Flow Pattern Effect on the Initial Shape of the Atheroma

Abstract

Atherosclerosis is the first cause of death in the first world countries nowadays and it will also become one of the firsts in the developing countries. It is a vascular disease that affects medium and great size arteries and it could partially or totally obstruct blood flow through them. The lack of blood supply to an organ implies the lack of oxygen and this could mean its temporary mal functioning (ischemia) or the death of the tissue (infarct). This disease implies the formation of plaques called atheromas, which grow in the arterial wall due to accumulation of fat, cholesterol, cell debris, calcium and smooth muscle cells. Since late seventies it has been hypothesized that hemodynamic forces over the endothelium, the innermost layer of arteries, are very important to the formation and development of atheromas. These hypotheses suggest that atheromas form in regions of complex flow patterns, such as bifurcations or regions of marked curvature, where recirculation and secondary flow develops. Together with flow patterns, blood pressure and cholesterol concentration in blood are other known factors that influence the development of the atherosclerotic plaques. The carotid bifurcation in the carotid artery has received and continues to receive a lot of attention for it supplies blood to some parts of the brain. Atheromas that develop in this bifurcation may cause a stroke, which is one of the major causes of death. In previous works we have shown a model of the formation and initial growth of these plaques. In the present work we use a slight modification of this model, combined with Finite Volume simulations of the blood flow through the artery, to predict the time evolution of the shape of an atheroma in the human carotid bifurcation.