January 22, 2008 - A new stent with a nanothin surface application known as Polyzene-F shows promise in opening and healing blocked heart arteries reportedly without the potential risks of thrombosis posed by drug-eluting stents, according to a study being presented at the 20th annual International Symposium on Endovascular Therapy (ISET).
The stent is made of cobalt chromium and uses a modified open-cell design. The stent is coated with Polyzene-F. The surface treatment is approximately 40 nanometers thick, too thin to be seen with a traditional microscope. The antithrombotic, bacterial-resistant coating essentially hides the stent so that the body doesn't react to the device as a foreign object as is the case for bare-metal stents. This, in turn, promotes the healing process so that the stent is incorporated into the body more naturally, preventing the formation of blood clots. After implantation of a traditional stent, the body essentially overreacts to the device, causing the scarring that leads to restenosis.
"Our preliminary data show that the inside of the blood vessel with this polymer-coated stent heals almost perfectly within 30 days, whereas with a drug-eluting stent, the blood vessel healing takes many months, if it ever happens," said Corrado Tamburino, M.D., Ph.D., principal investigator of the study and professor of cardiology at Ferrarotto Hospital at the University of Catania, Italy. "This polymer-coated stent is a very promising solution to restenosis and thrombosis."
In the study, the Assessment of the Latest Non-Thrombogenic Angioplasty (ATLANTA) Stent Study, which took place at the University of Catania, 55 patients received the new surface-treated stent to open up blockages in their coronary arteries, and six-month follow-up information is available for 40 patients. Six months after implantation, the patients were studied using angiography and intravascular ultrasound (IVUS). To date, none of the stents have developed thrombosis and the binary restenosis rate is below 10 percent.
An independent laboratory also used a diagnostic test called optical coherence tomography (OCT), which images the vessels at the cellular level. Performed at the time of the initial procedure and six months after implantation of the coated stent in 15 people (27 percent), OCT results suggest that the Polyzene-F promotes healing, rather than prompting scarring.
For more information: www.ISETnews.org