Hearing preservation surgery for vestibular schwannoma: experience with the middle fossa approach

Object. In the early 1960s William F. House developed the middle fossa approach for the removal of small vestibular schwannomas (VSs) with the preservation of hearing. It is the best approach for tumors that extend laterally to the fundus of the internal auditory canal, although it does have the potential disadvantage of increased facial nerve manipulation, especially for tumors arising from the inferior vestibular nerve. The aim of this study was to monitor the hearing preservation and facial nerve outcomes of this approach. Methods. A prospective database was constructed, and data were retrospectively reviewed. Results. Between December 2004 and January 2012, 30 patients with small VSs underwent surgery via a middle fossa approach for hearing preservation. The patients consisted of 13 men and 17 women with a mean age of 46 years. Tumor size ranged from 7 to 19 mm. Gross-total resection was accomplished in 25 of 30 patients. Preoperative hearing was American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) Class A in 21 patients, Class B in 5, Class C in 3, and undocumented in 1. Postoperatively, hearing was graded as AAO-HNS Class A in 15 patients, Class B in 7, Class C in 1, Class D in 2, and undocumented in 5. Facial nerve function was House-Brackmann (HB) Grade I in all patients preoperatively. Postoperatively, facial nerve function was HB Grade I in 28 patients, Grade III in 1, and Grade IV in 1. There were 3 complications: CSF leakage in 1 patient, superficial wound infection in 1, and extradural hematoma (asymptomatic) in 1. The overall hearing preservation rate of at least 73% and HB Grade I facial nerve outcome of 93% in this cohort are in keeping with other contemporary reports. Conclusions. The middle fossa approach for the resection of small VSs with hearing preservation is a viable and relatively safe option. It should be considered among the various options available for the management of small, growing VSs. (http://thejns.org/doi/abs/10.3171/2012.7.FOCUS12172)