Functional outcome and complications after the microsurgical removal of giant vestibular schwannomas via the retrosigmoid approach: a retrospective review of 16-year experience in a single hospital

BACKGROUND Intracranial vestibular schwannoma still remain to be difficulty for its unique microsurgical technique and preservation of neuro-function, as well as reducing common complications that may arise in surgery. METHODS We consecutively enrolled 657 unilateral giant (>4 cm diameter) vestibular schwannoma patients treated in Huashan Hospital via the suboccipital retrosigmoid approach in the past 16 years. The extension of tumor removal, surgical mortality, facial nerve function, hearing, and the other main short and long-term complications were the studied parameters. RESULTS Gross total resection was performed in 556 patients (84.6%); near-total resection was achieved in 99 patients (15.1%). The mortality rate is 0.6%. The main short-term complications included 'new' deafness (47.6%), intracranial infection (7.6%), lower cranial nerve defects (7.5%) and pneumonia (6.2%). The facial nerve was preserved anatomically in 589 cases (89.7%). Good facial nerve functional outcome (House-Brackmann Grades I and II) postoperatively was achieved in 216 patients (32.9%). Other 308 cases (46.9%) were House-Brackmann grade III, and 133 patients (20.2%) were House-Brackmann grade IV-VI. Follow-up data were available for 566 of the 657 patients (86.1%). The common long-term complications were hearing loss (85.2%), facial paralysis (HB grade IV-VI, 24.4%) and facial numbness (15.7%). CONCLUSIONS Trends in the data lead the authors to suggest that the microsurgical technique, intraoperative nerve monitoring, and multidisciplinary cooperation, were the keys to improving prognostic outcomes in giant intracranial vestibular schwannoma patients.