Patient-specific arterial system flow oscillation

Atherosclerosis formation depends on the biomechanical blood flow properties. The temporal variation during the cardiac cycle has been proposed as a decisive atherogenic factor. Patient-specific (complex configuration) of the vessel promotes flow disturbances. The present study analyses the factors simulating pulsatile blood flow in the human arterial system using patient-specific geometry.

With the aid of numerical techniques, we examine the relation between time-Averaged Wall Shear Stress (AWSS), time-Averaged Wall Shear Stress Vector (AWSSV), Oscillatory Shear Index (OSI) and Relative Residence Time (RRT).

The velocity vector oscillates and at the same time alters its direction in places with low AWSS values. Low AWSS and high OSI values do not always collocate. AWSSV tends to alter its values, compared to AWSS, in regions where AWSS is low. RRT present high values in areas with low AWSS. The inverse proportionality relation between RRT and AWSSV is established.

Regional differences between AWSS magnitude, OSI and RRT, may answer the question as to where atherosclerotic lesions predominately develop and progress at specific aortic regions. This analysis gives information for deeper understanding of the atherosclerosis mechanisms.