Elastase-induced Saccular Aneurysm Model In Rabbits: Model Creation And Pathological Study

Objective: To create the elastase-induced saccular aneurysm model in rabbits and observe the changes of experimental aneurysms in morphology and pathology.Methods: Firstly, we established porcine pancreatic elastase-induced aneurysm model in rabbits, MRA was performed at 3d,14d,and 28d respectively after the procedure, and then the size of aneurysms were compared at different time. Meanwhile, experimental aneurysmal samples were harvested and submitted to analyse pathologically with light and electronic microscopy using HE and EVG staining technique.Results: Elastase-induced experimental saccular aneurysms could spontaneously grow in the early stage after model establishment., and two weeks later their size became stable. Pathological examination of the experimental aneurysms revealed that layers of elastic fibers and vascular endothelial cells were obviously decreased or vanished. Four weeks later, However, aneurysmal wall became thicker due to collagen hyperplasia but elastin was not seen yet.Conclusion: The elastase-induced experimental aneurysms we have developed resemble intracranial aneurysms in human histologically and hemodynamically and have a spontaneous growth behavior. This model can not only be used to study coil embolization ,but it may also be good for research on aneurysmal formation.