Abdominal Aortic Aneurysm

 Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (often abbreviated to AAA) refers to the dilation of the abdominal aorta.

AAA is caused by the degeneration of muscular tissue in the artery. The condition is most prevalent in older individuals, with men and smokers both having a higher risk.

The most significant complication arising from AAA is rupturing of the artery wall, which is often fatal.

Causes

While the exact causes of AAA are unknown, there are a number of risk factors which have been identified, including:

·         Diminished elasticity of the artery wall due to age;

·         Genetic disorders; and

·         Exogenous factors, such as infection or trauma.  

Disease pathway

Weakening of the aorta is caused by a number of factors, such as:

·         Digestion of cellular proteins by enzymes;

·         Accumulation of calcium, fat and cholesterol deposits along the aorta (calcification); or

·         Ruptures within the layers of the artery.

The result is decreased elastin and collagen in the muscle wall, rendering it more susceptible to expansion due to the pressure from blood flow.

Symptoms and diagnosis

An aneurysm is generally considered to exist if the outer aortic diameter is measured to exceed 3cm. The normal diameter is about 2cm.

Most aneurysms are asymptomatic. Aneurysms with a higher risk of rupture are more likely to present with symptoms, which include:

·         Lower back, abdominal or groin pain;

·         A physically palpable mass in the abdomen; and

·         A pulsing sensation in the abdomen.

Treatment

For aneurysms of less than 5cm in diameter, the possible risks of surgery are seen to outweigh the benefits. As such, surveillance is the generally preferred option.

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