Influence of Posterior Fossa Volume on Clinical Outcomes After Vestibular Schwannoma Resection

Objectives: To determine the influence of posterior fossa dimensions on surgical outcomes after vestibular schwannoma management. Study Design: Retrospective chart review. Setting: Tertiary care academic medical center. Patients: Patients with sporadic vestibular schwannomas who underwent surgical resection via retrosigmoid or translabyrinthine techniques. Interventions: Diagnostic. Main Outcome Measures: One and two-way analysis of variance (ANOVAs) of the cohort based on volumetric and clinical outcome groupings. Results: A total of 95 patients were identified. A one-way ANOVA looking at the entire cohort of patients showed that outcomes like surgical time (p < 0.001) and whether a Good Outcome (House-Brackmann score of 1 or 2, no complications, and a complete resection) was achieved (p = 0.009) correlated very well with preoperative tumor volume, but not with posterior fossa volume (p = 0.412 and p = 0.345, respectively). However, in medium sized tumors, House-Brackmann group was correlated with posterior fossa volume (p = 0.032). Conclusions: The present data suggest a small effect of posterior fossa size on some clinical outcomes in medium sized vestibular schwannomas.