Abdominal Aortic Branch Occlusion

Abdominal Aortic Branch Occlusion

Occlusion is the blockage of a blood vessel; usually, but not necessarily, with a clot. The most commonly-affected branches of the aorta are the superior mesenteric arteries, the iliac arteries, the celiac axis and the renal arteries.

Abdominal aortic branch occlusions can take two forms: acute or chronic.

Disease pathway

Deposits of fatty materials, such as cholesterol, accumulate on the artery wall, causing it to thicken.

Decreased diameter of the artery wall results in the aggregation of blood platelets in the area, forming a clot.

Obstruction due to the clot and the fatty deposits can limit blood flow to distal areas, especially in situations where oxygen demand is increased, such as exercise.

Symptoms and diagnosis

Acute occlusion restricts the flow of blood to abdominal organs and muscles, resulting in severe pain disproportional to the minimal physical signs. A feeling of coldness in the legs may transpire, along with paralysis.

With blood flow impeded, gangrene and necrosis (the decay) of bodily tissue may also occur; which can, in turn, lead to sepsis (blood poisoning), shock and ultimately, death.

Chronic occlusion is rarely symptomatic, unless the affected blood vessels are significantly blocked. However, the symptoms are most prominent following a meal, since digestion requires a temporary increase in blood flow to and from the intestines. This leads to a persistent, severe pain, often causing patients to become averse to eating. As a result, weight loss, malabsorption, diarrhoea and constipation may occur.

Diagnosis is confirmed by imaging tests.

Treatment

Acute aortic occlusion is a potentially life-threatening emergency requiring immediate treatment.

Embolectomy and thrombectomy involve the surgical removal of fatty build-up and clots from the blood vessel, respectively.

Angioplasty is another possible form of treatment, involving the insertion of a collapsed balloon on a wire into the narrowed artery, and inflating the balloon at high pressure to crush the fatty deposits. 

As to chronic occlusion, surveillance and dietary modifications may relieve discomfort. If the condition is severe, the same treatments used for acute occlusion can help to improve blood flow.

References 

http://emedicine.medscape.com/article/461285-overview 

http://emedicine.medscape.com/article/460965-overview 

Pemsel HK. Rofo 1977. 126(2):129-33. 

Oderich G, Pannetron J. Seminars in Vascular Surgery 2002. 15(2):89-96. 

Ashida K, et al. Angiology 1993. 44:574-9.

Abendstein H, et al. Tidsskr Nor Laegeforen 1992. 112: 2637-9.

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