A stretched and bulging section in the wall of the aorta is called an aortic aneurysm; this can be a serious health risk because the aorta is the largest and most important artery, carrying oxygen-rich blood from the heart to the rest of the body. A bulging aorta is weakened and can burst, or rupture, resulting in life-threatening bleeding. A ruptured aortic aneurysm is the fifteenth most common cause of death in our country, and occurs in one out of every twenty older men.

Depending on where the aneurysm is located, it is sub-classified two different ways, as either a thoracic aortic aneurysm or an abdominal aortic aneurysm, that is, in the chest or stomach region respectively.

In the past, repairing an aortic aneurysm involved making a large incision in the chest or abdomen, redirecting blood flow around the aneurysm during the surgery, removing the aneurysm, and replacing the excised section of the aorta with a man-made graft.

A newer, and less invasive technique is the placement of a synthetic Dacron patch (called a stent graft) using a catheter instead of using the chest incision. This is called endovascular, i.e. "inside the blood vessel" aortic repair. The surgeon slides the patch through an artery in the groin to the stressed area of the aorta, to "patch" the inside of the affected part; the basic principle is similar to patching a bicycle or car tire. Stent grafts are usually considered an alternative to traditional surgical repair of aortic aneurysms, especially in situations where surgery might be too risky for a particular patient.