Stents Strut Their StuffStents Strut Their Stuff
September 16, 2011
An article over on MPMN highlights the advances made in coronary stents over the years. Since they came onto the market, stents have been used to perform the majority of percutaneous coronary interventions. Several hundred thousand peripheral stents are also implanted annually.
Over the years, stents have become both smaller and more complex. Owing to their unique properties, materials such as nitinol and cobalt-chromium are routinely used for many contemporary stenting applications. The use of these materials has enabled device companies to develop ever-smaller stents with intricate features.
Material Selection
Stent design is directly related to the choice of material. The clinical application that the stent will ultimately be used for influences both of those factors.
“Coronary stents are very different from peripheral stents, which may be very different from certain types of stent grafts,” explains Brad Beach, vice president of research and development at Burpee Materials Technology (BMT) and Flexible Stenting Solutions (Eatontown, NJ). “It really comes down to understanding this and properly designing components and devices to meet whatever the needs of the application are.”
To develop stents for superficial femoral artery (SFA) applications, manufacturers often turn to nitinol. Stents made of the shape-memory alloy can be used in longer, more-intricate stretches of artery than can traditional coronary or balloon-expandable stents.
The Flexstent from BMT is especially well suited for use in long, tortuous anatomies. That stent’s offers reconstrainability, enabling it to be recaptured back into its delivery catheter. “Given a properly designed delivery system, you have the potential to recapture and redeploy this stent, especially when treating peripheral diseases,” Beach says. Reconstrainability allows clinicians to retract and relocate the stent midway through the procedure, avoiding these pitfalls.
The article also describes the use of superalloys in stents to facilitate the trend of miniaturization, which, “is crucial for the future of stent design, placing special demands on materials development and manufacturing techniques.”
Also considered are bioresorbable stents. One example of such a product is Abbott’s Absorb, which has gained CE Mark approval and is now being investigated in clinical trials.
The entire article, titled "Shrinking Stents Strut Their Stuff" is available from MPMN's website.
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