[Clinical characteristics of thrombotic diseases of arteries and veins].

Thrombotic occlusion of the arteries and veins are categorized as acute and chronic presentations. Acute arterial occlusion results in severe ischemia because of poor or no development of the collateral arteries. They should be treated promptly by thrombectomy or thrombolysis. On the other hand, chronic arterial occlusion is preferably treated by bypass surgeries. Although the vascular surgeries in the chronic arterial occlusion have undergone remarkable development in the recent years, the treatment of acute occlusion still lags behind poor with prognosis. The treatment of acute venous occlusion is aimed to prevent postphlebitic syndrome except for the ischemic type such as venous gangrene. The purpose of the treatment of chronic venous occlusion is to assist the pump function of the calf muscles to avoid venous stasis. Pulmonary embolism is the most severe complication and its treatment remains controversial.