Which vascular change is linked to the development of abdominal aortic aneurysm as described?

• A. Hypertension
• B. Vasculitis
• C. Atherosclerosis
• D. Infection

Answer: (C)

Abdominal aortic aneurysm develops when the vessel wall becomes structurally weakened, and the most common vascular change linked to this is atherosclerosis. Lipid-filled plaques in the intima provoke chronic inflammation that can extend to the media, degrading elastic fibers and smooth muscle and often compromising the vasa vasorum. This medial degeneration weakens the wall, allowing a segment of the abdominal aorta to dilate under systemic blood pressure. Hypertension raises the risk of rupture by increasing wall stress but isn’t the primary change causing the aneurysm itself. Vasculitis or infection can cause aneurysm formation in other contexts, but they’re not the typical drivers of the common abdominal aortic aneurysm.