Acute Lower Limb Ischemia—Etiology, Pathology, and Management

Abstract Acute limb ischemia (ALI) is a vascular emergency associated with a high risk for limb loss and death. Most cases result from in situ thrombosis in patients with preexisting peripheral arterial disease or those who have undergone vascular procedures including stenting and bypass grafts. The other common source is cardioembolic. The incidence has decreased in recent times due to better anticoagulation strategies. Patients with suspected ALI should be evaluated promptly by a vascular specialist and consideration should be given for transfer to a higher level of care if such expertise is not available locally. Initial assessment should focus on staging severity of ischemic injury and potential for limb salvage. Neurological deficits can occur early and are an important poor prognostic sign. Duplex ultrasound and computed tomography angiography help plan intervention in patients with a still-viable limb and prompt catheter-based angiography is mandated in patients with an immediately threatened limb. Further investigations need to be pursued to differentiate embolic from thrombotic cause for acute occlusion as this can change management. Options include intravascular interventions, surgical bypass, or a hybrid approach. In this article, the authors discuss the common etiologies, clinical evaluation, and management of patients presenting with acute limb ischemia.