Giant vestibular schwannomas: Surgical nuances influencing outcome in 179 patients.

INTRODUCTION: Giant vestibular schwannomas (VSs; ≥4 cm in size) are considered a separate entity owing to their surgical difficulty and increased morbidity. We studied the clinical presentation and surgical outcomes in a large series of giant VS patients. We also present the surgical nuances, which we believe can improve surgical outcomes.

MATERIALS AND METHODS: The clinical profiles, radiology, surgical results, and complications of 179 consecutive patients with a unilateral giant VS were reviewed. The study population was classified into two groups: Group A (4-4.9 cm, 124 [69.3%] patients) and Group B (≥5 cm, 55 [30.7%] patients).

RESULTS: The mean tumor size in Group A was 4.3 ± 0.2 cm (range, 4-4.8 cm), and in Group B, it was 5.3 ± 0.4 (range, 5-6.7 cm). Patients in Group B were younger, with a mean age at presentation of 34.8 ± 12.3 years versus 41.8 ± 13.1 years in Group A (P < 0.05). There was no difference in the clinical presentation except for papilledema (81.8% vs. 66.9%) and VI cranial nerve (CN) dysfunction (9.1% vs. 2.4%; P< 0.05), which was higher in Group B. There was no difference in the rate of total excision (86.2% vs. 85.4%), anatomical and physiological facial nerve preservation rates between the two groups (approximately 2/3 and 1/3, respectively), and the facial function at discharge. The incidence of postoperative morbidity was not statistically different between the two groups, except for the occurrence of postoperative cerebrospinal fluid (CSF) rhinorrhea, which was greater in Group B (10.9% vs. 2.4%). There were two mortalities in each group (overall, 4/179; 2.2%; P= 0.58).

CONCLUSIONS: Patients with ≥5cm VSs were younger, with a higher incidence of papilledema and lateral rectus paresis. However, when compared with tumors ≥4 cm in size, there was no difference in the extent of excision, facial nerve preservation, and postoperative complications (except CSF rhinorrhea) or mortality. Thus, further subclassification of giant VSs does not seem to be necessary.