Are there modifiable risk factors to prevent a cerebrospinal fluid leak following vestibular schwannoma surgery?

OBJECT The following study was conducted to identify risk factors for a postoperative CSF leak after vestibular schwannoma (VS) surgery. METHODS The authors reviewed a prospectively maintained database of all patients who had undergone resection of a VS at the Mayo Clinic between September 1999 and May 2013. Patients who developed a postoperative CSF leak within 30 days of surgery were compared with those who did not. Data collected included patient age, sex, body mass index (BMI), tumor size, tumor side, history of prior tumor treatment, operative time, surgical approach, and extent of resection. Both univariate and multivariate regression analyses were performed to evaluate all variables as risk factors of a postoperative CSF leak. RESULTS A total of 457 patients were included in the study, with 45 patients (9.8%) developing a postoperative CSF leak. A significant association existed between increasing BMI and a CSF leak, with those classified as overweight (BMI 25-29.9), obese (BMI 30-39.9), or morbidly obese (BMI >= 40) having a 2.5-, 3-, and 6-fold increased risk, respectively. Patients undergoing a translabyrinthine (TL) approach experienced a higher rate of CSF leaks (OR 2.5, 95% CI 1.3-4.6; p = 0.005), as did those who had longer operative times (OR 1.04, 95% CI. 1.02-1.07; p = 0.0006). The BMI, a TL approach, and operative time remained independent risk factors on multivariate modeling. CONCLUSIONS Elevated BMI is a risk factor for the development of a postoperative CSF leak following VS surgery. Recognizing this preoperatively can allow surgeons to better counsel patients regarding the risks of surgery as well as perhaps to alter perioperative management in an attempt to decrease the likelihood of a leak. Patients undergoing a TL approach or having longer operative times are also at increased risk of developing a postoperative CSF leak.