External lumbar drain for fistula leakage in posterior fossa and spinal surgery: a systematic review with meta-analysis.

Cerebrospinal fluid (CSF) leakage is a frequent complication after posterior fossa and spinal surgeries. External lumbar drainage (ELD) is used to promote leak resolution, but its effectiveness and safety remain debated. This study aimed to evaluate the outcomes of ELD compared to conservative management. A systematic review and meta-analysis were conducted following PRISMA guidelines. Studies comparing ELD with conservative treatment for postoperative CSF leaks were included. Primary outcome was leak resolution; secondary outcomes included adverse events, meningitis, and headache. Random-effects models were used to calculate odds ratios (OR) with 95% confidence intervals (CI). Eight studies (519 patients: 317 ELD, 202 conservative) were included. ELD significantly increased CSF leak resolution (OR 2.19; 95% CI 1.18-4.07; p = 0.013). No significant differences were observed in subgroup analyses by surgical location. Adverse events did not differ significantly between groups (OR 0.82; p = 0.766), and the overall ELD-related complication rate was 1.8%. ELD improves CSF leak resolution rates with a low complication profile. The observed benefit for leak resolution was not robust, as significance was lost in sensitivity analysis. Its use should be individualized based on surgical context and patient risk. Further randomized studies are needed to guide standardized protocols.