Microsurgical Management of Vestibular Schwannoma (Acoustic Neuroma): Facial Nerve Outcomes, Radiographic Analysis, Complications, and Long-Term Follow-Up in a Series of 420 Surgeries

Abstract

The purpose of this study is to retrospectively evaluate the clinical and surgical outcomes of a large surgical series of vestibular schwannoma from North America over 20years. After institutional review board approval a retrospective review of the senior author's personal case logs to identify patients who had operations for vestibular schwannoma was performed. The clinical notes, operative record, preoperative and postoperative imagings, and long-term clinical follow-up notes were evaluated. A total of 415 patients who underwent 420 surgeries were identified from the years 1998-2021. The average length of follow-up was 3years and 9months. Overall, at last follow-up the rate of "good" facial nerve outcomes (House-Brackmann [HB] score I and II) was 86% and "poor" facial nerve outcomes (HB III-VI) was 14%. The amount of cerebellopontine angle extension (P= 0.023), tumor volume (P= 0.015), facial nerve consistency (P < 0.001), preoperative HB score (P < 0.001), and FN stimulation threshold at the end of the procedure (P < 0.001) were correlated to facial nerve function at the last follow-up. This study represents one of the largest recently reported surgical series of vestibular schwannoma in North American literature with available long term follow-up. Facial nerve outcomes correlated with cerebellopontine angle extension, tumor volume, facial nerve stimulation threshold, facial nerve consistency, preoperative facial nerve function, and history of a prior resection. Tumor recurrence remains significantly higher after subtotal resection. We believe the data supports a continuation of a strategy of general intent of gross total resection, greatly modifiable by intraoperative findings and judgment.