Antithrombotic Therapy in Peripheral Arterial Occlusive Disease
A therosclerosis is the cause of the vast majority of cases of chronic peripheral arterial occlusive disease. The arteries most frequently involved, in order of occurrence, include femoro-popliteal-tibial, aortoiliac, carotid and vertebral, splanchnic and renal, and brachiocephalic. Fibro-muscular dysplasia, inflammatory arteritides, and congenital arterial malformations are much rarer etiologies of arterial insufficiency. The causes of acute arterial occlusion are embolism, thrombosis, and trauma. The goals of therapy in chronic arterial occlusive disease are to relieve ischemic symptoms (intermittent claudication and rest pain), to alleviate disability, and to prevent progression that might lead to gangrene and limb loss. The objectives of therapy in acute arterial occlusion are to restore blood flow and to preserve life and limb. Antithrombotic therapy is a rational consideration in patients with peripheral arterial occlusive disease. In chronic disease, antithrombotic therapy is designed to prevent progression and thrombotic occlusion or to prevent thrombotic complications after vascular reconstructions and other interventions. In acute arterial occlusion from embolism or thrombosis, effective anticoagulant therapy will prevent propagation of thrombi into proximal and distal arterial branches with attendant compromise of collateral flow; may prevent reocclusion after surgical or interventional procedures to reestablish flow; or, in the case of embolism, may prevent recurrence. The antithrombotic agents available are anticoagulants, antiplatelet agents, thrombolytic drugs, and dextran (Table 1).
Chronic Extremity Arterial Insufficiency
Epidemiologic studies have documented that 2 to 3% of men and 1 to 2% of women 60 years of age or older have intermittent claudication buy tavist online.- The prevalence, however, is threefold to fourfold higher when sensitive noninvasive tests are applied to the limbs of asymptomatic as well as symptomatic individuals. The prevalence also increases with age. The natural course of chronic lower extremity arterial insufficiency is that after 5 to 10 years, approximately 70 to 80% of patients remain unchanged or improved, 20 to 30% have progression of symptoms and require intervention, and less than 10% require amputation. Progression of disease is greatest in patients with multilevel arterial involvement, low ankle/brachial pressure indexes, chronic renal insufficiency, diabetes mellitus, and, possibly, heavy smoking.
Table 1—Summary of Antithrombotic Therapy in Peripheral Vascular Disease
|Clinical Problem||Antithrombotic Therapy||Grade of Recommendation|
|Chronic lower-extremity ischemia||Aspirin (to reduce risk of stroke and MI)||A1|
|Acute arterial occlusion and ischemia||Heparin (IV)||Cl|
|Intraoperative anticoagulation during vascular surgery||Heparin||B1|
|Infrainguinal vein bypass||Aspirin (to reduce risk of stroke and MI)||A1|
|Infrainguinal prosthetic bypass||Aspirin and dipyridamole||B1|
|Infrainguinal bypass at high thrombotic risk||Aspirin and warfarin||B2|
|Peripheral PTA||Aspirin (to reduce risk of stroke and MI)||A1|
|Aspirin and ticlopidine||B2|
|Peripheral PTA (femoral)||Aspirin, heparin during PTA||C2|