Near Total Extirpation of Vestibular Schwannoma With Salvage Radiosurgery

Objectives/Hypothesis: The management of a sporadic vestibular schwannoma (VS) has changed with the introduction of stereotactic radiosurgery (SRS). Because functional outcome is important, particularly regarding the facial nerve, a policy of near-total surgical resection of a large-size VS has emerged, minimizing damage to the facial nerve. The debate remains whether the surgical remnant should be treated immediately or after established growth. Study Design: Retrospective case series. Methods: A consecutive cohort of 55 patients underwent a retrosigmoid craniotomy and near-total removal of a large-size VS at our university medical center between 2005 and 2011 and had a follow-up of a least 3 years. Documented growth of the VS remnant after surgery necessitating adjuvant SRS was the primary outcome measure using analysis of variance. Results: In 45 patients (81.8%), a small tumor remnant was left during surgery. The mean preoperative tumor volume was 12.2 cm(3) (range, 1.13-50.16 cm(3)); the mean volume of the remnant was 0.22 cm(3) (range, 0-1.52 cm(3)). The mean post-operative follow-up time was 35.4 months (range, 3-76 months). Salvage SRS was deemed necessary in seven patients (13.0%). The size of the postoperative tumor remnant was a significant predictor for the necessity of postoperative adjuvant SRS. Normal facial nerve function (House-Brackmann [HB] I) was preserved in 30 patients (57.7%), 17 patients (32.7%) experienced a permanent mild facial nerve deficit (HB II, III), and five patients (9.6%) experienced a severe facial nerve deficit (HB grade IV-VI). Conclusions: Initial observation after near total surgical removal of VS is a feasible strategy, with only a minority requiring salvage radiosurgery during follow-up.