The implications of antithrombotic agents on subdural hematoma evacuation: what does "reversal" truly entail?

OBJECTIVE: The optimal perioperative management of antithrombotic therapy (ATT) in patients requiring urgent neurosurgical intervention for subdural hematoma (SDH) is poorly understood. The delicate equilibrium of effective hemostasis while preventing thrombosis is complex and relies on numerous factors such as indication for and type of ATT, medical comorbidities, and extent of neurological injury. This study aimed to analyze the impact of ATT and reversal strategies on surgical outcomes to highlight current challenges in the management of these high-risk patients. METHODS: The authors performed a retrospective surgical cohort analysis of 100 patients undergoing urgent SDH evacuation at a level I trauma center between March 2020 and May 2021. The patients were first stratified into two cohorts based on preoperative ATT use and then further segregated by receipt of reversal agents. Statistical analysis included the chi-square test, Welch two-sample t-test, and multivariate logistic regression. The primary outcome was mortality. Secondary endpoints included radiographic SDH reexpansion, revision surgery, improvement in preoperative neurological deficits, and incidence of thromboembolism. A crossover cohort was secondarily analyzed in patients for whom ATT was interrupted for a minimum duration equal to effective drug metabolism. Finally, ATT reinitiation patterns were examined. RESULTS: Of 100 patients, 48% received ATT, 54.2% of whom were given reversal agents. ATT use was significantly associated with decreased rates of postoperative neurological improvement (p = 0.023) with trends toward increased mortality (p = 0.078), SDH reexpansion (p = 0.12), and need for revision surgery (p = 0.10). Patient crossover revealed a 4 times greater likelihood of death in patients without ATT interruption prior to surgery (p = 0.040) without an observable impact on secondary outcomes. ATT reversal contributed no improvement in outcomes other than a decreased intensive care unit length of stay when adjusted for in-hospital mortality (p = 0.014). The rate of postoperative thromboembolism following ATT reversal was 11.5%. ATT reinitiation was highly variable, occurring in 59.5% of patients, with median times of 17 and 15 days for antiplatelets and anticoagulants, respectively. CONCLUSIONS: Use of preoperative ATT portends poor clinical outcomes following nonelective SDH evacuation regardless of attempts to reverse these medications with replacement blood products. This study further reinforces the critical need for judicious use of ATT and optimization of reversal strategies in high-risk patient populations as best guided by multidisciplinary teams and evolving clinical practice guidelines.