Dr: Hamed Al-Ghamdi CONSULTANT VASCULAR SURGERY Acute Limb Ischemia Dr: Hamed Al-Ghamdi CONSULTANT VASCULAR SURGERY

Definition: Any sudden decrease or worsening in limb perfusion causing a potential threat to extremity viability. Amputation and death remain high despite intervention. It is often an end of life condition. Therefore careful clinical assessment of the individual is as important as the limb

Despite urgent revascularization with thrombolytic agents or surgery, amputation occurs in 10 to 15% of patients during hospitalization. A majority of amputations are above the knee. Approximately 15 to 20% of patients die within 1 year after presentation, often from coexisting conditions that predisposed them to acute limb ischemia.

Clinical presentation:

Categorizing (staging) patients with the acutely ischemic limb is crucial to offering patients maximum benefit of available therapeutic options. No person has contributed as much to the organized thinking of vascular disease as Dr. Robert B.Rutherford, who reviews clinical staging of acute limb ischemia as a basis for the choice of intervention.

“Viable” suggests that there is no immediate limb threat. “Marginally threatened” implies a mild-to- moderate threat to limb viability over a time frame that allows the limb to be salvaged if revascularized relatively soon. In contrast, “Immediately threatened” suggests that the limb is salvageable only with immediate revascularization. Finally, “Irreversible” is applied to advanced cases in which major tissue loss and/or permanent nerve damage is, in a practical sense, inevitable regardless of attempts at revascularization

Etiology of acute limb ischemia: Embolic Occlusion: An embolism occur when a material travels through blood stream and lodges itself to blood vessel. 80-90% originate in the heart. 60-70% having cardiac disease.

Thrombotic occlusion: It occurs in the sitting of previous vascular disease and is most often associated with atherosclerotic disease. this is usually a slow process, allow for collaterals formation.

Arteriographic Findings: Acute emboli appear to have a crescent-shaped occlusion(meniscuse sign), also can be seen as multiple filling defects and occlusion. Emboli tend to lodge at arterial bifurcation, and arteries other than the affected area usually normal.

Thrombotic occlusion occur at sites of chronic atherosclerotic disease such as SFA at adductor canal. Presence of collaterals usually indicate thrombotic occlusion

Strategies for Management: The goal of therapy for both acute embolic or thrombotic occlusion is reperfusion of the ischemic limb. The first step is anticoagulation with intravenous heparin. Tow strategies: 1-surgical intervention 2-endovascular thrombolysis

The decision between the two is based upon several considerations, including the degree of limb ischemia, location of occlusion, cause of the occlusion (embolic v thrombotic), And overall medical condition of the patient. A third option of anticoagulation alone should be reserved for unstable patients and those without limb-threatening ischemia who are sedentary

Surgical intervention is influenced by both the clinical presentation of the patient and the etiology of the acute limb ischemia Embolic occlusion usually requires only an embolectomy. Thrombotic occlusions usually require a correction of the patient’s underlying atherosclerotic disease, which frequently requires at least an endarterectomy or, more commonly, a bypass

Reperfusion Syndrome Reperfusion syndrome occurs when blood flow is restored to tissue after a period of ischemia.

Effects of reperfusion syndrome Local: compartment syndrome General—Acidosis and hyperkalaemia occur due to leakage from the damaged cells, causing cardiac arrhythmias Myoglobinaemia, which can result in acute tubular necrosis. Acute respiratory distress syndrome may also develop, and gastrointestinal endothelial oedema may lead to increased gastrointestinal vascular permeability and endotoxic shock.

Reperfusion Injury

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