Numerical study of how stent geometry and fluid rheology influence the restenosis risk in stented coronaries

The aim of this thesis is to unravel some aspects of coronary haemodynamics with the help of computational fluid dynamics (CFD). Computer simulations of the blood flow through vessels have gained popularity in the last thirty years, thanks to their reduced costs and study-time compared with the experimental method, and to the possibility of evaluating crucial quantities. In this work we focus on the effects that stent implantation inside coronary arteries has on blood dynamics. We present the milestones of stent development and their limits and problems, such as restenosis, and examinate clinical, experimental, and computational studies, focusing on the parameters that are frequently associated to restenosis. In our computation we model a simplified vessel in which we insert three different types of stents. We consider a laminar regime flow and use two different rheological models for the blood, Newtonian and non-Newtonian. We compute velocity, vorticity, and wall shear stress, and compare their spatial distributions considering the three stent geometries, the two rheology models, and the boundary condition imposed at the inlet. We complete our analysis by using a Lagrangian approach, performing particle tracking and evaluating particles arrival time to the outlet of the stented artery.