Biomechanical Considerations of Animal Models of Aortic Aneurysm

Aortic aneurysm is a focal enlargement of the aorta developing over years and carrying the risk of rupture and death. As aneurysms are a chronic disease, animal models have come to be used in both determining the underlying mechanisms that cause aneurysm formation and in designing new treatments for the disease. These models include mechanically and chemically induced methods used for both refining surgical techniques and stent graft device characterization. The latter are typically implemented in large animals (dog, pig, and sheep). Other models employ methods that rely on genetic manipulation, often with the addition of chemical induction, to induce aneurysm formation in small animals, predominantly mice. Recent efforts have also aimed at determining both the biomechanical alterations that occur with aneurysm formation and the potential for rupture. However, many animal models for aortic aneurysm do not exhibit some of the native characteristics of the disease and as such are not suitable for investigating disease initiation and progression. The current review summarizes the various approaches of animal models for aortic aneurysm in the context of their appropriateness for biomechanical investigation.