New Therapies Offer Novel, Minimally Invasive Options for Patients with PAD

New Therapies Offer Novel, Minimally Invasive Options for Patients with PAD

By Rebekah McCallister

MIAMI—The advantages of 2 novel therapies for the treatment of blocked leg arteries of patients with peripheral arterial disease (PAD) were presented at the 17^th Annual International Symposium on Endovascular Therapy recently.

Nonsurgical CryoPlasty

CryoPlasty is a relatively new therapy that cools and opens leg arteries clogged with plaque, which is characteristic of advanced stages of PAD. Preliminary data from the Below-the-Knee Chill trial, an ongoing, multicenter clinical study involving 30 US hospitals, have shown that this procedure successfully treated all 22 patients with PAD. The study intends to enroll up to 100 patients with critical limb ischemia.

Available data presented at the meeting and recently published (J Vasc Interv Radiol. 2004;15;1239-1243) show that treatment resulted in a ³50 reduction of artery stenoses in all 22 patients; specifically, the average blockage was 19%, compared with 87% before treatment. Ankle or toe pulses also improved immediately after treatment in 17 of 20 patients (85%), and no adverse events were reported.

CryoPlasty offers patients, including those with diabetes, an option other than amputation, James D. Joye, DO, director of the Cardiac Catheterization Lab, El Camino Hospital, California, and coinventor of the technique, told Internal Medicine World Report. “Previously, amputation was the only option for some people with such advanced disease in arteries below the knee, many of whom were diabetic,” Dr Joye explained.

Results also showed that 83% of patients’ arteries have remained open after 9 months, and 89% of patients have reported significant reduction in leg pain while walking.

“This technique was successful among all age groups, in diabetic and nondiabeteic patients, and above and below the knee,” Dr Joye said. He added that this new therapy “offers early, conservative management and can be used repeatedly—not only avoiding or delaying amputation, but postponing the use of more invasive procedures.”

Unlike traditional angioplasty, CryoPlasty involves the insertion of a new, smaller-sized catheter (approved by the FDA) to advance a balloon to the site of the blockage. The balloon is filled with nitrous oxide, rather than saline, which cools the balloon to -10°. This generates physical responses that unlock the artery, causing less scarring than traditional angioplasty.

“This area doesn’t get due attention. We hope this new technique will help raise awareness among primary care physicians that there is progress in the field,” Dr Joye said.

First Bioabsorbable Stent

The second therapy involves the first bioabsorbable metal stent for PAD. The new stent eliminates the possibility of recurrent stenosis, which occurs in as many as 40% of patients when treated by other methods or other types of stents.

Preliminary study results presented at the meeting and recently submitted to the Journal of Endovascular Therapy, show that 20 patients had the absorbable stent placed in severally blocked arteries below the knee; at 6 months posttreatment, 15 of 19 (79%) arteries remained open. Typically, after treatment with standard stents, approximately only 60% of below-the-knee arteries remain open, Marc Bosiers, MD, lead author of the study and head of the Department of Vascular Surgery at A.Z. Sint-Blasius Hospital, Dendermonde, Belgium, pointed out.

“A stent is really only needed a couple of weeks, to allow the blood vessel to reshape and get strong, and after that it is useless,” Dr Bosiers said.

The absorbable stent is made of an alloy of 90% magnesium and 10% rare earth elements. It takes approximately 7 to 10 days for the stent to begin to be absorbed by the body, with the stent being fully absorbed 60 days after implantation, according to study results.

Ongoing trials are investigating the use of this stent in coronary arteries; results are expected later this year.