Background: The incidence of small vestibular schwannomas in patients with serviceable hearing is increasing because of the widespread use of MRI. The middle fossa approach provides the patient with an opportunity for tumor removal with hearing preservation.
Objective: To determine the rate of hearing preservation and facial nerve outcomes after removal of a vestibular schwannoma with the use of the middle fossa approach.
Methods: A retrospective case review at a tertiary, academic medical center was performed identifying patients from 1998 through 2008 that underwent removal of a vestibular schwannoma by the middle fossa approach. Preoperative and postoperative audiograms were compared to determine hearing preservation rates. In addition, facial nerve outcomes at last follow-up were recorded.
Results: Forty-six patients underwent a middle fossa craniotomy for the removal of a vestibular schwannoma. Of the 38 patients that had class A or class B hearing preoperatively, 24 (63.2%) retained class A or B hearing and 29 (76.3%) retained class A, B, or C hearing. When tumors were 10 mm or less in patients with class A or B preoperative hearing, 22 of 30 patients (73.3%) retained class A or B hearing. When the tumor size was greater than 10 mm in patients with class A or B preoperative hearing, 2 of 8 patients (25%) retained class A or B hearing. At most recent follow-up, 76.1% of patients had House-Brackmann grade I facial function, 13.0% had House-Brackmann grade II facial function, and 10.9% had House-Brackmann grade III facial function.
Conclusion: Hearing preservation rates are excellent using the middle fossa approach, especially for smaller tumors. No patient experienced long-term facial nerve function worse than House-Brackmann grade III.