Current status of venous thromboembolism prophylaxis.

Postoperative venous thromboembolism (VTE) represents a serious and potentially fatal complication that affects 40% to 60% of patients undergoing major orthopedic surgery and not receiving antithrombotic prophylaxis. Several prophylactic modalities, including pharmacological agents such as oral vitamin K antagonists (VKA) and low molecular weight heparins (LMWH), have been shown to be effective and safe for most patients at high risk for VTE. However, some patients undergoing cancer or major orthopedic surgery remain at some residual VTE risk despite the use of these methods. Approaches to improve the results of prophylaxis include optimizing the timing and duration of pharmacological prophylaxis, combining mechanical methods with anticoagulants, and the development of new antithrombotics.