Association between external ventricular drain removal or replacement and prophylactic anticoagulation in patients with aneurysmal subarachnoid hemorrhage: a propensity-adjusted analysis

Background Withholding prophylactic anticoagulation from patients with aneurysmal subarachnoid hemorrhage (aSAH) before external ventricular drain (EVD) removal or replacement remains controversial. This study analyzed whether prophylactic anticoagulation was associated with hemorrhagic complications related to EVD removal. Method All aSAH patients treated from January 1, 2014, to July 31, 2019, with an EVD placed were retrospectively analyzed. Patients were compared based on the number of prophylactic anticoagulant doses withheld for EVD removal (> 1 vs. ≤ 1). The primary outcome analyzed was deep venous thrombosis (DVT) or pulmonary embolism (PE) after EVD removal. A propensity-adjusted logistic-regression analysis was performed for confounding variables. Results A total of 271 patients were analyzed. For EVD removal, > 1 dose was withheld from 116 (42.8%) patients. Six (2.2%) patients had a hemorrhage associated with EVD removal, and 17 (6.3%) patients had a DVT or PE. No significant difference in EVD-related hemorrhage after EVD removal was found between patients with > 1 versus ≤ 1 dose of anticoagulant withheld (4 of 116 [3.5%] vs. 2 of 155 [1.3%]; p = 0.41) or between those with no doses withheld compared to ≥ 1 dose withheld (1 of 100 [1.0%] vs. 5 of 171 [2.9%]; p = 0.32). After adjustment, withholding > 1 dose of anticoagulant versus ≤ 1 dose was associated with the occurrence of DVT or PE (OR 4.8; 95% CI, 1.5–15.7; p = 0.009). Conclusions In aSAH patients with EVDs, withholding > 1 dose of prophylactic anticoagulant for EVD removal was associated with an increased risk of DVT or PE and no reduction in catheter removal–associated hemorrhage.