Abdominal Aortic Aneurysm (AAA)

Aorta: AAA

What is it?

An aneurysm is a bulge in the wall of an artery, usually the aorta. The aorta is the largest blood vessel in the body. It receives all the blood from the left ventricle of the heart, and continues from the heart, through the chest, and on to the abdomen. It supplies blood to every organ in the body, except the lungs. An abdominal aortic aneurysm (AAA) affects the segment of the aorta that runs through the abdomen.

Who gets it?

Abdominal aortic aneurysm is common in older adults. There appears to be a genetic link because this type of aneurysm tends to run in families. People who smoke cigarettes are more likely to die from a ruptured abdominal aortic aneurysm than nonsmokers.

What causes it?

Abdominal aortic aneurysm usually occurs in people with atherosclerosis, also known as hardening of the arteries. As the arteries harden, the wall of the aorta is damaged and weakened. The pressure of the blood flow inside the aorta causes the weakened wall to bulge outward. High blood pressure also contributes to weakened aortic walls.

What are the symptoms?

Abdominal aortic aneurysm may not cause any symptoms at first. When symptoms do occur, they include a pulsing sensation in the abdomen, and pain ranging from mild to severe. Pain may be located in the abdominal, back, or groin area. Sudden, excruciating pain in the lower abdomen and back pain usually indicates a ruptured aorta, which needs to be treated immediately.

How is it diagnosed?

Because abdominal aortic aneurysms may not cause any symptoms until the condition has progressed, they are usually diagnosed by chance during a routine physical examination. The doctor may feel a pulsing, tumor-like mass in the middle of the abdomen. If the aneurysm is about to rupture, it may hurt or feel tender when pressed. It is important to determine its size because the larger the aneurysm, the greater the risk of rupture. The most commonly used test is an abdominal ultrasound, a painless procedure in which a small scanning device is pressed against the abdomen. Sound waves bounce off the internal organs and produce a picture on a video screen. The picture shows the size and length of the aneurysm.

What is the treatment?

Treatment depends upon the size of the aneurysm. If the aneurysm is less than 4 cm (1.5 in) wide, surgery is not necessary, but your doctor will monitor it carefully for an increase in size. Aneurysms between 4 and 5 cm (1.5 - 2 in) wide may be treated with surgery if you and your doctor determine that is the best course of treatment. Aneurysms that are larger than 5 cm (2 in) or are causing symptoms are always treated with surgery, unless it is considered risky because of other health problems. The surgeon makes an incision in the abdomen, removes the aneurysm, and repairs it with a synthetic patch, called a graft. This type of surgery has a very high success rate. There is also another type of surgery called endovascular grafting, which involves inserting a thin tube called a catheter through a groin artery into the abdominal aorta. The catheter's tip holds a deflated balloon that is covered by a tightly folded graft. When the catheter is in position, the balloon is inflated, which causes the graft to open to span the length and width of the aneurysm. Devices at each end of the graft secure it to the inner wall of the aorta to strengthen the wall and prevent it from rupturing. This surgical method may not be available at all hospitals at this time and is only used for non-emergency repairs. Emergency surgery is performed when the abdominal aortic aneurysm has ruptured or is about to rupture. Because a ruptured aneurysm causes internal bleeding, there is a risk of damage to internal organs, such as the kidneys, because their blood supply is interrupted. If a ruptured abdominal aortic aneurysm is not treated, it always results in death.