ABDOMINAL AORTIC ANEURYSM

An abdominal aortic aneurysm (AAA or triple A) is a balloon-like bulge that forms in a weakened area in the abdominal aorta, the major blood vessel in the abdomen. Abdominal aortic aneurysms are dangerous because they can rupture. Rupture is almost always fatal. If you know that you have an aneurysm of the abdominal aorta, you should be prepared to have it repaired and understand the warning signs of impending rupture while you wait for the surgery. You can take steps to treat the problem and prevent a rupture.

Understanding Abdominal Aortic Aneurysm

The aorta is the artery that carries blood directly from the heart. Blood then flows from the aorta into smaller arteries that supply the rest of the body. The abdominal aorta is the term used for part of the aorta that travels through the abdomen (stomach area).

An aneurysm occurs when part of the aortic wall is weakened. This weakened area thins as it expands which can lead to rupture, meaning it leaks, bursts open or tears. The risk of rupture is directly related to the size of the aneurysm and the rate at which it is growing. Aneurysms less than 4cm are unlikely to spontaneously rupture. The risk of rupture is moderate when the aneurysm in between 4 and 6cms. Greater than 6cm aneurysms are very likely to rupture, as are aneurysms that are growing quickly.

Signs and Symptoms

An abdominal aortic aneurysm is a "silent" problem because it usually causes no symptoms. A healthcare provider sometimes discovers it during a routine exam. More often, testing for unrelated problems may lead to the discovery of abdominal aortic aneurysms. Once found, your healthcare provider will order other tests to measure its size and follow its growth.

Aneurysms become symptomatic when a pulsing sensation is felt in the abdomen with each heartbeat; sudden severe lower back pain is present; or abdominal tenderness is noted. The abdominal aortic aneurysm may be rupturing when these symptoms are accompanied with dizziness and shortness of breath. Rupture is a life-threatening emergency. If you notice these symptoms and have been told you have an AAA, call 911 right away.

Risk Factors

The exact cause of abdominal aortic aneurysms is unknown. They are most common after the age of 60. Men are more likely to develop this condition than women are.

Other common causes include:

  • Atherosclerosis (a gradual buildup of plaques in blood vessels)
  • High cholesterol
  • Cigarette smoking
  • High blood pressure
  • Blood vessel disease in another part of the body
  • A close relative (parent, brother or sister) who has had an abdominal aortic aneurysm

Diagnosis

A physical exam and test results give your healthcare provider more information about your abdominal aortic aneurysm. The exam will include special attention to your abdomen and questions will be asked about your family's medical history as well as your own. Certain tests measure the size of the aneurysm. They can track changes in the aneurysm over time. Other tests assess blood flow. These may be done if it is decided that you need surgery.

Imaging Tests

Imaging tests create pictures of the arteries. This helps determine the size and shape of the aneurysm. Contrast fluids used for some tests may contain iodine, so be sure to tell the technician if you have any allergies to iodine or seafood.

  • Ultrasound uses sound waves to create an image of the blood vessels.
  • CT (computed tomography) is a series of x-rays taken with a special x-ray machine. Computers use these x-rays to create a picture of the aneurysm. Before this test, you may be given contrast fluid through an IV (intravenous) line. This helps arteries show up clearly.
  • MRI (magnetic resonance imaging) makes images by analyzing energy released by tissues in the body after exposure to a strong magnet. This test uses a different type of contrast.
  • Arteriography (aortogram) is a contrast study in which a catheter is inserted into the main artery in the groin. This catheter is then advanced under X-ray up into the abdominal aorta. An x-ray motion picture is then taken as the contrast dye is injected. This gives a picture of the inside of the aorta and the aneurysm and the blood vessels that come off of the aorta.
  • Doppler study uses a special probe that listens to the blood flow in arteries. It can detect blockages and areas of narrowing (stenosis).

Treatment

Your options for treatment depend on many factors. How big is the aneurysm? Is it growing? If so, how quickly? How is your overall health? Considering these and other factors can help you weigh the risks and benefits of each type of treatment. Then you and your healthcare provider can decide what to do. Before making a decision, be sure that all your questions have been answered.

Watchful Waiting

A small aneurysm (less than 4cm) is unlikely to rupture. If your aneurysm is small, your healthcare provider may suggest watchful waiting. This means that you see your healthcare provider for a re-examination and testing to watch the size and growth of the aneurysm. Watchful waiting includes:

  • Periodic ultrasounds or CT scans follow the progression of the aneurysm.
  • Reducing the risk of rupture. Controlling factors - such as blood pressure and blood sugar levels if you have diabetes - may make your aneurysm less likely to grow or rupture. It can also help improve the health of your arteries. This helps you prepare for surgery if that becomes necessary.
  • Being alert for symptoms of rupture.

If an aneurysm is moderate to large or growing quickly, the risk that it will rupture increase dramatically. Since the risk of dying with rupture of an abdominal aortic aneurysm is very high, elective repair of the aneurysm should be considered.

Open surgical repair is the most common treatment for abdominal aortic aneurysms. A single large incision is made in the abdomen. The portion of the aorta that contains the aneurysm is removed and a graft, made of strong synthetic material, is then sewn into the artery above and below the aneurysm. For some people, open surgery may be the only way to repair the aorta. Open surgery has been used for many years, and it has a good long-term track record. For younger people, open surgery may ensure that the graft lasts over time.

An endovascular stent graft repairs an aneurysm without major surgery. Benefits of this type of surgery include less blood loss and fewer days in the hospital allowing a quick return to normal activities.

Those who are at high risk for complications of open surgical repair because of pre-existing medical problems may be good candidates for endovascular repair. It consists of very small incisions made in the groin. The graft is inserted into an artery through an incision and guided to the aneurysm. This type of repair is newer than open repair. It requires close follow-up even if you feel fine. Also, be aware that in some cases the size and shape of a person's blood vessels rule out endovascular repair.

Your health care provider will discuss these types of repair with you and determine which treatment plan is best for you.

What to Do

Live a healthier life. Part of watchful waiting is reducing the risk that the abdominal aortic aneurysm will rupture. Even if your aneurysm has been fixed, you are still at risk of artery disease in other parts of the body. You cannot change your age or family history, but you can change many of the other factors. There are actions you can take to reduce your rupture risk and keep your arteries healthier.

  • Stop smoking. It is one of the most important things you can do. It lowers blood pressure and helps prevent further damage to the arteries, heart and lungs.
  • If you have hypertension, monitor your blood pressure closely, reduce sodium in your diet and take your medication as directed.
  • Maintain a healthy weight. If you are overweight, losing as little as 5 or 10 pounds can improve your health. Choose low fat, low-cholesterol foods.
  • Daily aerobic exercise can lower your risk of artery problems. It helps lower body weight and body fat, control blood pressure, reduce stress and help most persons with diabetes control their disease and strengthen the heart. Consult your healthcare provider before beginning an exercise program. Your clinician may order an exercise stress test to determine whether your heart is fit for exercise.
  • Control your blood sugar if you have diabetes. Diabetes raises the level of glucose (sugar) in the blood. This may damage arteries and worsen artery disease. Try to keep your blood sugar concentration as close to the goal suggested by your healthcare provider as possible.

Screening for Abdominal Aortic Aneurysm

AAA runs in families. This means that your parents, brothers, sisters and children could be at risk. Screening could save the life of someone you love. Urge your family members to ask their healthcare providers about screening for AAA.

When to Call Your Health Care Provider

A ruptured abdominal aortic aneurysm is an emergency! CALL 911 right away if you have severe back pain and tenderness in your stomach area. You may also feel lightheaded or dizzy.

What We Have Learned

An abdominal aortic aneurysm is a balloon-like bulge in a major blood vessel, the aorta.

True or False

The answer is True

A large aneurysm is likely to rupture.

True or False

The answer is True

The risk of dying with a ruptured aneurysm is very high.

True or False

The answer is True

For More Information

U.S. National Library of Medicine

8600 Rockville Pike

Bethesda, MD 20894

http://www.nlm.nih.gov/medlineplus

American Heart Association

National Center

7272 Greenville Avenue

Dallas, TX 75231

1-800-242-8721

http://www.americanheart.org/

National Heart Lung and Blood Institute

Health Information Center

P.O. Box 30105

Bethesda, MD 20824-0105

1-301-592-8573

http://www.nhlbi.nih.gov/

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