The role of fluid dynamics in plaque excavation and rupture in the human carotid bifurcation: a computational study

A 3D computational fluid dynamics model of the human carotid bifurcation has been created to explore plaque excavation and plaque rupture. The model considers different degrees of atherosclerotic stenosis, the form of which is determined using computerised tomography scans of a patient with moderate plaque stenosis. The results suggest that 70% stenosis will diminish blood flow to the brain from 245 ml/min to 71 ml/min. Pressure in the 50% stenosis model is increased by only 3.3%, while pressure in the 70% and 80% stenosis models are increased by 8.8% and 15.4%, respectively. Starting at 30% stenosis, each increase of 10% stenosis increases the peak wall shear stress value by a factor of two. Severely elevated magnitudes in the product of the pressure and the wall shear stress gradient were found on the upstream face of the stenosis. In specific cases, these peaks can be correlated to excavation points observed clinically.