State-of-the-Art Stent Testing: A Review of Protocols, Concerns, and Considerations for the End User

J.C. Conti, E.R. Strope, L.D. Spence

Dynatek Dalta Scientific Instruments, PO Box 254, Galena, MO 65656

Currently there are at least eighteen different stent designs used clinically worldwide. In addition, it is projected that there are as many as three dozen more under evaluation in non-clinical laboratory settings throughout the world. Although the primary concern for the cardiologist is long-term clinical efficacy, the plethora of stents presents a design engineer or interventional cardiologist with a dizzying array of possible design considerations in pursuit of the most appropriate device.

Over the years, information obtained in independent laboratories has provided for improved protocol design to test certain characteristics of stents, including mechanical properties, durability, and overall mechanical reliability.

A review of state-of-the-art testing used to evaluate the mechanical and flow characteristics of intravascular stents will be made. In order for dynamic products like stents to be tested, the accelerated mechanical properties of the stents and their individual components need to be evaluated. A review of the experimental procedures necessary to evaluate the high-speed mechanical properties of stents and their components will also be reviewed.

Finally, a more comprehensive picture of stent evaluation will be outlined by presenting standard protocols for high-speed stent durability testing as well as a review of the currently recommended test protocols that have been drafted by various regulatory agencies.

It is important to understand these various considerations when designing, testing, or using one of these products.