Hemodynamic of abdominal aortic aneurysm (AAA) and morphometryc characterization as a possible indicator of rupture

摘要

The rupture of abdominal aortic aneurysm (AAA) represents an important clinical event combining structural modifications that provoke a weakening of the arterial wall, coupled with the hemodynamic pressure acting on them. In an effort to increase understanding about this complex phenomenon, this paper studies the influence of abdominal aortic aneurysm asymmetry in the patterns of the main hemodynamics factors. Flow simulation in four 3D virtual AAA models with different asymmetry ranging from 0.2 to 0.8 were carried out under realistic pulsatile conditions to assess and identify regions with disturbed patterns flow and how it modifies the velocities fields and hemodynamic stress on the inside of the aneurysmatic sac. An explanation of the vortex structure changes and stress distribution during cardiac pulse, it is presented. The results obtained shown that the asymmetry is one of the main factors that influence the AAA rupture. On the other hand, the basis to establish a novel method, based on the morphometry of the AAA, to determine a numerical indicator characterizing the evolution and the rupture risk of aneurysm, regardless of size, it is approached. It is outlined the initial results of the validation, its current limitations and the future steps to improve the method.