Middle fossa approach for resection of vestibular schwannoma: impact of cochlear fossa extension and auditory monitoring on hearing preservation.

OBJECTIVE: To analyze the impact of patient selection and auditory monitoring on hearing results after middle fossa craniotomy approach for resection of a vestibular schwannoma (VS). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Patients undergoing a middle fossa craniotomy for resection of VS at a single institution between 1995 and 2006 were included in the study population. Patients presenting with Neurofibromatosis Type 2 or who underwent a combined approach (middle fossa and retrosigmoid) were excluded. MAIN OUTCOME MEASURES: Hearing preservation as measured by serial audiograms. RESULTS: Seventy-seven patients were identified. Before excluding patients with cochlear fossa enhancement and the use of auditory monitoring, 47% of the patients maintained serviceable hearing (American Academy of Otolaryngology-Head and Neck Surgery Class A or B). By selecting tumors that did not involve the cochlear fossa and using auditory monitoring, serviceable postoperative hearing was preserved in 76% of the patients. CONCLUSION: Modification of our selection criteria for surgery and the use of auditory monitoring have improved our hearing results for patients undergoing a middle fossa approach for resection of VS from 47% to 76%.