An Abdominal Aortic Aneurysm (AAA), a specific kind of aneurysm, is a condition in which the lining of the blood vessel called the aorta is enlarged within the abdomen. Abdominal aortic aneurysms pose a threat because they are usually silent until a medical emergency occurs.
The abdominal aorta is the largest blood vessel in the body and the main artery that originates in the heart. As the lining weakens from age and other risk factors, the vessel wall thins and expands. The most common location for an AAA is between where the aorta divides to supply blood to the kidneys and where it divides to supply blood to the pelvis and legs.
More than 80% of patients with ruptured abdominal aortic aneurysm (AAA) present without a previous diagnosis of AAA, which contributes to an initial misdiagnosis rate of 24-42%. A rational approach to the diagnostic evaluation is predicated on a high degree of suspicion.
Before rupture: As an AAA gets bigger, it may cause deep pain in the back or side of the abdomen or a throbbing feeling in the abdomen. Most AAAs cause no symptoms.
After rupture: If an AAA ruptures, symptoms could include sudden and severe pain in the lower abdomen or back, nausea and vomiting, clammy, sweaty skin and light-headedness, or loss of consciousness.
A doctor may recommend an abdominal ultrasound screening test if you are a man who is:
The main risk factor for AAA is smoking—past or present. Quitting smoking reduces the chance of developing an aneurysm or it getting worse.
Men with AAAs also often have clogged and stiffened arteries (atherosclerosis) and high blood pressure, most likely also related to smoking. Although lowering cholesterol and blood pressure would help such men improve their overall cardiovascular health, it won’t prevent aortic aneurysms. But there is still an important benefit of controlling high blood pressure and cholesterol for men at risk of AAAs.
It is better to have an abdominal ultrasound for AAA in order to prevent or diagnose the risk. Aneurysms run in families. If a first-degree relative has had an AAA, you are 12 times more likely to develop an abdominal aortic aneurysm. Of patients in treatment to repair an AAA, 15–25% have a first-degree relative with the same type of aneurysm.