Optimization of the model of abdominal aortic aneurysm--experiment in an animal model.

BACKGROUND Many studies have been performed in order to model abdominal aortic aneurysm (AAA) in an experimental animal, most commonly in small laboratory animals. In our study, we tried to find the best AAA model in a pig by using various mechanical and enzymatic mechanisms. METHODS Twenty-two pigs were operated on. We combined 3 mechanisms of creating an AAA, using an intraluminal infusion of porcine pancreatic elastase into the abdominal aortic segment, application of plastic cuff below the renal arteries causing turbulent blood flow, and inserting a patch into the longitudinal aortotomy. RESULTS We found different results in different groups according to the mechanisms used. In group A, with a combination of the intraluminal elastase infusion and application of a stenosing cuff, AAA developed in all 7 animals (100%). In this group, we also found the largest histological changes in the abdominal aorta samples. CONCLUSION The use of intraluminal pancreatic elastase infusion, together with increased turbulent flow caused by the stenosing cuff, seems to be the best model of AAA in pigs. This model is suitable for further research in the etiopathology of AAA. In fact, it is the first successful approach to a large-caliber native aneurysm model.