A Medical Device Daily

Fully 100% of people facing almost certain amputation were successfully treated with a new non-surgical therapy that cools and opens leg arteries clogged with plaque, according to preliminary data on 22 patients presented at the 17th annual International Symposium on Endovascular Therapy (ISET) this week in Miami Beach, Florida.

First available in August to treat patients with arteries that are blocked below the knee, the new CryoPlasty therapy is now offered at nearly 800 sites in the U.S., including most major hospitals. The therapy is delivered by the PolarCath System developed by CryoVascular Systems (Los Gatos, California).

CryoPlasty therapy offers hope to people with lower leg arteries severely blocked as a result of peripheral arterial disease (PAD). These blockages, common in diabetic patients, can put people at risk for infection, leg ulcers, gangrene and amputation, the company said.

PAD affects about 10 million people in the U.S. and is a strong risk factor for other cardiovascular diseases, including heart attack or stroke. CryoPlasty fits into the treatment spectrum before the use of angioplasty and appears to avoid some of the complications seen in that procedure, researchers said. It also can be used to treat other vessels affected by PAD, including arteries in the thighs and abdomen.

“Previously, amputation was the only option for some people with such advanced disease in arteries below the knee, many of whom are diabetic,“ said James Joye, DO, director of the cardiac catheterization lab at El Camino Hospital (Mountain View, California), and co-inventor of the CryoPlasty technique. “CryoPlasty is a 'no harm' treatment that offers early, conservative management and can be used repeatedly — not only avoiding or delaying amputation, but postponing the use of more invasive procedures.“

The data presented by Joye at ISET are the first results from Below the Knee Chill, an ongoing multi-center study at 30 hospitals across the U.S., which will enroll 100 patients likely facing amputation of a foot or leg within six months. All of the patients in the study have critical limb ischemia, causing extremely poor blood flow.

Treatment in all 22 patients resulted in procedural success. After treatment, the average blockage was 19%, compared to 87% before treatment. Immediately after the procedure, ankle or toe pulses improved in 17 of 20 patients (85%), meaning blood flow increased. Pulses were not measured in two patients. There were no procedural complications or adverse events. Follow-up is ongoing.

Other data, on 102 patients who received CryoPlasty therapy to treat blocked upper leg or knee arteries, have shown: 83% of the arteries still open after nine months — compared to the typical rate of 59% of blocked blood vessels treated with traditional angioplasty remaining open after one year; and 89% of people reported an improvement in leg pain while walking.

CryoPlasty therapy involves the use of nitrous oxide, rather than saline, to inflate the balloon and cool it to -10 degrees. This in turn prompts several physical responses that open the artery and cause less scarring than occurs with traditional angioplasty. Repeat procedures for patients treated with standard balloon angioplasty and stent technology of the arteries below the knee are reported as high as 45%.

The below-the-knee CryoPlasty procedure is performed using one of several new smaller-sized catheters, which received clearance from the FDA.

“While this is a relatively new technology, the process is very familiar to physicians who perform angioplasty and its use is rapidly spreading in hospitals across the country,“ according to Joye.

CryoVascular Systems has a partnership with Boston Scientific (Natick, Massachusetts), a leader in vascular disease technology, to distribute the PolarCath System globally.

In another report at ISET:

• Frank Veith, MD, professor and vice chairman of the department of surgery at Albert Einstein College of Medicine (Bronx, New York), presented data demonstrating the successful use of a minimally invasive alternative to open surgery to repair aortic aneurysms.

The data covered 476 patients worldwide who received endovascular repair for burst aneurysms, of whom 385 survived and the remainder (19%) died. This compares to an average of 40% to 50% typically who die when open surgery is used to treat a ruptured aortic aneurysm.

Veith also reported on 37 patients treated with the endograft endovascular system at the Montefiore Medical Center (New York) where he is the William J. von Liebig Chair in vascular surgery. Of these, five (15%) died.

Endovascular repair is an increasingly common treatment for elective repair of an aneurysm that is at risk for rupture. The technique involves threading an endograft through a blood vessel in the groin and into the aorta. The flow of blood is redirected through the graft so the pressure on the aneurysm is relieved. Not everyone is a candidate for this procedure since endografts cannot accommodate all anatomies. As the therapy has increased in popularity, more options and sizes are available, making the procedure more readily available in emergency situations.

Veith emphasized that endograft repair avoids many risks of surgical repair, which involves making a large chest incision and replacing the weakened portion of the aorta with a graft. The risks involve greatly increased blood flow, dangerously decreased body temperature and potential injury to other organs.

“Before and during endograft repair, we allow the patient's blood pressure to fall to low levels by restricting fluid resuscitation. This limits the bleeding, and we have found this approach — which we call hypotensive hemostasis — to be very effective,“ he said.

Veith estimated that “as many as two-thirds of people who need treatment for a ruptured aortic aneurysm could be candidates“ for the endovascular surgery as opposed to open surgery.