The surgical management of giant intracranial vestibular schwannoma via retrosigmoid approach: a retrospective review of 657 cases

Abstract

To discuss the surgical technique and common complications from the microsurgical treatment of giant intracranial vestibular schwannoma via suboccipital retrosigmoid approach and to propose strategies for minimizing such complications. Surgical outcomes and complications were evaluated in a consecutive series of 657 unilateral giant vestibular schwannomas treated in Shanghai Huashan Hospital via suboccipital retrosigmoid approach from 1999 to 2014. According to the international classification of vestibular schwannoma, giant tumor means tumor's size over 4 cm in diameter. Clinical status and complications were assessed postoperatively within 14 days and at follow-ups (range, 6-191 months; mean, 59.6 months). Follow-up data were available for 566 of the 657 patients (86.1%). The most frequent clinical symptoms were hearing loss in different levels (100%), deafness (36.4%), facial numbness (68.8%). Total tumor resection was achieved in 556 patients (84.6%), subtotal resection in 99 patients (15.1%), and partial resection in 2 patients (0.3%). The common postoperative complications included new deafness (49.6%), intracranial infection (7.6%), low cranial nerve defect (7.5%) and pneumonia (6.2%). The facial nerve was preserved anatomically in 589 cases (89.6%) after operation, and the functional valuation of facial nerve according to postoperative House-Brackmann showed 216 patients (32.9%) in grade Ⅰ-Ⅱ, 308 cases (46.9%) in grade Ⅲ, 133 patients (20.2%) in grade Ⅳ-Ⅵ. Long-term followed-up results showed 428 patients (75.6%) in grade Ⅰ-Ⅲ one year after surgical treatment. Many of these complications are avoidable. Surgical experiences and the clinical anatomy of the approach, accompany with using intraoperative nerve monitoring, preoperatively study the individual imaging and clinical data and multidisciplinary cooperation are the key points to avoid the complications of giant intracranial vestibular schwannoma via suboccipital retrosigmoid approach.