Is it worthwhile to attempt hearing preservation in larger acoustic neuromas?

Objective: To determine the hearing outcome in patients undergoing surgery via the retrosigmoid approach for acoustic neuromas with a substantial component in the cerebellopontine angle. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: The medical records of all patients undergoing acoustic neuroma removal via the retrosigmoid approach at a tertiary referral center were retrospectively reviewed. Sixty-four patients with both cerebellopontine angle component greater than or equal to15 mm and preoperative audiometry of class A or B (American Academy of Otolaryngology-Head and Neck Surgery) were identified. Main Outcome Measures: Postoperative average pure tone threshold and word recognition scores, categorized according to the classification of the American Academy of Otolaryngology-Head and Neck Surgery, were used to assess hearing outcome. Results: Overall, only 6.3% (4 of 63) retained good hearing (class A or B) postoperatively. Hearing preservation rate in the smallest (15- to 19-mm) group was 17.6% (3 of 17), which was better than that for the larger groups. No successful hearing preservation was achieved in tumors with greater than or equal to25 mm cerebellopontine angle component (0 of 23). Conclusions: Surgeon and patient alike would always choose a hearing preservation technique if there was no potential for increased morbidity in making the attempt. When compared with the non-hearing preservation translabyrinthine approach, the retrosigmoid approach had a higher incidence of persistent headache. In addition, efforts to conserve the auditory nerve prolong operating time, increase the incidence of postoperative vestibular dysfunction, and carry a slightly higher risk of tumor recurrence. Nevertheless, even though the probability of success is disappointingly small, when excellent hearing is present we favor offering the option of a hearing conservation attempt when the patient has been well informed of the pros and cons of the endeavor. Factors weighing against undertaking this effort include larger cerebellopontine angle component (greater than or equal to25 mm), deep involvement of the fundus, wide erosion of the porus, and marginal residual hearing.