Treatment of large vestibular schwannomas: towards a compromise between recurrence and facial function preservation

Ideal treatment of large vestibular schwannomas [VS] is complete removal without significant morbidity. The aim of this study is to assess the long-term outcome of surgery, focusing on factors influencing facial function and recurrence. Large VS were removed from 76 consecutive patients, through the retrosigmoid approach, from 1990-2004. Prognostic factors evaluated were age, size hydrocephalus, IX[th] and X[th] nerve signs, extent of surgical removal, and tumours's consistency. Statistics were taken by assessment of Chi-square, Fisher, student t-test. The mean age was 40 +/- 14 years, and the mean diameter was 45 +/- 9 mm. Preoperatively, 93% had significant hearing loss, 74% had cerebellar ataxia, 77% had high intracranial pressure and 40% had IX[th] and X[th] nerve signs. The perioperative mortality dramatically decreased from 17.6% in the earlier period [1990-1996] to 4.5% in the latter period [1997-2004]. At long-term follow-up, 84% of the patients had a Karnofsky score superior to 80%. Mean facial function was better for solid tumours [mean House-Brackmann [HB] standard deviation [SD], 3.7 [1.7] vs. 4.5 [1.7], p = 0.035]. Facial anatomical continuity was preserved in 76% of the cases [n = 58] and was correlated with a better facial function [mean HB [sd], 3.1 [0.7] vs. 5.8 [1.3], p < 0.001]. Excluding patients with a preoperative facial palsy, good facial function was achieved in 58% of the patients, without statistical difference between gross total and subtotal resection [mean HB [SD], 4.3 [1.4] vs. 4.8 [1.9], p=0.229]. The method resulted in improved outcome. Subtotal resection is a good strategy with high likelihood of preserving facial nerve function, without significantly increasing the risk of recurrence. New strategies associating subtotal resection and radiosurgery must be evaluated