ABSTRACT
Extensive studies have been carried out to understand the hemodynamics of blood flow within the aneurysms and the effect of the wall shear stress (WSS) development along the aneurysm dome, on the growth and rupture of aneurysms. Most of the previous work focused on regular lateral aneurysms. However, little is known about how the orientation of the aneurysm with respect to the primary blood flow direction will affect the blood flow within the aneurysm and WSS development along the dome of the tilted aneurysm. This paper presents a 3-dimensional Computational Fluid Dynamic (CFD) analysis of the blood flow inside the lateral aneurysm arising from the curved parent vessel at various tilting angles (β). The values of β explored in this study were 0°, 45° and 90° and their effect on the hemodynamic parameters such as primary velocity patterns, secondary velocity patterns, aneurysm wall shear stress and the area of elevated WSS have been quantified for steady flow conditions. We further utilize findings of immunohistochemical studies to arrive at a hemodynamic parameter to analyze the low flow region along aneurysm sac.
The computations indicate that the primary flow pattern was similar in all the cases, but the secondary flow patterns, the area of elevated WSS and the distribution of WSS along the neck region were found to vary dramatically with the angle β . We hope that our work will provide a fresh approach towards seeking indicators to predict the risk of aneurysm growth and rupture. Also a detailed analysis of the region along the aneurysm susceptible to growth and rupture would prove to be a valuable input towards understanding potential treatment effectiveness.
