Prognostic factors for hearing preservation in vestibular schwannoma surgery

Objective: To determine whether prognostic indicators for hearing preservat ion could he identified in patients with vestibular schwannoma undergoing m iddle fussa craniotomy resection. Study Design: Prospective case review. Setting: Private practice tertiary referral center. Patients: 333 patients with serviceable hearing and vestibular schwannoma r esected by middle fossa craniotomy From 1992 to 1998. Main Outcome Measures: Potential prognostic indicators, including tumor siz e and nerve of origin, preoperative pure-tone average, speech discriminatio n, distortion product otoacoustic emission testing, age, auditory brainstem response (ABR), and electronystagmography. Results: Postoperative hearing near preoperative levels was attained in 167 patients (50%), with an American Academy of Otularyngology-Head and Neck S urgery Class A hearing result in 33% and a Class B result in 26%. Compariso n of potential prognostic indicators between groups with hearing preserved and the group with no measurable hearing revealed significant differences i n preoperative hearing, ABR, and tumor origin data. Better preoperative hea ring, shorter intraaural wave V latency, shorter absolute wave V latency, a nd superior vestibular nerve origin were associated with higher rates of he aring preservation. Conclusions: Preoperative hearing status, ABR, and intraoperative tumor ori gin data were shown to be of value as prognostic indicators.