Computer Simulations of Pulsatile Blood Flow in Fusiform Models of Abdominal Aortic Aneurysms

Flow dynamics have been investigated in model aneurysms under physiologically realistic pulsatile flow condition via computational modeling techniques. The computer simulations are based on finite element method. Vortex pattern emergence and evolution were evaluated. Throughout the bulge in all models regardless of size, the systolic flow was found to be forward-directed. Vortices were initially evident in the bulge during deceleration from peak systole and further expanded during the retrograde flow phase. Flow in larger models become increasingly unstable compared to smaller models. It was also noted that these unstable flow fields were much significant towards the distal half of the bulge models. This increased intensity of turbulent flow fields in larger models may contribute significantly to wall shear stress magnitude and subsequently contributing to higher rupture risks.