(234v) Role of Bifurcation Geometry on Stability of Thrombus

An injury or a high shear gradient triggers the formation of a thrombus in a blood vessel. Though thrombus formation under flow involves understanding reaction kinetics and hydrodynamics in a dynamically changing geometry, the stability of thrombus is described through hydrodynamic forces around it. Platelet aggregation rate on a thrombus has a non-linear dependence on shear rate exhibiting a zero-aggregation rate at a critical shear rate. Complete occlusion or partial occlusion of a thrombus depends on the shear rate around the thrombus, controlled through fluid dynamics and geometry of the vasculature. Bifurcations are repeated structures in human vasculature geometry regulating blood flow and hydrodynamic forces in the blood vessel. The flow through one branch of a bifurcation is regulated by the other branch and vice-versa. The critical shear rate behaviour results in a critical bifurcation radius ratio determining the dynamics of occlusion of an evolving thrombus. In this study, we quantify the role of bifurcation geometry on thrombus evolution and stability through finite element simulations. Our theory is further validated using microfluidic blood flow experiments.