FDA investigates stent “shrinkage” in Boston Scientific’s Ion, Promus stents, others

Ion stent

The FDA is investigating reports that the thinner design of next-generation drug-eluting stents, including Boston Scientific’s (NYSE:BSX) Ion and Promus models, might be prone to deforming after implantation.

At least two studies and one case study presented at a recent cardiology conference reported incidents in which either a Boston Scientific Ion or Promus stent deformed after it was deployed inside a coronary artery.

“FDA is actively working with manufacturers, including Boston Scientific, to better understand longitudinal stent deformation with respect to its causes, predisposing underlying anatomic conditions, operator techniques that can reduce the likelihood of its occurrence, and treatment strategies should it occur,” the agency told Reuters in a email.

Sign up to get our free newsletters delivered straight to your inbox

Although there’s been only one reported incident of deformation involving a Promus stent from among more than 4,600 implantations in clinical trials, according to the federal watchdog agency, “an unspecified number of significant adverse events had been reported to the agency,” according to the news service.

“At this time, additional data collection and analyses are ongoing, but the information available to date indicates that the Ion paclitaxel-eluting platinum chromium stent remains safe and effective when used for its approved indications,” the FDA said, according to Reuters.

An Irish study published earlier this month found that thinner stents may have lower longitudinal strength, potentially leading to stent thrombosis and a “catastrophic late complication” and leaving the target lesion unprotected, according to scientists at the Belfast Health & Social Care trust.

Dr. Cindy Grines, editor of the Journal of Interventional Cardiology, detailed a case in the journal’s October issue involving “marked shortening, deformation and accordion of the Ion coronary stent,” something she claimed she hasn’t seen before in 25 years of practicing cardiology.

The stent involved in the case shortened by about 35 percent, Grines wrote.

“We believe that accordion of the stent caused technical difficulties in rewiring the vessel and ultimately stent thrombosis, [and] thus is of serious concern. Although recent reports from Europe noted this phenomenon in the Element and Omega stents (similar family of stent designs), to my knowledge this is the first published case in the stent approved in the United States, the Ion stent,” she wrote. “Although this shortening phenomenon may just require an additional stent to ensure adequate coverage of the lesion, in our case it appeared that the stent may have deformed and involuted, further compromising the lumen and preventing additional device interventions.”

Citing data from a second bench test conducted by Abbott (NYSE:ABT) “showing that the Element family of stents (including the Omega and Ion) may shorten up to 46 percent under the force that an interventional cardiologist may exert to advance a post-dilation balloon or intravascular ultrasound device, Grines called the results “very disturbing.”

“Hopefully, there will soon be new recommendations regarding the use of stents of this particular design for our community of interventional cardiologists. Until further data are available, our institution will use the Ion stent cautiously, and only when alternatives are unavailable for the size under consideration,” wrote Grines, who is vice president of clinical and academic affairs at Detroit Medical Center’s Cardiovascular Institute and a professor at Wayne State University.

The Irish researchers looked at stents made by Boston Scientific and Abbott, as well as stents from Medtronic (NYSE:MDT), Johnson & Johnson (NYSE:JNJ) and Biosensors International Group. Their study compared Abbott’s Xience V’s and Xience Prime’s 81-micrometer thickness, for example, with J&J’s 140-micrometer Cypher and Cypher Select Plus.

“Stents have a lot of different properties, which vary from one to another,” noted New York Presbyterian Hospital and Colombia University Medical Center director of cardiovascular research Dr. Gregg Stone 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.”

But the problem may not be a design flaw, Stone told Reuters, citing instances in which the balloon used to implant the device or the guide wire that carries the stent catch or pull on the stent and deform it.

“It can happen with any stent if you’re aggressive enough with it,” he said. “The metal is very thin – it’s 3/1,000 of an inch thick, so depending on the material and configuration … some are more prone (to deformation) than others.

“It seems to be a rare phenomenon. Millions of these are implanted and there are just a handful of these cases,” he said.

“Someone needs to put the cases together and look at them and decide about the signal of adverse events,” Mayo Clinic cardiologist Dr. David Holmes told Reuters, noting that the exact cause of the problem is still unclear. “This absolutely warrants more study.

“If it’s a mechanical problem, it needs to be fixed mechanically. If it’s a procedure issue, we need to make sure the initial deployment is ideal and we can do that by using imaging studies,” Holmes said.

RSS From Medical Design & Outsourcing

  • Molex delivers ISO 13485-compliant, medical-grade surgical cables from its class 100,000 clean room facility
    Molex, LLC operates a fully ISO 146441-1:1999 Class 8-certified clean room, satisfying strict particulate contamination levels specified by ISO-compliant requirements. Located in Thailand, the facility has less than 100,000 particulates (≥0.5µm) per cubic foot of air and manufactures a variety of ISO 13485-compliant medical cables and surgical cables used in operating theatres, hospitals, laboratories and […]
  • Swept-Source OCT: Patent license agreement between Massachusetts General Hospital and Heidelberg Engineering
    Heidelberg Engineering has entered into a patent license agreement with Massachusetts General Hospital (MGH) in Boston. The agreement grants global and exclusive rights to 77 basic patents and patent applications which relate to swept-source OCT technology and its application in ophthalmology. Spectral domain OCT has become indispensable to eye care professionals worldwide to diagnose and […]
  • MIT’s MultiFab presents a stark challenge to incumbent 3D Printer manufacturers’ hardware, software, and business Models
    MIT’s Computational Fabrication Group recently announced the MultiFab, a low-cost 3D printer that can combine up to 10 different resins in one part and also includes a 3D scanning system to identify and fix errors during production. According to Lux Research, these capabilities are rare in commercial 3D printers today due to the manufacturers’ need […]
  • AVX releases Accu-P MP medical grade film chip capacitors for medical devices
    AVX Corporation, a leading manufacturer of passive components and interconnect solutions, has released a new series of thin film chip capacitors specifically designed to meet the demanding performance specifications for implantable medical devices. Delivering extremely tight capacitive tolerances, exceptionally repeatable performance, and remarkably low ESR and high Q at high frequencies—including VHF, UHF, and RF […]
  • RIVANNA commences manufacturing of its Accuro device
    Rivanna Medical announced that it has begun manufacturing its FDA-cleared Accuro device, a handheld and untethered smart-phone-sized device that is designed to guide spinal anesthesia with automated 3D navigation technology in addition to ultrasound imaging of abdominal, musculoskeletal, cardiac and peripheral vascular anatomies. The product will be launched at the ASA annual meeting in San […]
  • FDA seeks public input on Quality Metrics guidance
    by Oliver Wolf, Senior Product Manager, MasterControl In line with the general shift towards risk-driven approaches in the quality management world, FDA is now taking steps towards applying those same principles to its own auditing schedule. At the end of July, the Center for Drug Evaluation and Research (CDER) and the Center for Biologics Evaluation […]
  • First ‘Ear Wear’ for Active Adults Debuts with MDHearingAid FIT
    If you’ve burned out your ears with earbuds, headphones or decades of other audio abuse but aren’t ready for your grandmother’s hearing aids, not to worry! The new MDHearingAid FIT gets you back in the game with a tiny, FDA-registered, one-size-fits-most solution that doesn’t block your ear canal like old-fashioned in-the-ear hearing aids. The FIT feels […]
  • CardioGenics enters into manufacturing agreement with Ontario-based Plasticap
    CardioGenics Holdings, developer for the In-Vitro-Diagnostics (“IVD”) testing market, announced that it has entered into a manufacturing agreement with Plasticap of Ontario, Canada, pursuant to which Plasticap will manufacture CardioGenics’ proprietary self-metering cartridges for its QL Care analyzer. The term of the agreement is three years and the purchase price for each cartridge shall be […]
  • MTD Micro Molding releases micro materials menu
    MTD Micro Molding, a long-time leader in micro-injection molding, has released an updated “Materials Menu” of materials that can be successfully micromolded to help guide engineers at medical device companies. Material selection is a crucial step in product manufacturability. The correct material drives tolerance, dimension, strength, usabality, speed-to-market, design, critical features, and cost. Through MTD’s […]
  • MedTech Chat: Elastic technology for drug delivery
    Dr. Zhen Gu and Dr. Yong Zhu from North Carolina State University are both co-senior authors of a research paper describing their recent work. Dr. Gu, Dr. Zhu and other researchers from North Carolina State University and the University of North Carolina at Chapel Hill have developed a drug delivery technology that consists of an […]
  • B. Braun’s OEM Division offers large bore normally closed low-pressure check valves
    Infusion therapy and pain management device manufacturer B. Braun said today it is offering normally closed large-bore low-pressure check valves through its valve-focused contract manufacturing OEM division. The valves, offered by Bethlehem, Pa.-based B. Braun, are designed for the intermittent injection of fluids during medical treatment and open automatically when pressure is applied. The newly […]

Leave a Reply