The Food and Drug Administration has approved the first fully absorbable stent used to treat coronary artery disease.
The plastic stent, already available in Europe and manufactured by Abbott Park, Ill.-based Abbott Vascular, is a scaffold that is implanted with a catheter to widen the artery to allow blood to pass through. But unlike conventional metallic stents, Abbott's new, biodegradable stent is gradually absorbed by the body over roughly three years, leaving little foreign material in the body.
Like most stents on the market today, the stent gradually releases a drug that works to prevent scar tissue from forming around the cage. Once the stent dissolves, four very small platinum markers remain embedded in the walls of the artery so cardiologists can see where the stent had been placed. Plastic doesn't show as well on imaging.
The recent advance shouldn't put a damper on the success of metallic stents, which have come a long way in the last decade, said Dr. Roxana Mehran, an interventional cardiologist at Mount Sinai Health System in New York. Initial stents were bare, without the drug everolimus that limits scar tissue. Drug-eluting stents have drastically improved outcomes, she said, and attributed the innovation to some extent to patient demand.
“Most patients would not like to have a foreign body in their arteries,” Mehran said. “We have to make sure that we're careful that we don't bash all of the work done to date. The metallic stents are incredibly effective.”
Nonetheless, the ability to have an artery that is virtually clear of any foreign objects is promising, because it ensures that the artery is open if additional bypass or surgery is required later in life, said Mehran, who is chair of the American College of Cardiology's Interventional Council. Physicians will still need to be careful in choosing the right patient for these new stents and will likely still use metallic stents until later generations of biodegradable stents are released and as further data are gathered on trial patients over the next five years, she said.
“It's not for everyone, and I think that the patients should allow the physicians to make those choices,” Mehran said.
An Abbott spokesman also said the new stent will better allow the artery to pulse and flex naturally and reduce the risk of future blockages that can occur with traditional stents. The stent is being launched immediately at sites that performed clinical trials of the device, including Mount Sinai, and will be expanded to other hospitals over time.
But a medical device expert at the ECRI Institute, a non-for-profit research firm, cautioned that there's still question of how patients stand to benefit over the long term. Abbott has shown the device to be equally safe and effective, but any long-term clinical benefit beyond conventional stents “isn't clear to us,” said Diane Robertson, ECRI's director of health technology assessment.
“It's hard to say whether there's a true benefit from that,” Robertson said. “When we look at the evidence it certainly seems to be as good as anything out there,” but it doesn't stop patients from having to take anti-coagulant drugs, as some had hoped, she said.
Robertson acknowledged that a dissolvable stent does clear the way for future surgeries, and that has potential. But at the end of the day, it's just another option for physicians, she said.
The Abbott spokesman said the device will be priced at a “modest premium” to its current stent offering. The company wouldn't disclose specific pricing or sales forecasts for competitive reasoning, but said the device will be will be coded similarly to existing drug-eluting stents.
Hospitals often bill $30,000 for stenting procedures, which includes the costs of the stent, medical staff and other equipment and services.
Coronary artery disease results in over 370,000 deaths each year, according to the National Heart, Lung and Blood Institute. Abbott controls a little more than a third of the stent market, though more than a dozen medical-device makers are working on their own dissolving stent technologies.
