Hypercoagulability in vascular surgery patients

Hypercoagulable (prethombotic) states are being recognized with increasing frequency in many patients with thromboembolic disease. The hypercoagulable state is defined as a clinical syndrome consisting of an unusual or increased predisposition to thrombosis. Situations that meet this definition include thrombosis at a young age, family history of unusual or frequent thrombosis, recurrent thrombosis, and thrombosis in unusual sites such as the portal or hepatic veins [1]. While the hypercoagulable state has most frequently been described in association with venous thrombotic events, increasing evidence indicates that many patients with arterial thrombosis may also suffer from one or more of these conditions. The frequency of various forms of the hypercoagulable state in the general population is not known with certainty but it has been estimated that 15 to 25% of young patients with venous thromboembolism likely have some underlying predisposing condition [2,3]. This figure may be even higher in patients with a positive family history suggesting a hereditary prethrombotic disorder [3,4]. The incidence of these conditions in vascular surgery patients is even less well studied, with only a few small prospective series available. Most published data in vascular patients come from case reports or highly selected small series. The most frequently described prethrombotic states are those caused by hereditary deficiencies of