Large and giant vestibular Schwannomas

Abstract

Background: The main objective in treating large and giant vestibular schwannomas (VS) (large - diameter exceeding 3.5 cm and giant - diameter exceeding 4.5 cm) is their complete removal without significant morbidity. Our experience on 7 cases (4 females, 3 males, mean age 42.5 years) with marked brainstem compression, operated between 2004-2009 focuses on factors influencing recurrence and morbidity, especially related to facial nerve function. These patients were included in a series of 32 consecutive vestibular schwannoma excisions.
Methods: This report is a retrospective analysis of the surgical outcome of 7 patients with large and giant VS using the retrosigmoid-transmeatal approach. Several prognostic factors were evaluated: patient age, tumor size and consistency, extent of surgical removal, concurring hydrocephalus, hearing loss, facial nerve function, trigeminal nerve deficits, cranial nerve VI, IX and X palsy, tongue edema, ataxic gait and motor deficits.
Results: The mean age was 42.3 years, the mean tumor diameter was 51.8 mm. There were no deaths and the tumors were histologically benign. Extensive microscopic tumor resection was performed in 5 cases related to solid tumor’s consistency. Preoperatively hearing loss and high intracranial pressure were encountered in all patients. 4 patients had cerebellar ataxia. Facial anatomical continuity was preserved in 6 cases with solid tumor consistency; 4 patients had a preoperative facial palsy, a good facial nerve function was achieved in 3 cases – House-Brackmann grade I/II. We have met other distinctive signs: cranial nerve V hypoesthesia, VI, IX and X palsy, tongue edema in 2 cases with slight contralateral motor deficit. All patients were clinical and MRI monitored at 3, 6 and 12 months postoperatively.
Conclusion: Total resection associated with a low morbidity rate is possible, avoiding recurrence, reintervention and severe scar tissue. In cases with subtotal resection, radiosurgery is recommended to improve outcome.