Risk factors for neurological complications after operative treatment for schwannomas

Schwannoma is a common benign soft tissue tumor. Although schwannomas can be theoretically enucleated without nerve damage, neurological complications occasionally develop following enucleation. The aim of this study was to elucidate the incidence of and risk factors for postoperative neurological complications following schwannoma enucleation. Ninety-eight schwannomas from 95 patients that were treated by surgical excision between January 2003 and December 2014 were included in this retrospective case series study. Patients were 49 men and 46 women with a median age of 60.5years (range, 22-87years). The incidence of postoperative neurological complications was evaluated in all the patients, and characteristics, such as age, tumor size, sex, preoperative symptoms, MRI findings, tumor location, and the nerve of origin, were compared between the cases with or without complications at the last follow-up. In our study population, postoperative neurological complications were observed in 18.4% of the cases. In univariate analysis, preoperative sensory disturbance, tumor location, and the nerve of origin were associated with the incidence of postoperative neurological complications (p<0.001, p=0.034, and p=0.003, respectively). In multivariate analysis, tumors showing preoperative sensory disturbance and tumors located in the proximal aspect of the limbs were identified as independent risk factors for postoperative neurological complications (p<0.001 and p=0.014, respectively). A certain percentage of schwannoma cases undergoing enucleation would show postoperative neurological complications. Therefore, patients with schwannoma, in particular, those with risk factors for postoperative neurological complications, should be informed regarding the possibility of postoperative complications. In cases of schwannoma enucleation, the procedure should be meticulously performed to minimize the damage to the affected nerve of origin.