Association between cerebrospinal fluid leak and meningitis after skull base surgery

Background. Meningitis and cerebrospinal fluid (CSF) leak are serious complications of skull base surgery, but whether postoperative CSF leak increases the risk of meningitis is unknown. Objective. To evaluate any association between meningitis and CSF leak after open or endoscopic skull base resection. Study Design and Setting. A retrospective case series with chart review in a tertiary care university-affiliated medical center. Methods. A total of 156 patients underwent intradural tumor resection in our institution between 1994 and 2009, 135 (86%) via the subcranial approach and 21 (14%) through the expanded endonasal approach. All occurrences of meningitis, brain abscess, and CSF leak had been recorded and were available for analysis. Results. Nine patients (5.7%) had postoperative meningitis, and 3 patients had postoperative CSF leak (1.9%). The risk of meningitis in patients without CSF leak was 4.5% (7/153) compared to 66% (2/3) in those with CSF leak. A statistical analysis revealed a significant association between CSF leak and meningitis, with a relative risk of 14.6 (95% confidence interval, 4.95-42; P = .008). Conclusion. Postoperative CSF leak significantly increases the risk of meningitis. Most cases of meningitis after skull base operation are probably associated with lumbar drainage infection or from an obscure leak.