Endolymphatic Sac Surgery in Refractory Ménière’s Disease: Exploratory Associations and Postoperative Clinical Outcomes in a Bicentric Cohort

<b>Background/Objectives</b>: Endolymphatic sac surgery (ELSS) is a non-destructive surgical option for medically refractory Ménière's disease (MD), yet factors influencing surgical outcomes remain poorly understood. This exploratory study aimed to describe clinical outcomes following ELSS and identify potential associations between preoperative characteristics and surgical success. <b>Methods</b>: This retrospective, bicentric cohort study included 45 patients with definite MD who underwent ELSS (predominantly endolymphatic duct blockage) between 2019 and 2024. Vertigo control was assessed using AAO-HNS criteria. Hearing outcomes were evaluated through pure-tone and speech audiometry. Univariate analyses explored associations between demographic, clinical, imaging, and surgical variables and treatment outcomes. <b>Results</b>: Surgical success (Class A/B vertigo control) was achieved in 66.7% of patients (95% CI: 51.0-80.0%). In a post hoc exploratory analysis, longer disease duration (>5 years) showed an association with better outcomes (87.5% vs. 55.2%, <i>p</i> = 0.029), though this threshold was not prespecified and requires validation. Hearing was preserved in 77.5% of patients at 45-day follow-up but declined progressively to 50% at 2 years. Seven patients developed postoperative Tumarkin attacks, with five requiring non-conservative interventions. ELSS demonstrated low morbidity, with one labyrinthitis as the only significant complication. <b>Conclusions</b>: ELSS was associated with vertigo control in two-thirds of patients with refractory MD, with a favorable safety profile. Longer disease duration before surgery may be associated with improved outcomes, though this exploratory finding requires confirmation in prospective studies. The progressive hearing decline may reflect both natural disease progression and potential surgical effects. Further research with larger cohorts is needed to establish robust predictive criteria for patient selection.