What Is the Best Treatment for Acute Limb Ischemia?

Key points

Background/overview

Acute limb ischemia (ALI) is a common vascular emergency that results from the interruption of blood flow to the limb and hypoperfusion of downstream tissue of less than 2 weeks duration. ALI affects between 15 and 26 patients per 100,000 each year in the United States and is associated with high rates of morbidity and mortality [1]. Previous studies cite perioperative mortality and limb loss rates of 20% to 40% and 12% to 50%, respectively, in cases of lower-extremity ALI [2,3].

Classification and cause

ALI presents with similar symptoms regardless of etiology; however, determination of its cause is important to guide management. In the lower extremity, ALI is most commonly a result of in situ thrombosis, owing to high prevalence of arterial occlusive disease; in the upper extremity, embolism is the most common cause of ALI. Other causes of ALI include trauma, iatrogenic injury, hypercoagulable states, arterial dissection, phlegmasia, hemodynamic perturbations, including low-flow states, such

Clinical presentation

The “Six Ps”: pain, pulselessness, poikilothermia , paresthesia, pallor, and paralysis characterize ALI. Depending on the location and duration of the occlusion, extent of collateral circulation owing to existing arterial occlusive disease, and underlying cause, the clinical presentation may vary.

History and physical examination help to elucidate cause of the ischemic event. Pertinent history includes prior embolic episodes, history of PAD, recent MI, arrhythmias, valvular heart disease,

Diagnostic examination

Imaging may help to elucidate the cause by identifying the responsible ulcerative plaque, dissection, thrombosed aneurysm, or acute thrombosis of an atherosclerotic vessel, bypass graft, or stent, as well as to aid in operative planning. Current imaging modalities include duplex ultrasonography, magnetic resonance angiography, computed tomographic angiography (CTA), and digital subtraction angiography. CTA of the chest, abdomen, or pelvis with lower-extremity runoff is preferred, as it can be

Management

When ALI is suspected, initial management includes intravenous fluid resuscitation and anticoagulation. In the absence of contraindications to therapeutic anticoagulation, a loading bolus of intravenous heparin, followed by initiation of a continuous infusion, should be administered to prevent propagation of the thrombus and maintain patency of collateral vessels. Direct thrombin inhibitors, lepirudin or argatroban, may be used in patients with intolerance to heparin. The use of anticoagulation

Postoperative management

Despite successful revascularization, limb loss may occur from development of acute compartment syndrome, as previously ischemic tissue swells within the confined fascial space of the calf or forearm. The more severe the ischemia, the more likely a reperfusion compartment syndrome is to develop. In patients with a history of prolonged ischemia (>6 hours) and those with limb edema observed after reperfusion, prophylactic fasciotomies are recommended [39]. Patients who have not undergone

Summary

ALI is a vascular emergency associated with high rates of limb loss and mortality. Expeditious diagnosis, anticoagulation, and revascularization are of utmost importance in reducing morbidity. Management of these patients is challenging given the severe systemic illness resulting from tissue ischemia and the high incidence of preexisting comorbid conditions and underlying PAD. Approach to revascularization depends on the severity of ischemia, location of occlusion, underlying cause, chance of

Clinics care points

Disclosure

The authors have nothing to disclose.