Whether through genetic lottery or the proliferation of Double Downs, a lot of arteries are under threat. Fortunately, there’s a golden business opportunity for improving their outlook: Heart stents, which were only hard little metal tubes holding open arteries, are now being made of corn-based plastics that dissolve when they’re no longer needed.
The new heart-opening design, created by Abbott, is known by the tongue-twisting name “bioresorbable vascular scaffold” (or, more simply, BVS). It promises to improve on metal stents, which usually last so long that they start causing health problems of their own.
Corn-based plastics are more and more common in big, fast-moving items such as biodegradable food packaging and even toys and sky boots. But the new BVS design is tiny enough to fit in an artery–and proof of how far bio-plastics have come.
The BVS spends two years propping a vessel open with the help of a pharmaceutical coating that prevents constriction, at which point the body slowly begins absorbing the corn-based device. “As water comes in and reacts with the structure,” explains Dr. Richard Rapoza, the chemical engineer in charge of developing the BVS, “it starts clipping the polymeric chains into smaller and smaller pieces.” After about fifteen to eighteen months, all of the clippings are absorbed. (If this sounds alarming, you might be reassured to know that PLA is already being used for other medical applications like dissolving sutures, and is considered biocompatible, and therefore safe for internal implants.)
As Rapoza explains, permanent metallic stents, once they’ve completed the initial job of stabilizing a vessel, might actually cause cardiac events as the years stretch on. The great advantage of the BVS disappearing act, he says, is that once the device has done its duty, it gets out of the way. “The hope is that you reset the clock on the disease progression.”
Abbott reports that the results of their clinical trials thus far have been promising, and the devices should be on the market by 2015.