The News Room

The Association for the Advancement of Medical Instrumentation (AAMI) has formed a new working group to focus on gaps in existing standards of bioabsorbable vascular implants such as coronary stents.

The AAMI working group will complement activities of a proposed working group by the International Organization for Standardization (ISO) on bioabsorbable vascular implants by reviewing and examining any standards created by ISO and possibly initiating the U.S. adoption of any ISO documents.

One important gap that will be examined focuses on the erosion of metallic and polymer-based stents, according to Peter Albrecht, director of research and development at Boston Scientific and managing director of the device manufacturer’s European R&D location. “The iron-alloy based technology has the potential for corrosion. You can measure the corrosion of a material in vitro with corrosion test methods, but what we can’t measure yet is the biological effects of the corrosion in the body,” says Albrecht, who is a member of the ISO working group. “The biological component is part of the absorption process, but it is not yet fully understood nor do we have clear bench tests defined. That is something the working group might address when they start to work."

Another area that needs further understanding is what happens with the by-products of the corrosion process. “Where does the degradation products go?” asks Albrecht. “Do we know the clearance paths from a metabolism perspective?”

The working group will also touch on the mechanical properties of bioabsorbable implants. “Say you have a stent in a coronary artery, and the chronic process of degradation or absorption takes a year or a couple of months,” he says. “We don’t have a clear specification of the mechanical properties. How do we measure the mechanical properties during degradation?”

The new working group will be initiated and officially started at the ISO’s international meeting in Orlando, FL, in September. For more information on the AAMI mirror group, including how to join, contact Cliff Bernier at cbernier@aami.org.

Founded in 1967, the Association for the Advancement of Medical Instrumentation (AAMI) is a nonprofit organization representing a unique alliance of nearly 6,000 members from around the world united by one mission — to increase the understanding and beneficial use of medical instrumentation through effective standards and educational programs, and publications.