Incidence and Prevention of Venous Thromboembolism in Orthopedic Surgery in Japan

Abstract

The rate of venous thromboembolism (VTE) in orthopedic surgery is higher in the lower extremities than in other areas because of the long rest period after surgery and impaired blood flow in the legs. According to the 6th ACCP Guidelines [1], the rate of occurrence of postoperative VTE is very high in the West. The incidence of deep venous thromboembolism (DVT) is 45%–57% in total hip replacement (THR), 40%–84% in total knee replacement (TKR), and 36%–60% in hip fracture surgery. The incidence of postoperative pulmonary thromboembolism (PTE) is reported to be as follows: THR, 0.7%–30%; TKR, 1.8%–7%; and hip fracture surgery, 4.3%–24%. The Guidelines therefore recommend preventive anticoagulant therapy using low molecular weight heparin or warfarin in these kinds of orthopedic surgeries. In Japan, there are few epidemiological surveys of the incidence of VTE after orthopedic surgery, and at present we have no guidelines for VTE prevention. Therefore, the method of prevention is decided by the individual institution or clinician. Two methods that are generally used in Japan after major orthopedic surgery such as THR or TKR are elastic stockings and intermittent pneumatic compression (IPC). Prophylactic anticoagulant therapy is not as prevalent as in the West, but low-dose unfractionated heparin is frequently considered when the patient to receive surgery is obese or has thrombotic risk factors. However, in Japan low-dose unfractionated heparin is usually administered at a dose of 2500 units given subcutaneously twice a day, which is lower than the Western dosage of 5000 units two to three times a day.