Intimal thickening under shear in a carotid bifurcation--a numerical study.

In the present study, a model for intimal thickening proposed by Friedman and his co-workers is employed to simulate the growth of intima in a carotid bifurcation with a steady flow. The computer code developed is a pressure-based, finite volume method in a boundary-fitted coordinate system. A model bifurcation is used to demonstrate the usefulness of the numerical tool. The predicted results are consistent with the available experimental observations. The localization of plaques is shown. It is found that thicker intima is formed in preferential regions near the junction and the carotid bulb due to relatively low wall shear stresses. The intimal thickening tends to reduce the size of low shear regions. It is also found that the new geometry resulting from the thickening yields a more even stress distribution over the bifurcation. The effect of the branching ratio on the distribution of intimal thickening is also studied. The computer code provides a potential tool for visualization of intimal thickening.