Abstract
Keywords
Background
Chronic obstructive eustachian tube dysfunction (ETD) results from the improper equalization of pressure between the middle ear and the outside environment. 1 Patients can experience a wide array of symptoms, including aural fullness, otalgia, tinnitus, and hearing loss. ETD accounts for a substantial number of healthcare visits annually. 1 While symptoms of ETD can be self-limiting, cases of chronic ETD (3 months or greater) can be difficult to manage. 1
Myringotomy with tympanostomy tube placement was the mainstay of treatment for medically refractory cases of ETD. 2 More recently, balloon dilation of the eustachian tube (BDET) has emerged as a treatment option.3,4 During BDET, a catheter with a balloon is briefly inserted and inflated in the cartilaginous portion of the eustachian tube. 2 The 2019 American Academy of Otolaryngology—Head and Neck Surgery (AAO) Clinical Consensus Statement outlines the indications for BDET, which include chronic ETD with elevated scores on validated symptom assessment tools, persistent middle ear effusion, non-adherent atelectasis, abnormal tympanometry, and/or inflammation at the eustachian tube orifice. 1
The recent literature has shown an increase in the publication of higher-quality studies reporting on outcomes of BDET for the treatment of chronic ETD. Moreover, many studies are using validated assessment tools, such as the Seven-item Eustachian Tube Dysfunction Questionnaire (ETDQ-7). Previous systematic reviews on this topic focused on heterogeneous, mixed-quality studies, which included retrospective case series, studies that did not report post-treatment ETDQ-7 scores for meta-analysis, and did not cover the emerging data on BDET performed in office-based settings.2,5
Our study reports on recent advances in the applications of BDET for chronic ETD in higher-quality studies [randomized controlled trials (RCTs) or prospective], utilizing validated assessment tools and cumulates data on the role of performing BDET under local anesthesia (LA).
Materials and Methods
Protocol and Research Question
This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A focused research question was formulated using the patient/population, intervention, comparison, and outcomes (PICO) criteria:
Study Identification
A computerized search of EMBASE, PUBMED, and Cochrane Library databases from inception to November 20, 2024, was performed at Dalhousie University in Halifax, Nova Scotia, Canada (Figure 1). The search strategy included synonyms for

Literature search flow diagram based on the PRISMA. PRISMA, Preferred Reporting Items for Systematic Review and Meta-Analyses.
Randomized Controlled Trials of BDET for Chronic ETD.
Abbreviations: BDET, balloon dilation of the eustachian tube; ETD, eustachian tube dysfunction; ETDQ-7, Eustachian Tube Dysfunction Questionnaire; MM, medical management.
Prospective Cohort Studies of BDET Under General Anesthesia.
Abbreviations: BDET, balloon dilation of the eustachian tube; ETDQ-7, Eustachian Tube Dysfunction Questionnaire; ET, eustachian tube; ETS, eustachian tube score; pETOD, eustachian tube opening duration; pETOF, eustachian tube opening frequency; pETOP, eustachian tube opening pressure; PTA, pure tone audiometry; MM, medical management.
Studies of BDET Under LA.
Abbreviations: BDET, balloon dilation of the eustachian tube; ETDQ-7, Eustachian Tube Dysfunction Questionnaire; ETMIS, Eustachian Tube Mucosal Inflammation Scale; GA, general anesthesia; LA, local anesthesia.
Data Extraction
A standardized extraction form was generated for all articles. The form included the following items for data extraction: authors, country, participant number, sex distribution, age, study design, BDET technique, anesthesia, time to outcome assessment, outcome results, and statistics. Subjective and objective outcomes were collected. Quantitative data were recorded as mean or median values with standard deviation or quartile ranges when available. Significance was recorded as
Quality Assessment
Studies that were not RCTs were assessed using the Methodological Index for Non-Randomized Studies (MINORS). 6 This is a validated assessment tool designed specifically for non-RCT studies using 12 items, each of which is scored as 0 (not reported), 1 (reported but inadequate), or 2 (reported and adequate). The tool allows separate evaluation of comparative and noncomparative methods by assigning the first 8 items to noncomparative studies only (a total of 16 points) and an additional 4 items for comparative studies (a total of 24 points). Quality of RCTs was assessed using the Cochrane modified Risk of Bias Tool (RoB 2.0). The overall quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.
Synthesis of Results
A descriptive and meta-analysis approach was undertaken to report the results of this systematic review. Qualitative and quantitative data were tabulated. Univariate comparisons were conducted using a χ2 test for categorical variables and Student’s
Results
Study Selection
The initial literature search identified a total of 365 articles following the removal of duplicates (Figure 1). Abstract screening led to the inclusion of 46 articles for full-text review. Twenty-nine articles were excluded during the full-text review for the following reasons: wrong study design or patient population (21) or non-English articles with no translations (4). Therefore, a total of 23 articles met the inclusion criteria for final synthesis.3 -27 Wrong study designs included retrospective case series, cadaveric or animal studies, or technique papers without clinical subjects. Studies investigating a patient population that included pediatric subjects were also omitted.
Study Characteristics
A total of 23 studies, encompassing 1443 patients (including non-surgical control groups) evaluated BDET for chronic ETD. These investigations were conducted across diverse international institutions, including the United States (n = 8), Canada (n = 1), Nordic (n = 1), Germany (n = 1), Republic of Korea (n = 2), United Kingdom (n = 2), Switzerland (n = 1), China (n = 1), Denmark (n = 1), Portugal (n = 1), Finland (n = 2), France (n = 1), and the Czech Republic (n = 1). Seven studies (N = 207) assessed BDET under LA (Table 3), while the remainder utilized GA (Tables 1 and 2).
Across studies, outcomes were primarily assessed using the ETDQ-7, tympanometry, and eustachian tube opening parameters such as pressure, duration, and frequency. Additional measures included hearing levels, pure tone audiometry, patient satisfaction, revision and complication rates, and, in studies under LA, pain levels. Although the diagnostic inclusion criteria varied—ranging from ETDQ-7, tympanometry, otoscopy, and/or otologic symptoms—there was consistency in defining chronic ETD as persisting for more than 3 months and refractory to medical management. Due to outcome heterogeneity, tympanometry results were not pooled in the analysis.
Quality Assessment
The quality assessment of RCTs using RoB 2.0 demonstrated that the majority of RCTs had “low risk” or “some concerns” for risk of bias. Most non-RCT studies were assessed as good quality using the MINORS criteria with an average score of 14/24. However, areas where bias was high were the patients lost to follow-up, prospective calculation of study size, and blinding of assessors.
ETDQ-7 results
The ETDQ-7 score was the most reported outcome measure across included studies (Tables 4–6). For our study, we looked at normalization of ETDQ-7 scores, which we defined as achieving a mean score <2.1 on the ETDQ-7 post-treatment. Follow-up durations varied widely, ranging from as early as 3 weeks to several years post-treatment. While all studies demonstrated improvement in mean ETDQ-7 scores following BDET, not all provided specific post-treatment values, which limited the ability to perform pooled analyses across the entire dataset.
ETDQ-7 Outcomes From Randomized Controlled Trials of BDET for Chronic ETD.
Abbreviations: BDET, balloon dilation of the eustachian tube; ETD, eustachian tube dysfunction; ETDQ-7, Eustachian Tube Dysfunction Questionnaire.
Studies with overlapping datasets due to reporting of initial short-term results followed by long-term results.
ETDQ-7 Outcomes From Prospective Studies of BDET for Chronic ETD.
Abbreviations: BDET, balloon dilation of the eustachian tube; ETD, eustachian tube dysfunction; ETDQ-7, Eustachian Tube Dysfunction Questionnaire; IQR, interquartile range.
Studies with overlapping datasets due to reporting of initial short-term results followed by long-term results.
ETDQ-7 Outcomes of BDET Under LA for Chronic ETD.
Abbreviations: BDET, balloon dilation of the eustachian tube; ETD, eustachian tube dysfunction; ETDQ-7, Eustachian Tube Dysfunction Questionnaire; GA, general anesthesia; LA, local anesthesia.
RCTs (Table 4) consistently reported significant improvement in ETDQ-7 scores, with some studies noting normalization rates and strong statistical significance at 6 weeks post-treatment. Prospective studies (Table 5) similarly showed improvements, with reported normalization rates ranging from 28% to 39% at different follow-up points. Retrospective data (Table 6) also confirmed substantial normalization rates, with differences observed between LA and GA groups.
A total of 6 RCTs and prospective studies that met the inclusion criteria for meta-analysis provided mean ETDQ-7 scores 6 to 12 months post BDET (309 patients). Pooled analysis using a random-effects model demonstrated a significant mean difference of 2.03 (95% CI 1.47-2.59;

Forrest plot showing ETDQ-7 scores 6 to 12 months post BDET (309 patients) for studies (general anesthesia) providing mean ETDQ-7 scores pre- and post-treatment. BDET, balloon dilation of the eustachian tube; ETDQ-7, Eustachian Tube Dysfunction Questionnaire-7.
Valsalva Maneuver
The ability to perform the Valsalva maneuver was reported less commonly, and a summary is presented in Table 7. Overall, most studies reported improvements in the ability to perform the Valsalva maneuver post-BDET (Table 7). One study investigating LA versus GA for BDET and 1 study investigating LA for BDET reported improvements in Valsalva for both cohorts (Table 7). 15
Valsalva Maneuver Outcomes from Prospective Studies of BDET for Chronic ETD.
Balloon dilation—GA versus LA
BDET was performed under LA protocols in several studies.10,15,17 -19 A meta-analysis was not feasible for this subgroup as the data were heterogeneous. The different protocols are summarized in Table 8. The procedures were performed in the office or under Monitored Anesthesia Care (MAC) for safety or research purposes. In some cases, diazepam was given prior to any LA to prevent vestibular events. 19 Local nasal decongestant was used by all groups. Local decongestant was frequently applied with a LA intranasally, such as lidocaine, lidocaine/tetracaine, or cocaine.10,15,17 -19 In some cases, LA drops of lidocaine/tetracaine were applied to an intact tympanic membrane.15,19 LA was also applied to the eustachian tube orifice using a catheter device. 10 Most commonly, a lidocaine-prilocaine cream or lidocaine-tetracaine cream was used for this purpose. Most patients (>90%) were able to complete the procedure under LA with no significant adverse events. Rare events of abortion from the procedure occurred due to discomfort, pain, or coughing associated with ET dilation.10,15,17 -19
Anesthesia and Procedural Setting From Prospective Studies of BDET for Chronic ETD.
Abbreviation: MAC, Monitored Anesthesia Care.
There were no significant differences in major outcomes for BDET performed under GA versus LA (Table 9). Normalization of tympanometry and ETDQ-7 scores was present in both groups. Most patients would undergo LA again if given the choice. 10 The indications for BDET varied, with a minority of patients being treated for barro-challenge ETD. For patients undergoing procedures under MAC, the operative times were significantly lower in the LA group. 10
Clinical Outcomes From Prospective Studies of BDET for Chronic ETD.
Abbreviations: ETDQ-7, Eustachian Tube Dilation Questionnaire; GA, general anesthesia; LA, local anesthesia.
Discussion
BDET demonstrates an improvement in short- and long-term outcome measures of chronic ETD and can be safely employed under LA in select patients using an established protocol.9,15,17 -19,23 Our systematic review builds on the emerging role of BDET in the treatment of chronic ETD, particularly with robust prospective and RCT data for assessing overall efficacy, and provides a summary of strategies for expanding the role of BDET in the office setting.
The 2019 AAO clinical consensus statement on BDET emphasizes the role of the ETDQ-7 in the evaluation of chronic ETD in clinical settings. 1 Therefore, our systematic review and meta-analysis focused on this outcome measure in prospective studies. Our results corroborate previous research on this topic, while adding a meta-analysis of 6 prospective studies or RCTs demonstrating a mean decrease in score by 2.03. The scores in most studies reached a near normal value of <2.1 (Tables 4–6). The data presented in this study also outline the sustained improvement in ETDQ-7 at and beyond the 12-month mark, as demonstrated in Tables 4 and 5, and Figure 2. The improvement in ETDQ-7 scores across the most consistent RCTs in our meta-analysis suggests the clinical benefit of BDET as a procedure for chronic ETD. This also emphasizes the need for careful patient selection criteria and standardization of chronic ETD diagnosis. For instance, some studies that were excluded included many patients who had a confounding otologic history, such as the presence of active middle ear effusion. While the normalization of ETDQ-7 scores is reported, there is also a high heterogeneity in the data. There may be several reasons for this, including the subjectivity of the ETDQ-7 score, variance in ETDQ-7 symptoms among patients, length of follow-up, and confounding otologic symptoms (eg, chronic tinnitus, ie, unrelated to ETD but is mentioned on the questionnaire).
While tympanometry remains an essential component of diagnosing chronic ETD, the post-operative improvement can be difficult to quantify in a meaningful meta-analysis. A controversial point in the 2019 AAO clinical consensus statement on BDET is the lack of consensus regarding tympanometry as an outcome measure, while the role of ETDQ-7 did reach consensus. 1 Although Froehlich et al have previously presented the proportional improvement or normalization in tympanometry following BDET, this remains an understudied outcome measure following BDET in more recent prospective studies. 2 The role of the Valsalva maneuver is also critical for assessing BDET outcomes; however, this is not well represented in the current literature despite reaching consensus agreement in the most recent guidelines. 1
Recent publications have demonstrated the efficacy and safety of BDET performed using LA protocols.9,15,17-19,23 While these studies were limited and of a lower quality, they provide insights into the expansion of BDET in an office-based setting.10,15,17-19,23,26,27 Our study pools data from several articles emphasizing the lack of significant adverse events. Most adverse events were asymptomatic hemodynamic changes or pain that did not lead to significant abortions of LA procedures.10,15,17 -19,23,26,27 In addition, there was a high patient-reported willingness to choose LA (Table 8).10,15,17 -19,23,26,27 The protocols for LA shared similarities. All surgeons used a combination of a decongestant such as oxymetazoline with a LA (lidocaine, tetracaine, or cocaine) intranasally, followed by an anesthetic cream (lidocaine with tetracaine or prilocaine) placed in the eustachian tube orifice under endoscopic guidance.10,15,17 -19,23,26,27 The otologic outcomes (ETDQ-7 and tympanometry normalization) were also similar in studies comparing GA versus LA. There is potential for patient selection bias that might skew results in the LA cohort, given that surgeons are choosing which patients would be able to tolerate in-office-based procedures. While patient inclusion criteria are important consideration when providing in-office based BDET, there needs to be more evidence on what criteria can be used to determine which patients are eligible for in-office BDET. These criteria can include the anatomical factors, such as the feasibility of performing trans-nasal endoscopy, but also medical (comorbidities) and psychosocial (phobias). More research is required in this area to help standardize criteria for patient selection.
Assessment of study quality has identified several limitations in the current literature evaluating BDET, resulting in an overall low to moderate certainty in evidence using the GRADE approach. There remains a lack of control groups when evaluating BDET in chronic ETD. The indications for BDET are also variable among studies, with a minority including barro-challenge ETD. 21 A minority of groups also performed BDET alongside other endoscopic procedures, which can confound results. 21 The definition of chronic ETD is not consistent among studies, and there is varying concordance with the AAO guidelines, both in terms of evaluation of ETD and implementation of BDET. The ETDQ-7 score itself is a subjective measure that can harbor confounding otologic symptoms, and variance in interpretation of the questions can skew the quality of the data. Future studies should also aim toward a multi-variable comparison of LA versus GA outcomes using a randomized approach.
Conclusion
BDET demonstrates an improvement in outcome measures of chronic ETD and is being utilized in the office-based setting in a safe manner. However, LA protocols require further optimization to maximize patient comfort. Higher-quality studies that directly compare LA and GA outcomes are required to strengthen the evidence base regarding BDET in office-based settings.
Footnotes
Author Contributions
U.K. participated in data collection, data analysis, statistical analysis, and writing of the manuscript. J.N. was involved with data collection, data analysis, and writing of the manuscript. C.M. was involved in data analysis and writing of the manuscript. N.S. participated in study conceptualization, study design, manuscript writing, and editing.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Ethical Considerations
Not applicable.
Consent to Participate
Not applicable.
Data Availability Statement
Datasets are available upon reasonable request.
