Complications and Management of Large Intracranial Vestibular Schwannomas Via the Retrosigmoid Approach.

OBJECTIVE: To investigate the common complications from the microsurgical treatment of large intracranial vestibular schwannoma (VS) via suboccipital retrosigmoid approach and to propose strategies for minimizing such complications. METHODS: We selected all patients with large unilateral VS from the collected database (1999-2013) who underwent microsurgical resection as their initial treatment for histopathologically confirmed VS. Tumors larger than 30 Chi 20 mm were defined as large. RESULTS: A total of 1167 patients with VS were included. Gross total tumor resection was achieved in 1006 patients (86.2%). The mortality rate is 0.77%. The facial nerve was preserved anatomically in 1083 cases (92.8%), and the functional valuation of the facial nerve according to postoperative House-Brackmann scale showed 423 patients (36.2%) in grades I-II, 534 cases (45.8%) in grade III, and 210 patients (18.0%) in grade IV-VI. The main short-term postoperative complication included new hearing loss (American Institute of Otolaryngology-Head and Neck Surgery grade D) in 634 cases (54.3%), disequilibrium in 250 cases (21.4%), labial herpes in 127 cases (10.9%), meningitis in 115 (9.85%) and lower cranial nerve deficit in 77 cases (6.59%). Follow-up data were available for 978 of the 1167 patients (83.8%). Long-term complications include hearing loss (American Institute of Otolaryngology-Head and Neck Surgery grade D) (75.8%), permanent facial paralysis (11.9%), facial numbness (10.9%), tinnitus (2.96%), chronic headache (2.25%), and taste disturbance (1.43%). CONCLUSIONS: The key factors for reducing surgical complications include careful assessment of the functions of acoustic and facial nerves as well as a thorough understanding of anatomy via the retrosigmoid approach before operation, skillful microsurgical technique, and monitoring of multiple cranial nerves during resection.