Tumor Resection Volumes and Facial Nerve Outcomes for Vestibular Schwannomas

Objective: To correlate tumor volume relationship with accepted nomenclature alongside surgical outcomes in subtotal resections. Study Design: Retrospective study. Setting: Charing Cross Hospital, London, a tertiary referral center. Participants: Total 16 patients with vestibular schwannoma managed with subtotal resection between 2002 and 2011. Main Outcome Measures: Surgical technique; tumor volume; recurrence; postoperative facial nerve function. Results: Mean preoperative and postoperative volumes for all patients were 14.7 and 3.7 cm respectively. Tumor volumes do not correlate with diameter (p?0.05). Mean reduction in volume of these subtotal resections was 75%. Long-term facial nerve outcome was good in the majority of patients: House-Brackmann grade I/II in 12 (75%), grade III/IV in 2 (12.5%), and Grade V/VI in 2 patients (12.5%). Notably, two patients with grade I/II House-Brackmann grading later developed grade V/VI palsy following adjunctive radiotherapy. Seven of the 16 subtotal resections had subsequent radiotherapy or microsurgery. Mean follow-up was 26.5 months. Conclusion: Subtotal resections lead to good facial nerve outcomes but may require further treatments. Radiation treatment can worsen facial nerve function. There is no standardized use of tumor volumes or accepted guidelines for resection terminology. We propose the use of tumor volumes to define this further.