Next-generation stents with thinner profiles and increased flexibility may not be as strong as their thicker forbears, according to researchers.
Thinner stents may have lower longitudinal strength or compressibility, an aspect of stent engineering that hasn’t traditionally held much significance in design.
An implanted stent that becomes warped under the pressure inside the vessel may lead to stent thrombosis and a "potentially catastrophic late complication," according to an Irish research team. The scientists at the Belfast Health & Social Care trust also noted that a vulnerable blood vessel area intended to be covered by the stent may be left exposed and unsupported.
The study was added to the docket of the upcoming Transcatheter Cardiovascular Therapies meeting set to take place next week in San Francisco.
Researchers looked at stents made by Boston Scientific (NYSE:BSX), Medtronic (NYSE:MDT), Abbott (NYSE:ABT), Johnson & Johnson (NYSE:JNJ) and Biosensors International Group, comparing the 81-micrometer thickness of Abbott’s Xience V and Xience Prime drug-eluting stents, for example, with J&J’s 140-micrometer Cypher and Cypher Select Plus DES models.
If determined to be a flaw, the news could affect the $4 billion stent market, according to Bloomberg. That would leave Boston Scientific, which gets 20 percent of its revenues from drug-eluting stents, especially vulnerable, Wells Fargo Securities analyst Larry Biegelsen wrote in a note to investors.
Stent shrinkage is relatively rare compared to other problems associated with clearing blocked vessels, Boston Scientific interim CEO Hank Kucheman told investors during the company’s third-quarter conference call.
Abbott’s Xience stent features horizontal bars at connecting points that add to its longitudinal strength; Medtronic’s Integrity uses single-wire engineering to boost its strength, company representatives told the news service.
"Stents have a lot of different properties, which vary from one to another," New York Presbyterian Hospital and Colombia University Medical Center director of cardiovascular research Dr. Gregg Stone said during a conference call discussing the Belfast report. "Some stents will be more prone to this complication than others. The question is to understand how frequent it is, when does it occur, how to prevent it and how to manage it."