Abstract Abdominal Aortic Aneurysm (AAA) is an irreversible dilation of the abdominal aorta that carries significant risk of rupture if not adequately screened and treated. This condition poses severe threat, with mortality rate exceeding 80% in certain age groups. The enlargement of abdominal aorta leads to notable hemodynamic alterations in AAAs, characterized by flow separation and vortical structures. Current understanding acknowledges a correlation between growth and rupture mechanisms of AAA and disturbed hemodynamics, emphasizing metrics such as time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell activation potential (ECAP), and relative residence time (RRT). In this study, we utilized a quantitative velocity measurement technique, particle image velocimetry (PIV), to characterize the flow structure and wall shear stress in a patient-specific aneurysmal abdominal aorta phantom. Phase-averaged flow fields for 12 phases of physiological flow are investigated, constructing velocity contours, streamline patterns, vorticity contours, and swirling strength contours in AAA at three different PIV planes. In addition, a method previously developed and validated to extract wall shear stress from PIV measurements is applied to obtain shear stress indexes, including TAWSS, OSI, ECAP, and RRT. The progression of vortex structures in the bulge along with flow separation and reattachment zones in relation to the shear stress indexes are presented and discussed in detail. Here we present in detail generating AAA phantoms from patient CT images, and PIV based flow examination through the phantom, which will contribute to experimental investigations for understanding the influence of disturbed hemodynamics on AAA biomechanics.
Susar et al. (Sat,) studied this question.