3% versus 41.7% (P=0.009), and EWL of 64.1% versus 75.3% (P=0.014). Comorbidities resolution for SADI-S and DS was 44.4% versus 76.9% for diabetes (P=0.029) and 36.4% versus 87.5% for hypertension (P=0.006); with no differences for resolution of dyslipidemia (72.7% vs. 88.9%, P=0.369) and OSA (93.3% vs. 91.7%; P=0.869). DS individuals required more extra nutritional supplementation; three SADI-S individuals needed conversion to DS: two for biliary reflux and one for WR. The authors concluded that after a failed SG, revisional DS permitted better weight control and diabetes and hypertension resolution than SADI-S, at the expense of higher supplementation needs.

SADI-S is a bariatric surgery conceived to simplify the DS in order to reduce its postoperative complications, according to Admella et al., 2021. These researchers examined the safety and effectiveness of SADI-S, comparing its results in both direct and two-step procedure. A total of 232 individuals were included, 192 were submitted to direct SADI-S, and 40 had previously undergone a SG. The severe complications rate (Clavien-Dindo ≥IIIA) was 7.8%, with hemoperitoneum and duodenal stump leak being the most frequent ones. One individual​ was exitus between the first 90 days after surgery (0.4%). Individuals who underwent direct SADI-S had an initial BMI of 49.6 kg/m² in comparison to 56.2 kg/m² in the two-step SADI-S (P<0.001). The mean EWL at 2 years was higher in direct SADI-S (77.3% vs. 59.3%; P<0.05). The rate of comorbidities resolution was 88.5% for diabetes, 73.0% for hypertension, 77.0% for dyslipidemia, and 85.7% for sleep apnea, with no differences between both techniques. The authors concluded that in the medium term, SADI-S was a safe and effective technique that offered a satisfactory weight loss and remission of comorbidities. Individuals undergoing two-step SADI-S had a higher initial BMI and presented a lower EWL than direct SADI-S.

LOOP GASTRIC BYPASS​

Although the basic concept of gastric bypass remains intact, numerous variations are being performed at this time. Recent data demonstrate that surgeons are moving from simple gastroplasty procedures, favoring the more complex gastric bypass procedures as the surgical treatment of choice for the severely obese individual. The gastric bypass operation can be modified to alter the absorption of food by moving the Roux-en-Y-connection distally down the jejunum, effectively shortening the bowel available for absorption of food. The weight loss effect is then a combination of the very small stomach, which limits intake of food, with malabsorption of the nutrients, which are eaten, reducing caloric intake even further. In a sense, this procedure combines the least desirable features of the gastric bypass with the most troublesome aspects of the BPD. Although individuals can have increased frequency of bowel movements, increased fat in their stools, and impaired absorption of vitamins, recent studies have reported good results. The loop gastric bypass developed years ago has generally been abandoned by most bariatric surgeons as unsafe. Although easier to perform than the RYGBP, it has been shown to create a severe hazard in the event of any leakage after surgery, and seriously increases the risk of ulcer formation, and irritation of the stomach pouch by bile. As the ASMBS reported in their 2004 "Story of Obesity Surgery," bile reflux frequently occurred; thus this procedure and is ​now instead performed as a Roux-en-Y gastric bypass.

MINI GASTRIC BYPASS/ONE ANASTOMOSIS GASTRIC BYPASS (MGB, MGB-OAGB, OAGB)

The "mini gastric bypass" has been promoted as a new surgical treatment for severe obesity. It involves laparoscopic construction of a large and elongated gastric pouch and a loop gastric bypass with distal diversion (200 cm or up to 50% of the small bowel) to reduce food absorption. Although the name mini gastric bypass implies "small" and "simple," this is a major surgical procedure. The MGB uses a jejunal loop directly connected to a small gastric pouch, instead of a Roux-en-Y anastomosis. In this way, the MGB is similar to the loop gastric bypass, a procedure that has been abandoned by bariatric surgeons because of its inherent risks. Specifically, performing a loop, rather than a Roux-en-Y, anastomosis to a small gastric pouch in the stomach may permit reflux of bile and digestive juice into the esophagus where it can cause esophagitis and ulceration, and may thus increase the risk of esophageal cancer. The Roux-en-Y modification of the loop bypass was designed to divert bile downstream, several feet below the gastric pouch and esophagus to minimize the risk of reflux. The trend toward use of Roux-en-Y and away from loop gastric bypass was based on sound surgical experience of multiple surgeons with large series of individuals.

Georgiadou et al. (2014) summarized the available evidence about the efficacy and safety of laparoscopic MGB (LMGB). These investigators performed a systematic search in the literature, and PubMed and reference lists were scrutinized (end-of-search date: July 15, 2013). For the assessment of the eligible articles, the Newcastle-Ottawa quality assessment scale was used. Ten eligible studies were included in this study, reporting data on 4899 individuals. According to all included studies, LMGB induced substantial weight and BMI reduction, as well as substantial excess weight loss. Moreover, resolution or improvement in all major associated medical illnesses and improvement in overall Gastrointestinal Quality of Life Index score were recorded. Major bleeding and anastomotic ulcer were the most commonly reported complications. Re-admission rate ranged from 0% to 11%, whereas the rate of revision operations ranged from 0.3% to 6%. The latter were conducted owing to a variety of medical reasons such as inadequate or excessive weight loss, malnutrition, and upper gastrointestinal bleeding. Finally, the mortality rate ranged between 0% and 0.5% among primary LMGB procedures. The authors concluded that LMGB represents an effective bariatric procedure; its safety and minimal postoperative morbidity seem remarkable. Randomized comparative studies seem mandatory for the further evaluation of LMGB.

Since 2014, there have been many publications regarding the use of MGB for the treatment of obesity. Additionally, in 2022, the ASMBS has endorsed the procedure, named as “one anastomosis gastric bypass (OAGB)". In the literature, the procedure is often recognized as “mini gastric bypass-one anastomosis gastric bypass (MGB-OAGB)".

There are several recent systematic reviews and meta-analyses of RCTs that evaluate the safety and effectiveness of OAGB. In 2024, Onzi et al. published a meta-analysis and systematic review of 11 RCTs, totaling 854 individuals. Studies comparing OAGB to RYGB or SG (controls) were included. BMI at 6 and 12 months of follow-up was not different between OAGB and controls, although at 5 years BMI was significantly lower among those who received OAGB compared to controls. However, this was only reported in two studies. Greater excess weight loss was seen among those who received OAGB at 1 year compared to controls, but this difference was lost at 5 years. Several other health outcomes, including T2DM remission, complications, and GERD were similar among OAGB and controls. Overall, many of these results have high heterogeneity and many of the studies were deemed to have a high risk of bias, resulting in a low certainty of evidence. This meta-analysis is further limited by the combination of RYGB and SG as controls, when the safety and effectiveness of these interventions have different profiles. Additionally, all of the included studies were conducted outside of the United States.

Elsaigh et al. (2024) conducted a systematic review and meta-analysis of 12 RCTs, totaling 1057 participants. As in Onzi et al.'s analysis, none of the trials were conducted in the United States. However, unlike their analysis, the studies included in this meta-analysis compared OAGB to RYGB, exclusively. Operative time and hospital stay were shorter among those who received OAGB, and fewer early postoperative complications were reported compared to those who received RYGB. Follow-up outcomes were similar among both interventions, although remission of dyslipidemia and hypertension favored RYGB. Change in BMI was no different between interventions at 6 and 24 months, although at 12 months, a greater BMI reduction was seen among those who received OAGB. TWL and EWL similarly mixed results over time, although was superior overall, leading to the authors' suggestion that RYGB may be more effective for weight loss long term.

In 2024, Kapellas et al. conducted a systematic review and meta-analysis of nine RCTs, totaling 643 individuals. The primary aim of the analysis was to compare OAGB to RYGB in the treatment of GERD among individuals with obesity. The authors concluded that OAGB was associated with an increased risk of GERD compared to RYGB.

Similarly, in 2025, Ahmed et al.​ conducted a systematic review and meta-analysis of 12 RCTs, totaling 904 individuals. This analysis compared OAGB to RYGB. Generally, there was no difference in total weight loss at 36 months' follow-up, and EWL was comparable out to 60 months. Similarly, comorbidities were resolved in similar proportions. However, GERD and marginal ulcers were more frequent among those who received OAGB compared to RYG.

Overall, the evidence is insufficient to establish the safety and effectiveness of OAGB in the treatment of obesity. The alternative bariatric procedures have been established as mainstay treatment options due to their reproducibility in routine clinical practice, or have a safety and/or effectiveness profile that exceeds gold standard options (i.e., SG or RYGB). OAGB is yet to accomplish either of these metrics;​ in fact, OAGB use is declining in the United States. Additionally, while OAGB is continuing to increase in use outside the United States, there is a lacking characterization of the safety and effectiveness within the United States. 

NATURAL ORIFICE TRANSORAL ENDOSCOPIC SURGERY (NOTES) TECHNIQUES FOR BARIATRIC SURGERY 

Synopsis

Natural orifice transluminal endoscopic surgery (NOTES) is being explored for a variety of surgeries, including bariatric procedures. NOTES procedures are incisionless surgeries performed with an endoscope passed through the mouth. Tissue approximation and closure devices are being developed for use in conjunction with various endoscopic procedures, including NOTES. Examples of NOTES techniques for bariatric surgery include, but may not be limited to, endoscopic duodenal-jejunal bypass, intragastric balloon (also called gastric balloon), restorative obesity surgery (ROSE), endoluminal ROSE procedure, and transoral gastroplasty (TG) (also referred to as vertical sutured gastroplasty or endoluminal vertical gastroplasty). Endoscopic closure devices proposed for use in conjunction with NOTES include: Over the Scope Clip (OTSC) System Set, OverStitch Endoscopic Suturing System, and StomaphyX Endoluminal Fastener and Delivery System (EndoGastric Solutions, Inc.).

The ROSE procedure is suggested for the treatment of WR following gastric bypass surgery due to a gradual expansion of the gastric pouch. The stomach is accessed orally via an endoscope and reduced in size using an endoscopic closure device.

Erridge et al. (2016) summarized the clinical applications of NOTES in bariatric surgery. These investigators carried out a review of data, until December 2014 regarding techniques and outcomes of bariatric NOTES procedures. Nine publications were included in the final analysis, with another six papers describing procedures included for comparison. All NOTES studies adopted a hybrid procedure. Hybrid NOTES sleeve gastrectomy (hNSG) was described in four humans and two porcine studies. In humans, six subjects (23.1%) were underwent conversion to conventional laparoscopic methods, and one postoperative complication (3.8%) was reported. Mean excess weight loss was 46.6% (range of 35.2 to 58.9). The authors concluded that transvaginal-assisted SG appeared feasible and safe when performed by appropriately trained professionals. However, they stated that improvements must be made to overcome current technical limitations. 

An UpToDate review on "Natural orifice transluminal endoscopic surgery (NOTES)" (Pasricha and Rivas, 2018) states that "Natural orifice transluminal endoscopic surgery (NOTES) is an emerging field within gastrointestinal surgery and interventional gastroenterology in which the surgeon accesses the peritoneal cavity via a hollow viscus and performs diagnostic and therapeutic procedures … There is much more that needs to be learned about this procedure, including the risk of peritoneal contamination. So far, the available body of clinical experience does not demonstrate deleterious effects related to contamination and subsequent infection. At present, NOTES still should be considered primarily experimental and should be performed only in a research setting."

Brunaldi et al. (2018) stated that RYGBP is the most commonly performed bariatric procedure; however, despite its high efficacy, some individuals regain part of their lost weight. Several endoscopic therapies have been introduced as alternatives to treat WR, but most of these articles were relatively small with unclear long-term data. In a systematic review and meta-analysis, t​hese researchers examined the efficacy of endoscopic therapies for WR after RYGBP. They searched Medline, Embase, Scopus, Web of Science, Cochrane, Ovid, CINAHL/EBSCo, LILACS/Bireme, and gray literature. Primary outcomes were absolute weight loss (AWL), EWL, and TWL. Thirty-two studies were included in qualitative analysis; 26 described full-thickness (FT) endoscopic suturing (ES) and pooled AWL, EWL, and TWL at 3 months were 8.5 ± 2.9 kg, 21.6 ± 9.3%, and 7.3 ± 2.6%, respectively. At 6 months, they were 8.6 ± 3.5 kg, 23.7 ± 12.3%, and 8.0 ± 3.9%, respectively. At 12 months, they were 7.63 ± 4.3 kg, 16.9 ± 11.1%, and 6.6 ± 5.0%, respectively. Subgroup analysis showed that all outcomes were significantly higher in the group with FT suturing combined with argon plasma coagulation (APC) (P<0.0001). Meta-analysis included 15 FT studies and showed greater results; three studies described superficial-thickness suturing with pooled AWL of 3.0 ± 3.8, 4.4 ± 0.07, and 3.7 ± 7.4 kg at 3, 6, and 12 months, respectively; two articles described APC alone with mean AWL of 15.4 ± 2.0 and 15.4 ± 9.1 kg at 3 and 6 months, respectively. The authors concluded that full-thickness suturing was effective at treating WR after RYGBP; and performing APC before suturing appeared to result in greater weight loss. Moreover, these researchers stated that head-to-head studies are needed to confirm these findings; and few studies adequately examined the effectiveness of other endoscopic techniques.

Fayad et al. (2019) stated that transoral outlet reduction (TORe) by devitalization and/or ES has been implemented in the management of WR post-RYGBP. These investigators examined the safety and efficacy of TORe following an insurance-based algorithm. They reviewed the prospectively maintained database of individuals who underwent TORe between September 2015 and January 2018 at a single academic center. An algorithm was followed whereby management was based on insurance coverage. As part of the algorithm, all individuals presented for a repeat endoscopy at 8 weeks. Individuals did not receive any diet, lifestyle intervention, or pharmacotherapy. Fifty-five individuals were included (median age, 48 years), of which 50 were women (90.9%). Individuals presented for evaluation at a mean of 8.7 years post-RYGBP. The main presenting symptom was combined dumping syndrome and WR (49.1%), followed by WR alone (45.5%); 29 individuals required treatment at their second procedure, and 11 required treatment at their third procedure. Average percentage of TWL after TORe observed at 3-, 6-, 9-, and 12-month follow-up was 8.2, 9.3, 8.4, and 5.5%, respectively. The mean Dumping Syndrome Severity Score was significantly reduced from 23.3 ± 12.4 before TORe to 16.3 ± 6.51 after TORe (P<0.01). The AE rate from TORe was 14.5%. The authors concluded that TORe was effective in halting ongoing WR and achieving moderate short-term weight loss as well as improving DS in post-RYGBP individuals. Moreover, durability at 1 year remains questionable due to weight recidivism.

In 2020, Goh et al. conducted a systematic review of endoluminal techniques or the revision of a primary bariatric surgery. Twenty-six studies were included in the review, which varied in study design and endoluminal technique (e.g., ROSE, TORe, StomaphyX). Mean weight loss after RYGB revision at 3 months was 6.27 kg, which was sustained for up to 2 years after a procedure; however, excess weight loss was not maintained at 2 years. Minor and moderate complications were commonly reported, but no major complications were reported. Given the heterogeneity of study design, intervention, and primary bariatric surgery, it is difficult to interpret these findings. Nevertheless, it does not appear as though the safety and effectiveness of these endoluminal procedures can be established.

Furthermore, an UpToDate review on endoscopy in patients who have undergone bariatric surgery, Huang (2021) states that “A multicenter randomized, sham-controlled trial evaluated the effectiveness of transoral outlet reduction (TORe) via ES in 77 patients who had undergone RYGBP with inadequate weight loss or WR. Subjects who underwent TORe had a greater mean weight loss from baseline than those who underwent a sham procedure (3.5 vs. 0.4%). Weight loss or stabilization was achieved in 96% of TORe subjects, compared with 78% of controls. Full-thickness suturing has also been combined with APC therapy to promote greater weight loss than suturing alone". TORe is not mentioned in the “Summary and Recommendations" section of this review.

Gastrointestinal Liners (Endoscopic Duodenal-jejunal Bypass, Endoscopic Gastrointestinal Bypass Devices; e.g., EndoBarrier and the ValenTx Endo Bypass System)

Endoscopic duodenal-jejunal bypass is the endoscopic placement of a duodenal-jejunal bypass sleeve (e.g., EndoBarrier) that lines the first section of the small intestine causing food to be absorbed further along the intestine. Once implanted, the device is purported to influence gastrointestinal hormones and satiety. It is suggested to promote weight loss in individuals who are potential candidates for bariatric surgery, but are too heavy to safely undergo the procedure.

An UpToDate review on "Bariatric surgical operations for the management of severe obesity: Descriptions" by Lim (2015) lists "Endoscopic gastrointestinal bypass devices" as investigational. It states that "Endoscopic gastrointestinal bypass devices (EGIBD) – A barrier device is deployed to prevent luminal contents from being absorbed in the proximal small intestine. The EndoBarrier is 60-cm long and it extends from the proximal duodenum to the mid-jejunum and thus mimics a duodenojejunal bypass. It is a safe procedure but is hallmarked by an up to 20% rate of early removal due to patient intolerance. The ValenTx is a 120-cm barrier device that extends from the gastroesophageal junction to the jejunum. This too has a high rate of early removal, but excess weight loss at 3 months was reported to be 40%, and significant improvement was seen in 7 out of 7 diabetic patients within those 3 months. Data are still lacking about the longevity of these endobarriers and their outcomes once the barrier is removed."

The EndoBarrier, an endoscopically delivered duodeno-jejunal bypass liner (DJBL), is a plastic flexible tube that is placed in the duodenal bulb, directly behind the pylorus. It extends from the duodenum to the proximal jejunum. Recent studies have suggested that the use of EndoBarrier has resulted in significant weight reduction in comparison to control-diet individuals.

Schouten et al. (2010) noted that the endoscopically placed duodenal-jejunal bypass sleeve or EndoBarrier Gastrointestinal Liner has been designed to achieve weight loss in morbidly obese individuals. These researchers reported on the first European experience with this device. A multicenter, randomized clinical trial was performed. Forty-one individuals were included and 30 underwent sleeve implantation; 11 individuals served as a diet control group. All individuals followed the same low-calorie diet during the study period. The purpose of the study was to determine the safety and effectiveness of the device. Twenty-six devices were successfully implanted. In four individuals, implantation could not be achieved. Four devices were explanted prior to the initial protocol end point because of migration (n = 1), dislocation of the anchor (n = 1), sleeve obstruction (n = 1), and continuous epigastric pain (n = 1). The remaining individuals all completed the study. Mean procedure time was 35 minutes (range, 12–102) for a successful implantation and 17 minutes (range, 5–99) for explantation. There were no procedure-related AEs. During the study period, the 26 duodenal-jejunal bypass sleeve individuals (100%) had at least one AE, mainly abdominal pain and nausea during the first week after implantation. Initial mean BMI was 48.9 and 47.4 kg/m² for the device and control individuals, respectively. Mean EWL after 3 months was 19.0% for individuals with the device versus 6.9% for control individuals (P<0.002). Absolute change in BMI at 3 months was 5.5 and 1.9 kg/m², respectively. T2DM was present at baseline in eight individuals of the device group and improved in seven individuals during the study period (lower glucose levels, glycated hemoglobin [HbA1c], and medication requirements). The authors concluded that the EndoBarrier Gastrointestinal Liner is a feasible and safe noninvasive device with excellent short-term weight loss results. The device also has a significant positive effect on T2DM. Moreover, they stated that long-term randomized and sham studies for weight loss and treatment of diabetes are necessary to determine the role of the device in the treatment of morbid obesity.

Gersin et al. (2010) examined the effects of an endoscopic DJBL for preoperative weight loss in bariatric surgery candidates. Twenty-one obese subjects in the DJBL arm and 26 obese subjects in the sham arm comprised the intent-to-treat population. The subjects in the sham arm underwent an esophagogastroduodenoscopy and mock implantation. Both groups received identical nutritional counseling. The primary endpoint was the difference in the percentage of EWL at week 12 between the two groups. Secondary endpoints were the percentage of subjects achieving 10% EWL, total weight change, and device safety. Thirteen DJBL arm subjects and 24 sham arm subjects completed the 12-week study. EWL was 11.9% ± 1.4% and 2.7% ± 2.0% for the DJBL and sham arms, respectively (P<0.05). In the DJBL arm, 62% achieved 10% or more EWL compared with 17% of the subjects in the sham arm (P<0.05). Total weight change in the DJBL arm was −8.2 ± 1.3 kg compared with −2.1 ± 1.1 kg in the sham arm (P<0.05). Eight DJBL subjects terminated early because of gastrointestinal bleeding (n = 3), abdominal pain (n = 2), nausea and vomiting (n = 2), and an unrelated preexisting illness (n = 1). None had further clinical symptoms after DJBL explantation. The authors concluded that the DJBL achieved endoscopic duodenal exclusion and promoted significant weight loss beyond a minimal sham effect in candidates for bariatric surgery. The main drawbacks of this study were that study personnel were not blinded, and there was a lack of data on caloric intake.

Escalona et al. (2012) evaluated safety, weight loss, and cardiometabolic changes for 1 year in obese individuals who received the DJBL implant. Morbidly obese subjects were enrolled in a single-arm, open-label, prospective trial and underwent the DJBL implantation. Primary endpoints included safety and weight change from baseline to week 52. Secondary endpoints included changes in waist circumference, blood pressure, lipids, glycemic control, and metabolic syndrome. The DJBL was implanted endoscopically in 39 of 42 subjects (mean age, 36 ± 10 years; 80% female; mean weight of 109 ± 18 kg; mean BMI of 43.7 ± 5.9 kg/m); 24 completed 52 weeks of follow-up. Three subjects could not be undergo implantation because of short duodenal bulb. Implantation time was 24 ± 2 minutes. There were no procedure-related complications and there were 15 early endoscopic removals. In the 52-week completer population, total body weight change from baseline was −22.1 ± 2.1 kg (P<0.0001) corresponding to 19.9 ± 1.8% of total body weight and 47.0 ± 4.4% excess of weight loss. There were also significant improvements in waist circumference, blood pressure, total and LDL cholesterol, triglycerides, and fasting glucose. The authors concluded that the DJBL is safe when implanted for 1 year, and results in significant weight loss and improvements in cardiometabolic risk factors. They stated that these results suggested that this device may be suitable for the treatment of morbid obesity and its related comorbidities. Main drawbacks of this study were its small sample size and only 24 of 39 subjects (62%) completed the 52-week follow-up.

Verdam et al. (2012) stated that the prevalence of obesity is increasing worldwide. Its primary treatment consists of lifestyle changes. In severely obese (BMI >40 kg/m² or ≥35 kg/m² with comorbidity) individuals, though, bariatric surgery has been found to be the only way to achieve permanent weight loss. Operations such as the placement of a gastric band or a gastric bypass can, however, lead to complications and necessitate secondary interventions. In search of less- invasive treatments, placement of the EndoBarrier duodenal jejunal bypass liner appears to be a promising, safe, and effective method for facilitating weight loss. Concomitant positive effects on cardiovascular risk factors including T2DM were observed. The authors noted that a multicenter trial is currently underway to examine the mechanism behind these effects. 

Mathus-Vliegen (2012) stated that the EndoBarrier is a unique concept that starts to ameliorate the symptoms of T2DM soon after positioning. Weight-loss results are moderate, with 85% of individuals showing a more than 10% excess weight loss in the 12 weeks preoperatively. Sufficient implant training is required, but problems can still occur (e.g., due to a short duodenal bulb length). The stability of the anchors and the tolerability of the device still leave much to be desired. In 25% of individuals, the EndoBarrier is explanted early due to migration, physical symptoms, gastrointestinal hemorrhage, rotation, and obstruction. Only seven studies on the EndoBarrier are available and these are mostly small in size, short-term and with limited follow-up, and many questions regarding the safety and long-term effects of the device remain. The author concluded that this calls for a large, long-term, randomized, placebo-controlled, double-blind trial. Lessons should have been learned from the disastrous results with intragastric balloon implantation before commercializing another such product.

In 2019, van Rijn et al. published a 4-year follow-up of an RCT on the effect of EndoBarrier. Twenty-nine individuals were enrolled, and 10 individuals who did not seek additional therapy after explantation had follow up-data available with a median duration of 42 months. Four years after explantation of EndBarrier, median weight, BMI, and TWL were not different from baseline. Given the small sample size, loss of follow-up, and lack of effectiveness, the clinical utility of EndoBarrier remains to be seen.

Balint et al. (2021) published a systematic review and meta-analysis comparing the EndoBarrier device to pylorus-preserving bariatric surgeries. Seventeen studies were included in the review, represented by various study designs. In the EndoBarrier studies, a high rate of adverse and serious AEs were reported, and almost 20% of the devices were explanted earlier than planned. Pylorus-preserving bariatric surgeries had lower rates of AEs. All weight loss metrics (e.g., EWL, TWL) at 1 year favored pylorus-preserving bariatric surgeries as well. When compared statistically in the meta-analysis, the results were less clear. However, the authors conclude that bariatric surgeries were both safer and more effective than EndoBarrier.

In 2022, Ruban et al. conducted an open-label RCT comparing the EndoBarrier device to intensive medical care. The participants were required to be obese and to have both T2DM and inadequate glycemic control. The primary outcome was an HbA1c reduction of greater than or equal to 20% at 12 months. A total of 170 individuals were randomly assigned, while 79% of the intervention arm and 79% of the control arm were followed through 12 months. At 24 months (1 year after EndoBarrier explantation), 71% of the intervention arm and 62% of the control arm were followed. At both 12- and 24-months, there was no difference in the proportion of individuals who achieved the primary endpoint. More individuals who received EndoBarrier lost 15% or more of their bodyweight compared with controls at 12-months; however, this was not sustained to 24 months (1 year postexplantation). Although this RCT is the largest to date, it does not change the conclusions that have been previously drawn. There is still a lack of evidence that demonstrates a net health improvement from EndoBarrier, particularly after it is removed.

In 2024, Chen et al. conducted a systematic review and meta-analysis evaluating the safety and efficacy of EndoBarrier on treating obesity and T2DM. Thirty studies involving 1751 individuals were in the analysis. At 12 months after implantation, the average BMI was reduced by 4.8, EWL was 41.3%, and TWL was 13.1%. HbA1c and fasting glucose were also significantly lower compared to baseline. However, the authors note that these results were only partially sustained after explantation. 

Intragastric Balloon (e.g., the Obalon Balloon System, and the ReShape Integrated Dual Balloon System)

The intragastric balloon (also known as the silicone intragastric balloon or SIB) has been developed as a temporary aid for obese individuals who have had unsatisfactory results in their clinical treatment for obesity and super obese individuals with a higher surgical risk (Fernandes et al., 2004). The intragastric balloon is intended to reduce gastric capacity, causing satiety, making it easier for individuals to take smaller amounts of food. Randomized, controlled clinical studies, however, have found no increase in weight loss with the intragastric balloon plus dieting versus dieting alone (Rigaud et al., 1995; Geliebter et al, 1991; Mathus-Vliegen et al., 1990; Lindor et al., 1987). One nonrandomized controlled clinical study that reported positive results reported that results were not maintained after gastric balloon removal (Ramhamadany et al., 1989). In addition, the intragastric balloon has been associated with potentially severe adverse effects, including gastric erosion, reflux, and obstruction. An assessment of the intragastric balloon from the Canadian Coordinating Office for Health Technology Assessment (2006) concluded that "[m]ore data on the benefits, harms, and cost-effectiveness are required before the intragastric balloon can be compared with other short-term weight loss interventions, including low-calorie diets."

On July 28, 2015, the FDA approved the ReShape Integrated Dual Balloon System (ReShape Medical Inc., San Clemente, CA) to treat obesity without the need for invasive surgery (FDA, 2015). This new device is intended to facilitate weight loss in obese adult individuals by occupying space in the stomach, which may trigger feelings of fullness, or by other mechanisms that are not yet understood. The ReShape Dual Balloon device is delivered into the stomach via the mouth through a minimally invasive endoscopic procedure. The outpatient procedure usually takes less than 30 minutes while an individual is under mild sedation. Once in place, the balloon device is inflated with a sterile solution, which takes up room in the stomach. The device does not change or alter the stomach's natural anatomy. Individuals are advised to follow a medically supervised diet and exercise plan to augment their weight loss efforts while using the ReShape Dual Balloon and to maintain their weight loss following its removal. It is meant to be temporary and should be removed 6 months after it is inserted.

The ReShape Dual Balloon was studied in a clinical trial with 326 obese participants aged 22 to 60 (BMI, 30 kg/m²–40 kg/m²) who had at least one obesity-related health condition (FDA, 2015). In the study (Ponce et al., 2015), 187 individuals randomly selected to receive the ReShape Dual Balloon lost 14.3 pounds on average (6.8% of their total body weight) when the device was removed at 6 months, while the control group (who underwent an endoscopic procedure but were not given the device) lost an average of 7.2 pounds (3.3% of their total body weight). Six months following the device removal, individuals treated with the ReShape Dual Balloon device kept off an average of 9.9 pounds of the 14.3 pounds they lost. Potential side effects for the procedure include headache, muscle pain, and nausea from the sedation and procedure; in rare cases, severe allergic reaction, heart attack, esophageal tear, infection, and breathing difficulties can occur. Once the device is placed in the stomach, individuals may experience vomiting, nausea, abdominal pain, gastric ulcers, and feelings of indigestion. This device should not be used in individuals who have had previous gastrointestinal or bariatric surgery or who have been diagnosed with inflammatory intestinal or bowel disease, large hiatal hernia, symptoms of delayed gastric emptying or active ​Helicobacter pylori​ infection; those who are pregnant or use aspirin daily should also avoid the device (FDA, 2015).

There is a lack of data on the durability of the results with the ReShape Integrated Dual Balloon System. It is unclear what benefit there is from a temporary reduction in weight. An UpToDate review on "Obesity in adults: Overview of management" (Bray, 2015) does not mention the intragastric balloon as a therapeutic option. Furthermore, an UpToDate review on "Bariatric surgical operations for the management of severe obesity: Descriptions " (Lim, 2015) lists intragastric balloon as an investigational procedure. It states that "As much as 33% excess weight loss has been reported in trials conducted outside of the United States with devices not approved by the FDA. After 5 years of surveillance, however, only 23% of patients maintained more than 20% of their excess weight loss."

Popov et al. (2017) examined the effect of intragastric balloons on metabolic outcomes associated with obesity. Medline, Embase, and the Cochrane database were searched through July 2016. Dual extraction and quality assessment of studies using Cochrane risk of bias tool were performed independently by two authors. Primary outcomes included the change from baseline in metabolic parameters. Secondary outcomes included resolution and/or improvement in metabolic comorbidities and association with baseline parameters. Ten RCTs and 30 observational studies including 5668 subjects were analyzed. There was moderate-quality evidence for improvement in most metabolic parameters in subjects assigned to intragastric balloon therapy as compared to conventional nonsurgical therapy in RCTs: mean difference (MD) in fasting glucose change: −12.7 mg/dL (95% CI, −21.5 to −4); MD in triglycerides: −19 mg/dL (95% CI, −42 to 3.5); MD in waist circumference, −4.1 cm (95% CI, −6.9 to −1.4); MD in diastolic blood pressure, −2.9 mm Hg (95% CI, −4.1 to −1.8). The OR for diabetes resolution after intragastric balloon therapy was 1.4 (95% CI, 1.3–​1.6). The rate of serious AES was 1.3%. The authors concluded that intragastric balloons were more effective than diet in improving obesity-related metabolic risk factors with a low rate of AEs; however, the strength of the evidence was limited given the small number of participants and lack of long-term follow-up.

On August 10, 2017, the FDA announced that it has received five reports of unanticipated deaths that occurred from 2016 to the present in individuals who received a liquid-filled intragastric balloon to treat obesity; four reports involved the Orbera Intragastric Balloon System (Apollo Endosurgery) and one report involved the ReShape Integrated Dual Balloon System (ReShape Medical). All five individuals died within 1 month or less of balloon placement; three individual​s died 1 to 3 days after the balloon was placed. The FDA stated that "At this time, we do not know the root cause or incidence rate of patient death, nor have we been able to definitively attribute the deaths to the devices or the insertion procedures for these devices (e.g., gastric and esophageal perforation, or intestinal obstruction)." The FDA has also received two additional reports of deaths from 2016 to the present related to potential complications associated with balloon treatment: one gastric perforation with the Orbera Intragastric Balloon System and one esophageal perforation with the ReShape Integrated Dual Balloon System. As part of the ongoing, FDA-mandated postapproval studies for these devices, the FDA will obtain more information to help evaluate the continued safety and effectiveness of these approved medical devices (Brooks, 2017).

In 2025, Kermansaravi et al. published a systematic review and meta-analysis on the use of gastric balloons as a bridge to bariatric surgery. While individuals lost weight with the gastric balloon, there was no difference in weight lost as a result of the bariatric surgery. Further, there was no difference in post-bariatric surgery complication rates. As such, there is no benefit of a gastric balloon to serve as a bridge intervention prior to bariatric surgery, as the balloon itself is not free from causing complications.

Edathodu et al. (2025) published a systematic review and meta-analysis of gastric balloon safety and efficacy. Fifteen studies were included in the analysis, varying in gastric balloon, study design, country, and follow-up. It was found that at the time of gastric balloon removal (approximately 6 months), mean weight loss was 14.9 kilograms, and mean EWL was 38.4%. Long-term follow-up, which varied across studies, revealed a mean weight loss of 8.01 kilograms, but excess weight loss is not reported. The authors note that at 6 months after removal, approximately 35% of individuals experienced WR. Additionally, high heterogeneity and publication bias are among top concerns from the authors.

Mini Sleeve Gastrectomy

There is no high-quality peer reviewed evidence that permits the conclusion of the safety and effectiveness of a mini sleeve gastrectomy.

Restorative Obesity Surgery, Endoluminal (ROSE) Procedure For The Treatment Of Weight Regain After Gastric Bypass Surgery

There is no high-quality peer-reviewed evidence that permits conclusions on the safety and effectiveness of ROSE.

Transoral gastroplasty (TG) (Vertical Sutured Gastroplasty; Endoluminal Vertical Gastroplasty; Endoscopic Sleeve Gastroplasty) 

​

Transoral gastroplasty (TG), also referred to as vertical sutured gastroplasty or endoluminal vertical gastroplasty, is an incisionless procedure in which the stomach is purportedly restricted with staples or sutures by using endoscopic surgical tools guided through the mouth and esophagus.

In a single-center, pilot feasibility study (n = 4), Abu Dayyeh et al. (2013) demonstrated the technical feasibility of transoral endoscopic gastric volume reduction with an ES device in a fashion similar to SG for the treatment of obesity. Main outcome measure was technical feasibility. These researchers successfully used an endoscopic free-hand suturing system in four subjects, thus demonstrating the technical feasibility of a novel technique to mimic the anatomic manipulations created by surgical SG endoscopically. The authors concluded that ESG for treatment of obesity is feasible. The main drawback of this study was that it was a pilot feasibility study with small number of subjects.

Sharaiha et al. (2015) stated that novel endoscopic techniques have been developed as effective treatments for obesity. Recently, reduction of gastric volume via endoscopic placement of full-thickness sutures, termed ESG, has been described. These investigators evaluated the safety, technical feasibility, and clinical outcomes for ESG. Between August 2013 and May 2014, ESG was performed on 10 individuals using an ES device. Their weight loss, waist circumference, and clinical outcomes were assessed. Mean individual age was 43.7 years and mean BMI was 45.2 kg/m². There were no significant AEs noted. After 1 month, 3 months, and 6 months, excess weight loss of 18%, 26 %, and 30 %, and mean weight loss of 11.5 kg, 19.4 kg, and 33.0 kg, respectively, were observed. The differences observed in mean BMI and waist circumference were 4.9 kg/m² (P = 0.0004) and 21.7 cm (P= 0.003), respectively. The authors concluded that ESG is effective in achieving weight loss with minimal AEs. They stated that this approach may provide a cost-effective outpatient procedure to add to the steadily growing armamentarium available for treatment of this significant epidemic. These findings from a small (n=10) study need to be validated by well-designed studies.

Lopez-Nava et al. (2015) described the ESG used in 50 individuals. The goal of this procedure is to reduce the gastric lumen into a tubular configuration, with the greater curvature modified by a line of sutured plications. General anesthesia with endotracheal intubation is needed. An ES system requiring a specific double-channel endoscope delivers full-thickness sets of running sutures from the antrum to the fundus. Individuals were admitted and observed, with discharge planned within 24 hours. Post-procedure outpatient care included diet instruction with intensive follow-up by a multidisciplinary team. Voluntary oral contrast and endoscopy studies were scheduled to evaluate the gastroplasty at 3, 6, and 12 months. The technique was applied in 50 individuals (13 men) with an average BMI of 37.7 kg/m² (range, 30–47) with 13 having reached 1 year. Procedure duration averaged 66 minutes during which six to eight sutures on average were placed. All individuals were discharged in less than 24 hours. There were no major intraprocedural, early, or delayed AEs. Weight loss parameters were satisfactory, mean BMI changes from 37.7 ± 4.6 to 30.9 ± 5.1 kg/m² at 1 year, and mean percentage TBWL was 19.0 ± 10.8. Oral contrast studies and endoscopy revealed sleeve gastroplasty configuration at least until 1 year of follow-up. The authors concluded that ESG is a safe, effective, and reproducible primary weight loss technique. The main drawbacks of this study were its small sample size (n = 50) and short-term follow-up (1 year and only 13 subjects reached 1-year follow-up). Furthermore, a Cochrane review, "Surgery for weight loss in adults" (Colquitt et al., 2014), as well as an UpToDate review, "Bariatric surgical operations for the management of severe obesity: Descriptions" (Lim, 2015), do not mention ESG as a therapeutic option.

In 2022, Abu Dayyeh et al. published the only RCT of ESG, comparing ESG with lifestyle modifications (intervention) to lifestyle modifications alone (control). A total of 209 individuals were randomly assigned to the intervention and control in a 1:1.5 ratio, respectively. The primary endpoint was the percentage of EWL at 52 weeks, at which point those in the control group who completed two thirds of their study visits were allowed to crossover (i.e., undergo ESG). The primary endpoint was not analyzed in an intent-to-treat basis, but rather a modified intent-to-treat basis, which excluded participants who did not receive their assigned treatment. The mean percentage of EWL was significantly different between the intervention and control groups (49.2% vs. 3.2%, respectively), although the difference between the two was smaller in the modified intent-to-treat analysis (44.7% vs. 12.6%, respectively). Sixteen of 68 participants (20%) underwent suture reinforcement at 52 weeks. Additionally, 93% of individuals in the intervention arm with T2DM improved compared to 15% in the control arm. A total of 927 AEs experienced by 150 participants (93%) were reported by those in the intervention arm and by those who crossed over. Most of the AEs were mild or resolved quickly; however, three participants had serious AEs, while six participants required hospitalization.

There are several things to consider when using the Abu Dayyeh et al. study to evaluate the safety and effectiveness of ESG on the treatment of obesity. First, only those with a BMI between 30 and 40 were included in the study, so the effect of ESG on obesity outside of this range is unknown. Second, the mean EWL did not achieve the standard for bariatric procedures, that is, a 50% excess weight loss, of which many bariatric procedures far exceed this standard. Additionally, approximately 23% of individuals in the intervention group did not even achieve an EWL of 25%. Third, 20% of individuals received reinforcement within 1 year of the procedure, which exceeds the lifetime proportion of individuals needing revisional bariatric surgery. Fourth, while improvement of T2DM is always beneficial, other bariatric surgeries (including LSG) provide remission of T2DM. Finally, even after limiting the analysis to only those who achieved at least 25% EWL, approximately 30% of individuals were unable to maintain their weight loss at 2 years, leading to durability concerns.

Thus, among the highest quality study of ESG, there are many limitations, and some evidence to suggest that ESG may not provide effectiveness comparable to that of other well-established bariatric surgeries.

In meta-analyses conducted by Beran et al. (2022), Marincola et al. (2021), and Mohan et al. (2020), ESG is compared to LSG. In Beran et al., only studies that compared ESG and LSG were utilized. A total of 6775 individuals were included in the review, which concluded that LSG was superior to ESG in weight loss outcomes and remission of T2DM, both of which are primary indications for bariatric surgery. Additionally, ESG only trended to have a better safety profile than LSG, but it was not statistically significant. However, new-onset GERD was lower among those who received ESG compared to LSG. The authors conclude with several limitations, including the use of observational studies (i.e., not RCTs, which are lacking), the lacking ability to conclude effectiveness beyond 24 months, and the concerns with generalizability given the locations of the studies. In Marincola et al., 16 studies, totaling 2188 individuals with BMIs between 30 and 40 were included in the review. Those who received LSG had a mean EWL of 80% at 12 months, while those who received ESG only lost a mean of 62% of excess weight. Additionally, there was no difference in AE rates between the two procedures. In Mohan et al., 15 studies with 3994 individuals were included in the analysis. The primary outcome was the difference in weight loss between interventions at 12 months. In fact, TWL, EWL, and BMI reduction did not all move in the same direction at 12 months. Only TWL was statistically significantly greater among those with LSG compared to ESG, while the other two outcomes were not statistically significantly different at 12 months. Additionally, AEs, bleeding, and GERD were greater among those who received LSG compared to ESG. The authors note that limitations include, the inclusion of retrospective analyses, the lacking knowledge of comorbidities, and that LSG studies report long-term outcomes, yet ESG studies do not.

Thus, in recent meta-analyses, it becomes evident that the body of literature investigating ESG is limited. It is limited by study design and lack of long-term follow up, and fails to establish that it is a clinical alternative to LSG. 

Additionally, recent clinical guidelines, while supportive of ESG, use tentative language that is not characteristic of a strong endorsement. In IFSO's 2024 Position Statement, 44 articles and 15,715 individuals were included in the review. However, these studies varied quite significantly in size, study design, and follow up. Overall, mean excess weight loss varied from a minimum of 45.3% at 60 months to a maximum of 57.98% at 18 months. However, IFSO notes the very low quality of the evidence base, yet still concludes that ESG is safe and effective. It is worth noting that the lead author of this IFSO Position Statement is the same author as the only RCT of ESG. In 2024, the National Institute for Health and Care Excellence (NICE) published a recommendation for ESG, supporting its use among those with a BMI over 30 and BMI over 40 if they are a high-risk individual. In the ASGE-ESGE 2024 guideline on primary endoscopic bariatric and metabolic therapies, ESG received a "conditional" recommendation based on "moderate" evidence for use in conjunction with lifestyle modification compared to lifestyle modification alone. This tentative recommendation required a combination of evidence from different systems beyond Apollo. It is worth noting that many of the authors, including the lead author, disclosed receiving financial compensation for the device manufacturer.

In the 2023 IFSO Delphi Study, comments regarding ESG can be found. While there is great consensus from experts that ESG is preferable to lifestyle interventions (89%), there is disagreement when ESG is compared to alternatives. For example, the experts agreed that ESG was more effective than lifestyle changes (74% agree), but that antiobesity medication is more effective than ESG (56% agree).

Use Of Any Endoscopic Closure Device (Over the Scope clip [OTSC] system set, Apollo OverStitch endoscopic suturing system, StomaphyX endoluminal fastener and delivery system) In Conjunction With NOTES

StomaphyX

In March 2007, the FDA granted 510(k) pre-marketing clearance to the StomaphyX endoluminal fastener and delivery system used to tighten esophageal tissue. There is only limited evidence on the effectiveness of the StomaphyX in bariatric surgery repair/revision.

Overcash (2008) reported two cases of the safe and successful use of the StomaphyX device to alter the flow of gastric contents and repair gastric leaks resulting from bariatric revision surgery. Both individuals were at a high risk and could not undergo another open or laparoscopic surgery to correct the leaks that were not healing. The author reported that the StomaphyX procedures lasted approximately 30 minutes, were performed without any complications, and resulted in the resolution of the gastric leaks in both individuals. The findings of these cases need to be validated by well-designed clinical studies.

In a prospective, single-center, randomized, single-blinded study, Eid et al. (2014) examined the safety and effectiveness of endoscopic gastric plication with the StomaphyX device versus a sham procedure for revisional surgery in RYGBP(performed at least 2 years earlier) individuals to reduce regained weight. These researchers planned for 120 individuals to be randomly assigned 2:1 to multiple full-thickness plications within the gastric pouch and stoma using the StomaphyX device with SerosFuse fasteners or a sham endoscopic procedure and followed up for 1 year. The primary efficacy endpoint was reduction in pre-RYGBP excess weight by 15% or more excess BMI loss (calculated as weight in kilograms divided by height in meters squared) and BMI less than 35 at 12 months after the procedure. AEs were recorded. Enrollment was closed prematurely because preliminary results indicated failure to achieve the primary efficacy endpoint in at least 50% of StomaphyX-treated individuals. One-year follow-up was completed by 45 individuals treated with StomaphyX and 29 individuals in the sham treatment group. Primary efficacy outcome was achieved by 22.2% (10) with StomaphyX versus 3.4% (1) with the sham procedure (P<0.01). Individuals undergoing StomaphyX treatment experienced significantly greater reduction in weight and BMI at 3, 6, and 12 months (P≤ 0.05). There was one causally related AE with StomaphyX, that required laparoscopic exploration and repair. The authors concluded that StomaphyX treatment failed to achieve the primary efficacy target and resulted in early termination of the study.

Bolton et al. (2013) stated that WR secondary to VBG pouch dilation is a typical referral for bariatric surgeons. These investigators compared an endoluminal pouch reduction (StomaphyX) to RYGBP for revision. A retrospective review was completed for individuals with a previous VBG presenting with WR between 2003 to 2010. Thirty individuals were identified (StomaphyX; n = 14). Significant postprocedure BMI loss was seen in each cohort (RYGBP, 47.7 ± 7 kg/m² to 35 ± 7 kg/m²; StomaphyX, 43 ± 10 kg/m2 to 40 ± 9 kg/m²; P=0.0007). Whereas nausea and headache were the only complications observed in the StomaphyX group, the RYGBP group had a 43.5% complication rate and one death.

Complications following RYGB included incisional hernia (13%), anastomotic leak (8.7%), respiratory failure (8.7%), fistula (8.7%), and perforation (4.35%). The median LOS following RYGB was 6 days compared to 1.5 ± 0.5 days following StomaphyX. The authors suggested that while RYGBP revision may achieve greater weight loss, the complication rates and severity is discouraging. StomaphyX may be a safe alternative. Moreover, they stated that further technical modifications of the device and longer follow-up may clarify the role of this approach.

Goyal et al. (2013) examined if endoluminal reduction of gastric pouch and stoma using StomaphyX results in sustained weight loss in individuals who regain weight after gastric bypass. Retrospective chart review was performed on 59 post-gastric bypass individuals who underwent revision of gastric pouch using StomaphyX from 2007 to 2008. Postprocedure weight at 1 week, 1 month, and 6 months follow-up as well as weight at the time of the review was recorded for each individual. Average weight loss and excess body weight loss (EBWL) were 2.6 ± 2.3 kg and 7.3 ± 7.1% (n = 42) at 1 week, 3.7 ± 2.9 kg and 11.6 ± 12.1% (n = 31) at 1 month, and 3.8 ± 4.5 kg and 11.5 ± 17.9% (n = 10) at 6 months, respectively. At the time of review, the average follow-up was 41 months, average weight loss was 1.7 ± 9.7 kg, and EBWL was 4.3 ± 29.8% (n = 53). Endoscopy in 12 individuals at average 18 months follow-up showed no sustained reduction in pouch and stoma size. The authors concluded that StomaphyX resulted in weight loss that is not sustained on long-term follow-up. Pouch and stoma tend to regain their pre-procedure size on follow-up. They stated that StomaphyX cannot be recommended as a weight loss strategy in post-gastric bypass individuals who regain weight.

The OverStitch Device 

RYGB may result in stenosis of the gastrojejunal anastomosis (GJA; Campos et al., 2012). There is currently no well-defined management protocol for this complication. Through systematic review, these investigators analyzed the results of endoscopic dilation in individuals with stenosis, including complication and success rates. The PubMed database was searched for relevant studies published each year from 1988 to 2010, and 23 studies were identified for analysis. Only papers describing the treatment of anastomotic stricture after RYGBP were included, and case reports featuring less than three individuals were excluded. The mean age of the trial populations was 42.3 years and mean preoperative BMI was 48.8 kg/m². A total of 1298 procedures were undertaken in 760 individuals (81% female), performing 1.7 dilations per individual. Through-the-scope balloons were used in 16 studies (69.5%) and Savary-Gilliard bougies in four studies. Only 2% of individuals needed surgical revision after dilation; the reported complication rate was 2.5% (n = 19). The annual success rate was greater than 98% each year from 1992 to 2010, except for a 73% success rate in 2004; seven studies reported complications, perforation being the most common, reported in 14 individuals (1.82%) and requiring immediate operation in two individuals. Other complications were also reported: one esophageal hematoma, one Mallory-Weiss tear, one case of severe nausea and vomiting, and two cases of severe abdominal pain. The authors concluded that endoscopic treatment of stenosis is safe and effective; however, further high-quality RCTs are needed to confirm these findings.

Thompson et al. (2013) stated that WR or insufficient loss after RYGBP is common. This is partially attributable to dilatation of the GJA, which diminishes the restrictive capacity of RYGBP Endoluminal interventions for gastrojejunal reduction are being explored as alternatives to revision surgery. These researchers performed a randomized, blinded, sham-controlled trial to evaluate weight loss after sutured TORe. Individuals with WR or inadequate loss after RYGBP and gastrojejunal diameter greater than 2 centimeters were assigned randomly to groups that underwent TORe (n = 50) or a sham procedure (controls, n = 27). Intraoperative performance, safety, weight loss, and clinical outcomes were assessed. Subjects who received TORe had a significantly greater mean percentage weight loss from baseline (3.5%; 95% CI, 1.8%–5.3%) than controls (0.4%; 95% CI, 2.3% weight gain to 3.0% weight loss) (P=0.021), using a last observation carried forward intent-to-treat analysis. As-treated analysis also showed greater mean percentage weight loss in the TORe group than controls (3.9% and 0.2%, respectively; P=0.014). Weight loss or stabilization was achieved in 96% subjects receiving TORe and 78% of controls (P=0.019). The TORe group had reduced systolic and diastolic blood pressure (P<0.001) and a trend toward improved metabolic indices. In addition, 85% of the TORe group reported compliance with the healthy lifestyle eating program, compared with 53.8% of controls; 83% of TORe subjects said they would undergo the procedure again, and 78% said they would recommend the procedure to a friend. The groups had similar frequencies of AEs. The authors concluded that a multicenter randomized trial provided Level I evidence that TORe reduces WR after RYGBP. These results were achieved using a superficial suction-based device; greater levels of weight loss could be achieved with newer, full-thickness suturing devices. These researchers stated that TORe is one approach to avoid WR; moreover, they noted that a longitudinal multidisciplinary approach with dietary counseling and behavioral changes are needed for long-term results.

Jirapinyo et al. (2013) evaluated the technical feasibility, safety, and early outcomes of a procedure using a commercially available ES device to reduce the diameter of the GJA. This was a retrospective analysis of 25 consecutive individuals who underwent TORe for dilated GJA and WR. An ES device was used to place sutures at the margin of the GJA in order to reduce its aperture. On chart review, clinical data were available at 3, 6, and 12 months. Individuals had regained a mean of 24 kg from their weight loss nadir and had a mean BMI of 43 kg/m² at the time of endoscopic revision. Average anastomosis diameter was 26.4 mm. Technical success was achieved in all individuals (100%) with a mean reduction in anastomosis diameter to 6 mm (range, 3–​10), representing a 77.3% reduction. The mean weight loss in successful cases was 11.5 kg, 11.7 kg, and 10.8 kg at 3, 6, and 12 months, respectively. There were no major complications. The authors concluded that this case series demonstrated the technical feasibility, safety, and effectiveness of performing gastrojejunal reduction using a commercially available ES device. They stated that this technique may represent an effective and minimally invasive option for the management of WR in individuals with RYGBP.

Weight recidivism after RYGBP is a challenging problem for individuals and bariatric surgeons alike (Dakin et al., 2013). Traditional operative strategies to combat WR are technically challenging and associated with a high morbidity rate. Endoluminal interventions are thus an attractive alternative that may offer a good combination of results coupled with lower periprocedure risk that might one day provide a solution to this increasingly prevalent problem. These investigators systematically reviewed the available literature on endoluminal procedures used to address WR after RYGBP, with specific attention to the safety profile, effectiveness, cost, and current availability. This retrospective review focused only on endoluminal procedures that were performed for WR after RYGBP, as opposed to primary endoluminal obesity procedures. Several methods of endoluminal intervention for WR were reviewed, ranging from injection of inert substances to suturing and clipping devices. The literature review showed the procedures on the whole to be well-tolerated with limited effectiveness. The majority of the literature was limited to small case series. Most of the reviewed devices were no longer commercially available. The authors concluded that endoluminal therapy represents an intriguing strategy for WR after RYGBP. However, the current and future technologies must be rigorously studied and improved such that they offer durable, repeatable, cost-effective solutions.

Despite advances in many areas of therapeutic endoscopy, the development of an effective ES device has been elusive (Pauli et al., 2013). Pauli et al. evaluated the safety and effectiveness of a suturing device to place and secure sutures within normal, in vivo human colonic tissue prior to surgical resection. Individuals undergoing elective colectomy were enrolled in this treat-and-resect model. The OverStitch ES device (Apollo Endosurgery, Austin, TX) was used to place sutures in healthy colonic tissue during a 15-minute, time-limited period. Following colectomy, the explanted tissue was evaluated to determine the depth of suture penetration and the effectiveness of the suture and cinch element. Clinical and operative data were recorded. Four individuals (50% female) were enrolled. Seven sutures were successfully placed, incorporating a total of 10 tissue bites in a mean of 13.5 minutes. On inspection of the explanted tissue, all sutures were found to be located subserosal (no full thickness bites were taken). The suture and cinch elements were judged to be effective in the majority of cases. One device-related issue did not inhibit the ability to oppose tissue or place the cinch. There were no intraoperative or postoperative complications. The authors concluded that the OverStitch permitted safe and effective suturing in an in vivo human colon model. The sutures were placed at a consistent subserosal depth and at no point risked iatrogenic injury to adjacent structures. Technical issues with the device were infrequent and did not inhibit the ability to place sutures effectively.

A clinical trial entitled "Endoscopic Surgery for Bariatric Revision after Weight Loss Failure" is not yet open for participant recruitment (NIH, 2014). This clinical trial is designed to study the Apollo OverStitch ES device that has already been approved by the FDA as an option for bariatric surgery revision without having to re-operate on the individual. The investigators believe that the endoscopic technique may be able to provide weight loss without having to re-operate on the individual.  

TORe is an endoscopic procedure used in individuals with weight gain after RYGBP. In a systematic review and meta-analysis, Dhindsa et al. (2020) examined the safety and efficacy of TORe with an FT suturing device for treating individuals with WR after RYGBP. They carried out a comprehensive search of several databases and conference proceedings including PubMed, Embase, Google-Scholar, Medline, Scopus, and Web of Science databases (earliest inception to March 2020). The primary outcomes evaluated were technical success, AWL, and percentage TWL at 3, 6, and 12 months after the procedure. The secondary outcomes evaluated were pooled rate of AEs, AE subtypes and association of size of GJA and percentage of TWL. Thirteen studies on 850 individuals were included. The pooled rate of technical success was 99.89%. The absolute weight loss (kg) at 3, 6, and 12 months was 6.14, 10.15, and 7.14, respectively. The percentage TWL at 3, 6, and 12 months was 6.69, 11.34, and 8.55, respectively. The pooled rate of AE was 11.4%, with abdominal pain being the most common AE. The correlation coefficient (r) was −0.11 between post-TORe GJA size and weight loss at 12 months. The authors concluded that TORe is an endoscopic procedure that is safe and technically feasible for post-RYGBP with weight gain. These researchers stated that TORe showed promising results in the short-term; however, more studies are needed to evaluate the long-term success of this procedure.

Dhindsa et al. (2020) ​reported that the drawbacks of this review/meta-analysis included that some of the studies were retrospective in nature, most of the studies had short-term follow-up, and there was loss of follow-up. Moreover, their pooled rates were limited by heterogeneity and there was increased risk of confounding bias due to the majority of the studies being retrospective. For inexperienced endoscopists, this procedure may be technically challenging, thus affecting the generalizability. These investigators stated that more long-term studies should be carried out to determine the durability; future studies should include follow-up endoscopy post-TORe to examine the GJA to evaluate its durability and to see if this correlates with weight recidivism after TORe is done.

TORe is an endoscopic approach for individuals with WR after RYGBP with a dilated GJA. In a retrospective review of prospectively collected data, Jirapinyo et al. (2020) examined the long-term efficacy of TORe. This trial included RYGBP individuals who underwent TORe for WR or inadequate weight loss after RYGBP. The primary outcome was efficacy of TORe at 1, 3, and 5 years; and secondary outcomes were procedure details, safety profile, and predictors of long-term weight loss after TORe. A total of 331 RYGBP individuals underwent 342 TORe procedures and met inclusion criteria. Of these, 331, 258, and 123 individuals were eligible for 1-, 3- and 5-year follow-ups, respectively. Mean BMI was 40 ± 9 kg/m². Pre-TORe GJA size was 23.4 ± 6.0 mm, which decreased to 8.4 ± 1.6 mm after TORe. Individuals experienced 8.5% ± 8.5%, 6.9% ± 10.1%, and 8.8% ± 12.5% TWL at 1, 3, and 5 years with follow-up rates of 83.3%, 81.8%, and 82.9%, respectively. Of 342 TORe procedures, 76%, 17.5%, 4.4%, and 2.1% were performed using single purse-string, interrupted, double purse-string, and running suture patterns, respectively, with an average of 9 ± 4 stitches per GJA. Pouch reinforcement suturing was carried out in 57.3%, with an average of 3 ± 2 stitches per pouch. There were no severe AEs. Some individuals (39.3%) had additional weight loss therapy (pharmacotherapy or procedure), with 3.6% undergoing repeat TORe. Amount of weight loss at 1 year (β = 0.43; P​=0.01) and an additional endoscopic weight loss procedure (β=8.52; P=0.01) were predictors of percentage of TWL at 5 years. The authors concluded that TORe appeared to be safe, effective, and durable at treating WR after RYGBP.

The authors stated that this study had several drawbacks. First, the study was conducted at a single bariatric center of excellence. Although this may affect the generalizability of the findings, most cases were carried out with the participation of trainees under the supervision of an expert bariatric endoscopist. Furthermore, all consecutive TORe cases that met the inclusion and exclusion criteria from 2010 to 2018 were included in the analysis. Throughout this period, techniques at the authors' institution continued to evolve, such as APC settings, suture pattern, and final GJA size. Thus, these investigators suspected that the heterogeneity of experience levels and techniques would reflect real life experience of TORe. Another drawback was a retrospective design without a control group, which may have introduced bias. In addition, it was possible that individuals who were willing to undergo TORe were more ready to adhere to lifestyle modification compared to the general WR population, leading to selection bias. Also, in this study, about one of the individuals received adjunctive therapy after the initial TORe. Nevertheless, the majority were APC alone, which was performed as a reinforcing procedure, with a small number of individuals undergoing repeat TORe. This report likely reflected the real-life experience in which an adjunctive weight loss procedure may be added to enhance and maintain the long-term outcome. In the regression analysis, any individual who received at least one prescription for any of the FDA-approved medications for obesity between TORe and 5-year follow-up were included regardless of the duration of medication usage and/or early discontinuation due to intolerance and/or AEs. As most individuals were prescribed medications when they experienced early weight plateau or inadequate weight loss after initial TORe and duration of usage was unclear, the negative correlation between adjunctive medication usage and amount of weight loss at 5 years must be interpreted with caution.

Dolan et al. (2021) noted that an enlarged GJA is associated with WR after RYGBP and can be corrected with endoscopic or surgical revision; however, there has been no direct comparison between techniques. In a retrospective study, these researchers compared serious AE (SAE) rates and weight loss profiles between endoscopic and surgical revisional techniques over a 5-year period. This trial included RYGBP individuals who underwent endoscopic or surgical revision for WR with an enlarged GJA (>12 mm). Individuals undergoing endoscopy were matched 1:1 to those individuals undergoing surgery based on completion of 5-year follow-up, age, sex, BMI, initial weight loss, and WR. Demographics, GJA size, SAEs, and weight profiles were collected. The primary outcome was comparison of SAE rates between groups; secondary outcomes included weight loss comparisons. A Fisher exact test was used to compare the SAE rate, and a Student's t-test was used for weight comparisons. Sixty-two RYGBP individuals with WR and an enlarged GJA (31 endoscopic, 31 matched surgical) were included. Baseline characteristics were similar between the two groups. The AE rate in the endoscopic group (6.5%) was lower than that of the surgical group (29.0%); P=0.043. There was a total of zero (0%) and six (19.4%) SAEs in the endoscopic and surgical groups, respectively (P=0.02). There was no significant difference in weight loss at 1, 3, and 5 years. The authors concluded that endoscopic revision of the GJA was associated with significantly fewer total and severe AEs and similar long-term weight loss when compared with surgical revision. The main drawbacks of this study were its retrospective design and relatively small sample size (n = 31 for the endoscopic group). These findings need to be validated by well-designed studies.

In 2024, Valats et al. conducted a prospective, multicenter, randomized study comparing TORe to conventional management alone, among those who regained weight from RYGB. The primary outcome was the difference in percentage of excess weight loss at 12 months. Fifty individuals were randomly assigned. At 12 months, the average percentage of EWL was significantly greater among those who were randomly assigned to TORe compared to those who were randomly assigned to conventional management. However, there were no significant differences in obesity-related comorbidities and AEs were frequently reported in the TORe group.

OPEN ADJUSTABLE GASTRIC BANDING

There is a lack of high-quality peer-reviewed evidence suggesting that open adjustable gastric banding is safe and effective. Only the laparoscopic version of the procedure had sufficient evidence to establish safety and effectiveness.

PROPHYLACTIC MESH PLACEMENT FOR PREVENTION OF INCISIONAL HERNIA AFTER OPEN BARIATRIC SURGERY

In a systematic review and meta-analysis, Dasari et al. (2016) examined if mesh prevents postoperative incisional hernia in open and laparoscopic bariatric surgery individuals. Seven studies met inclusion criteria. These investigators abstracted data regarding postoperative incisional hernia development, surgical site infection, and seroma or wound leakage and performed a meta-analysis. The prophylactic mesh group had significantly decreased odds of developing incisional hernia than the standard closure group (OR, 0.30; 95% CI, 0.13–0.68; P=0.004). No included studies evaluated outcomes after prophylactic mesh during laparoscopic bariatric surgery. The authors concluded that prophylactic mesh during open bariatric surgery appeared to be beneficial in reducing postoperative incisional hernia without significantly increasing the odds of surgical site infection or seroma or wound leakage. Moreover, they stated that higher quality studies, including those in laparoscopic individuals, and cost-utility analysis, are needed to support routine use of this intervention.

PROPHYLACTIC PYLOROPLASTY VIA BOTULINUM TOXIN INJECTION FOLLOWING LAPAROSCOPIC SLEEVE GASTRECTOMY

Yang et al. (2019) stated that gastric leakage is a common complication after LSG and causes severe morbidity and mortality. Recent reports suggested that nonoperative management is favored for the leaks following LSG whenever possible. Endoscopic treatments, including self-expanding stent, clips, and glue, have been used to treat the leaks; however, the outcome varied in different situations. Recently, several improvements have been made in the designs and sizes of through-the-scope (TTS) clips, which induced the precise location of placement and extend the limitation in the management of perforations. Over-the-scope clip (OTSC) is a novel clipping system of endotherapy. The edges of the lesion are grasped by the jaw of the grasper; thus, the OTSC system could accomplish a full-thickness or near-fullness closure. Furthermore, given that high intragastric pressure after LSG5 is one of the risk factors that delays the healing of perforation, these investigators added botulinum toxin (BTX) injection to keep the pylorus open to release the intragastric pressure to enhance recovery. These researchers reported on the case of a 30-year-old diabetic woman with severe obesity who received LSG for her WR 4 years after primary bariatric surgery. However, an oral contrast–enhanced computed tomography (CT) scan 12 days after LSG showed gastric leak. Esophagogastroduodenoscopy confirmed three perforators over the gastroesophageal junction and upper body of stomach; multiple Sureclips were applied to the leaks. Furthermore, 25 units of BTX were injected into the four separate quadrants of pyloric area. The authors concluded that their initial experience revealed that endoscopic TTS clips and intrapyloric BTX injection was technically feasible, safe, and effective in individuals with leaks following primary LSG, whereas OTSC was suggested for revisional cases.

ROUX-EN-Y GASTROJEJUNOSTOMY FOR THE TREATMENT OF PERSISTENT GASTROESOPHAGEAL REFLUX DISEASE FOLLOWING ANTIREFLUX SURGERY IN PERSONS NOT MEETING MEDICAL NECESSITY CRITERIA FOR OBESITY SURGERY ABOVE

Grover and Kothari (2015) stated that individual satisfaction with primary antireflux surgery is high, but a small percentage of individuals experience recurrent reflux and dysphagia, requiring reoperation. The major anatomic causes of failed fundoplication are slipped fundoplication, failure to identify a short esophagus, and problems with the wrap. Minimally invasive surgery has become more common for these procedures. Options for surgery include redo fundoplication with hiatal hernia repair if needed, conversion to RNY anatomy, or, as a last resort, esophagectomy. The authors asserted that conversion to RNY anatomy had a high rate of success, making this approach an important option in the properly selected individual. This review did not provide any clinical data; however, it did cite the studies by Awais et al. (2008) and Makris et al. (2012).

Intractable GERD after prior antireflux operation presents a difficult challenge. Awais et al. (2008) examined the role of Roux-en-Y near esophagojejunostomy (RNYNEJ) in the management of intractable reflux symptoms after prior antireflux surgery. Between June 2000 and October 2005, 25 individuals with GERD after antireflux surgery underwent RNYNEJ. The endpoints evaluated were improvement in GERD symptoms using the GERD-Health Related Quality of Life (HRQL) scale, overall individual satisfaction, overall individual weight loss, and improvement of comorbid conditions. There were four men and 21 women (mean age, 51 years; range, 35–74); 72% had a BMI of greater than 30; 44% had more than one antireflux surgery and 40% had a previous Collis gastroplasty. The perioperative mortality was 0%; six individuals (24%) developed major postoperative complications, including anastomotic leak (n = 2) and Roux-limb obstruction (n = 1). The median LOS was 6 days; 80% of the individuals reported satisfaction at mean follow-up time of 16.5 months. Their BMI reduced from 35.8 to 27.7 (P<0.001); 73% of comorbid conditions were improved and the GERD HRQL score improved from 29.9 to 7.3 (P<0.001). The authors concluded that the RNYNEJ for persistent GERD after prior anti-reflux surgery was technically challenging with significant morbidity. However, the majority of the individuals reported satisfaction with significant improvement in symptoms. Many individuals had associated benefits of weight loss and improvement in comorbid conditions. They stated that RNYNEJ should be considered as an important option for the treatment of intractable GERD after prior antireflux surgery, particularly in obese individuals. Moreover, they stated that there is a need to further investigate and analyze individual variables that influence outcomes because this may help physicians and surgeons to better select individuals for a particular type of operation. They noted that these variables need to be prospectively studied to define optimal candidates, and further work is needed for optimizing individual selection. This was a small study (n = 25) with short-term follow-up (mean, 16.5 months).

Revisionary fundoplication is the mainstay of treatment for failed previous fundoplication, but it is not always feasible. Makris et al. (2012) reported their experience with use of short-limb RNY reconstruction for failed antireflux procedures. Prospectively collected data were retrospectively analyzed for morbidity, mortality, pre- and postprocedure symptom scores (scale 0–3), BMI, and individual satisfaction (scale 1–10). Seventy-two individuals with one to four (median, one) previous antireflux procedures underwent RNY reconstruction, either to gastric pouch (n = 64) or to the esophagus (n = 8). There were 37 laparoscopic, 24 open abdominal, and two combined thoracic-abdominal procedures; nine additional individuals underwent conversion from laparoscopy to open surgery. Mean follow-up of 20.7 months (± 12.9 months) was available in 63 (88%) individuals. The overall median scores for heartburn, regurgitation, dysphagia, chest pain, and nausea were 0 or 1. Seventy-two major and minor complications were noted that affected 33 (46%) individuals, with no in-hospital or 30-day mortality observed. The most common complications were anastomotic strictures, bowel obstructions, respiratory complications, and dumping. Mean postoperative BMI was 24.6 (± 4.4) kg/m² compared with preoperative BMI of 31.4 (± 6.1) kg/m². Mean reported satisfaction score was 8.2 (± 2.1), and 89% of the individuals would recommend the procedure to a friend. Pre- and postoperative symptoms could be compared in 57 individuals, and significant decrease in median symptom scores for heartburn (2–0; P<0.05), regurgitation (1–0; P<0.05), and dysphagia (2–0; P<0.05) was confirmed. There was an increase in reported nausea (0–​1; P< 0.05). The authors concluded that short-limb RNY reconstruction was an effective remedial procedure for a subset of individuals with failed antireflux surgery, but morbidity was significant. Moreover, they stated that the main drawback of this study was retrospective studies performed on prospective databases and that studies with longer follow-up are needed to validate these findings.

SCLEROTHERAPY FOR THE TREATMENT OF DILATED GASTROJEJUNOSTOMY FOLLOWING BARIATRIC SURGERY

Townsend, in the Sabiston Textbook of Surgery (2012) stated that, in regard to investigational bariatric procedures, "endoscopic incisionless surgery has focused on patients after RYGBP who have inadequate weight loss or significant WR and who have a dilated gastrojejunostomy​. It is thought that these patients lose restriction because of the dilated gastrojejunostomy and thus overeat. Surgeons have tried endoscopic injection of sclerosing agents to create scar and a smaller anastomosis, with variable effects."

In 2008, Loewen and Barba evaluated the injection of morrhuate sodium as sclerotherapy to decrease the diameter of the GJA anastomosis following gastric bypass. Seventy-one individuals underwent sclerotherapy at their GJA between July 2004 and August 2006. A retrospective review was performed of this group, including chart review, follow-up data with weight checks, and telephone interview findings. The average age of the individuals was 45 years and all but four individuals were women. Sclerotherapy was done an average of 2.9 years after gastric bypass. The starting weight at endoscopy was an average of 218 pounds–18 pounds heavier than the average nadir weight. The average diameter of the GJA  was 2.3 centimeters. An average of 13 mL morrhuate sodium was injected circumferentially. Repeat therapy was performed in 35 individuals (49%). No hospital admissions or complications occurred in relation to the procedure. During the 12-month follow-up period, 72% of patients maintained or lost weight. The analysis showed a high BMI (at endoscopy) to be the only predictive factor for successful weight maintenance or loss. The authors reported that "a randomized controlled study is necessary to validate these findings."

In a 2007 article, Spaulding et al. studied endoscopic sclerotherapy with sodium morrhuate of a dilated GJA in 147 gastric bypass individuals. In a retrospective review, 32 individuals were identified for whom 12 or more months of postprocedure data were available. Their weight trends before and after treatment were assessed by paired t-test. Thirty-two individuals who were gaining weight after gastric bypass underwent sclerotherapy of their dilated GJA. The timing of treatment ranged from 10 to 140 months (average, 56) after RYGBP. Before sclerotherapy, individuals were gaining weight at a rate of 0.36 kg per month. After treatment, they were losing weight at a rate of 0.39 kg per month. After treatment, 56.3% of individuals began to lose weight, 34.4% had their weight stabilize, and 9.4% continued to gain weight.

SILASTIC RING VERTICAL GASTRIC BYPASS (FOBI POUCH) 

The Fobi pouch, developed by California surgeon Mathias A.L. Fobi, is a modification of gastric bypass surgery. The modifications to gastric bypass surgery are designed to prevent postsurgical enlargement of the gastric pouch and stoma.

In a traditional gastric bypass procedure, surgeons create a smaller stomach by stapling off a large section. A problem with the traditional procedure is that the staples can break down, causing the stomach to regain its original shape—and individuals to start gaining weight again. Also, the stomach opening that leads into the intestines, which in surgery is made smaller to allow less food to pass through, often stretches as the years go by. With the Fobi pouch, there is no use of staples; rather, the stomach is bisected and hand-sewn to maintain the separation. A synthetic band is placed around the stomach opening to keep it from stretching.

However, there is a paucity of direct comparative studies of the Fobi pouch to traditional gastric bypass surgery, causing colleagues to "question whether his technique is really an improvement on the traditional procedure" (Davis, 2000). All of the published literature has been limited to descriptive articles, case series, and a prospective nonrandomized controlled study. These studies were from a single group of investigators, raising questions about the generalization of the findings.

VERTICAL BANDED GASTROPLASTY 

VBG limits dietary intake by stapling along the vertical axis to incapacitate part of the stomach. Food empties slowly into the bottom portion of the stomach through a rate-limiting stoma, which is created by a band placed through the stomach wall. VBG was a common surgical procedure in the late 1980s and early 1990s, but because stoma dilation often causes WR, VBG has been largely replaced by adjustable band procedures.

Of note, VBG is a purely restrictive procedure that is largely not performed in the United States and has been replaced by laparoscopic adjustable gastric banding (LAGB) or SG. Weight loss with VBG is substantial, but there are high rates of revisions and reoperations due to staple line disruption, perforation, band erosion or disruption, and stenosis at the band site. Overall rates of revisions and reoperations at up to 10 years may be as high as 50% (Balsiger et al., 2000; Miller et al., 2007). VBG is not included on the list of endorsed procedures by the ASMBS (https://asmbs.org/resources/endorsed-procedures-and-devices.).

In an RCT, Werling et al. (2013) evaluated the long-term results associated with RYGBP and VBG. Of the initial 82 study participants, ultimately 80% (n=66) were randomly assigned to RYGB or VBG and followed for up to 6 years. Outcome measurements included BMI, body composition, eating habits, and gastrointestinal hormones. Frequency of reoperation was also assessed up to 10 years following surgery. Intent-to-treat analyses demonstrated a statistically significantly greater weight loss after RYGB compared with VBG at 6-year follow-up (P=0.036). RYGBP caused a larger loss of fat mass and better preservation of lean tissue as well. Approximately 89% of individuals who initially had VBG had undergone, or were scheduled for, conversion to RYGBP at last follow-up. The authors concluded that RYGBP was superior to VBG with respect to weight loss, body composition, and dietary composition.

VAGUS NERVE BLOCKING (VBLOC THERAPY)

Vagus/vagal nerve block, vagal blocking for obesity control (VBLOC [e.g., Maestro]) involves laparoscopic placement of two leads (electrodes) in contact with vagal nerve trunks and a subcutaneously implanted neuromodulation device that is externally programmed to intermittently send electrical impulses via the implanted electrodes. The electrical impulses are purported to block vagus nerve signals in the abdominal region, inhibiting gastric motility and increasing satiety.

On January 15, 2015, the FDA approved VBLOC vagal blocking therapy, delivered via the Maestro system, for the treatment of adult individuals with obesity who have a BMI of at least 40 to 45 kg/m², or a BMI of at least 35 to 39.9 kg/m² with a related health condition (e.g., high blood pressure or high cholesterol levels, and who have tried to lose weight in a supervised weight management program within the past 5 years).

However, there is currently insufficient evidence to support the VBLOC vagal nerve blocking therapy for the treatment of obesity.

In an open-label, three-center study, Camilleri et al. (2008) evaluated the effects of vagal blocking (VBLOC therapy) on EWL, safety, dietary intake, and vagal function. This clinical trial was conducted in obese subjects with BMI between 35 and 50 kg/m²). Electrodes were implanted laparoscopically on both vagi near the esophagogastric junction to provide electrical block. Individuals were followed for 6 months for body weight, safety, electrocardiogram, dietary intake, satiation, satiety, and plasma pancreatic polypeptide (PP) response to sham feeding. To specifically assess device effects alone, no diet or exercise programs were instituted. Thirty-one individuals (mean BMI, 41.2 ± 1.4 kg/m²) received the device. Mean EWL at 4 and 12 weeks and 6 months after implant was 7.5%, 11.6%, and 14.2%, respectively (all P< 0.001); 25% of individuals lost greater than 25% EWL at 6 months (maximum of 36.8%). There were no deaths or device-related serious AEs. Calorie intake decreased by greater than 30% at 4 and 12 weeks and 6 months (all P≤0.01), with earlier satiation (P<0.001) and reduced hunger (P=0.005). After 12 weeks, plasma PP responses were suppressed (20 ± 7 versus 42 ± 19 pg/mL). Average percent EWL in individuals with PP response less than 25 pg/ml was double that with PP response greater than 25 pg/ml (P=0.02). Three individuals had serious AEs that required brief hospitalization, 1 each for lower respiratory tract, subcutaneous implant site seroma, and Clostridium difficile diarrhea. The authors concluded that intermittent, intra-abdominal vagal blocking is associated with significant EWL and a desirable safety profile. This was a small study (n = 31) with shorter-term follow-up (6 months); its findings need to be validated by well-designed studies with larger sample size and longer follow-up.

In a prospective, double-blind, RCT, Sarr et al. (2012) examined the feasibility of vagal blockade (VBLOC therapy) to induce weight loss in individuals with morbid obesity. A total of 503 subjects were enrolled at 15 centers. After informed consent, 294 subjects underwent implantation with the vagal blocking system and were randomly assigned to the treated (n = 192) or control (n = 102) group. Main outcome measures were percentage EWL at 12 months and serious AEs. Subjects controlled duration of therapy using an external power source; therapy involved a programmed algorithm of electrical energy delivered to the subdiaphragmatic vagal nerves to inhibit afferent/efferent vagal transmission. Devices in both groups performed regular, low-energy safety checks. Data were mean ± SEM. Study subjects consisted of 90% female individuals, BMI of 41 ± 1 kg/m², and age of 46 ± 1 years. Device-related complications occurred in 3% of subjects. There was no mortality; 12-month percentage EWL was 17% ± 2% for the treated and 16% ± 2% for the control group. Weight loss was related linearly to hours of device use; treated and controls with greater than or equal to 12 hours/day use achieved 30 ± 4 and 22 ± 8% EWL, respectively. The authors concluded that VBLOC therapy to treat morbid obesity was safe, but weight loss was not greater in treated compared to controls; clinically important weight loss, however, was related to hours of device use. Poststudy analysis suggested that the system electrical safety checks (low charge delivered via the system for electrical impedance, safety, and diagnostic checks) may have contributed to weight loss in the control group.

In an open-label study, Shikora et al. (2013) evaluated the effect of intermittent VBLOC on weight loss, glycemic control, and blood pressure (BP) in obese individuals with T2DM. Twenty-eight individuals underwent implantation with a VBLOC device (Maestro Rechargeable System) at five centers. Effects on weight loss, HbA1c, fasting blood glucose, and BP were evaluated at 1 week to 12 months; 26 individuals (17 females/nine males, 51 ± 2 years, BMI of 37 ± 1 kg/m², mean ± SEM) completed 12 months of follow-up. One serious AE (pain at implant site) was easily resolved. At 1 week and 12 months, mean percentage EWLs were 9% ± 1% and 25% ± 4% (P<0.0001), and HbA1c declined by 0.3% ± 0.1% and 1.0% ± 0.2% (P=0.02; baseline 7.8 ± 0.2%). In T2DM individuals with elevated BP (n = 15), mean arterial pressure reduced by 7 ± 3 mm Hg and 8 ± 3 mm Hg (P=0.04; baseline 100 ± 2 mm Hg) at 1 week and 12 months. All subjects MAP decreased by 3 ± 2 mm Hg (baseline 95 ± 2 mm Hg) at 12 months. The authors concluded that VBLOC was safe in individuals with obesity and T2DM and was associated with meaningful weight loss, early and sustained improvements in HbA1c, and reductions in BP in hypertensive T2DM subjects. This was a small study (n = 28) with shorter term follow-up (12 months); its findings need to be validated by well-designed studies with larger sample size and longer follow-up.

Shikora et al. (2015) noted that the ReCharge trial is a double-blind RCT of 239 participants with BMI of 40 to 45 kg/m or 35 to 40 kg/m with one or more obesity-related conditions. Interventions were implantation of either vBloc or sham devices and weight management counseling. Mixed models assessed percentage EWL and percentage TWL in intent-to-treat analyses. At 18 months, 142 (88%) vBloc and 64 (83%) sham individuals remained enrolled in the study. Eighteen-month weight loss was 23% EWL (8.8% TWL) for vBloc and 10% EWL (3.8% TWL) for sham (P<0.0001). Individuals who received the VBLOC largely maintained 12-month weight loss of 26% EWL (9.7% TWL). Sham regained over 40% of the 17% EWL (6.4% TWL) by 18 months. Most WR preceded unblinding. Common AEs of VBLOC through 18 months were heartburn/dyspepsia and abdominal pain; 98% of events were reported as mild or moderate and 79% had resolved. The authors concluded that weight loss with VBLOC was sustained through 18 months, while sham resulted in regained weight between 12 and 18 months. They stated that VBLOC is effective with a low rate of serious complications. This study had several drawbacks: frequency of missing data was appreciable at 18 months, statistical analysis of the ReCharge study was not pre-specified after 12 months, and all participants were not blinded through 18 months and were unblinded on a rolling basis, making interpretation more difficult. The authors stated that additional long-term data and continued follow-up of the ReCharge study are needed to further characterize the safety and effectiveness profile of VBLOC therapy.

BARIATRIC SURGERY PRIOR TO TOTAL HIP OR KNEE ARTHROPLASTY TO REDUCE POSTOPERATIVE COMPLICATIONS AND IMPROVE CLINICAL OUTCOMES FOR OBESE INDIVIDUALS

Smith et al. (2016) examined whether bariatric surgery prior to total hip arthroplasty (THA) or total knee arthroplasty (TKA) reduces the complication rates and improves the outcome following arthroplasty in obese individuals. These researchers performed a systematic literature search of published and unpublished databases through November 5, 2015. All papers reporting studies comparing obese individuals who had undergone bariatric surgery prior to arthroplasty, or not, were included. Each study was assessed using the Downs and Black appraisal tool. A meta-analysis of RR and 95% CI was performed to determine the incidence of complications including wound infection, deep vein thrombosis (DVT), pulmonary embolism (PE), revision surgery, and mortality. From 156 potential studies, 5 were considered to be eligible for inclusion in the study. A total of 23,348 individuals (657 who had undergone bariatric surgery, 22,691 who had not) were analyzed. The evidence-base was moderate in quality. There was no statistically significant difference in outcomes such as superficial wound infection (RR, 1.88; 95% CI, 0.95–0.37), deep wound infection (RR, 1.04; 95% CI, 0.65–1.66), DVT (RR, 0.57; 95% CI, 0.13–2.44), PE (RR, 0.51; 95% CI, 0.03–8.26), revision surgery (RR, 1.24; 95% CI, 0.75–2.05) or mortality (RR, 1.25; 95% CI, 0.16–9.89) between the two groups. The authors concluded that for most perioperative outcomes, bariatric surgery prior to THA or TKA did not significantly reduce the complication rates or improve the clinical outcome. They stated that the findings of this study questions the previous belief that bariatric surgery prior to arthroplasty may improve the clinical outcomes for individuals who are obese or morbidly obese. This finding is based on moderate-quality evidence.

SINGLE-INCISION LAPAROSCOPIC SLEEVE GASTRECTOMY

Single-incision laparoscopic surgery has attracted a great deal of interest in the surgical community in recent years, including bariatric surgery (Dimitrokallis et al., 2017). Single-incision LSG (SILSG) has been proposed as an alternative to the multiport laparoscopic procedure; however, it has yet to meet wide acceptance and application. These researchers summarized existing data on SILSG and checked the procedure's feasibility, technical details, safety, and, if possible, outcomes. They checked the most important databases for studies concerning SILSG and included all these that summarized the criteria placed and contained the data needed for this review. They excluded case reports. Nineteen studies (1679 individuals) met the selection criteria of this review. Their mean age was 38.91 years and the mean preoperative BMI was 41.8 kg/m². In the majority of cases (60.5%), a left upper quadrant incision was carried out; and in 97.6%, a commercially available multiport system was employed. A wide variety of instruments had been used and mean operating time was 94.6 minutes. One conversion to open surgery was reported and 7.4% required the placement of additional ports. There was a complication rate of 7.38% (most common being bleeding with a rate of 2.5%) and a reoperation rate of 2.8%. Mean EWL for a follow-up of 1 year was achieved in 53.7% of individuals and was 70.06%. A tendency for less analgesia and better wound satisfaction was reported. The authors concluded that SILSG was safe and feasible. However, there is insufficient evidence to recommend it as the new gold standard for SG in the place of conventional LSG. These investigators stated that RCTs are needed to analyze the results and the possible benefits of this technique.

GASTRIC BYPASS FOR CRANIOPHARYNGIOMA-RELATED HYPOTHALAMIC OBESITY

Ni and Shi (2018) stated that craniopharyngiomas (CPs) and their treatment are associated with hypothalamic damage that causes hypothalamic obesity (HO) in 30% to 70% of cases. Therefore, there is ongoing investigation regarding solutions for HO because these individuals have unrelenting resistance to basic weight-loss interventions. These investigators summarized the interventions that are used to treat CP-related HO (CP-HO), including pharmacotherapy and bariatric surgery. The Cochrane Library, Embase, and PubMed databases were searched up to June 2017 for relevant reports; two reviewers conducted independent evaluations of the studies identified. Eighteen articles were included in the systematic review, with three reports describing pharmacotherapy in RCTs and 15 reports describing bariatric surgery. Although several studies described effective interventions for treating CP-HO, the evidence base was limited by its low quality and the inability to perform a meta-analysis, which was related to a lack of adequate or integrated data. The authors concluded that octreotide appeared to be a preferred treatment for individuals with CP-HO, based on limited data. Gastric bypass surgery may also be suitable for select individuals with CP-HO, based on a review of various procedures in this setting. Microsurgical preservation of the hypothalamic structures is mandatory to decrease CP-HO–related morbidity and mortality. Moreover, they stated that further studies with adequate analytical power and sufficient follow-up are needed to identify effective strategies for CP-HO treatment.

CANDY CANE SYNDROME (ROUX SYNDROME)

Candy cane syndrome (CCS), also known as Roux syndrome or Candy cane Roux syndrome, is a rare complication in individuals after RYGBP surgery. It occurs when there is an excessive length of roux limb proximal to GJA, creating the possibility for food particles to lodge and remain in the blind redundant limb.

Aryaie et al. (2017) noted that CCS has been implicated as a cause of abdominal pain, nausea, and emesis after RYGBP; however, it remains poorly described. These investigators reported that CCS is real and can be treated effectively with revisional bariatric surgery. All individuals who underwent resection of the "candy cane" between January 2011 and July 2015 were included in this study. All had preoperative work-up to identify CCS. Demographic data; pre-, peri-, and postoperative symptoms; data regarding hospitalization; and postoperative weight loss were examined via retrospective chart review. Data were analyzed using Student's t-test and χ² analysis where appropriate. Nineteen individuals had resection of the "candy cane" (94% women, mean age of 50 ± 11 years), within 3 to 11 years after initial RYGBP. Primary presenting symptoms were epigastric abdominal pain (68%) and nausea/vomiting (32%), especially with fibrous foods and meats. On upper gastrointestinal study and endoscopy, the afferent blind limb was the most direct outlet from the GJA. Only individuals with these preoperative findings were deemed to have CCS; 18 (94%) cases were completed laparoscopically. Length of the "candy cane" ranged from 3 to 22 cm; median LOS was 1 day. After resection, 18 (94%) individuals had complete resolution of their symptoms (P<0.001). Mean BMI decreased from 33.9 ± 6.1 kg/m² preoperatively to 31.7 ± 5.6 kg/m² at 6 months (17.4% EWL) and 30.5 ± 6.9 kg/m² at 1 year (25.7% EWL). The average length of latest follow-up was 20.7 months. The authors concluded that CCS is a real phenomenon that could be managed safely with excellent outcomes with resection of the blind afferent limb. A thorough diagnostic work-up is critical for proper identification of CCS; surgeons should minimize the size of the blind afferent loop left at the time of initial RYGBP.

According to Stier et al. (2020), CCS is a rarely reported and neglected complication of proximal RYGBP surgery. In a retrospective study, forty-seven cases of CCS that underwent candy cane resection were analyzed for pain remission to examine if intussusception is a possible underlying mechanism. Forty-three individuals (89.6%) benefited from laparoscopic candy can resection (P<0.001). The highly sensitive diagnostic tests were upper gastrointestinal series (91%) and gastroscopy (96%). Intussusception of the candy cane into the gastric pouch was demonstrated in most cases and was postulated as the trigger for CCS. In some cases, retroperistaltic intussusception led to nonspecific upper gastrointestinal bleeding. The authors concluded that a vast majority of individuals with CCS benefited significantly from candy cane resection. The long-described retroperistaltic intussusception of the candy cane was suggested as an important underlying mechanism of the symptoms. These researchers stated that although candy cane resection remains a stop-gap, evidence on its clinical significance has been shown for a century. Building on this wealth of experience and the already vast storage of practical knowledge, awareness of this underestimated complication after RYGBP should be raised.

In an observational study, Kamocka et al. (2020) examined the sensitivity of preoperative diagnostic tools for CCS, as well as perioperative outcomes and symptom resolution following CCS revision surgery. Twenty-eight CCS revision cases were identified (mean age, 45 ± 9 years; women:men, 9:1). Presenting symptoms were abdominal pain (86%), regurgitation/vomiting (43%), suboptimal weight loss (36%) and acid reflux (21%). Preoperative tests provided correct diagnosis in 63% of barium contrast swallows, 50% of upper gastrointestinal endoscopies, and 29% of computed tomography scans. Individuals presenting with pain had significantly higher candy cane size as compared with the pain-free group (4.2 vs. 2 cm; P=0.001). Perioperative complications occurred in 25% of cases. Complete or partial symptom resolution was documented in 73% of individuals undergoing CCS revision. The highest success rates were recorded in the regurgitation/vomiting group (67%). The authors concluded that surgical revision of the candy cane was associated with good symptom resolution in the majority of individuals, especially those presenting with regurgitation/vomiting. However, it carried certain risk of complications. These investigators stated that CCS diagnosis may frequently be missed; hence more than one diagnostic tool should be considered when examining symptomatic individuals after RYGBP.

Furthermore, an UpToDate review on late complications of bariatric surgical operations (Ellsmere, 2020) stated that "Candy cane Roux syndrome in individuals who have undergone RYGBP refers to an excessively long blind afferent Roux limb at the gastrojejunostomy causing postprandial pain often relieved by vomiting. It is believed that the blind afferent limb ("candy cane") acts as an obstructed loop when filled with food (often preferentially), and the distention of the loop causes pain until the food either spills into the Roux limb or is vomited back out. Individuals have been reported presenting as early as 3 months and as late as 11 years after their initial RYGBP, typically with symptoms of postprandial epigastric pain, nausea, vomiting, and reflux or food regurgitation. The diagnosis is confirmed by upper gastrointestinal contrast studies or endoscopy. On upper gastrointestinal series, the afferent limb fills before contrast spills into the Roux limb. On upper endoscopy, the afferent limb is usually the most direct outlet of the gastrojejunostomy. The treatment is revision bariatric surgery, most commonly laparoscopic resection of the afferent limb, which ranged in length from 3 to 22 cm in one study (mean, 7.6 cm). Symptoms resolve after revision surgery in most individuals. Surgeons should minimize the length of the blind afferent loop left at the time of initial RYGBP to prevent candy cane Roux syndrome."

MEASUREMENT OF SERUM C-REACTIVE PROTEIN AS A PREDICTOR FOR COMPLICATIONS FOLLOWING BARIATRIC SURGERY

Kroll et al. (2018) stated that early intra-abdominal infections (IAI) compromise short-term outcomes in bariatric surgery. The timely detection of IAI is challenging but essential to prevent major sequelae of such complications. C-reactive protein (CRP) is a reliable marker for detecting IAI after colorectal surgery. In bariatric surgery, data on CRP as a marker for IAI are limited, especially for postoperative day 1 (POD1). These researchers evaluated CRP on POD1 as a predictor for early IAI (within 7 days following surgery) in individuals after LSG and LRYGBP. Individuals who underwent bariatric surgery between August 2010 and June 2017 were included. The predictive capacity of CRP for early IAI was determined using a receiver operating characteristics (ROC) analysis. In 523 individuals (68.5% female, LSG = 358, LRYGBP = 165), 16 (3%) early IAI were observed. ROC analysis revealed a significant predictive capacity of POD1 CRP for early IAI, with a sensitivity and a specificity of 81.2% and 94.3%, respectively, at a CRP cut-off value of 70 mg/L. In individuals with confirmed early IAI, 81.3% had a CRP level of greater than or equal to 70 mg/L (LSG 85.7%, LRYGBP 77.8%). The negative predictive value (NPV) for a CRP level of less than 70 mg/L was 99.4% overall and was 100% and 98% for LSG and LRYGBP, respectively. The authors concluded that in individuals with a CRP level of less than 70 mg/L on POD1, early IAI could be excluded with high accuracy in bariatric individuals; thus, these researchers stated that early postoperative CRP may be used to examine the risk of early IAI in enhanced recovery programs.

Bona et al. (2019) noted that post​operative leak and IAI are common following bariatric surgery with a significant impact on perioperative outcomes, hospital LOS, and readmission rates. In the era of enhanced recovery programs, with individuals being discharged from the hospital 24 to 36 hours following surgery and potentially before developing any complications, an early indicator of postoperative complications may be decisive. Bona et al. examined the predictive role of the CRP in the early diagnosis of complications in individuals undergoing LSG and LRYGBP. PubMed, Embase, and Web of Science databases were consulted. A systematic review and a fully Bayesian meta-analysis were conducted. Seven studies (1401 individuals) met the inclusion criteria. Overall, 57.7% underwent LSG while 42.3% underwent LRYGBP. The pooled prevalence of postoperative complications was 9.8% (95% CI, 5%–16%). The estimated pooled CRP cut-off value on POD1 was 6.1 mg/dL with a significant diagnostic accuracy and a pooled area under the curve of 0.92 (95% CI, 0.73–0.98). The positive and negative likelihood ratios (PLR and NLR) were 13.6 (95% CI, 8.40–15.9) and 0.16 (95% CI, 0.04–0.31), respectively. The authors concluded that a CRP value lower than the derived cut-off of 6.1 mg/dL on POD1, combined with reassuring clinical signs, could be useful to rule out early postoperative leak and complications following LSG and LRYGB. In the context of enhanced recovery after surgery protocols, the integration of a CRP-based diagnostic algorithm as an additional complementary instrument may be valuable to reduce cost and improve outcomes and individual care.

In a retrospective chart review, Villard et al. (2019) examined the use of CRP in early identification of postoperative complications following bariatric surgery. The ability of this marker to acutely predict postoperative complications in bariatric surgery individuals has not been determined. This trial was carried out in adult individuals who underwent a primary and revisional LRYGB or LSG between 2013 and 2017 at a single institution. Individuals were identified using the prospective Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database; CRP levels were drawn on POD1 per standard protocol. Univariate analyses were carried out to determine the predictive impact of CRP levels on postoperative complications, readmissions, and reoperations. There were 275 individuals who underwent bariatric surgery: 222 primary and 53 revisional. Of the 275 individuals, 36 (13.1%) had a complication. Bariatric surgery individuals with a postoperative complication had higher CRP levels compared to those who did not (4.8 ± 4.6 vs. 2.9 ± 2.0; P=0.02). A CRP of greater than or equal to 5 mg/dL had a sensitivity for a complication of 27% and a specificity of 88%. There was no difference in CRP levels for individuals with a 30-day reoperation or readmission; and there were no mortalities. The authors concluded that bariatric surgery individuals with elevated postoperative CRP levels were at increased risk for 30-day complications. The low sensitivity of a CRP of greater than or equal to 5 mg/dL suggested that a normal CRP level alone did not rule out the possibility of a postoperative complication; however, with its high specificity, there should be an elevated clinical suspicion of a postoperative complication in individuals with a CRP of greater than or equal to 5 mg/dL.

NONINVASIVE TESTING IN METABOLIC DYSFUNCTION-ASSOCIATED STEATOTIC LIVER DISEASE (MASLD)

In an UpToDate review entitled “Management of nonalcoholic fatty liver disease in adults", Chopra and Lai (2021) noted that “NAFLD ranges from the more benign condition of nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), which is at the more severe end of the spectrum. In NAFL, hepatic steatosis is present without evidence of inflammation, whereas in NASH, hepatic steatosis is associated with lobular inflammation and apoptosis that can lead to fibrosis and cirrhosis."

In an UpToDate review entitled “Epidemiology, clinical features, and diagnosis of nonalcoholic fatty liver disease in adults", Sheth and Chopra (2021) provide a distinction between NAFLD and NASH. They note that “NAFLD is subdivided into nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH). In NAFL, hepatic steatosis is present without evidence of significant inflammation, whereas in NASH, hepatic steatosis is associated with hepatic inflammation that may be histologically indistinguishable from alcoholic steatohepatitis." The only method to definitively confirm or exclude a diagnosis of NASH and to assess disease severity is via a liver biopsy. Furthermore, the histologic diagnosis of NASH is based on the presence of hepatic steatosis in relation to hepatocyte ballooning degeneration and hepatic lobular inflammation (usually in acinar zone 3)." Although fibrosis may be visible, it is not a required diagnostic feature for NASH.

In "The diagnosis and management of nonalcoholic fatty liver disease: Practice guidance from the American Association for the Study of Liver Diseases", Chalasani et al.(2018) noted the utility of serum biomarkers (e.g., Enhanced Liver Fibrosis [ELF] panel, Fibrometer, FibroTest, and Hepascore) and imaging (e.g., transient elastography [TE], magnetic resonance elastography [MRE], acoustic radiation force impulse imaging, and supersonic shear wave elastography) as noninvasive assessment of advanced fibrosis in individuals with NAFLD.

Castera et al. (2019) note key issues in NAFLD individuals as the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. Although liver biopsy remains the gold standard for identification of NASH and advanced hepatic fibrosis in individuals with NAFLD, the procedure has inherent limitations (i.e., invasiveness, poor acceptability, sampling variability, cost). The emergence of noninvasive testing has become important in determination of the two previously mentioned endpoints in NAFLD individuals. The most accurate and validated methods that were noted for the identification of advanced fibrosis included magnetic resonance elastography (MRE), transient elastography (TE), fibrosis-4 index (FIB-4), and nonalcoholic fatty liver disease fibrosis score (NFS). Additionally, FIB-4 and NFS show best application as first-line tools in the primary health care setting to conclusively exclude advanced fibrosis. TE and MRE are better suited for referral centers to choose individuals who require a liver biopsy.

Recently, the nomenclature of NAFLD has changed to MASLD, and NASH to MASH.

SUMMARY

Morbid obesity (Class III obesity) remains a concern in both the adult and adolescent populations. There currently exists a large body of literature on bariatric surgery, but few are high-quality RCTs. The available peer-reviewed literature primarily consists of nonrandomized comparative studies and case series that support the conclusion that compared to nonsurgical treatments, bariatric surgery results in greater weight loss and improvements in obesity-related comorbidities. RYGBP remains the gold standard to which other procedures should be compared, although there is evidence that SG, BPD, SADI-S/SIPS, and LAGB improve obesity-related outcomes.

There remain concerns about the long-term outcomes associated with LAGB, which include band erosion and device slippage. Sakran et al. (2013) indicated that one of the most serious AEs associated with LAGB is a staple line leak, which requires revision surgery or conversion. However, there exist prospective RCTs that indicate that LAGB is associated with successful outcomes and resolution of obesity-related comorbidities. In addition, there exist prospective longitudinal cohort studies that demonstrate a durable weight loss that may be maintained up to 15 years.

Bariatric surgery is a treatment for class III obesity in individuals who fail to lose weight with conservative measures. There are numerous gastric and intestinal surgical techniques available. While these techniques have heterogeneous mechanisms of action, the result is a smaller gastric pouch that leads to restricted eating. However, these surgeries may lead to malabsorption of nutrients or eventually to metabolic changes. Based on clinical input, the available peer-reviewed literature, and guidance from relevant medical societies, bariatric surgery for the treatment of morbid obesity may be appropriate in a select population of individuals with morbid obesity who have a documented failed history of medical weight loss and have participated in a comprehensive preoperative surgical preparatory regimen.

ADULTS WITH CLASS III OBESITY

For individuals who are adults with class III obesity who receive gastric bypass, the evidence includes RCTs, observational studies, and systematic reviews. Relevant outcomes are overall survival (OS), change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. TEC Assessments and other systematic reviews of RCTs and observational studies found that gastric bypass improves health outcomes, including weight loss and remission of type T2D. A TEC Assessment found similar weight loss with open and laparoscopic gastric bypass. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive LAGB, the evidence includes RCTs, observational studies, and systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Systematic reviews of RCTs and observational studies have found that LAGB is a reasonable alternative to gastric bypass. There is less weight loss with LAGB than with gastric bypass, but LAGB is less invasive and is associated with fewer serious AEs. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive SG, the evidence includes RCTs, observational studies (evaluating SG alone and comparing SG with gastric bypass), as well as systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Systematic reviews of RCTs and observational studies have found that SG results in substantial weight loss and that this weight loss is durable for at least 5 years. A meta-analysis found that short-term weight loss was similar after SG compared with gastric bypass. Long-term weight loss was greater after gastric bypass, but SG is associated with fewer AEs. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive BPD-DS, the evidence includes nonrandomized comparative studies, observational studies, and a systematic review. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Nonrandomized comparative studies have found significantly higher weight loss after BPD with DS compared with gastric bypass at 1 year. A large case series found sustained weight loss after 7 years. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive BPD without DS, the evidence includes observational studies and systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. A TEC Assessment reviewed the available observational studies and concluded that weight loss was similar after BPD without a DS or gastric bypass. However, concerns have been raised about complications associated with BPD without DS, especially long-term nutritional and vitamin deficiencies. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive vertical-banded gastroplasty (VBG), the evidence includes observational studies and systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. A TEC Assessment identified eight nonrandomized comparative studies evaluating VBG, and these studies found that weight loss was significantly greater with open gastric bypass. Moreover, VBG has relatively high rates of complications, revisions, and reoperations. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive two-stage bariatric surgery procedures, the evidence includes a small RCT, observational studies, and case series. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. There is a lack of evidence that two-stage bariatric procedures improve outcomes compared with one-stage procedures. The small RCT compared intragastric balloon plus gastric bypass with the standard of care plus gastric bypass and did not detect a difference in weight loss at 6 months postsurgery. Case series have shown relatively high complication rates in two-stage procedures, and individuals are at risk of complications in both stages. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive LGP, the evidence includes an RCT, an observational study, and systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. A 2021 systematic review demonstrated that laparoscopic SG is superior to laparoscopic greater curvature gastric plication with regard to providing effective weight loss through 24 months; statistical significance was not reached at 36 months. The difference in the improvement of comorbidities and risk of major complications or mortality did not reach statistical significance between groups. One additional RCT compared endoscopic gastric plication with a sham procedure, reporting 1-year follow-up results in favor of the intervention. Additional comparative studies and RCTs with longer follow-up are needed to permit conclusions about the safety and efficacy of LGP. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive single anastomosis duodenoileal bypass with SG (SADI-S), the evidence includes a systematic review of observational studies and case series. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. A systematic review of 12 observational studies concluded that SADI-S was associated with promising weight loss and comorbidity resolution. A comparative chart review found that individuals without diabetes experienced significantly better weight loss and lipid profiles with SADI-S than with RYGBP and individuals who had diabetes experienced significantly higher rates of remission with SADI-S than with RYGBP.

For individuals who are adults with class III obesity who receive a duodenojejunal sleeve, the evidence includes RCTs, systematic reviews, and an observational study. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. A systematic review of duodenojejunal sleeves included five RCTs and found significantly greater short-term weight loss (12 to 24 weeks) with the sleeves compared with medical therapy. There was no significant difference in symptoms associated with diabetes. All RCTs were small and judged by systematic reviewers to be at high risk of bias. High-quality comparative studies are needed to permit conclusions on the safety and efficacy of the procedure. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive IGB devices, the evidence includes RCTs, systematic reviews, and case series. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. RCTs assessing the two IGB devices approved by the FDA have found significantly greater weight loss with IGB than with sham treatment or lifestyle therapy alone after 6 months (maximum length of device use). Some AEs were reported, mainly related to accommodation of the balloon in the stomach; in a minority of cases, these AEs were severe. One RCT followed individuals for an additional 6 months after IGB removal and found sustained weight loss. There are limited data on the durability of weight loss in the long-term. Comparative data are lacking. A large case series found that individuals gradually regained weight over time. Moreover, it is unclear how 6 months of IGB use would fit into a long-term weight loss and maintenance intervention. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are adults with class III obesity who receive an aspiration therapy (AT) device, the evidence includes an RCT and case series. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. The RCT found significantly greater weight loss with AT than lifestyle therapy at 1 year. Forty of 58 individuals (69%) achieved at least 10% total weight loss at 4 years or at time of study withdrawal; however, only 15 of 111 initial AT individuals completed the study through 4 years. In addition to a high degree of missing data, the Pivotal Aspiration Therapy with Adjusted Lifestyle (PATHWAY) study noted a potentially large number of AEs related to A-tube malfunction, an element of the therapy that is expected to require replacement within approximately 3.5 years postgastrostomy in 50% of cases. The impact of this on health outcomes compared to existing surgical approaches is unknown. One small case series reported on 15 individuals at 2 years. The total amount of data on AT remains limited and additional studies are needed before conclusions can be drawn about the effects of treatment on weight loss, metabolism, safety, nutrition, and long-term durability of treatment. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

SUBSEQUENT BARIATRIC SURGERIES

For individuals who are adults with class III obesity and failed bariatric surgery who receive revision bariatric surgery, the evidence includes systematic reviews, case series, and registry data. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Systematic reviews and case series have shown that individuals receiving revision bariatric surgery experienced satisfactory weight loss. Data from a multinational bariatric surgery database has found that corrective procedures following primary bariatric surgery are relatively uncommon but generally safe and efficacious. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

ADULTS WITH TYPE 2 DIABETES

For individuals who have T2DM and do not have class III obesity who receive gastric bypass, SG, BPD, or LAGB, the evidence includes systematic reviews of RCTs and observational studies. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Systematic reviews of RCTs and observational studies have found that certain types of bariatric surgery are more efficacious than medical therapy as a treatment for T2DM in obese individuals, including those with a BMI between 30 and 34.9 kg/m². The greatest amount of evidence is on gastric bypass. Systematic reviews have found significantly greater remission rates of diabetes, decrease in hemoglobin A1c levels, and decrease in BMI with bariatric surgery than with nonsurgical treatment. The efficacy of surgery is balanced against the short-term risks of the surgical procedure. Most RCTs in this population have 1 to 3 years of follow-up; with a few having 5-year follow-up data. 

ADOLESCENT CHILDREN WITH CLASS III OBESITY GASTRIC BYPASS, LAPAROSCOPIC ADJUSTABLE GASTRIC BANDING, OR SLEEVE GASTRECTOMY

For individuals who are adolescent children with class III obesity who receive gastric bypass, or LAGB, or SG, the evidence includes RCTs, observational studies, and systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Systematic reviews of studies on bariatric surgery in adolescents, who mainly received gastric bypass or LAGB or SG, found significant weight loss and reductions in comorbidity outcomes with bariatric surgery. For bariatric surgery in the adolescent population, although data are limited on some procedures, studies have generally reported that weight loss and reduction in risk factors for adolescents are similar to that for adults. Most experts and clinical practice guidelines have recommended that bariatric surgery in adolescents be reserved for individuals with severe comorbidities, or for individuals with a BMI greater than 50 kg/m². Also, greater consideration should be placed on the individual developmental stage, on the psychosocial aspects of obesity and surgery, and on ensuring that the individual can provide fully informed consent. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

PREADOLESCENT CHILDREN WITH CLASS III OBESITY

For individuals who are preadolescent children with class III obesity who receive bariatric surgery, there are no studies focused solely on this population. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. Several studies of bariatric surgery in adolescents have also included children younger than 12 years old. A recent (2021) cohort study included 801 children ages 5 to 14 years in their total cohort of children and adolescents, and excess weight loss and comorbidity resolution were substantial and long-lasting without safety concerns across all age groups. However, comparative studies are still lacking. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

HIATAL HERNIA REPAIR WITH BARIATRIC SURGERY

For individuals with class III obesity and a preoperative diagnosis of a hiatal hernia who receive hiatal hernia repair with bariatric surgery, the evidence includes a systematic review, cohort studies, and case series. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, QOL, and treatment-related mortality and morbidity. A systematic review found that hiatal hernia repair during SG was superior to SG alone for GERD remission, but not de novo GERD. Results from the cohort studies and case series have shown that, when a preoperative diagnosis of a hiatal hernia has been present, repairing the hiatal hernia during bariatric surgery resulted in fewer complications. However, the results are limited to individuals with a preoperative diagnosis. There was no evidence on the use of hiatal hernia repair when the hiatal hernia diagnosis is incidental. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.​​

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