What is an aortic aneurysm?

Your doctor ordered the ultrasound of your abdomen to check for gallstones. But it revealed something unexpected — a bulge in the main artery (the aorta) in your abdomen. An aortic aneurysm. You've had no symptoms, nothing to warn you that one of your blood vessels could burst.

An aneurysm is a bulge in the wall of an artery. It usually occurs when an artery wall becomes weak or damaged by the accumulation of fatty deposits (atherosclerosis). Atherosclerosis is sometimes referred to as hardening of the arteries.

Aneurysms can form in any artery, anywhere in your body, including an artery in your brain (brain aneurysm). However, most aneurysms occur in the aorta — the body's largest artery. The aorta, which resembles a garden hose in thickness, runs from your heart down the center of your chest and abdomen, eventually splitting off into two arteries, one that serves each leg.

Although an aneurysm can develop anywhere along your aorta, most occur in the section running through your abdomen (abdominal aneurysms). The rest occur in the section that runs through your upper chest (thoracic aneurysms).

Chest X-rays: Useful images of your heart and lungs What is ultrasonography? Computerized tomography MRI

Complications

Aneurysms are serious because they may rupture, causing life-threatening internal bleeding. In general, the larger the aneurysm, the greater the risk of rupture. The risk of rupture is high when an aortic aneurysm exceeds 2 inches (about 5 centimeters, or cm) in diameter. Normally, the diameter of a healthy aorta ranges between 3/4 inch and 1 inch (about 2 to 2.5 cm).

Symptoms that an aortic aneurysm has ruptured — which is a medical emergency — include sudden, intense and persistent abdominal pain that may radiate to the back or legs, with sweatiness, clamminess, dizziness, low blood pressure, fast pulse and possible loss of consciousness.

Aortic aneurysms can house small blood clots. These clots may break loose and block a blood vessel downstream from the aneurysm, causing pain or potentially life-threatening problems, such as a ministroke (transient ischemic attack, or TIA) or a full-blown stroke.

Transient ischemic attacks and aortic aneurysms: Any connection? Stroke

Treatment

Treatment for an aortic aneurysm depends on its size and location and your general health. If your aortic aneurysm is small and you have no symptoms, your doctor may suggest a watch-and-wait approach. In general, people with small abdominal aneurysms — less than 2 inches (about 5 cm) in diameter — can be safely monitored with ultrasound and don't require surgery to repair the weakened section of artery until the risk of rupture outweighs the risk of surgery.

However, if you have an abdominal or chest aneurysm that is large or enlarging rapidly, is leaking or is showing signs that rupture is likely, you'll probably need surgery. The two main types of surgery for an aortic aneurysm are:

• Open abdominal or chest surgery. This standard operation repairs an aortic aneurysm. It involves your doctor opening your abdomen or chest and stopping blood flow in the aorta so that the damaged section can be replaced with a synthetic tube (graft), which is sewn into place. Although this surgery is generally successful, because it requires an incision in your abdomen or chest, the recovery time is lengthy. Recovery may take longer than 6 weeks, including a weeklong stay in the hospital.
  
  
• Endovascular surgery. Doctors at major medical centers are using this newer procedure on abdominal aortic aneurysms. In the procedure, a synthetic graft is attached to the end of a thin tube (catheter) that's inserted into your bloodstream, usually through an artery in your leg. The catheter is threaded upstream to your aorta and used to position the graft, which is basically a woven tube covered by a metal mesh, at the site of the aneurysm. Once in place, the graft is inflated and fastened in place with small hooks or pins. The graft reinforces the weakened section of the aorta to prevent rupture of the aneurysm. Although endovascular surgery reduces recovery time to a few days, it still carries risk. And long-term results are unknown. Still the procedure may benefit those who need surgery to repair an aortic aneurysm but are at high risk of complications because of pre-existing medical problems.

A ruptured aortic aneurysm may be repaired with emergency surgery. But the outcome generally is less successful than if the problem is detected and treated before rupture. Many people who experience a ruptured aortic aneurysm die before they reach the hospital. Of those who have emergency surgery to fix a ruptured aortic aneurysm, only about half survive.

Fortunately, most aortic aneurysms never rupture. And doctors continue to research new methods to diagnose and treat aortic aneurysms. For example, researchers are studying a small sensor device that could be implanted within an aortic aneurysm to help doctors gauge whether an aneurysm is enlarging and at what rate.

Prevention

There's no pill you can take to prevent an aortic aneurysm. Researchers are studying whether heart drugs called beta blockers and a class of antibiotics called tetracyclines slow growth of small aortic aneurysms. It's too early to say whether these drugs will be effective.

For now the best approach to prevent an aortic aneurysm is to keep your blood vessels as healthy as possible. That means taking these steps:

• Keep your blood pressure under control.
  
  
• Don't smoke.
  
  
• Get regular exercise.
  
  
• Reduce cholesterol and fat in your diet.

Stopping smoking is particularly important because smoking increases the risk of aneurysm enlargement.

If you're 55 or older and have hardening of the arteries (atherosclerosis), talk to your doctor about your potential risk. If you're at risk, your doctor may recommend additional measures, including medications to lower your blood pressure and relieve stress on weakened arteries.

High blood pressure Monitoring your blood pressure at home High blood cholesterol Physical activity: It all adds up to good health Exercise Program Healthy Weight Stop Smoking Program

— October 1, 2002 —

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