Function and Performance of Nitinol Vascular Implants

Abstract

Nitinol, an intermetallic compound of Titanium and Nickel has found widespread use as material for vascular implants. Its unusual stress hysteresis and superelasticity makes these devices biomechanically compatible with the body's structures. Nitinol also exhibits excellent corrosion resistance, biocompatibility and MR compatibility. The paper focuses on the material specific properties of self expanding stents to treat peripheral vascular disease, like biased and temperature dependent stiffness, kink resistance, stent durability and fatigue, and describes the design aspects of different Nitinol stents. The function and performance of other Nitinol implants is also explained, like vena cava filters, cardiac septal re- pair devices, and self-expanding heart valve prosthesis. A separate section describes the performance of endovascular Nit- inol implants in Magnetic Resonance Imaging, MRI.