Stent overlapping and geometric curvature influence the structural integrity and surface characteristics of coronary nitinol stents.

摘要: Preliminary studies have revealed that some stents undergo corrosion and fatigue-induced fracture in vivo, with significant release of metallic ions into surrounding tissues. A direct link between in-stent restenosis has not been clearly established; nonetheless vitro shown relatively high concentrations heavy metal can stimulate both inflammatory fibrotic reactions, which are the main steps process restenosis. To isolate mechanical effects from local biochemical effects, accelerated biomechanical testing was performed on single overlapping Nickel-Titanium (NiTi) subjected to various degrees curvature. Post testing, were evaluated using Scanning Electron Microscopy (SEM) identify type surface alterations. Fretting wear observed cases, straight curved configurations. Stent strut fractures occurred presence geometric fatigue following simulation similar those previously reported human stent explants. It factors such as arterial curvature combined enhance incidence degree when compared a tube configuration.