A Novel Approach to Modeling Coronary Stents Using a Slender Curved Rod Model: A Comparison Between Fractured Xience-like and Palmaz-like Stents

We present a novel mathematical model to study the mechanical properties of endovascular stents in their expanded state. The model is based on the theory of slender curved rods. Stent struts are modeled as linearly elastic curved rods that satisfy the kinematic and dynamic contact conditions at the vertices where the struts meet. A weak formulation for the stent problem is defined and a Finite Element Method for a numerical computation of its solution is used to study mechanical properties of two commonly used coronary stents (Palmaz-like and Xience-like stent) in their expanded, fractured state. A simple fracture (separation), corresponding to one stent strut being disconnected from one vertex in a stent, was considered. Our results show a drastic difference in the response of the two stents to the physiologically reasonable uniform compression and bending forces. Department of Mathematics, University of Zagreb, Bijenička 30, 10000 Zagreb, Croatia ([email protected]). Research supported in part by MZOS-Croatia under grant 0370693014-2765 and by the NSF/NIH under grant DMS-0443826 Department of Mathematics, University of Houston, 4800 Calhoun Rd., Houston TX 77204-3476, USA ([email protected]). Research supported in part by the NSF under grant DMS-0806941, Texas Higher Education Board ARP 003652-0051-2006, NSF/NIH under grant DMS-0443826, by UH GEAR-2007 grant. Co-Director, Cardiac Catheterization Laboratories Michael E. DeBakey Veterans Medical Center, Assistant Professor of Medicine Baylor College of Medicine, St Luke’s Episcopal Hospital/Texas Heart Institute