Occlusion of abdominal aortic branches: causes, symptoms, diagnosis, treatment

Various branches of the aorta may become occluded due to atherosclerosis, fibromuscular dysplasia, or other conditions, resulting in symptoms of ischemia or infarction.

Diagnosis is made with imaging studies. Treatment involves embolectomy, angioplasty, or (sometimes) bypass surgery.

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Causes of occlusion of the branches of the abdominal aorta

Acute occlusion of the abdominal aortic branches may result from embolism, thrombosis of an atherosclerotic vessel, or dissection. Chronic occlusion results from atherosclerosis, fibromuscular dysplasia, or extrinsic compression (many causes). Common sites of occlusion include organ arteries (eg, superior mesenteric artery, celiac trunk, renal arteries) and the aortic bifurcation. Chronic occlusion of the celiac trunk is more common in women for unclear reasons.

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Symptoms of abdominal aortic branch occlusion

Symptoms (eg, pain, organ failure, necrosis) may result from ischemia or infarction. Acute mesenteric artery occlusion causes intestinal ischemia and infarction, resulting in severe widespread abdominal pain ("acute abdomen"). Acute occlusion of the celiac axis may result in splenic or hepatic infarction. Chronic mesenteric vascular insufficiency rarely causes symptoms unless both the superior mesenteric artery and the celiac axis are significantly narrowed or occluded because there is extensive collateral circulation between the major arterial trunks. Signs of chronic mesenteric arterial circulatory insufficiency usually occur after meals (as in intestinal angina) because digestion requires increased mesenteric blood flow. The pain begins approximately 30 minutes or 1 hour after eating and is persistent and severe, localized around the navel (it may be reduced by taking nitroglycerin sublingually). Patients begin to fear eating, and weight loss often occurs (even to a critical level). Malabsorption sometimes develops, contributing to weight loss. Rumbling in the abdomen, nausea, vomiting, diarrhea or constipation, and dark stools are possible.

Acute occlusion due to embolism in the renal artery causes sudden pain in one side of the body, accompanied by hematuria. Chronic occlusion may be asymptomatic or lead to the development of hypertension, its resistance to treatment, and other complications of renal failure.

Acute occlusion of the aortic bifurcation or distal branches may cause sudden pain at rest, pale skin and mucous membranes, paralysis, loss of peripheral pulse, and cold extremities. Chronic occlusion may cause intermittent claudication (in the legs and buttocks) and erectile dysfunction (Leriche syndrome). Femoral pulse is absent. Limb loss is possible.

Diagnosis and treatment of occlusion of the branches of the abdominal aorta

Diagnosis is based primarily on history and physical examination. Confirmation is by 2D ultrasound, CTA, MRA, or conventional angiography. Acute occlusion is a surgical emergency requiring embolectomy or percutaneous angioplasty (PACE) with or without stenting. Chronic occlusion, if causing clinical symptoms, may require surgery or angioplasty. Risk factors and antiplatelet drugs must be excluded.

Acute occlusion of a mesenteric artery (eg, superior mesenteric artery) causes significant morbidity and mortality and requires rapid replacement of the arterial segment. The prognosis is poor if intestinal blood supply is not restored within 4 to 6 hours.

In chronic occlusion of the superior mesenteric artery and celiac trunk, nitroglycerin may temporarily reduce symptoms. If symptoms are severe, surgical bypass of the aorta to the organ arteries distal to the occlusion is usually used, which usually restores blood supply. The long-term effect exceeds 90%. In some patients (especially in the older age group, where there is a high risk of surgical intervention), revascularization using PCI with or without stenting may be successful. Rapid disappearance of clinical symptoms with restoration of body weight is possible.

Acute renal artery occlusion is an indication for embolectomy, and sometimes PCI can be performed. Initial treatment of chronic occlusion includes antihypertensive drugs. If blood pressure is not corrected or renal function deteriorates, PCI with stenting is performed. If PCI cannot be performed, open surgical anastomosis or embolectomy can improve blood flow.

Aortic bifurcation occlusion is an indication for emergency embolectomy, usually performed via the femoral artery. If chronic aortic bifurcation occlusion causes claudication, aortoiliac or aortofemoral bypass grafting can be performed to surgically bypass the obstruction. PVA is an alternative for some patients.

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