Venous thromboembolism represents a true worldwide medical problem that is encountered within all realms of practice. Venous thromboembolism (VTE) occurs in approximately 100 patients per 100,000 population yearly in the United States and increases exponentially with each decade of life (White, 2003). Approximately one-third of patients with symptomatic deep vein thrombosis (DVT) experience a pulmonary embolism (PE). Death occurs within 1 month in 6% of patients with DVT and 12% of those with PE. Early mortality is associated strongly with presentation as PE, advanced age, malignancy, and underlying cardiovascular disease. An experience dating back several decades has provided a better understanding of disease states and conditions associated with VTE (Anderson and Spencer, 2003). Given the potential morbidity and mortality associated with VTE, it is apparent that prophylaxis represents an important goal in clinical practice. A variety of anticoagulants including unfractionated heparin, low-molecular-weight heparin (LMWH), and warfarin have been studied. More recently, two new agents have been developed that warrant discussion. Fondaparinux underwent a worldwide development program in orthopedic surgery for the prophylaxis of VTE. The program consisted mainly of four large, randomized, double-blind phase II studies comparing fondaparinux (SC), at a dose of 2.5 mg starting 6 hours postoperatively, with the two enoxaparin regimens approved for VTE prophylaxis—40 mg qd or 30 mg twice daily beginning 12 hours postoperatively. The results support a greater protective effect with fondaparinux, yielding a 55.2% relative risk reduction of VTE (Bauer et al., 2001; Eriksson et al., 2001; Lassen et al., 2002; Turpie et al., 2001, 2002; ). A European program of three large-scale clinical trials (MElagatran for THRombin inhibition in Orthopedic surgery [METHRO] I, II, and III, and EXpanded PRophylaxis Evaluation Surgery Study [EXPRESS]) (Eriksson et al., 2002a, b, 2003a, b) evaluated the safety and efficacy of subcutaneous melagatran followed by oral ximelagatran compared with LMWH for thromboprophylaxis following total hip replacement (THR) and total knee replacement (TKR) surgery.
Fondaparinux vs Enoxaparin for the Prevention of Venous Thromboembolism in Major Orthopedic SurgeryA Meta-analysis of 4 Randomized Double-blind Studies