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%.