Quality of hearing preservation in acoustic neuroma surgery

Objective: This study aimed to investigate the factors affecting the quality of postoperative hearing in acoustic neuroma. Study Design: The study was designed as a retrospective case review. Setting: The study was performed at the Department of Otolaryngology, School of Medicine, Keio University, Tokyo, Japan. Patients: The subjects were 94 patients with unilateral acoustic neuroma. Intervention: Hearing preservation surgery was performed in the subjects via the extended cranial fossa approach or the middle cranial fossa approach. Main Outcome Measures: The outcome measures included patient's age and gender, hearing level, speech discrimination score, tumor size, and surgical approach. The relationship between the qualities of preoperative and postoperative hearing and the lone-term prognosis of preserved hearing also was investigated. Results: In 94 subjects, there were 47 patients whose hearing was preserved (HP group) and 47 patients whose hearing was not preserved (non-HP group). Overall, hearing preservation rate was 50%. There were no significant differences in age, gender, and turner size between the two groups. The hearing preservation rate was significantly higher in patients with an intracanalicular tumor than that with a larger tumor. The better the preoperative quality of hearing was, the higher the postoperative one. Although the preserved hearing deteriorated after surgery in 4 patients, no significant hearing deterioration was observed in the other 43 patients. Conclusions: The results of this study indicated that the diagnosis for acoustic neuroma in the early stage with serviceable hearing is the most important to improve the quality of postoperative hearing.