Association between postoperative thromboembolic and hemorrhagic complications and clinical outcomes after surgery for chronic subdural hematoma in patients with anticoagulation therapy for atrial fibrillation

PURPOSE: A substantial proportion of patients undergoing surgery for chronic subdural hematoma (CSDH) use anticoagulation medication due to atrial fibrillation (AF). We assessed the risk of postoperative thromboembolic and hemorrhagic complications in CSDH surgery patients with a history of anticoagulation for AF and their association with outcome. METHODS: This posthoc analysis of a nationwide multicenter randomized controlled trial conducted during 2020-2022 included CSDH patients undergoing surgery with a history of preoperative anticoagulation use for AF. We assessed the incidence of thromboembolic and hemorrhagic complications and their associations with functional outcomes and mortality. RESULTS: Of 589 patients, 128 patients (median age 83 years, 24% females) were on anticoagulation medication due to AF. The incidences of postoperative thromboembolic and hemorrhagic complications were 8% and 6%, respectively. A significantly higher proportion of patients with a thromboembolic complication had unfavorable functional outcome (70% vs. 21%, p < 0.001) and higher mortality (50% vs. 14%) than those without. After adjusting for risk factors, a thromboembolic complication was independently associated with a higher risk for unfavorable outcome (OR 16.8, 95% CI 3.0-94.2) and death (OR 11.1, 95% CI 2.4-52.0). Similarly, hemorrhagic complications associated independently with unfavorable outcome, although the effect size was smaller than for thromboembolic complications. CONCLUSION: The risk for thromboembolic complications seemed to be slightly higher than the risk for postoperative hemorrhagic complications after CSDH surgery in patients with a history of preoperative anticoagulation medication use due to AF. The occurrence of a thromboembolic complication was detrimental for patient prognosis, underscoring the importance of strategies to prevent thromboembolic events. There is an urgent need for a trial assessing the optimal timing of restarting anticoagulation medication after CSDH surgery. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT04203550.