University of Pennsylvania Health System
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Rebecca Harmon, (215) 662-2560,

February 26, 2004

Cryoplasty: Using Sub-Zero Cold to Open Blocked Arteries
HUP Introduces Cryoplasty Procedure to Philadelphia

(Philadelphia, PA) -- Yesterday, physicians at the Hospital of the University of Pennsylvania (HUP) performed the city’s first cryoplasty procedure on a 73-year-old male with a severely blocked artery in the right leg. Like angioplasty, cryoplasty restores blood flow by carefully positioning a tiny balloon inside the vessel, at the site of the blockage, and then slowly inflating the balloon to expand the diameter of the vessel. Unlike usual angioplasty, however -- which uses a saline-contrast solution to inflate the balloon -- cryoplasty uses nitrous oxide, which cools to a temperature of –10 degrees Celsius.

The sheer coldness of nitrous oxide appears to limit restenosis (late re-narrowing of the artery) by reducing tearing and subsequent inflammation of the affected vessel. In traditional angioplasty, balloon inflation causes uncontrolled tearing of the vessel wall, and triggers inflammation and consequent local scar-tissue formation. Nitrous oxide, on the other hand, is associated with more controlled tearing and little or no inflammation. It appears to do so, in part, by selectively destroying the cells involved in scar formation (endothelial and smooth-muscle cells). “Cryoplasty is a new tool for opening blocked arteries, and it appears to be a very promising approach in the treatment of peripheral vascular disease,” said interventional cardiologist Herbert Aronow, MD, MPH, who, as Director of HUP’s Peripheral Intervention Program in Cardiovascular Medicine, led today’s cryoplasty procedure. “Preliminary data suggest that cryoplasty may be superior to traditional angioplasty or stenting.”

Indeed, in a study of 91 patients treated with cryoplasty for leg-artery blockages – which was presented at the International Symposium of Endovascular Therapy last month -- 75 patients, or 85%, showed no signs of restenosis nine months after treatment. This compares favorably to traditional angioplasty and stenting series where the rates of restenosis have ranged from 40-50%.

More than 12 million Americans suffer from peripheral vascular disease (PVD), also known as atherosclerosis of the blood vessels of the arms, legs, and other branches of the aorta. “As many as one in three of those patients have pain so severe that it affects their quality-of-life and limits their functional status,” explains Aronow, who is also an Assistant Professor of Medicine in Penn’s School of Medicine and Director of the Cardiac Catheterization Laboratory at the Philadelphia Veterans Administration Medical Center. “Cryoplasty appears to be a significant advance in the treatment of this painful, debilitating disease.”

The cryoplasty performed today at the Hospital of the University of Pennsylvania utilized the PolarCath™ System, manufactured by Boston Scientific, Inc., of Boston, MA.

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Editor’s Note: Dr. Aronow has no financial interest in Boston Scientific, Inc.

PENN Medicine is a $2.2 billion enterprise dedicated to the related missions of medical education, biomedical research, and high-quality patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System (created in 1993 as the nation’s first integrated academic health system).

Penn’s School of Medicine is ranked #2 in the nation for receipt of NIH research funds; and ranked #4 in the nation in U.S. News & World Report’s most recent ranking of top research-oriented medical schools. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.

Penn Health System consists of four hospitals (including its flagship Hospital of the University of Pennsylvania, consistently rated one of the nation’s “Honor Roll” hospitals by U.S. News & World Report), a faculty practice plan, a primary-care provider network, three multispecialty satellite facilities, and home health care and hospice.

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