High-Tech Relief For Peripheral Arterial Disease
Peripheral Arterial Disease
University of Pennsylvania School of Medicine researchers are the first in the Philadelphia region to begin using an innovative new drug-eluting stent to treat patients with peripheral arterial disease, the clogging and hardening of arteries that supply blood to the legs and feet. Afflicting ten million Americans, the disease is common among patients with diabetes and those who smoke, but studies show that only 25 percent of patients with the disease are undergoing treatment -- which doctors say is essential, since PAD can cause debilitating leg pain that makes it difficult to walk and even lead to amputations.
"We know that earlier diagnosis and interventions saves limbs," says Jeffrey Carpenter, MD, a professor of vascular surgery who is the principal investigator for the Zilver PTX Drug-Eluting Stent trial site at Penn.
Penn physicians say the Zilver trial allows them to build on university's long history of developing and advancing minimally invasive treatments for PAD, including those employing lasers and balloon angioplasties performed via catheter.
The Zilver stent, modeled on the same devices used to prop open blocked coronary arteries, is the first of its kind used to treat blockages in the major artery in the thigh. The stent is designed to provide both a mechanical and a chemical treatment for the blocked artery - placed through a minimally invasive catheter in the groin, the stent pops open like a scaffold inside the artery, and its paclitaxel drug coating aims to keep additional plaques from accumulating. This Phase II trial will test the effectiveness of that combination at keeping arteries open over time.
It's hoped that the device will help restore patients' function, decrease pain and eliminate the need for more invasive treatment such as bypass surgery. The trial will enroll 420 patients worldwide, about 80 at Penn. Participants will be randomized into two groups, one to receive the Zilver PTX Stent (manufactured by Cook Medical) and one to receive balloon angioplasty, a more traditional treatment for the disease. The safety phase of the trial, which was completed in 2006, involved 60 patients, none of whom showed breakage of the stent or major complications similar to angioplasty.
Doctors also hope that use of the investigational device will increase awareness about the causes of the disease. Although studies show that PAD sufferers who quit smoking typically double the distance they can walk, patients remain confused about what causes the pain in their legs.
"People are so aware that smoking causes heart disease and lung disease," Carpenter says, "but they're often not aware of the consequences of smoking on really every part of the body."