Multi-objective optimization of bypass grafts in arteries

Abstract

Bypass grafts yield excellent results and remain the modern standard care for treatment of stenosed arteries in the vascular system. Geometry configuration of grafts and anastomosis has profound influences on the hemodynamics, such as flow patterns, pressure distribution and shear stress. Blood flow from the grafts strongly strikes the wall vessel, resulting in flow stagnation and reversed flow which are correlated with postoperative possibility of restenosis. The main goal of the present work is to develop a computational tool that enables the design of optimal geometries improving graft longevity. The optimization methodology considers the weight coefficients approach combining multiple objectives-into one. A developed computer program models blood flow in artery and graftusing the finite element method. A coupled genetic algorithm searches optimal graft geometries. Solutions exhibit the benefits of numerical shape optimization in achieving graftsinducing small gradient hemodynamic flows and minimizing reversed flow and residence times.