331 Early Warfarin Resumption Following Burr-Hole Drainage for Chronic Subdural Hematoma

Abstract

INTRODUCTION: There are very limited data on resuming antico-agulation after chronic subdrual hematoma (CSDH), and there are often cases whose resumption of anticoagulation is delayed for more than several weeks after burr-hole drainage. However, patients on anticoag-ulation typically have a pre-existing risk factor and are at higher risk of a thromboembolic (TE) event, while they are off anticoagulation. It is therefore important to keep a right balance between the TE risk and the bleeding risk. To evaluate the potential safety for early warfarin resumption, we conducted a retrospective matched cohort study. METHODS: Between May 2008 and April 2015, we enrolled a series of 187 patients of CSDH who were and were not receiving warfarin therapy at the time of admission. We prospectively treated the warfarin cohort focusing on the discontinuation of warfarin, INR correction, postoperative management, timing of warfarin resumption, and resumption dosage of warfarin. As to the ordinary cohort, retrospective observational study was conducted using medical charts, surgical reports, and CT scan reviews. And then, 2 cohorts were analyzed using propensity score matching. RESULTS: Among the 187 patients, 36 patients had been taking warfarin before surgical treatment, and the others had not. The mean time to recurrence was similar in the warfarin cohort (82.7 ± 3.4) compared to the ordinary cohort (82.0 ± 1.8) (log-rank test, P =.878). After propensity score matching, 33 patients in the warfarin corhort and 74 patients in the ordinary cohort were matched. When analyzed using the generalized estimating equation, there was no significance difference in the recurrence rate of CSDH between 2 groups (P = 0.411). In addition, we found that the recurrence of CSDH in warfarin corhort was not related with postoperative INR levels (linear mixed model, P =.332). CONCLUSION: There is no strong consensus on the optimal timing for warfarin resumption and therefore each patient should be managed individually based on underlying TE risks and hemorrhagic burden. However, warfarin-related CSDH patients with a strong indication for anticoagulation would benefit from restarting warfarin about 3 d after burr-hore drainage.