The aorta is the largest artery in the human body, transporting oxygenized blood directly from the left ventricle of the heart to the rest of the body. An aortic aneurysm is a local dilation in the aorta of more than 1.5 times the original diameter [27]. Although aneurysms can be present in every part of the aorta, the majority of the aortic aneurysms are situated in the abdominal aorta (AAA, Fig. 6.1), below the level of the renal arteries and above the aortic bifurcation to the common iliac arteries [7]. A diameter of 3 cm or more is generally used as indication for an AAA (abdominal aortic aneurysm). In most AAAs, thrombus is found between the perfused flow lumen and the aortic wall. Thrombus is a fibrin structure with mainly blood cells, platelets, and blood proteins, which is deposited onto the vessel wall [21].