Outcome after microsurgery for meningiomas involving the internal auditory canal

Background: The subset of patients suffering from meningiomas truly originating in or extending into the internal auditory canal is not well described in the literature. Objective: To evaluate postoperative facial motor and hearing outcomes in patients undergoing resection of meningiomas originating in or extending into the internal auditory canal. Methods: Chart reviews were done of 19 consecutive patients undergoing surgery for meningiomas originating in or extending into the internal auditory canal at the Mayo Clinic, Rochester, with emphasis on clinical exam and audiometry. Results: Median follow-up for the entire group was 29 months. Seventy-four percent of patients had stable facial nerve function. One patient experienced improvement. Postoperative cochlear nerve function was unchanged in 74% of patients and worsened in 21% of patients. One patient with a sudden preoperative hearing loss improved to full hearing at 3 months. Conclusion: Every attempt should be made to preserve hearing and facial motor function in surgical removal of posterior fossa meningiomas that originate in or extend into the internal auditory canal. Normal or nearly normal facial nerve function can be preserved in 88% of patients presenting with normal facial nerve function; serviceable hearing can be preserved in 92% of patients who present with normal hearing. A standard retrosigmoid craniotomy with drilling of the posterior canal wall of the internal auditory canal worked well in the majority of cases.