Optimization of Cardiovascular Stent Design Using Computational Fluid Dynamics
Journal of Biomechanical Engineering
Coronarystent design affects the spatial distribution of wall shear stress(WSS), which can influence the progression of endothelialization, neointimal hyperplasia,and restenosis. Previous computational fluid dynamics (CFD) studies have onlyexamined a small number of possible geometries to identify stentdesigns that reduce alterations in near-wall hemodynamics. Based on apreviously described framework for optimizing cardiovascular geometries, we developed amethodology that couples CFD and three-dimensional shape-optimization for use instent design. The optimization procedure was fully-automated, such that solidmodel construction, anisotropic mesh generation, CFD simulation, and WSS quantificationdid not require user intervention. We applied the method todetermine the optimal number of circumferentially repeating stent cells (NC)for slotted-tube stents with various diameters and intrastrut areas. Optimalstent designs were defined as those minimizing the area oflow intrastrut time-averaged WSS. Interestingly, we determined that the optimalvalue of NC was dependent on the intrastrut angle withrespect to the primary flow direction. Further investigation indicated thatstent designs with an intrastrut angle of approximately 40 degminimized the area of low time-averaged WSS regardless of vesselsize or intrastrut area. Future application of this optimization methodto commercially available stent designs may lead to stents withsuperior hemodynamic performance and the potential for improved clinical outcomes.