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 >or=15 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 >or=25 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 (>or=25 mm), deep involvement of the fundus, wide erosion of the porus, and marginal residual hearing.