Various branches of the aorta can be occluded by atherosclerosis, fibromuscular dysplasia, or other conditions, causing symptoms and signs of ischemia or infarction. Diagnosis is by imaging tests. Treatment is with embolectomy, angioplasty, or sometimes surgical bypass grafting.
Occlusion of branches of the abdominal aorta may be
Acute: Resulting from embolism, atherothrombosis, or dissection
Chronic: Resulting from atherosclerosis, fibromuscular dysplasia, or external compression by mass lesions
Common sites of occlusion include
Superior mesenteric arteries
Celiac axis
Renal arteries
Aortic bifurcation
Chronic occlusion of the celiac axis is more common among women for unclear reasons.
Symptoms and Signs of Abdominal Aortic Branch Occlusion
Clinical manifestations (eg, pain, organ failure, necrosis) result from ischemia or infarction and vary depending on the artery involved and acuity.
Acute mesenteric occlusion causes intestinal ischemia and infarction, resulting in severe, diffuse abdominal pain typically out of proportion to the minimal physical findings. Acute occlusion of the celiac axis may cause liver or spleen infarction.
Acute renal artery embolism causes sudden flank pain, followed by hematuria; it can be misdiagnosed as nephrolithiasis. Chronic occlusion may be asymptomatic or result in new or hard-to-control hypertension and other sequelae of renal insufficiency.
Acute occlusion of the aortic bifurcation or distal branches can cause sudden onset of pain at rest, pallor, paralysis, absence of peripheral pulses, and coldness in the legs (see Acute Peripheral Arterial Occlusion). Chronic occlusion can cause intermittent claudication in the legs and buttocks and erectile dysfunction (Leriche syndrome). Femoral pulse are absent, and ankle-brachial index is abnormal. A limb may be jeopardized.
Diagnosis of Abdominal Aortic Branch Occlusion
Imaging tests
Diagnosis is based primarily on history and physical examination and is confirmed by duplex ultrasonography, CT angiography, magnetic resonance angiography, or conventional angiography.
Treatment of Abdominal Aortic Branch Occlusion
Embolectomy or percutaneous transluminal angioplasty for acute occlusion
Surgery or angioplasty for chronic, severe occlusion
Acute occlusion is a surgical emergency requiring embolectomy or percutaneous transluminal angioplasty (PTA) with or without stent placement. A laparotomy with bypass graft and bowel resection may be necessary if embolectomy or PTA is unsuccessful.
Chronic occlusion, if symptomatic, may require surgery or angioplasty. Risk factor modification and antiplatelet medications may help.
Acute mesenteric occlusion (eg, in the superior mesenteric artery), which causes significant morbidity and mortality, requires prompt revascularization. Prognosis is poor if the intestine is not revascularized within 4 to 6 hours.
For chronic occlusion of the superior mesenteric artery and celiac axis, dietary modifications may temporarily relieve symptoms. If symptoms are severe, surgical bypass from the aorta to the splanchnic arteries distal to the occlusion usually results in revascularization. Long-term patency of the grafts exceeds 90%. In appropriately selected patients (particularly among older patients who may be poor candidates for surgery), revascularization by PTA with or without stent placement may be successful. Symptoms may resolve rapidly, and weight may be regained.
Acute renal artery occlusion requires embolectomy; sometimes PTA can be done. Initial treatment of chronic occlusion involves antihypertensives. If blood pressure is not controlled adequately or if renal function deteriorates, PTA with stent placement or, when PTA is impossible, open surgical bypass or endarterectomy can improve blood flow.
Occlusion of the aortic bifurcation requires urgent embolectomy, usually done transfemorally. If chronic occlusion of the aortic bifurcation causes claudication, an aortoiliac or aortofemoral graft can be used to surgically bypass the occlusion. PTA is an alternative for selected patients.
Key Points
Abdominal aortic branch occlusion can be acute or chronic.
Symptoms vary depending on the acuity of the occlusion and the artery involved.
Diagnose abdominal aortic branch occlusion based on history and physical examination and confirm with imaging tests.
Treat acute occlusion as a surgical emergency with embolectomy, percutaneous transluminal angioplasty, or surgical bypass. Treat chronic occlusion with medications and lifestyle changes and, if severe, surgery or angioplasty.
