Abstract
Abdominal aortic aneurysm (AAA) is a cardiovascular disease occurring when the aorta becomes weak and develops a balloon expansion in its wall. This balloon diameter can reach sizes up to 4 times the normal aortic diameter, with the diameter enlarging at rates of 0.2-1.0 cm/year. Ruptured aneurysm leads to death in 78% - 94% of diseased aortas [1]
Aneurysm rupture is a biomechanical event that occurs when the mechanical stresses in the wall of the aorta exceed the failure strength of the aortic tissue [2].
In medical practice, when the maximum diameter of AAA exceeds 5 cm it is considered at risk of rupture. Surgical repair is usually not considered until the diameter reaches at least 5 cm. However, It is frequently observed that AAAs with diameters less than 4 cm can rupture which raise the need of finding a more reliable method to assess rupture risk.
The role of the intraluminal thrombus (ILT) which exists in more than 75% of AAA was examined using variable thickness and material properties of the thrombus. The role of the ILT has been experimentally examined in number of studies [4; 5; 6].
ILT with variable thicknesses were used here to examine the effect of ILT on wall stresses compared with AAA without ILT.