Limb Threatening Ischemia
A 62-year old man with history of hypertension, dyslipidemia and stable angina is admitted to the hospital for elective coronary artery bypass graft (CABG) due to extended three vessel coronary disease. The patient has a history of left carotid artery revascularization with stenting due to severe stenosis 3 years ago and has a history of intermittent claudication and dyspnea with exertion that started 5 months ago. The patient undergoes elective CABG operation of left circumflex (LCX) and left anterior descending (LAD) coronary arteries, utilizing a left saphenous vein conduit and the left internal thoracic artery (ITA) respectively. The surgery completes uneventfully but after 24 hours the patient complains of acute pain in his lower left foot. Clinical examination reveals a pale, not swollen, cold limb with faint distal pulses. His vitals are unrevealing. Computed tomography (CT) angiography demonstrates 80% stenosis of the abdominal aorta due to extensive atheromatous disease and an occluded left common iliac artery. The patient eventually undergoes emergent revascularization.
Which is the pathophysiologic mechanism of patient's acute limb ischemia?