Acute limb ischemia (ALI) Rapid decrease in lower limb blood flow due to acute occlusion of peripheral artery or bypass graft, and etiology is broadly divided into embolism and thrombosis with various comorbidities. The symptoms of ALI are abrupt with pain, numbness, and coldness of lower limb, and paresthesia, contracture, and irreversible purpura will appear with the exacerbation of ischemia. Critical Limb ischemia Etiology: obstructive atherosclerotic disease; atheroembolic or thromboembolic disease, vasculitis, in situ thrombosis related to hypercoagulable states, thromboangiitis obliterans, cystic adventitial disease, popliteal entrapment, or trauma. pathophysiology: chronic & complex process that affects the macrovascular, microvascular systems & surrounding tissues. The twin Saints Comas and Damian were ascribed to have saved a gangrenous limb in the 13th century and became patrons of future surgeons. In 1960s, Charles Dotter, developed techniques to image diseased arteries during a recanalization procedure. The development of guide wires, angioplasty balloons, & stents quickly followed. Satyendra Dhar MD, @DharSaty #acutelimbischemia, #embolectomy, #endovascular #treatment, #hybridtherapy, #thrombolysis #ALI #CLI #heparin #amputation #thrombosis