Accurate prediction of blood flow transients : a fluid-structure interaction approach

Numerical studies are widely employed in establishing blood flow transients in arteries. Unfortunately,
many of these are based on rigid arterial geometries where the physiological interaction between the
flowing blood and the dynamics of a deforming arterial wall is ignored. Although many recent studies
have adopted a fluid-structure interaction (FSI) approach, they lack the necessary validation and, thus,
cannot guarantee the accuracy of their predictions. This work employs a well-validated FSI model to
establish the dependency of WSS transients on arterial flexibility and predict flow transients in arterial
geometries. Results show a high dependency of WSS transients on arterial wall flexibility, with hoop
strains of as low as 0.15% showing significant differences in these transients compared to that seen in a
rigid geometry. It is also shown that flow in the atherosclerosis susceptible regions of the vascular tree
is characterised by a highly disturbed flow. In these regions, WSS magnitudes are at their lowest, while
the WSS spatial gradients, rate of change and oscillatory shear index are at their highest.