AAA: Are You at Risk?

By: Dr. David Neschis

The aorta is the largest blood vessel in the human body. It carries blood from your heart up to your head and arms and down to your abdomen, legs, and pelvis. The walls of the aorta can swell or bulge out like a small balloon if they become weak. This is called an abdominal aortic aneurysm (AAA) when it happens in the part of the aorta that's in your abdomen.

AAAs don't always cause problems, but a ruptured aneurysm can be life-threatening. Therefore, if you're diagnosed with an aneurysm, your doctor will probably want to monitor you closely, even if they don't intervene right away.

An abdominal aortic aneurysm (AAA) occurs when the wall of the aorta, the main artery in the chest and abdomen, progressively weakens. This causes a dilation of the vessel. The aneurysm will grow larger and eventually rupture if not diagnosed and treated. Most aneurysms are caused by a breakdown in the proteins providing structural strength to the wall of the aorta. While these proteins can gradually deteriorate with age, some conditions accelerate the process, including atherosclerosis, an excess of certain enzymes and in rare cases, infection.

Major risk factors for AAA are as follows:

• Age over 60 years
• A family history of AAA
• Smoking
• Hypertension (high blood pressure)
• More common in men than in women

Most patients have no symptoms at the time an AAA is discovered. In fact, many are detected during tests performed for unrelated reasons. One common symptom is severe back or abdominal pain. AAAs are usually classified by their size and the speed at which they're growing. These two factors can help predict the health effects of the aneurysm.

Small (less than 5.5 centimeters) or slow-growing AAAs generally have a much lower risk of rupture than larger aneurysms or those that grow faster. Doctors often consider it safer to monitor these with regular abdominal ultrasounds than to treat them.

Large (greater than 5.5 centimeters) or fast-growing AAAs are much more likely to rupture than small or slow-growing aneurysms. A rupture can lead to internal bleeding and other serious complications. The larger the aneurysm is, the more likely that it will need to be treated with surgery. These types of aneurysms also need to be treated if they're causing symptoms or leaking blood.

When diagnosed early, treatment is safe and effective, and the aneurysm is cured. Minimally invasive catheter-based technologies using endovascular grafts have changed the treatment of AAAs. In the past, all patients with AAAs required major surgery with an extended recovery period. Today, up to 70% of all AAAs can be treated using endografts. The advantages of using endografts include:

• Small incisions in the groin rather than a major abdominal incision
• Lower risk – especially for patients with other serious medical problems
• Hospital stay is usually 1-2 days compared to 7-10 days for open surgery
• Return to normal activity in days rather than weeks

Special CAT scan imaging techniques are used to find out if an AAA can be treated with an endograft since this less invasive treatment cannot be performed in every case. Some AAAs still require open surgical treatment which is still the most effective and durable. When AAAs have been treated with an endograft, extended follow up with ultrasound and CAT scans is required.

It is always important to have an annual physical and consult with your health care provider. A simple ultrasound test is all it takes to find out if you are at risk for AAA.

- David Neschis, M.D., is a vascular surgeon at The Vascular Center at University of Maryland Baltimore Washington Medical Center. He can be reached at 410-553-8300.