Szycher M, Ph.D.*; Armini A, Ph.D.; Bajgar C, Sc.D.; Lucas A
* CardioTech International, Inc., 78E Olympia Avenue, Woburn, MA 01801, and Implant
Sciences Corporation, 107 Audubon Road, Suite 5, Wakefield, MA 01880.
Copyright 2002. All rights reserved.
IMX Paper v2
Background – The development of coronary stents has revolutionized the practice of interventional cardiology over the past 5 years. More than 70 coronary stents have been approved in Europe and over 20 stents are commercially available in the United States.
Unfortunately, epidemiological data shows that 20-25% of coronary stents will restenose.
Moreover, in the Stent …show more content…
Stents cover about 10-15% of vessel luminal surface, thus severely limiting the surface area available for drug loading and release. A delicate balance exists between drug release kinetics and drug diffusion and distribution; drug elution is maximal at points adjacent to the struts, and increasingly lower levels at points progressively further from the struts, creating an uneven activity distribution. Thus, stents made from struts that are spaced far apart produce drug-starved areas, while stents spaced close together will produce areas of overlap.
The I-PlantTM anti-restenosis stent is totally encapsulated in a microporous polyurethane elastomeric mesh. Since the polyurethane is pre-loaded with rapamycin, and all struts are equally covered, the drug distribution pattern into the vessel tissue is even and uniform.
The biocompatibility of the polymer used for coating the carotid stent is crucial. The polymer must be non-inflammatory, capable of being stretched without flaking