Austrian study reports reduced recurrence rate

MONDAY, Nov. 27 (HealthScout) -- Austrian doctors say they may have solved a persistent problem for people with fat-clogged leg arteries that make walking painful or impossible: radiation therapy.

The arteries can be cleared by angioplasty, in which a balloon is used to widen the artery and improve blood flow. But the chance that a leg artery will become clogged again (the medical term is restenosis) is 50 percent or greater.

The solution, say doctors at the University of Vienna, is to give the clogged portion of the artery a brief dose of radiation, implanting a wire with a radioactive tip for three to five minutes. A group led by Dr. Erich Minar, professor of internal medicine at the University of Vienna, reports that a controlled study found major benefits for radiation therapy immediately after angioplasty. The study appears in the Nov. 28 issue of Circulation: Journal of the American Medical Association.

Only 34 percent of the radiation-treated arteries in 63 patients became clogged again one year after therapy, compared with a 65 percent recurrence rate in 50 patients who got only angioplasty. And none of the radiation-therapy patients had full blockage, which occurred in four angioplasty-only patients.

This is not a treatment for all patients with clogged leg arteries, says Minar. "We only advise it for patients with a high risk of restenosis or long lesions, 5 centimeters (2 inches) or more."

Few side effects

The side effects are minimal, because Minar says only a small area is exposed to radiation for a brief period. There is a possibility that radiation could cause long-term damage to the arterial wall, "but we haven't seen it in our patients," he says.

Radiation therapy for clogged leg arteries is a logical extension of its use for clogged heart arteries, says Dr. Lynn Smaha, immediate past president of the American Heart Association and senior vice president for academic affairs of the Guthrie Clinic in Sayre, Pa. About 20 to 30 percent of heart arteries become clogged again after angioplasty, even when cardiologists insert a stent, a metal tube, in the artery. This year, the Food and Drug Administration approved radiation therapy for such cases.

"The restenosis rate in peripheral arteries is even worse, 50 to 70 percent," Smaha says. "There tends to be a long lesion and a worse reduction in blood flow."

In a few cases the blood supply is so poor that gangrene sets in, he says. Much more often, the complaint is intermittent claudication, severe cramps of the leg muscles that set in after even a brief walk, so that the patient has to stand still for a few minutes until the pain abates.

So the question is, "Will this radiation procedure help prevent restenosis? This study makes you think that it might," Smaha says.

But the case is not proven, Smaha says. The one-year follow-up in the Austrian study may not be enough to determine the long-term effects of radiation therapy, "and we need more studies to look at both safety and efficacy. But it raises an idea of where we might go," Smaha says.

Nevertheless, Minar says, "This is the first time we have demonstrated an intervention that can possibly reduce the incidence of restenosis." And the technique is still being refined, he says.

"We did get a recurrence rate of 33 percent in the treatment group. We are trying to abolish restenosis completely by developing an optimal dose of radiation and perhaps combining radiation with stenting," Minar says.

What To Do

Persons experiencing intermittent claudication can ask their doctors about angioplasty and other treatments, including radiation. The American Heart Association has more on stenosis of the arteries and angioplasty.

(From HealthScout)