Degradable Stent Found Safe for Long Term Coronary Treatment

Igaki-Tamai stent (Kyoto Medical Planning Co.)

Researchers in Japan and the Netherlands completed a 10-year study that found a stent that degrades and is absorbed into the blood vessel tissue to be safe for patients with coronary artery disease. The findings are published online ahead of print in the journal Circulation.

Stents are mesh tubes inserted to prop open coronary arteries and allow for blood flow to the heart muscle. Metal stents, sometimes coated with drugs, remain in the body, however, and can become clogged again.

The biodegradable Igaki-Tamai stent tested in this study (pictured left) is approved for use in Europe to treat peripheral artery disease, a disorder which results from fatty deposits that narrow leg arteries. However, no countries have approved the Igaki-Tamai stent for treating clogged heart arteries.

The Igaki-Tamai stent is made of poly-l-lactic acid, a cornstarch-based material, which dissolves into the artery wall within a few years after implantation. As a result, the stent leaves no foreign material permanently in an artery and reduces the occurrence of an in-stent blood clot. The stent is marketed by Kyoto Medical Planning Company in Japan that took part in the study, but was not involved in the analysis of data.

In the study, researchers tracked 50 Japanese patients — 44 men and 6 women with an average age of 61  — who received 84 Igaki-Tamai stents, without any drug coating, between September 1998 and April 2000. After an average of 10 years, the researchers found 98 percent of the stent recipients to be free from cardiac death and 87 percent free from death from all causes. Half (50%) of the patients experienced no major adverse cardiac events.

The authors caution that the trial was an observational, single-center, non-observational study. Nonetheless, the researchers found rates of major adverse cardiac events for the Igaki-Tamai stent to be similar for traditional bare metal stents.

Read more: Grant to Fund Research on Biodegradable Implant Materials

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