Developing an Absorbable Heart Stent
Novel Design Could Prevent Blood Clot Formation That Plagues Current Stents
Stent Made of Biodegradable Polyester
The new stent is made of a biodegradable material that slowly releases the drug everolimus to prevent blood vessels from reclogging. Everolimus is not FDA approved for use in the U.S.
Serruys says its design eliminates two possible causes of blood clots: the metal scaffold and the polymer coating.
There are other potential advantages as well. Because the stent is absorbed over time, it may be easier to take MRI or CT images of the stented vessel so doctors can monitor for problems. Also, it will be easier to perform new stenting procedures on the same vessel, he says.
Most importantly, it’s a more natural process, Serruys says.
"When you put a metal cage in a vessel, the fate of the vessel is doomed. It [the stent] controls the size of the vessel, which can never get bounce back and get bigger.
"With the absorbable stent, you have natural healing, and the flexibility of the vessel returns," he tells WebMD.
Studies in animals show that the stent is fully absorbed by the body in 12 to 18 months. Though it is not yet known how long it will take to dissolve in humans, Serruys suspects it will take about two years.
The stent has already been redesigned to make it stronger, Serruys says. Studies using the new device will begin later this year.
Serruys says he has no doubt the stent will eventually be on the market, although it may take years. "This is the beginning of a new era. I am convinced."
Absorbable Stent a Welcome Option
Though more study is needed, doctors say an absorbable stent could prove a welcome option.
"Given the whole question of late-stage blood clots associated with drug-eluting stents, there is a lot of interest in making changes," says Spencer B. King, MD, head of interventional cardiology at Piedmont Hospital in Atlanta.
"If the metal goes away ... it’s certainly possible you’ll have fewer problems," he tells WebMD.