Newer Stents: Materials and Designs

We aim to present here the experience with newer stents for coronary and peripheral interventions. Specifically, the design and technical considerations of the self-expanding nitinol coil stents for coronary and vascular indications, as well as the design and clinical experience with the tubular stainless steel balloon-expandable serpentine stents for coronary and peripheral interventions are discussed. The animal and clinical experience with both types of stent have shown that the mechanisms of deployment and expansion are different for these inherently different stents. The self-expanding coil stent, providing adequate scaffolding in various types of coronary lesions is deployed by self expansion, aided to a significant extent by balloon expansion. Long-term outside pressure on the wall may lead to further stent expansion as has been shown with this stent, which may be an important parameter in the restenosis process. The tubular balloon-expandable serpentine stent does not have the feature of long-term expansion, however, is characterized by superior scaffolding properties and unique features that allow its safe use in the most complex coronary diseases. Long-term clinical results are pending for these two families of stents.