Abstract
Various aortic aneurysm models have been developed in animals to simulate human aortic aneurysms. Although all of the models are similar in shape, differences in mechanical properties among models remain unclear. In this study, two aneurysm models were constructed and their mechanical properties and composition of elastic fibers were evaluated. After the abdominal aorta of Wister rat was exposed, elastase (Group E) or both elastase and CaCl2 (Group EC) were applied to its surface. Incision was then closed and the rat was kept for four weeks. Normal untreated rat was used as control (Group N). After the aorta was excised, the pressure-diameter test and the Elastic Van Gieson stain were performed. Diameter was significantly larger at 80 mmHg and the pressure-strain elastic modulus and area fraction of elastic fibers were significantly lower in Group EC than N, but the difference was insignificant between Group E and N. These results indicate that mechanical properties and tissue composition are different between aneurysm models, and thus a suitable aneurysm model should be selected depending on purposes of studies.
