Risk Factors for Postoperative Cerebrospinal Fluid Fistulas After Craniotomy and Craniectomy: A Systematic Review and Meta-Analysis.

INTRODUCTION: Postoperative CSF fistulas are a common complication in cranial neurosurgery. While efforts to prevent CSF leaks typically focus on surgical technique, it remains unclear whether tumor location, type of pathology, or specific closure methods independently influence fistula development. Clarifying these risk factors is essential to guide intraoperative decision-making and improve patient outcomes. METHODS: We conducted a systematic search limited to peer-reviewed studies published in English on multiple databases. The search algorithm retrieved 1,348 results. After the exclusion phase, we included 26 comparative studies in the final analysis, collectively reporting data on 8,248 patients who underwent either craniotomy or craniectomy. After a systematic review, we performed a meta-analysis when sufficient data were available from multiple studies for a specific risk factor. RESULTS: Infratentorial surgeries had a higher CSF leak rate (7.9%) than supratentorial ones (4.6%). Tumor surgeries showed greater risk than vascular procedures (OR: 1.82). Primary closure had a higher leak rate (12.3%) compared to patch grafts (8.5%). Watertight closure showed a trend toward fewer leaks than non-watertight closure, though not statistically significant. CSF leaks were strongly associated with postoperative infections (34.1%). CONCLUSION: Infratentorial location, tumor surgery, and sural closure increase the risk of postoperative CSF leaks. Patch grafts and watertight techniques lower this risk. Given the strong association with infections, preventing CSF leaks is essential to improve surgical outcomes.