Thromboembolism after total hip replacement

Abstract

Total hip replacement (THR) is an elective procedure associated with an increased risk of venous thromboembolic events such as deep vein thrombosis (DVT) and pulmonary embolism (PE). Routine prophylaxis against thromboembolic events after THR remains the standard of care in the United States. Thrombus formation is associated with Virchow's triad (stasis, endothelial injury, and a hypercoagulable state) and occurs during the course of THR surgery. The choice of anesthesia and operative technique can affect the incidence of thromboembolic events. Warfarin and various low-molecular-weight heparins have been studied extensively in randomized trials and in large cohort studies. Both agents have been demonstrated to provide safe and effective prophylaxis, but they also have certain limitations. Recently, aspirin has received increased attention as a potential prophylaxis agent. Although aspirin appears to reduce symptomatic PE rates, further studies of this drug in randomized control trials are necessary. There is no consensus on the optimal length of postoperative thromboprophylaxis, although the occurrence of late thromboembolic events is recognized. Postdischarge prophylaxis is safe and effective and is recommended in this era of short hospital stays. Routine ultrasound surveillance appears to be unreliable and does not appear to reduce the risk of subsequent venous thromboembolic events in patients already receiving thromboprophylaxis. At the present time, all THR patients require prophylaxis to prevent symptomatic thromboembolic events. Balancing the risk and benefits of each prophylactic agent or a particular prophylactic regimen, the individual surgeon must choose and meticulously implement the method of prophylaxis that best fits his/her practice and patient population.