Comparative Outcomes of Exoscopic Versus Microscopic Retrosigmoid Vestibular Schwannoma Surgery.

OBJECTIVE: To compare clinical outcomes of vestibular schwannoma (VS) resection with the operating microscope versus an exoscope. STUDY DESIGN: Retrospective single-center cohort study. SETTING: Tertiary referral skull base center. PATIENTS: A total of 245 adults underwent retrosigmoid VS resection: 103 microscope (2017-2020) and 142 exoscope (2021-2024); exclusions: NF2, revision surgery, and translabyrinthine approaches. INTERVENTIONS: Microscope-assisted or exoscope-assisted retrosigmoid VS resection using identical surgical technique and intraoperative neuromonitoring. MAIN OUTCOME MEASURES: Operative time; tumor volume; extent of resection; facial nerve continuity and function (House-Brackmann grade at discharge and ≥1-year follow-up); cochlear nerve continuity and hearing preservation; CSF leak and revision surgery rates. RESULTS: Operative duration was comparable between groups (median: 6.5 vs. 7.0 h; P=0.37). On multivariate analysis, Koos grade was the only significant predictor of duration. Cochlear nerve preservation (38.3% vs. 36.3%), HB I-II at discharge (63.4% vs. 64.1%), facial nerve intraoperative interruption (4.2% vs. 8.7%), nerve reconstruction (4.9% vs. 8.7%), CSF leak, and revision surgery rates were also similar (all P>0.05). At follow-up, the exoscope group showed lower House-Brackmann scores (adjusted OR: 2.54, 95% CI: 1.31-4.94; P=0.006). CONCLUSIONS: Exoscope-assisted retrosigmoid VS resection achieves comparable clinical outcomes to the operating microscope without prolonging operative times. Exoscope adoption, therefore, provides ergonomic and educational advantages without compromising patient outcomes.