Optimal duration of postoperative drainage following burr hole surgery for chronic subdural hematoma: A systematic review and network meta-analysis.

Abstract

<h4>Background</h4>Chronic subdural hematoma (CSDH) is a prevalent neurosurgical condition with a high recurrence rate after burr-hole surgery. The optimal duration of postoperative drainage remains controversial, with varying clinical practices worldwide.<h4>Objective</h4>This systematic review and network meta-analysis aimed to determine the optimal postoperative drainage duration to minimize recurrence while maintaining favorable clinical outcomes.<h4>Methods</h4>A comprehensive search was conducted across five databases up to January 2025, including randomized controlled trials (RCTs) and cohort studies evaluating the postoperative drainage duration in CSDH patients undergoing burr-hole surgery. The primary outcome was recurrence rate, while the secondary outcomes included mortality and functional outcomes. A random-effects network meta-analysis was performed, and the risk of bias was assessed using standardized tools.<h4>Results</h4>Seven studies with 1,842 patients were included, comprising three RCTs and four cohort studies. Drainage durations of 3 and 6 days significantly reduced recurrence rates compared with shorter durations (0-8 h and 17-24 h). Notably, the 6-day drainage had the highest probability (86.2%) of minimizing recurrence, followed by the 3-day drainage (13.8%). A shorter drainage duration (< 24 h) was associated with higher recurrence risks. However, no significant differences in mortality rates were observed across the drainage durations.<h4>Conclusion</h4>This study highlights that longer postoperative drainage durations (3-6 days) may reduce recurrence rates after burr-hole surgery for chronic subdural hematomas. However, its effect on mortality remains unclear. These findings support the importance of optimizing the drainage duration and call for further high-quality studies to guide clinical practice.