May 17, 2010
In this SMST-2010 presentation, Jennifer presents data comparing the corrosion and biocompatibility performance of wire formed and laser cut stents having virtually identical starting geometry. Both groups were electropolished to remove <5%, <10%, and <25% material. Results indicate that the corrosion resistance increases with the amount material removal, and less material removal is required for wire formed stents to achieve comparable performance. Read on for more… Read more »
May 14, 2003
By the year 2003, Nitinol stents played a dominant role in the treatment of peripheral vascular disease. A great variety of designs had been launched into clinical service, some more successfully than others. This review was authored by the familiar NDC trio of Dieter Stoeckel, Alan Pelton, and Tom Duerig, and published in European Radiology. It’s just about tied for for first place in the prestigious race for most popular download from Nitinol.com! This paper presents some of the earliest data to describe nickel ion release for various surface conditions, including mechanically polished, electropolished, and passivated surfaces, and compared Nitinol with stainless steel and MP35N. The conclusions of this study reinforce what we know well today: the corrosion and biocompatibility performance of Nitnol is excellent when processed properly, but can be compromised if improper processes are applied. The paper presents a visual survey of various stent designs from 2003, including laser cut, wire formed, and sheet welded varities. It also discusses the concepts of radial resistive force (RRF) and chronic outward force (COF), as well as radiopacity enhancments such as tantalum crimps and rivets. Still a good read for anyone interested in Nitinol stent design. Read more »
May 14, 1999
When mining our server logs in preparation for creating NitinolUniversity.com, we found that two articles in our literature database had far and away more hits than any other. So, it seems fitting that the first paper in our spotlight should be this 1999 classic by our own Tom Duerig, Alan Pelton, and Dieter Stöckel. Though now over a decade old, this paper reads like Nitinol’s Greatest Hits, touching on superelastic design, thermal deployment, kink resistance, biocompatibility, constancy of stress, biomechanical compatibility, dynamic intereference, and hysteresis. But wait, there’s more: MR compatibility, fatigue resistance, and uniform plastic deformation. It highlights such applications as stents (of course!), endoscopic instruments, septal occluders, vena cava filters, and graspers, among other things. If you read only one paper on Nitinol medical applications today, make this the one! Read more »
