Impact of Perioperative Maintenance or Interruption of Low-dose Aspirin on Recurrence Rate and Thrombotic Events After Burr-hole Drainage of Chronic Subdural Hematoma: a Randomized, Placebo Controlled, Double Blinded Study

Chronic subdural hematoma (cSDH) is one of the most common neurosurgical conditions. Its significantly higher prevalence among patients older than 65 (69%) versus younger (31%) explains why 41% of the patients are taking blood thinners. Antiplatelet therapy in patients with chronic subdural hematoma (cSDH) presents significant neurosurgical challenges. Studies investigating the effect of acetylsalicylic acid (ASA) in cranial neurosurgery are sparse and mostly based on case reports. Given the lack of guidelines regarding perioperative management with antiplatelet therapy, it is difficult to balance the patient's increased cardiovascular risk and prevalence of cSDH. The aim of our randomized, blinded, placebo controlled clinical study is to compare the peri- and postoperative bleeding and cardiovascular complication rates of patients undergoing burr-hole trepanation for cSDH with and without discontinuation of low-dose ASA. We will include patients receiving low-dose ASA as secondary prophylaxis for various reasons (e.g. coronary artery disease (CAD), cerebrovascular disease, etc.) and will randomize them either to a Placebo- or Aspirin-arm. The patients will receive placebo or ASA for 12 days whereas the normal ASA treatment will be resumed 12 days after randomization. Our study primarily seeks to evaluate the risk of recurrence after burr-hole trepanation for cSDH under low-dose ASA treatment compared to placebo treatment. Secondary objectives are to assess the rate of thrombotic events, perioperative blood loss, postoperative anemia, intra- and postoperative blood transfusion rate, and clinical outcome (mRS, GOS, Markwalder score). The study will be performed in cooperation with the Department of Cardiology of the University Hospital of Basel.