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.