Outcomes of Near-Total and Subtotal Resection of Sporadic Vestibular Schwannoma: A Systematic Review and Meta-Analysis

Objective. To evaluate tumor control and facial nerve outcomes after gross-total (GTR), near-total (NTR), and subtotal resection (STR) of sporadic vestibular schwannomas (VS). Data Sources. PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched in August 2021 through inception following PRISMA guidelines. Review Methods. English language articles reporting tumor control and facial nerve outcomes of adults (>= 18 years) with NTR and STR of VS were evaluated. Study characteristics, demographics data, tumor characteristics, type of surgical intervention, and outcome measures on tumor control and facial nerve function were collected. Pooled relative risk (RR) estimates for tumor recurrence and facial nerve outcomes were calculated and stratified by extent of resection. Results. From an initial search of 2504 articles, 48 studies were included in the analysis. When comparing 1108 patients who underwent NTR to 3349 patients with GTR, the pooled RR of recurrence in the NTR cohort was 2.94 (95% confidence interval [CI] 1.65-5.24, P = .0002). When comparing 1016 patients who underwent STR to 6171 patients with GTR, the pooled RR of recurrence in the STR cohort was 11.50 (95% CI 6.64-19.92, P < .0001). Estimates for risk of tumor regrowth for less-than-complete resection are presented. There was no elevated risk of adverse facial nerve outcome (defined as House-Brackmann grade III and above) in each category of extent of resection compared to GTR. Conclusion. Extent of resection predicts risk of tumor recurrence/regrowth following microsurgical resection. Favorable facial nerve outcome should be weighed against the increased risk of regrowth and the potential need for further treatment.