Venous thromboembolism (VTE) including deep vein thrombosis(DVT) and pulmonary embolism(PE).Its occurs in about 1 per 1 000 individuals per years.Thrombosis is a serious disorder. It may be fatal by PE (case fatality rate of venous thrombosis is estimated at 1% to 2%)(Figure 1 ). A substantial proportion of these deaths occur in the postoperative period, and many events are fatal before diagnosis can be made and therapy initiated. Just as well, the prophylactic treatment of thrombosis is focused on preventing first events and recurrences through adequate knowledge about risks and risk factors.