When the diagnosis of acute limb ischemia is known or suspected, immediate intravenous heparinization should be started if no contraindications exist. This may help prevent clot extension, recurrent emboli, venous thrombosis, and the appearance of microthrombi distal to the obstruction. 12 Fluid resuscitation and treatment of heart failure and dysrhythmias is necessary to improve limb perfusion.
Definitive treatment of an obstructing clot should be done in conjunction with a vascular surgeon. Prompt surgical embolectomy is the optimal therapy for an acute arterial embolism causing limb-threatening ischemia. Catheter embolectomy has been the choice technique for removal of clot ever since the development of the Fogarty balloon catheter in 1963.12 It has reduced mortality from arterial emboli by 50 percent and need for amputation by 35 percent. Overall mortality from an arterial embolus is about 15 percent and is usually due to the underlying cardiovascular disease. The limb salvage rate ranges from 62 to 96 percent. 12
Intraarterial thrombolysis with streptokinase, urokinase, or tPA infused near or into the clot for a few hours to days is an alternative to surgery, with a rate of successful reperfusion of 50 to 85 percent.12 It should be considered for distal thromboembolic occlusions in surgically inaccessible small arteries, acute thrombosis in a limb with chronic arterial insufficiency and adequate collateral flow, or in poor surgical candidates. Follow-up balloon angioplasty or surgical grafts may be needed to prevent rethrombosis in patients with atherosclerotic plaques. Systemic thrombolysis has been compared with intraarterial lytic agents in randomized trials and has been shown to produce inferior results.12
Since thrombotic occlusion usually occurs in arteries with advanced atherosclerosis and a developed collateral supply, it is often not a dramatic event and is occasionally silent.12 Management of these occlusions therefore is conservative, with heparin alone. An angiogram is helpful to direct therapy and exclude embolic occlusion (radiologically seen as an abrupt cutoff of blood flow) when limb viability is acutely threatened. It is still unclear whether heparin improves outcome in the clinical circumstances of thrombosis in a plaque-laden artery.
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