Abdominal Aortic Aneurysm or Dilation

Abdomen | Cardiology | Abdominal Aortic Aneurysm or Dilation (Disease)


Aneurysms are defined as a focal dilatation in an artery, with at least a 50% increase over its normal diameter. Thus, an enlargement of at least 3 cm of the abdominal aorta fits the definition. Abdominal aortic aneurysms (AAAs) are relatively common and are potentially life threatening.

Most AAAs are asymptomatic, and many are detected as an incidental finding on diagnostic imaging obtained for other reasons. There is a wide spectrum of clinical presentations and AAA should be considered in the differential diagnosis for a number of symptoms.

Causes and Risk factors

AAA usually results from degeneration in the media of the arterial wall, leading to a slow and continuous dilatation of the lumen of the vessel. Uncommon causes include infection, cystic medial necrosis, arteritis, trauma, inherited connective-tissue disorders, and anastomotic disruption.

AAAs generally affect elderly white men. Smoking appears to be the risk factor most strongly associated with AAA. In addition to increasing age and male sex, other factors include increased height, weight, body mass index, and body surface area. A familiar clustering has been noted in 15-25% of patients undergoing surgical repair of AAA. Female sex, African American race, and presence of diabetes mellitus are negatively associated with AAA.

Diagnosis and Treatment

Ultrasonography is the standard imaging tool for AAA. Bedside emergency ultrasonography should be performed immediately if AAA is suspected.

Treatment of abdominal aortic aneurysms (AAAs) is with surgical repair. When indicated, unruptured aneurysms can undergo elective repair. The combination of ultrasonographic screening, reduced preoperative risk, and new minimally invasive techniques extend aortic aneurysm treatment into an increasingly elderly population. Ruptured AAAs require emergent surgical repair....