Analytical and Computational Model for Aortic Hemodynamics Accounting for Aortic Elasticity and Arterial Branch-Flow Effects

The causes of atherosclerotic plaque formation in the abdominal aorta has been researched for many years. It has been hypothesized that certain hemodynamic factors, such as wall shear stress, blood velocity, and blood pressure, may play an important role in its development. In order to study these properties, several models have previously been developed to try and simulate blood flow through the abdominal section of the aorta since it is at this location along the length of the aorta where the greatest incidence of atherosclerosis is known to occur. Many of these models depict the abdominal aorta as being a rigid tube and do not account for elasticity. In this study an analytical and computational model that accounts for both elasticity and taper is developed. This model is used to determine the effects that blood flow through the abdominal aorta, when modeled as a straight rigid tube, straight elastic tube, tapered rigid tube, and tapered elastic tube without branches, has on the blood velocity, blood pressure, wall shear stress, and anatomical and physiological diameters.The effect that the seven major branch flows has on these hemodynamic factors is also studied. It has been found that taper and elasticity do have an effect and certainly should be accounted for when modeling the aorta. It has also been found that the addition of branch flows causes the blood velocity and wall shear stress to decrease at the infrarenal section of the abdominal aorta. Other studies have found that it is at this location along the aorta where atherosclerotic plaque is more prone to develop.