Endolymphatic duct blockage for Ménière’s disease: insights from a double-blind randomised controlled trial

Ménière’s disease (MD) is a chronic, relapsing disorder in which fluctuating vertigo, hearing loss and tinnitus often persist despite best-practice medical therapy.^1,2 For decades, endolymphatic surgery has occupied an uneasy space between destructive procedures that reliably control vertigo at the cost of potential cochleovestibular injury and non-destructive options whose benefits have largely been inferred from uncontrolled series and longstanding surgical habits rather than robust trial data.3, 4, 5 Within this context, the evidence base for endolymphatic duct blockage (EDB) has been shaped by small randomised trials and observational studies suggesting favourable vertigo control, yet without adequately accounting for the pronounced placebo responsiveness and natural fluctuation that characterise MD outcomes.3, 4, 5 The double-blind, randomised trial by Schenck and colleagues in this issue of The Lancet Regional Health – Europe directly addresses this gap by providing higher-quality, prospectively captured data comparing EDB with endolymphatic sac decompression (ESD) in patients with medically refractory disease.⁶

In this issue of the Lancet Regional Health – Europe, Schenck et al. report a double-blind, multicentre randomised controlled trial comparing EDB with EDS in patients with refractory Ménière’s disease, and find no clear short-term advantage of EDB over ESD in vertigo, quality of life, inner-ear function, or need for further treatment.⁶ Notably, patients who entered the trial with stronger expectations that surgery would improve their condition were more likely to experience benefit in the primary outcome, underscoring the influence of patient expectancy. This observation is consistent with prior evidence that self-reported outcomes in MD, particularly vertigo improvement, are highly susceptible to placebo effects.⁴ By combining blinding, multicentre recruitment, and prospective symptom capture via a smartphone-based application, the investigators provide rare high-quality evidence in a space long dominated by unblinded series and longstanding surgical practice patterns.⁶ Their findings challenge the assumption that EDB is a clearly superior non-destructive option and instead suggest that expectancy and the natural fluctuation of MD must be carefully considered when interpreting surgical outcomes.3, 4, 5, 6

Surgical intervention for MD is generally reserved for patients with medically refractory disease following failure of comprehensive conservative therapies.¹ Surgical approaches are broadly categorised as either destructive or non-destructive. Destructive interventions, such as labyrinthectomy and vestibular nerve section, provide highly effective vertigo control but are associated with substantial morbidity and limited eligibility, particularly in patients with serviceable hearing.^1,2 Non-destructive options include triple semicircular canal occlusion and ESD, which carry a lower risk of audiovestibular loss.¹ Nevertheless, the role of ESD remains controversial, as reflected in the cautious recommendations of the AAO–HNS clinical practice guideline for MD.¹ Within this context, ESD and related endolymphatic procedures continue to be examined and compared, with the aim of optimizing symptom control while minimizing procedural morbidity.

Recently, Jiang et al. reported a comparative study of long-term vestibular and audiometric outcomes after EDB, endolymphatic sac drainage (EDD), or endolymphatic sac decompression (ESD) in 51 patients with MD (24 EDB, 15 EDD, 12 ESD).³ Over the 4-year follow-up period, patients undergoing EDB had significantly lower vertigo attack ratios than those receiving ESD, and between 25 and 48 months vertigo recurred in 25% of the EDB group compared with 75% of the ESD group.³ Audiometric data showed hearing improvement in 6 of 24 EDB patients, whereas no hearing improvement was detected in the EDD or ESD cohorts, and mean hearing thresholds did not differ significantly among surgical groups.³ These findings suggest a potential long-term advantage of EDB over ESD in vertigo control, which contrasts with the short-term equivalence observed in the current double-blind randomised controlled trial. As compellingly described by the authors of the current study, placebo effects may partially account for the striking 96.5% complete vertigo control reported in the earlier randomised trial by Saliba et al. in the EDB group.⁵ Across these studies, hearing has generally been preserved, with no consistent pre- to post-operative deterioration in audiovestibular function.^3,5

An important point of consideration is the duration of follow-up. Although the current study did not detect a difference in vertigo attack frequency between EDB and ESD at 12 months, both the Jiang et al. and the Saliba et al. studies reported superior vertigo control with EDB over longer follow-up intervals.^3,5,6 The present randomised controlled trial followed patients for one year, whereas Saliba et al. reported outcomes at 24 months and Jiang et al. extended follow-up to 48 months.^3,5,6 Taken together, these data raise the possibility that any advantage of EDB over ESD may emerge over the longer term, while short-term outcomes remain similar.^3,5,6 However, definitive conclusions will require longer-term follow-up within a blinded randomised controlled trial framework to mitigate bias and better characterise durability of effect.⁶ As with many surgical trials in MD, the current study is also limited by sample size, follow-up duration, and reliance on patient-reported outcomes, all of which should be considered when extrapolating findings to broader clinical practice.

EDB remains a relatively novel technique, and current data consists of early results from a limited number of studies.^3,5,6 In a recent Cochrane review, Webster et al. underscored the importance of placebo controls in surgical trials for MD.⁷ The authors noted that the subjective nature of many outcome measures, limited understanding of the underlying mechanism of action, potential for serious harm from some surgical interventions, and the unpredictable disease course of MD together make placebo-controlled designs particularly warranted.⁷ The present trial, by incorporating blinding and rigorous methodology, represents higher-quality evidence with reduced risk of bias; nonetheless, future studies that integrate appropriate placebo or sham controls would further strengthen the evidence base and refine surgical treatment options for patients with MD. Sham surgery offers the most methodologically robust approach, but raises serious ethical concerns that limit feasibility.^6,7 Alternative strategies could include contemporaneous control arms with randomized waiting periods or minimally invasive sham procedures, such as myringotomy alone, to partially account for placebo effects while maintaining ethical acceptability.⁷

For clinicians, these data support viewing ESD as a reasonable non-destructive surgical option for carefully selected patients with refractory MD, while suggesting that short-term superiority claims for EDB should be interpreted with caution. For researchers, the trial sets a useful benchmark: blinded, multicentre designs with prospective digital symptom capture and explicit attention to expectancy should become the standard for future MD surgical trials. Only longer-term, rigorously controlled studies, ideally incorporating ethically acceptable placebo elements, will determine whether EDB offers durable advantages beyond ESD and help move endolymphatic surgery for MD from eminence-based practice toward evidence-based care.

Contributors

Omar Azmeh and Renate Ma contributed equally as co-first authors and prepared the initial draft of the commentary. Shaun A. Nguyen provided critical revisions for intellectual content and supervised the project. All authors reviewed and approved the final manuscript.

Declaration of interests

Omar Azmeh, BA, MS, Renate Ma, BS and Shaun A. Nguyen, MD, MA declare no competing interests.