Impact of discontinuation of antithrombotic therapy after surgery for chronic subdural hematoma [Impact de l'interruption des antithrombotiques après traitement chirurgicale de l'hématome sous dural chronique]

Introduction: The management of antithrombotic therapy (AT) after surgery for chronic subdural hematoma (cSDH) requires taking account of the balance of risk between hemorrhage recurrence (HR) and the prophylactic thromboembolic effect (TE). The goal of the present study was to evaluate the prevalence of vascular events (VE: TE and/or HR) in the first 3 postoperative months after cSDH evacuation in patients previously treated by AT. The impact of AT resumption was also evaluated. Patients and methods: This observational prospective multicenter collaborative study (14 French neurosurgery centers) included patients with cSDH treated by AT and operated on between May 2017 and March 2018. Data collection used an e-CRF, and was principally based on an admission questionnaire and outcome/progression at 3 months. Results: In this cohort of 211 patients, VE occurred in 58 patients (27.5%): HR in 47 (22.3%), TE in 17 (8%), with mixed event in 6 cases (2%). Median overall time to onset of complications 26 days ± 31.5, and specifically 43.5 days ± 29.25 for HR. Non-resumption of AT significantly increased the relative risk of VE [OR: 4.14; 95% CI: 2.08 - 8.56; P < 0.001] and especially of TE [OR: 7.5; 95% CI: 1.2 - 42; P < 0.001]. The relative risk of HR was significantly increased when AT was resumed at less than 30 days (P = 0.015). Conclusion: The occurrence of VE in patients operated on for cSDH and previously treated by AT was statistically significant (27.5%). HR was the most common event (22.3%), whereas TE accounted for only the 8%, although with shorter time to onset. In order to prevent TE risk, AT should be restarted after 30 days, as HR risk is greatly decreased beyond this time.