Microsurgical Treatment of Small Acoustic Neuromas

Introduction: Modalities considered for the management of small acoustic neuromas include observation, radiosurgery, and microsurgery. In this retrospective review, we assess microsurgical intervention, specifically affecting facial function and hearing preservation, in patients with small acoustic neuromas.

Methods: Thirty-five patients underwent microsurgery for presumed acoustic neuroma with less than a 1-cm extension into the cerebellopontine angle (2003 to 2006). All patients presented with hearing loss and intact facial function. Surgical approaches included retrosigmoid (71%), translabyrinthine (26%), and middle fossa (3%). Pre- and postoperative facial and hearing functions were reviewed.

Results: In all patients, the facial nerve was in anatomic continuity at the end of surgery. Gross total resection was performed in 91% of patients. Mean follow-up time was 6 months. At last follow-up, facial function was normal in 83% and good (House-Brackmann 1 or 2) in 92%. Of 3 patients with delayed facial palsy, 2 resolved completely. Functional hearing was preserved in 38% of patients who underwent a potential hearing preservation procedure. Of 3 patients (8%) with CSF leak, 1 required re-exploration. Two cases of presumed acoustic neuroma were histologically meningiomas and 1 of presumed meningioma was histologically schwannoma.

Conclusions: Microsurgical resection of small acoustic neuromas results in excellent tumor control with preservation of good facial function in most patients and low complication rates. By allowing for definitive histological diagnosis, resection ultimately reduces the need for radiation exposure to nearby eloquent structures.