TitleImpact of geometry on blood flow patterns in abdominal aortic aneurysms
NamePatel, Vashishth (author), Li, John K-J (chair), Shoane, George (internal member), Drzewiecki, Gary (internal member), Rutgers University, Graduate School - New Brunswick,
DescriptionThe rupture of abdominal aortic aneurysm (AAA) is the 13th leading cause of death in the US. The dilation of aneurysm and the risk of rupture depend on hemodynamic stresses on the wall and changes in wall mechanics and structural properties, which are both impacted by blood flow patterns. Flow patterns in AAA are affected by the changes in the geometry of aneurysm bulge and associated vessels. So it becomes obvious that the flow patterns pertaining to various geometrical aspects of AAA should be understood in order to better understand stress and physiological impacts and etiology of AAA rupture. Using computational fluid dynamics (CFD), the impact of geometrical parameters in combination with boundary conditions on the flow patterns and pressure distribution in AAA models was evaluated in this study. Bifurcation angle in combination with asymmetry has significant impact on blood flow patterns and pressure distribution in the aneurysm bulge. Increase in aneurysm bulge size leads to increased turbulence and instability in the flow characterized by complex flow patterns and increased vortex sizes in both axi-symmetric and asymmetric bulges. Larger asymmetric aneurysms are more prone to increased wall stress distributions, high wall shear stresses and increased overall pressure in the aneurysm bulge making it more likely to rupture. The rupture risk for large asymmetric aneurysm is highest at the posterior distal end of the aneurysm bulge due the complex flow patterns in this region and high fluid shear stresses generated due to high velocity gradients. The neck angle dramatically changes the flow patterns in both the symmetric and asymmetric aneurysms leading to aggravating blood flow patterns with irregular vortices formation that lead to high wall shear stresses and stress concentrations at the proximal neck and distal end of the aneurysm bulge. The increase in Re number leads increased turbulent flow and high fluid shear stresses near the distal end of the aneurysm bulge. Change in outlet pressure at the iliac arteries does not impact either the flow patterns or pressure distribution patterns for aneurysms.
NoteIncludes bibliographical references
Noteby Vashishth Patel
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.