Arterial Occlusive Disease of the Aorta and Its Branches
Aortoiliac occlusion
Leriche syndrome - buttock and thigh claudication, absent femoral pulses, erectile dysfunction - indicates infrarenal aortic occlusion. TASC II grades aortoiliac and femoropopliteal lesions from A (focal, endovascular-friendly) to D (diffuse, surgical); favorable iliac lesions are stented with good patency, while extensive disease is best treated with aortobifemoral bypass. Acute aortic occlusion from a saddle embolus or in-situ thrombosis is limb- and life-threatening, often with neurologic deficit and mottling; treat with embolectomy or urgent revascularization.
Mesenteric ischemia
Chronic mesenteric ischemia produces postprandial pain, food fear, and weight loss, and generally requires disease in at least two of the three visceral vessels; celiac stenosis alone is usually silent because of collaterals. Acute mesenteric ischemia from an atrial fibrillation embolus presents with pain out of proportion to examination and a soft abdomen; CT angiography is the study of choice. The embolus typically lodges distal to the middle colic artery, sparing the proximal jejunum - a classic question. SMA thrombosis occurs at the ostium in a patient with prior chronic symptoms. Nonocclusive mesenteric ischemia complicates low-flow states and is managed with vasodilators and laparotomy for dead bowel.
Renal and other branches
Fibromuscular dysplasia affects young women in the mid-to-distal renal artery with a string-of-beads appearance; atherosclerotic stenosis is ostial. ASTRAL and CORAL tempered enthusiasm for routine stenting. Median arcuate ligament syndrome causes celiac compression with postprandial pain worse in expiration.
Rule of thumb: in acute mesenteric ischemia, believe the pain, not the abdomen - and never rely on a normal lactate to exclude it.