A rat model of aortic arch aneurysm with excellent survival

Background: The complex mechanisms of aortic arch aneurysm have not been well studied. An animal model of aortic arch aneurysm would be beneficial to study this fatal disease. In this study, we tried to establish a rat model of aortic arch aneurysm by constricting the aortic isthmus.

Methods: Forty-eight male Sprague-Dawley rats were randomly divided into three groups. Rats with no aortic isthmus constriction were assigned to group A (control group). The aortic isthmus was constricted to 1.5 mm in group B and to 0.8 mm in group C. The blood pressure of the rats was measured at 0, 1, 3 and 6 months after the operation. The diameter and wall thickness of aortic arch were measured at 3 and 6 months after surgery.

Results: Compared to group A, group B showed no significant increase in blood pressure or aortic diameter after the operation. Compared to the control group, group B showed a marked increase in wall thickness at 3 and 6 months after surgery (p < 0.05). Compared to group A, group C showed significant increases in both blood pressure (p < 0.05) and aortic diameter (p < 0.05) after the operation. Group C also showed a more than 50% increase in wall thickness at 3 and 6 months after surgery (P < 0.05).

Conclusions: By constricting the aortic isthmus to 0.8 mm, a rat model of aortic arch aneurysm could be induced at 3 and 6 months after surgery.