Long-term effects of cerebellar retraction in the microsurgical resection of vestibular schwannomas

OBJECTIVE: To determine the long-term effects, if any, of the greater cerebellar retraction that is required for retrosigmoid vestibular schwannoma versus resection as compared with the minimal, if any, cerebellar retraction required for translabyrinthine versus resection. STUDY DESIGN: Retrospective case control. METHODS: All patients who underwent retrosigmoid versus resection between 1988 to 2000 by one surgeon were identified. These patients were contacted and asked to complete the Dizziness Handicap Inventory (DHI). These patients were then matched to patients who underwent translabyrinthine versus resection according to age at surgery, age at time of study, sex, and size of tumor. Total DHI and subcategory DHI scores were compared using the Student t test. RESULTS: Thirty-three patients underwent the retrosigmoid approach, and 27 were contacted for completion of the survey, with a 81.3% response rate. Forty-six patients who underwent translabyrinthine versus resection were matched to the retrosigmoid group. Thirty-six were contacted and completed the survey for a 75% response rate. Twenty-seven patients that most closely matched the retrosigmoid group comprised the translabyrinthine group used for comparison. Minimal differences were seen between the two groups. Mean total DHI score for the retrosigmoid group was 17.6, which was not significantly different from the mean score of 16.8 seen in the translabyrinthine group (P =.888). When comparing small tumors (<1.5 cm), total DHI scores were not found to be significantly different (P =.859). We observed similar findings in those with intermediate-sized tumors (1.5-3 cm). CONCLUSION: The significantly greater cerebellar retraction that is necessary for retrosigmoid versus resection does not result in greater long-term balance and disability as compared with those patients who have undergone the translabyrinthine approach.