Predictive haemodynamics in a one-dimensional human carotid artery bifurcation. Part I: Application to stent design

A diagnostic technique is proposed to identify patients with carotid stenosis who could most benefit from angioplasty followed by stent implantation. This methodology involves performing a parametric study to investigate the haemodynamic behavior due to alterations in the stenosis shapes in the internal carotid artery (ICA). A pulsatile 1-D Navier-Stokes solver incorporating fluid-wall interactions for a Newtonian fluid which predicts pressure and flow in the human carotid artery bifurcation is used for the numerical simulations. In order to assess the performance of each individual geometry, we introduce pressure variation factor as a metric to directly compare the global effect of variations in the geometry. It is shown that the probability of an overall catastrophic effect is higher when the stenosis is present in the upstream segment of the ICA. Furthermore, maximum pressure is used to quantify the local effects of geometry changes. The location of the peak and extent of stenosis are found not to influence maximum pressure. We also show how these metrics respond after stent deployment into the stenosed part of the ICA. In particular, it is found that localized pressure peaks do not depend on the length of a stent. Finally, we demonstrate how these metrics may be applied to cost-effectively predict the benefit of stenting.