Abdominal Aortic Aneurysms (AAA)

Aneurysms are caused by the weakening of the wall of an artery resulting in a "ballooning" of the artery. The aneurysm can grow larger and eventually burst if it is not found and treated. Aneurysms occur most often in the aorta, the main artery in the chest and abdomen, and the most frequent form is the abdominal aortic aneurysm (AAA). The aorta carries blood from the heart to all parts of the body including vital organs and the legs and feet.

There are about 15,000 deaths a year related to the rupture (bursting) of an aneurysm. Ruptured aortic aneurysms are the 10th leading cause of death in men over 50 in the U.S. A ruptured aneurysm is an emergency and procedures must take place immediately to save one's life and avoid serious complications.

Cause of Aortic Aneurysms
Certain structural proteins in the wall of the aorta provide strength and flexibility to this large artery. This is similar to muscles and tendons that provide strength to the arms and legs. Aneurysms are caused by a breaking or wearing down over time of these structural protein elements that lead to a weakness of the wall of the aorta which can make it expand like a balloon. These structural proteins, collagen and elastin, may gradually break down with age or when other diseases are present. For example, inflammation associated with atheroscerosis (hardening of the arteries) may accelerate this process, which can occasionally occur in people in their 50's. Some of the body's naturally occurring enzymes may also contribute to the breakdown in the wall of the aorta. An excess of these enzymes or conditions that activate the enzymes may cause an aneurysm to form, or suddenly grow. An aneurysm may occur more frequently in members of the same family. There is still much to be learned about the cause of aneurysms and their growth.

Symptoms and Detection
Most of the time there are no major symptoms for AAA prior to rupture. Occasionally, patients may feel abdominal, back or side pain. Some people may feel a "heart beat" in the abdomen or may notice their book bouncing while reading. Seventy-five percent of the aneurysms that are discovered are detected from diagnostic tests (such as x-rays, or ultrasound or CAT scan studies) that were given for other health problems. Many aneurysms can be detected by a carefully performed abdominal examination by a physician, but many cannot be felt. If the person is overweight, this is difficult. Overall, relying on symptoms or an examination to detect AAA's will miss many.

Who Is At Risk?

• People over 60 years old (Or over 50 with a family history of AAA)
• Tobacco use
• A family history of AAA
• History of an aneurysm in another place
• High blood pressure
• History of heart disease
• Peripheral arterial disease (PAD) or hardening of the arteries outside the heart

The risk of AAA increases with age and AAA's are 5-10 times more common in men than in women. People who smoke are eight times more likely to be affected than non-smokers.

How is it Diagnosed?
When AAA's are found early, treatment is usually safe, effective and the aneurysm is cured! Aneurysms are often found when diagnostic tests are performed for entirely different reasons, such as checking the spine, kidneys or gallbladder. Most patients have no symptoms, so if you are at risk, it is important to tell your risks for AAA to your doctor. Your doctor will probably examine your abdomen as a first method to detect an AAA.

Although AAA can be found by physical examination, most are diagnosed today using an abdominal ultrasound scan or computerized tomographic (CT) scan. These are simple, non-invasive examinations done on an outpatient basis. These tests also measure the size and shape of the AAAÑa very important factor when deciding the best treatment.

What are the Treatment Options?
If the AAA is larger than 5.5 centimeters in diameter (about the size of a lemon), it will need treatment. A doctor's decision to fix the AAA will take into account the risk of the aneurysm bursting, as well as the risk of the procedure and the general health of the patient with regard to other illnesses (such as heart disease or diabetes). Not all aneurysms, even large ones, will be safe to repair in individuals who are in poor health. As well, some smaller aneurysms that cause back or abdominal pain may need treatment, especially if they are found to be increasing in size rapidly.

Surgery
Open surgery on AAA has been performed routinely in this country for about 50 years. If done before the aneurysm ruptures, it is a very successful and long lasting procedure. During the surgery, the surgeon makes an abdominal incision, then replaces the diseased part of the aorta with a Dacron® or Teflon® graft that is carefully matched to the size of the person's normal aorta. This graft is sewn in place by the surgeon. Most patients stay in the hospital 5-7 days if no complications occur. It may take one to two months to return to a full and normal life.

After fifty years of doing this surgery, the facts show that:

• More than 95% of patients make a full recovery from surgery
• Once patients have recovered, their aneurysms are permanently cured in most patients.

Endovascular Treatment of AAA
Recent advances in catheter-based technologies have led to exciting new treatments for aortic aneurysms. Now, endovascular grafting allows the repair of the AAA by inserting a graft through a small incision in the groin. The graft is placed through the incision into a catheter or tube inserted into a groin artery. X-rays are used to make sure the graft is positioned in the right place in the AAA. The graft is then expanded inside the aorta and held in place with metallic hooks rather than stitches. The stay in the hospital is only one or two days and most patients can return to work or normal daily activities in about a week. Patients with other medical problems or those that could not survive major surgery can be considered for repair by an endovascular graft.

Endovascular grafting may not be possible or the best choice in every case. Endovascular grafts are specially manufactured and don't "fit" for every case. Regular surgery may still be best choice for many people. Endografts are fairly new, having been utilized for AAA repair for only a few years, as compared to a 50-year track record of success with surgery for AAA. Talk to your doctor about the best choice for you.

When an AAA ruptures it is an emergency!

• Ruptured (burst) aortic aneurysm is the 10th leading cause of death in men over 50 in this country.
• Many people with a ruptured AAA don't make it to the hospital. If they do, they often have very serious complications
.
• More than 15,000 Americans die each year due to ruptured aneurysms!

If I'm at risk, how can I prevent AAA?
All individuals at risk for AAA should control high blood pressure, high cholesterol, stop smoking, and avoid weight gain and inactivity. Regular checking by ultrasound, beginning at age 45-50, to make an early diagnosis is essential. Be sure to remind your doctor of your risks and the need for an ultrasound or other diagnostic test.

Dacron® and Teflon® are registered trademarks of DuPont.

For more information about AAA, visit our web site at www.vdf.org