Abstract
Major orthopaedic surgeries such as total hip and total knee replacements are considered a major risk factor for venous thromboembolism (VTE). Without prophylaxis, DVT occurs in 10–40% of general surgical or medical patients and 40–60% of patients following major orthopaedic surgery. There has, however, been a perception that VTE is less common in Asia than in Western countries. New evidence has emerged recently that contradicts this perception. Results from multinational epidemiological studies (SMART, AIDA, ENDORSE) clearly showed that the rate of venographic and symptomatic thrombosis after major joint replacement in Asian patients is similar to that previously reported in patients in Western countries. However, thromboprophylaxis is not routinely used in Asia, even in situations considered high risk in Western countries. The ENDORSE study reported that less than 20% of at-risk surgical patients in Asia received prophylaxis compared with over 80% in Western countries. This leaves the majority of patients at risk of developing VTE and VTE-related conditions, which continues after hospital discharge. Current guidelines recommend the use of thromboprophylaxis for at least 10 days and up to 35 days in patients undergoing total joint replacement. Available anticoagulants are effective at preventing VTE but are associated with various limitations, such as parenteral administration as in the case of UFH and LMWH. A narrow therapeutic window, unpredictable pharmacology, frequent coagulation monitoring and dose-adjustment as in the case of vitamin K antagonists (VKAs). Several new, oral anticoagulants are in advanced clinical development, including the direct thrombin inhibitor, dabigatran, and the direct Factor Xa inhibitors, rivaroxaban and apixaban.
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