Which is better in the management of chronic subdural hematoma: Irrigation, or no irrigation? A systematic review and meta-analysis of randomized controlled trials

Background: Chronic subdural hematoma (CSDH) is a prevalent neurological disorder, especially among the elderly, where blood accumulates between the brain and its outer covering. The primary treatment for CSDH involves surgical intervention, such as burr-hole craniotomy, with or without irrigation of the subdural space. The efficacy of irrigation versus no irrigation in reducing recurrence, mortality, and postoperative complications remains debated. The study aimed to compare the effectiveness and safety of irrigation versus no irrigation in the surgical management of CSDH through a systematic review and meta-analysis of randomized controlled trials (RCTs). Methods: A systematic review and meta-analysis were conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Databases searched included PubMed, Scopus, Web of Science, and Cochrane Library, targeting RCTs published in English comparing irrigation with no irrigation in CSDH management. Four RCTs with a total of 843 patients met the inclusion criteria. Two reviewers extracted data independently, and the risk of bias 2 tool was used for quality assessment. The primary outcome was recurrence; secondary outcomes included mortality and postoperative complications. Statistical analyses were performed using RevMan 5.3. Results: The meta-analysis included four RCTs with 843 patients, revealing that irrigation significantly reduces the recurrence of CSDH compared to no irrigation (odds ratios [OR] = 0.66, 95% confidence interval [CI]: 0.44–0.98, P = 0.04), with no observed heterogeneity (I2 = 0%). Mortality rates showed no significant difference between the irrigation and no irrigation groups (OR = 1.10, 95% CI: 0.59–2.06, P = 0.77), also with no heterogeneity (I2 = 0%). Postoperative complications initially showed no significant difference (OR = 0.39, 95% CI: 0.09–1.69, P = 0.21) and moderate heterogeneity (I2 = 52%). However, sensitivity analysis resolving the heterogeneity indicated a significant reduction in complications favoring the irrigation group (P = 0.03). Conclusion: This meta-analysis suggests that irrigation during burr-hole drainage significantly reduces CSDH recurrence without increasing mortality or postoperative complications, supporting its use in clinical practice. Further, high-quality RCTs are necessary to confirm these findings and assess long-term outcomes.