Paranasal sinuses are cavities within the skull that lead into the nose and are lined with the same type of membranes that line the inside of the nose. When one or more of the sinus cavities are inflamed and the sinuses cannot drain properly, a condition known as rhinosinusitis develops. Sinusitis often results in an infection that can be bacterial, fungal, or viral, and that can be caused by inflammation and allergies.
CHRONIC RHINOSINUSITIS (CRS)
Chronic rhinosinusitis (CRS) may persist for 3 months or longer. Symptoms may include nasal congestion, facial pain, headache, fever, general malaise, purulent nasal discharge, increased sensation of facial fullness on bending over, or aching teeth. Medical management remains the primary treatment option for CRS. This typically includes various oral and topical agents such as antibiotics, steroids, antihistamines, leukotriene receptor antagonists, saline irrigations, and mucolytics.
To quantify the severity of chronic sinusitis and to assess treatment response, various outcomes measures can be used, including radiologic scores, participant-reported quality of life (QOL) measures, and endoscopic grading. The Lund-Mackay scoring system uses radiologist-rated information derived from computed tomography (CT) scans regrading opacification of the sinus cavities, generating a score from 0 to 12. Several disease-specific participant-reported QOL scores have been used. Commonly used is the Sino-Nasal Outcome Test-20 (SNOT-20) which is a validated questionnaire in which individuals complete 20 symptom questions on a categorical scale, from 0 (no bother) to 5 (worst symptoms can be). Average ranking can be reported over all 20 symptoms, as well as by four subclassified symptom domains. The SNOT-22 is a variation of the SNOT-20, which includes two additional questions of nasal obstruction and loss of smell and taste. The minimal clinically important difference for the SNOT-22 has been estimated to be 8.9 points. In addition, QOL may be reported based on overall health-related QOL score, such as the Short Form Health Survey-36. The health survey consists of eight scales scores on various health domains, which are transformed into a 0 to 100 scale.
The natural history of the disorder includes resolution with medical therapy or no therapy in a large proportion of individuals. However, if aggressive medical management does not improve symptoms, surgical drainage of the sinuses may be necessary. Functional endoscopic sinus surgery (FESS) has become important in the surgical management of CRS. A nasal endoscope is used to visualize the sinuses. Inflamed tissue and bone are removed and any obstruction found in the sinus ostia is corrected. This restores patency allowing mucous transport through the natural ostium, removes diseased tissue, and also improves access for topical therapy.
Balloon catheter dilation (BCD) of sinus ostia, or balloon ostial dilation (BOD), has been used as an adjunct to FESS. Compared with FESS, where the tissue and bone are removed, the balloon compresses the mucosa and causes microfracture of the underlying bone (Ahmed et al., 2011). Additionally, BOD has been investigated as a stand-alone procedure as an alternative to FESS. Unlike most endoscopic sinus surgery, which requires tissue reduction (such as inferior turbinate reduction), in the BOD procedure, a device such as the Relieva® Sinus Balloon Inflation Device (Acclarent®, Inc.; Menlo Park, CA) or the Relieva® Sinus Balloon Dilation Catheter (ExploraMed® NCI, Inc.; Mountain View, CA) is used to stretch and open the sinus ostia to improve sinus drainage.
There is a growing body of published literature and/or clinical studies regarding BOD as a stand-alone procedure. The published literature consists of randomized controlled trials (RCTs), noncomparative studies, and meta-analyses. The long-term safety and efficacy of BOD is emerging. Randomized studies on the need for subsequent revision still exists, but the safety and efficacy of BOD has now been established.
PEER-REVIEWED LITERATURE
Minni et al. (2018) published a prospective, multicenter randomized study that evaluated the validity and safety of BCD, or BOD, compared to endoscopic sinus surgery (ESS) in symptomatic CRS in the frontal sinus. This trial randomly assigned 102 individuals (64 men and 38 women; 148 frontal sinuses) with nonpolypoid CRS at three hospitals. In postprocedure analyses, the researchers reviewed both radiological (Lund-Mackay CT scoring modified by Zinreich) and symptomatic results (SNOT-20 questionnaire). The authors divided the affected persons into two groups. One group had light to mild frontal CRS and the other with moderate to severe frontal CRS, based on radiological findings. Each group was then divided in two smaller subgroups: in one arm the investigators used BOD and in the other they used traditional ESS. The current literature does not support the suggestion that indications for BOD and ESS are identical, and additional research is needed to determine the role for BOD in specific participant populations. The results showed a not statistically significant difference between BOD and conventional ESS of the frontal sinus in individuals with light to mild CRS and in individuals with moderate to severe CRS based on Lund-Mackay modified by Zinreich scores. Similar not statistically significant difference was observed comparing the results of SNOT-20 questionnaire in the group of light to mild frontal CRS. However, researchers noticed a statistically significant better outcome of SNOT-20 score in individuals with moderate to severe CRS who underwent BOD of frontal sinus compared to ESS. The authors concluded that BOD and ESS are both potential treatments as both therapies presented similar outcomes, safety and effectiveness for the population of light to mild and moderate to severe CRS of the frontal sinus. The study resulted in statistically significant better outcome of SNOT-20 scores in individuals who underwent BOD of the frontal sinus for a moderate to severe CRS, compared to those who underwent a traditional ESS.
Soler et al. (2017) performed a prospective, multicenter, single-arm study, investigating the effectiveness of BOD in children with CRS who had failed medical management and were followed up to 6 months postprocedure. Across four centers, 50 children were treated (aged 2 to 21 years), 33 of which were between the ages of 2 and 12 years old and the remaining 17 individuals were older than 12 to 21 years. A total of 157 BOD procedures were attempted on 98 maxillary, 30 frontal, and 29 sphenoid sinuses. The authors report all procedures were successful with no complications. At 6 months postoperation, significant improvement from baseline scores in the Sinus and Nasal Quality of Life Survey (SN-5) were observed for all children (4.6 ± 1.2 vs. 1.7 ± 0.8; P<0.0001) and based on the SN-5, 92 percent of participants improved by at least 1.0 or more. Children aged 2 to 12 years with stand-alone BOD also showed significant SN-5 improvements between baseline and follow-up (4.5 ± 1.0 vs. 1.9 ± 0.8; P<0.0001). For adolescents, overall SNOT-22 mean scores were significantly improved at 6 months (42.2 ± 19.2 vs. 10.4 ± 9.7; P<0.0001). The authors concluded that BOD was safe and effective for children with CRS as young as 2 years and older.
In a meta-analysis, Xu et al. (2017) evaluated the postoperative clinical effects of balloon sinuplasty, or BOD, on CRS. Published trials were searched and prospective control studies were selected for CRS treated by BOD up through March 2017. Lund-Mackay and SNOT-20 scores were used as the primary outcomes of interest, and the methodological quality of the studies was assessed. The authors included seven prospective pre-post self-controlled studies, and the overall quality was determined to be relatively high. Meta-analysis showed that the Lund-Mackay scores at 6 months postoperation, the SNOT-20 scores at 6 months, and more than 1 year postoperation were significantly lower than baseline for BOD. SNOT-20 scores at more than 1 year postoperation were lower than baseline when a stand-alone BOD was performed. All the results were reported to be statistically significant (P<0.05). The authors concluded that the postoperative effect of BOD on CRS was demonstrated, and the self-reported symptoms in participants were effectively relieved.
The 2017 American Academy of Otolaryngology-Head and Neck Surgery's (AAO-HNS) position statement on “Dilation of sinuses, any method (e.g., balloon, etc.)” stated that sinus ostial dilation (e.g., BOD) is a therapeutic option for selected individuals with CRS in whom appropriate medical therapy has failed. Clinical diagnosis of CRS should be based on symptoms of sinusitis and supported by nasal endoscopy documenting sinonasal abnormality or mucosal thickening on CT of the paranasal sinuses. This approach may be used alone to dilate an obstructed sinus ostium (frontal, maxillary, or sphenoid) or in conjunction with other instruments.
Bikhazi et al. (2014) published results from a prospective, multicenter, randomized trial performed to evaluate and compare 1-year outcomes from the Randomized Evaluation of Maxillary Antrostomy Versus Ostial Dilation Efficacy Through Long-Term Follow-Up (REMODEL) study. The study compared office-based BOD and FESS, and expanded on the 6-month study findings previously reported by Cutler et al. (2013). Ninety-two adults with maxillary CRS, including those with anterior ethmoid disease, who failed medical management and were surgical candidates for FESS, underwent either stand-alone BOD or FESS (50 BOD; 42 FESS) in a 1:1 randomization scheme. They were followed up for a minimum of 1 year. Sinonasal symptom improvement was assessed using the SNOT-20 survey. Standardized effect sizes were computed to further assess clinical significance. Also compared between the two groups were ostial patency rate; rhinosinusitis episode frequency; impact of sinus disease on activity and work productivity (using the validated Work Productivity and Activity Impairment Survey); complications; and revision rate. Eighty-nine participants (96.7 percent) completed 1-year follow-up. Both groups showed improvement in mean overall SNOT-20 scores and in all four SNOT-20 subscales. The 1-year mean change in SNOT-20 after BOD (−1.64) was noninferior to FESS (−1.65; P<0.001). The standardized effect size was large, showing improvement for both interventions. Ostial patency was 96.7 percent and 98.7 percent after BOD and FESS, respectively, and each group reported reductions (P<0.0001) in rhinosinusitis episodes (mean decrease, 4.2 for BOD and 3.5 for FESS). Overall work productivity and daily activity impairment due to chronic sinusitis were improved (P<0.001) in both groups. There were no complications. Revision surgery rate was two percent in each arm through 1 year. Limitations of this trial include an unblinded design, lack of blinded outcome assessment across the range of outcome measures, and differential dropout between groups, such that 13 individuals withdrew consent prior to treatment, 11 in the FESS group (21 percent) and two in the BOD group (four percent). The study population also included more than 25 percent of individuals with seasonal allergies and 60 percent of individuals with septal deviation, such that the effect of including concomitant conditions in the study population is unknown. In addition, more information is needed to determine which individuals and which sinuses benefit from the BOD as an adjunct to traditional FESS, and which individuals should get standard approaches.
As a follow-up publication, Bizaki et al. (2015) reported on nasal airway resistance and sinus symptoms between FESS and BOD-treated groups. For this analysis, 62 individuals were included (32 from the FESS group and 30 from the BOD). Individuals in the BOD group had significant improvements in nasal volume from pre- to postoperative measurements, but there were no significant differences between groups pre- or postoperatively in nasal volume.
An additional publication by Bizaki et al. (2014) reported on an RCT that compared BOD with FESS with a focus on mucociliary clearance. It was conducted at the same institution as the previously enrolled 36 individuals who were randomly assigned to BOD or FESS; however, it is not specified that it was the same set of individuals. In addition, seven individuals dropped out and were not included in the analysis. SNOT-22 scores improved in both groups for pre- to postoperative analyses. However, change in total SNOT-22 scores did not differ significantly between groups. There were no significant change in mucociliary clearance before or after either treatment, and no significant between-group difference in mucociliary clearance.
In 2016, Chandra et al. reported the final results of up to 2 years postprocedure for subjects in the REMODEL study, along with an additional 30 subjects treated with either FESS or in-office BOD, for a total of 61 FESS participants and 74 BOD participants. Follow-up data were available for 130, 66, and 25 subjects at 12, 18, and 24 months, respectively. Details about group-specific treatment received and loss to follow-up are not reported for the additional 30 subjects not described by Cutler et al. (2013). The BOD group required 0.2 debridements per individual, compared with 1.0 per individual in the FESS group (P<0.0001). The mean change in SNOT-20 scores from baseline to 12-month follow-up was −1.59 (P<0.0001) and −1.60 (P<0.0001) for the BOD and FESS groups, respectively, which was considered clinically significant. These changes were maintained at 24 months. At 18 months, overall revision rates were 2.7 percent and 6.9 percent in the BOD and FESS groups, respectively. In addition to the longer term results of the REMODEL trial, this article includes a meta-analysis of stand-alone BOD studies including the REMODEL BOD-treated individuals and data from six manufacturer-sponsored trials, three of which had previously been reported in peer-reviewed form. The meta-analysis included 846 individuals who were treated with BOD, including 121 who were not described in prior publications. In a random-effects model, overall mean and subscale values for the SNOT-20 scores improved compared with baseline at every follow-up time point. This evidence supports superiority for balloon ostial dilation as an alternative to FESS in individuals with CRS. The limitations of this study are consistent with earlier REMODEL reports.
In a prospective multicenter study, Gould et al. (2014) reported the 1-year outcomes from 81 individuals treated with an office-based BOD under local anesthesia for multisinus disease. Intraoperative procedure technical success and subject procedure tolerance were recorded. Efficacy was assessed using the participant-reported SNOT-20 and Rhinosinusitis Symptom Inventory (RSI). Complications and revision surgeries were also recorded. Analysis of data showed that among the study participants, mean procedure tolerance was 2.8 ± 2.2 (0 = no pain; 10 = severe pain). The participants also showed symptom improvement in mean overall SNOT-20 scores (P<0.0001) observed at 1 and 6 months and sustained through 1 year. The RSI showed a treatment effect for all major rhinosinusitis symptoms, and improvement (P<0.0001) in each was noted. Compared with the previous 1-year period, individuals reported an average of 2.3 fewer acute sinus infections (P<0.0001), 2.4 fewer antibiotic courses taken (P<0.0001), and 3.0 fewer sinus-related physician visits (P<0.0001) after BOD. No serious device- or procedure-related adverse events occurred. One individual (1.3 percent) underwent revision surgery. The study authors concluded that office-based multisinus BOD is safe, effective, and well tolerated. Although evidence may show some support for office-based multisinus BOD, this study had several limitations. For example, it lacked a comparison group to compare BOD to standard care in order to determine efficacy. Additionally, although all individuals were required to have documented CRS or recurrent acute rhinosinusitis and failure of maximal medical therapy, the specific medical therapy was not controlled, and adherence to medical treatment is unknown such that individual compliance reports could be inaccurate. The study population also included 65.8 percent of individuals with asthma and 59.8 percent of individuals with septal deviation, such that the effect of including concomitant conditions in the study population is unknown. Furthermore, the results of pre-enrollment CT scans were not provided to give a quantitative measure of disease severity. Concomitant turbinate reduction procedure was allowed and performed in 57 percent of the study participants, so it is unclear how this concomitant procedure affected the study outcomes. It is also unclear if SNOT-20 was validated for the different types of rhinosinusitis and was subject to the reliability of recall of individually reported outcomes. Other limitations included small size, need for long-term follow-up time, and a lack of a control group, which prevented assessment of possible placebo effects.
A single-arm study reported by Tomazic et al. (2013) evaluated the feasibility of BOD in routine treatment of individuals with CRS refractory to medical therapy. Forty-five consecutive individuals were included in this study, in whom 112 sinuses were approached by BOD. Of the 112 sinuses, 68 (60 percent) were planned as a balloon-only procedure and 44 (40 percent) were planned as a hybrid procedure. Of the 68 sinuses in the balloon-only group, 44 sinuses failed, equating to a failure rate of 65 percent. Forty-four sinuses were planned for hybrid procedures. In 29 of these sinuses, BOD failed, giving a failure rate of 66 percent. The authors concluded that according to literature, BOD can be a useful adjunct technique to standard FESS. In their experience with this study, however, a failure rate of 65 percent for balloon-only and of 66 percent for hybrid procedures occurred, which was regarded as unacceptable. Therefore, the study, initially scheduled for a cohort of 200 individuals, was abandoned.
A retrospective comparative study was published in 2012 by Koskinen et al. that included 53 participants with refractory CRS without previous sinonasal operations. The study was composed of 29 participants in the FESS group and 24 participants in the BOD group. The intent of this study was to compare the symptom outcomes after maxillary sinus surgery with either the FESS or the BOD technique. No previous or additional sinonasal operations were accepted. The individuals who met with the inclusion criteria replied to a mailed questionnaire that contained questions on symptoms, exacerbations of CRS, medication use, work exposure, and the Lund-Mackay score. The Lund-Mackay score was assigned to each sinus based on the degree of mucosal inflammation or hypertrophy within the sinus. The mean symptom score was worse in the BOD group compared to the FESS group (4.37 vs. 3.22; P=0.04). Individuals in the BOD group reported a greater number of exacerbations compared to the FESS group. The majority of other outcome measures were similar between groups, and there were no measures on which the BOD group showed superior outcomes compared to the FESS group. The authors recommended that prospective RCTs with an increased number of participants are warranted.
Plaza et al. (2011) performed a randomized clinical trial comparing BOD/hybrid with FESS to FESS alone, for 32 individuals who had frontal sinus disease refractory to medical management. Primary outcome measurements at 12 months of follow-up included symptoms, the rhinosinusitis disability index, CT results of sinus patency, and the patency of the frontal recesses as assessed by endoscopy performed in an office setting. For both groups, there were improvements in symptoms and standardized rhinosinusitis scoring indices, but there were no differences between groups. There were also improvements in CT results of sinus patency in both groups but no differences between groups. There are several limitations to this study. It was inadequately powered and did not evaluate differences in outcomes between the two treatments, nor did it demonstrate that BOD is as safe and effective when compared to existing techniques.
An industry-sponsored prospective multicenter case series study, named the Clinical Evaluation to Confirm Safety and Efficacy of Sinuplasty in the Paranasal Sinuses (CLEAR), compared the individual's baseline status to outcomes up to 2 years after surgery. The CLEAR study included consecutive individuals with CRS unresponsive to medical management who had either BOD alone for disease in the maxillary, frontal, or sphenoid sinuses, or had hybrid FESS if the disease was also located in the ethmoid sinus. Three articles were published from the CLEAR study (Bolger 2007, Kuhn 2008, Weiss 2008). The longest follow-up was 24 months, and outcomes from as many as 43 percent of individuals were lost to follow-up. Methodological flaws include potential biases created by lack of controls, no blinding, participant selection, a mixed population of primary and revisional surgeries, the proportion of individuals lost to follow-up, and manufacturer sponsorship of the study, all of which may impact the results of the reported data, so that efficacy cannot be determined.
Levine et al. (2008) discussed a multicenter retrospective uncontrolled review of 1036 individuals who underwent FESS that included the use of balloon catheters. Although in such combined procedures, it is difficult to assess which procedure contributed to clinical success or failure, these case series uniformly report symptom improvement, which appears to be durable in the subset of individuals followed for up to 2 years. Revision rates ranged between three and nine percent, but the follow-up time varied across studies. Acute adverse event rates appeared low. The authors report that there were differences between the groups with regard to blood loss, operation time, debridements, and endoscopies, with outcomes favoring BOD. However, no statistical data were provided to support this finding. Although none of the studies specify a protocol or procedure for identifying and recording adverse events, it might be presumed that the known adverse events of FESS, such as cerebral spinal fluid leakage or excessive bleeding, would be reasonably reported. In addition, the authors of this study cautioned that they did not provide a comparative outcome analysis of this retrospective review.
RECURRENT ACUTE RHINOSINUSITIS (RARS)
Recurrent acute rhinosinusitis (RARS) is defined by AAO-HNSF guidelines as having four or more episodes of acute bacterial rhinosinusitis per year, which are described as symptoms and signs of acute rhinosinusitis that fail to improve after 10 days or initially improve but then worsen within 10 days. Between episodes, there are no signs or symptoms of rhinosinusitis.
PEER-REVIEWED LITERATURE
Two RCTs of BOD reported results separately for individuals with RARS. A third RCT, reported by Bizaki et al. (2014), compared BOD with FESS among individuals with CRS or RARS, but results were not reported separately by diagnosis. The study authors stated, "For this study, both CRS and RARS were considered to be 1 disease."
In the REMODEL trial, 32% (N=29) of the individuals enrolled had a diagnosis of RARS. The CABERNET (Comparison of Balloon Sinuplasty In-Office Versus Medical Management for Recurrent Acute Sinusitis Patients) trial compared BOD plus medical therapy to medical therapy alone in 59 individuals with RARS. Both trials used the AAO-HNS diagnosis of RARS to select eligible participants: four or more episodes of acute rhinosinusitis in the past 12 months. In CABERNET, evidence of sinus or osteomeatal complex disease during an acute episode from a CT scan was also required for enrollment. In REMODEL, all individuals met criteria for medically necessary FESS, but explicit CT requirements for patients with RARS were not specified.
Among the 29 individuals diagnosed with RARS in the REMODEL trial, there was a significant improvement in QOL for those who received either BOD or FESS, and the difference between treatment arms was not significant (P=0.838). Twelve-month results from REMODEL were reported by Bikhazi et al. (2014). Data were not reported separately by diagnosis, but the publication states, "At 1 year, symptom improvement in each of the 4 subgroups [including based on diagnosis] remained statistically significant (P<0.001) in both treatment arms and there was no difference (P=NS) in improvement between patients who underwent balloon dilation or FESS." REMODEL results were not reported separately by diagnosis for secondary outcomes, or for the primary outcome (SNOT-20) at 24 months.
In Sikand et al. (2019), the primary outcome was the difference between arms in change in Chronic Sinusitis Survey (CSS) score from baseline to 24 weeks. The change in CSS was significantly greater in the BOD group compared to the control group (mean change 37.3 vs 21.8; P=0.0424). The study authors did not specify whether this was considered clinically significant. Patients in the BOD group had a lower mean number of sinus infections through the 24-week follow-up period (0.2 vs. 0.9; P=0.0015). Durability of the outcome measure differences was demonstrated up to 48 weeks. After the 24-week follow-up period, 18 of 30 patients who were randomly assigned to the control arm elected to receive BOD. Of those who crossed over at 24 weeks, 0 reported no change or worsening of symptoms, three reported improved symptoms but still used nasal sprays at high rates, four had improved symptoms to varying degrees but were not eliminated, and one reported a sinus infection just before their 24-week visit. There was one procedure-related serious adverse event in the BOD group (the patient sought treatment for a headache in the emergency department the evening after the procedure), two possibly procedure-related nonserious adverse events, and no device-related adverse events.
SUMMARY
BCD of sinus ostia, or BOD, has been studied as a minimally invasive alternative to FESS, or as an adjunct to endoscopic sinus surgery. The current literature has proven BOD to be safe and effective in the treatment of CRS. The variations observed in the literature for success rates, adverse event rates, and revision rates may be due to influences of disease severity. A complicating factor in the evaluation of this technology is depending on the individual and the judgment of the treating professional provider, FESS and BOD may be combined during one operation as a hybrid procedure. This creates challenges in deciphering what specific role each treatment is responsible for in the treatment outcomes. An opportunity exists for additional information on the durability of the procedure and which subset of individuals may require subsequent revision. Overall, the available scientific literature and professional societal guidelines endorse BOD. Balloon sinus ostia dilation, or BOD, can be considered as a course of treatment for individuals with persistent CRS or RARS.
