Venous thromboembolism prophylaxis after major orthopaedic surgery: a pooled analysis of randomized controlled trials.

The use of aspirin for venous thromboembolism (VTE) prophylaxis after major orthopaedic surgery is controversial. The hypothesis of the present study is that aspirin will decrease the rate of operative site bleeding without increasing thromboembolic events when aspirin is used for VTE prophylaxis after major orthopaedic surgery. A pooled analysis of 14 randomized controlled trials (RCTs) cited by the American College of Chest Physicians (ACCP) guidelines was performed to determine pooled rates of symptomatic deep vein thromboses, pulmonary emboli (PE), fatal PE, and operative site bleeding rates. The VTE rates with aspirin were not significantly different than the rates for vitamin K antagonists (VKA), low molecular weight heparins (LMWH), and pentasaccharides. The operative site bleeding relative risks of VKA, LMWH, and pentasaccharides versus aspirin, are 4.9, 6.4, and 4.2, respectively. A pooled analysis of RCTs supports the use of aspirin for VTE prophylaxis after major orthopaedic surgery.