Paclitaxel-Coated Angioplasty Balloons Beneficial in PAD

MIAMI BEACH?Coating an angioplasty balloon with a drug used in the treatment of breast cancer can prevent restenosis in narrowed leg arteries, ?investigators reported at the 18th annual International Symposium on Endovascular Therapy.

The technique for using paclitaxel (Taxol) to coat angioplasty balloons was developed by a team of German re?searchers and described by Gunnar Tepe, MD, of the University of T?bingen.

Drug coating of the stents used to open blocked coronary arteries and keep them open has become a common and effective practice. As Dr Tepe explained, the drug prevents the growth of scar tissue that can cause the blood vessels to renarrow. "We are employing the same drug concept used in drug-coated stents, except that the drug is delivered in a much shorter period of time, and we don't leave behind a foreign object, a coated stent, which itself can cause problems down the road," he said.

The new technique holds promise for the 8 million to 12 million people in the United States diagnosed with peripheral artery disease (PAD), in which plaque in the leg arteries interferes with circulation. Angioplasty, the common treatment for PAD, has to be repeated in about 40% to 50% of cases because of restenosis. Although using drug-coated stents to prevent restenosis in the coronary arteries is not new, until now the technique had failed to show any superiority over bare-metal stents in the ?considerably larger leg arteries.

This trial was started in 3 centers with 135 patients and was expanded to 154 patients who were divided into 3 groups, which Dr Tepe described as "one with a normal balloon, another with a balloon coated with paclitaxel, and a third that had the same amount of paclitaxel added to the contrast media for control." He said that about 50 patients received the drug-coated balloon.

Key points

PAD patients often require a second angioplasty due to restenosis.

Drug-coated stents help prevent restenosis in coronary arteries.

Coating angioplasty balloons with paclitaxel reduces risk of restenosis in leg arteries.

Because of the low dose used, there are no side effects.

Interim analysis of early data from 25 patients with an uncoated balloon and 20 with a coated balloon found a significant difference between the 2 groups. "It seems to work," Dr Tepe said. "We did not see any adverse effects, no late thrombosis, no subacute thrombosis. The restenosis rate was very low."

A cancer drug was chosen to coat the angioplasty balloon, because it is easy to deliver and stops cell proliferation as soon as the cells come into contact with it. With other drugs, after the drugs are taken away, restenosis begins. The balloon delivers paclitaxel in 1 dose to the blood vessel's wall, where it starts working immediately and where it stays. Animal experiments have shown that the effect persists despite a rapidly decreasing drug concentration. There are no side effects, in part because the dose is very low?1% to 2% of that used for chemotherapy. The investigators plan to follow the patients for at least 2 years to be sure that no restenosis occurs.

Based on these early results, Dr Tepe is confident that the drug-coated ?balloons are superior to the uncoated ones. He believes more research and careful analysis of the data will confirm the findings of this study and lead to other applications. "If research bears out, drug-coated balloons could be a useful option for treating blocked arteries. In particular, they could play a major role in peripheral arteries, because the incidence of restenosis is higher than that in all other parts of the body," he said.?L.D.