Impact of Subdural Drain Omission on Recurrence After Chronic Subdural Hematoma Surgery: A Retrospective Study.

Although subdural drain (SDD) placement reduces recurrence after burr-hole surgery for chronic subdural hematoma (CSDH), complications have led our institution to discontinue its routine use. During the first year following this change, the recurrence rate was 14.6%, comparable to the recurrence rate observed prior to discontinuation. Therefore, we retrospectively compared 150 cases with SDD (SDD+ group) and 129 recent cases without SDD (SDD- group). Patient characteristics, recurrence rates, complications, operative time, hospital stay, and costs were analyzed. Recurrence occurred in 13.9% of the SDD+ group and 8.0% of the SDD- group (p = 0.119). Post-hoc analysis revealed low statistical power (34.1%), suggesting a risk of Type II error. The SDD- group had significantly shorter operative time (40.9 vs. 54.9 minutes) and hospital stay (6.0 vs. 11.8 days), with a cost reduction of $811.8 per case. Complication rates were similar (4% vs. 1%), but three serious SDD-related complications were noted in the SDD+ group. Multivariate analysis identified preoperative hematoma thickness and postoperative subdural thickness as independent recurrence factors, while SDD use was not. In conclusion, omitting SDD placement did not significantly increase recurrence but was associated with shorter operative times, reduced hospital stays and costs, and fewer serious complications. While the study may be underpowered to definitively rule out a difference in recurrence, these findings support the feasibility of omitting SDD in initial surgeries. Future randomized controlled trials are warranted to confirm these results.