Comparing coronary stent performance on a common geometric platform through simulated bench testing.

Absorbable metallic stents (AMSs) are a newly emerging cardiovascular technology whichhas the potential to eliminate long-term patient health risks associated with conventionalpermanent stents. AMSs developed to date have consisted of magnesium alloys or iron,materials with inferior mechanical properties to those used in permanent stents, such asstainless steel and cobaltchromium alloys. However, for AMSs to be feasible for widespreadclinical use it is important that their performance is comparable to modern permanentstents. To date, the performances of magnesium, iron, and permanent stent materialshave not been compared on a common stent platform for a range of stent performancemetrics, such as flexibility, radial strength, and recoil. In this study, this comparison is madethrough simulated bench testing, based on finite-element modelling. The significance ofthis study is that it allows potential limitations in current AMS performance to be identified,which will aid in focusing future AMS design. This study also allows the identificationof limitations in current AMS materials, thereby informing the on-going development ofcandidate biodegradable alloys. The results indicate that the AMSs studied here can matchthe recoil characteristics and radial strength of modern permanent stents; however, toachieve this, larger strut dimensions are required. It is also predicted that the AMSs studiedare inferior to permanent stents in terms of maximum absolute curvature and longitudinalstiffness.