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Professor Edelman featured MIT news story: Study reveals why polymer stents fail

Monday, February 26, 2018

Professor Elazer Edelman, featured in MIT news story about his paper which appears in the Feb. 26 Proceedings of the National Academy of Sciences.

Study reveals why polymer stents failed



Many patients with heart disease have a metal stent implanted to keep their coronary artery open and prevent blood clotting that can lead to heart attacks. One drawback to these stents is that long-term use can eventually damage the artery.

Several years ago, in hopes of overcoming that issue, a new type of stent made from biodegradable polymers was introduced. Stent designers hoped that these devices would eventually be absorbed by the blood vessel walls, removing the risk of long-term implantation. At first, these stents appeared to be working well in patients, but after a few years these patients experienced more heart attacks than patients with metal stents, and the polymer stents were taken off the market.

MIT researchers in the Institute for Medical Engineering and Science and the Department of Materials Science and Engineering have now discovered why these stents failed. Their study also reveals why the problems were not uncovered during the development process: The evaluation procedures, which were based on those used for metal stents, were not well-suited to evaluating polymer stents.

“People have been evaluating polymer materials as if they were metals, but metals and polymers don’t behave the same way,” says Elazer Edelman, the Thomas D. and Virginia W. Cabot Professor of Health Sciences and Technology at MIT. “People were looking at the wrong metrics, they were looking at the wrong timescales, and they didn’t have the right tools.”

The researchers hope that their work will lead to a new approach to designing and evaluating polymer stents and other types of degradable medical devices.

“When we use polymers to make these devices, we need to start thinking about how the fabrication techniques will affect the microstructure, and how the microstructure will affect the device performance,” says lead author Pei-Jiang Wang, a Boston University graduate student who is doing hid PhD thesis with Edelman.

Edelman is the senior author of the paper, which appears in the Proceedings of the National Academy of Sciences the week of Feb. 26. Other authors include MIT research scientist Nicola Ferralis, MIT professor of materials science and engineering Jeffrey Grossman, and National University of Ireland Galway professor of engineering Claire Conway.

Read full story here: http://news.mit.edu/2018/study-reveals-why-polymer-stents-failed-0226