Secondary Flow and Wall Shear Stress in Three-Dimensional Steady Flow AAA Hemodynamics

Abdominal Aortic Aneurysms (AAAs) are balloon-shaped expansions commonly found in the infrarenal segment of the abdominal aorta, between the renal arteries and the iliac bifurcation. The mean age of patients with AAA is 67 years and males are affected more often than women in a ratio of 4:1. Abdominal aortic aneurysm rupture is the 13th leading cause of death in the United States, affecting 1 in 250 individuals greater than 50 years of age. AAAs usually remain asymptomatic while slowly enlarging over a period of years or even decades. Factors that are known to affect the risk of aneurysm rupture are: maximum transverse dimension of the aneurysm, its expansion rate, its relative size compared to the patient’s body size, smoking, and family history of the patient. The five-year survival rate is only 19% and the overall mortality rate following rupture may exceed 90% [1]. Therefore, aneurysm screening and determination of the factors that may have an important role in aneurysm growth and rupture have become important elements in the investigation of this clinical problem.