What is AAA?

An abdominal aortic aneurysm (AAA) is a sac-like enlargement of the lower portion of the aorta.  While the exact cause is unknown, AAA begins with a weakened spot in the aortic wall.  Over time, the constant pressure of circulating blood can stretch out the aorta, much like an inflating balloon.  If the aorta grows to 1.5 times its normal diameter, this by definition constitutes AAA.

The silent killer that no one knows about

Each year approximately 15,000 Americans die from a ruptured AAA, making the condition similar in magnitude to emphysema or renal disease.  While those better-known conditions have recognizable signs and symptoms, however, AAA is generally asymptomatic.  Rarely will the condition bring patients into the office with complaints.

In fact, 75% of AAAs are detected incidentally-usually during an imaging scan performed for unrelated reasons.

Who is at risk?

People over the age of 60, especially men, have the highest risk of developing AAA.   There is also strong correlation with smoking.  A 1999 study found that current smokers were 7.6 times more likely to have AAA than non-smokers, and that former smokers were 3 times more likely.

A family history of AAA, however, is an independent risk factor.  Individuals diagnosed with AAA have a 20% chance of having a close relative with the condition.

Early detection

During your physical exam your physician can perform an abdominal palpation of the aorta.  They can then look for an unusually wide aorta, as well as a pulsating or tender mass.

Ultrasound examination (the screening method of choice) is 82-99% accurate in diagnosing AAA.  It can frequently identify aneurysms that are not discovered by palpation.

For those with a family history, ultrasound screenings should not be delayed until the patient reaches age 60.  If a close relative experienced a rupture at 45, for example, it makes sense to have your physician screen you before or around that same age.

Should I see a specialist for AAA?

If you have a small aneurysm, the risk of rupture is low-approximately 1%.  This typically warrants a "watchful waiting" approach, where regular ultrasound surveillance is employed to closely track the aneurysm's growth and morphology.

If the AAA attains a diameter of 4.0-5.0 cm, or causes symptoms, a procedure may be recommended to repair the aorta and prevent a rupture.

Thus, if you have an aneurysm it may be appropriate for your physician to refer you to a vascular specialist.  This could be a surgeon or, in some cases, an interventional radiologist with training and experience in minimally invasive AAA repair.