Demetrios Spanos was shocked when his doctor told him that he had found a potentially life-threatening weak spot in his aorta during a check-up.

He had no symptoms, partly because the weak spot, called an aneurysm, was still small.

For the next few years, doctors monitored Spanos's aortic aneurysm until it reached a dangerous size and required surgery to prevent it from bursting and causing potentially fatal internal bleeding. Today, almost a year after his successful surgery, Spanos credits early detection with saving his life.

Routine screenings are important in early detection and treatment of aortic aneurysms, especially because frequently there are no symptoms or warning signs.

This kind of screening may soon become routine. As of this year, many newly qualified Medicare patients will be able to receive screening for aneurysms as part of their regular physical exam. Men age 65 and older who are current or former smokers, and both men and women who have a family history of aortic aneurysms, are eligible for the free screening - a painless ultrasound test similar to the kind performed on pregnant women.

Routine screenings are important in early detection and treatment of aortic aneurysms, especially because frequently there are no symptoms or warning signs.

"Most of us recognize the recent changes in Medicare law as the beginning of something that is very logical. It's a real benefit to society, and these early screening programs will save many lives," says vascular surgeon James Stanley, M.D., of the University of Michigan Cardiovascular Center, who operated on Spanos.

Approximately 15,000 Americans die each year from ruptured aortic aneurysms, and it is the 10th most common cause of death in the United States. An aortic aneurysm occurs when the walls of the aorta weaken and the artery begins to bulge. If left untreated, the aorta may eventually burst.

"When that happens, it's a disaster," says Stanley, the Handleman Research Professor of Vascular Surgery. "If rupture occurs outside of a hospital setting, there's at least an 80 percent chance that the patient will die. So the whole idea is to recognize these aneurysms beforehand and treat them before they can rupture."

If an abdominal aneurysm is detected and needs attention immediately, it can be easily treated. There are two basic types of therapy. One type of treatment, widely used for the past 50 years, is to make an incision in the abdomen and clamp the aorta above and below the aneurysm, and replace it with a Dacron or Teflon tube graft. A newer, so-called endovascular method, is minimally invasive and involves eliminating blood flow into the aneurysm by re-channeling the blood from above the aneurysm to below it. This method uses a tube graft that is threaded into the aorta from an artery in the groin, the same artery used for heart catheterizations. Both types of therapy have over a 95 percent chance of success.