Self Expanding Nitinol Stents
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.