Background: A large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. Methods: 10 pigs (group A) underwent infrarenal aortic dissection, balloon dilatation, infusion of elastase into the lumen and placement of a stenosing cuff around the aorta. 10 control pigs (group B) underwent a sham procedure. The subsequent 28 days the AP-diameters of the aneurysms were measured using ultrasound, hereafter the pigs were euthanized for inspection and AAA wall sampling for histological analysis. Results: In group A, all pigs developed continuous expanding AAA's with a mean increase in AP-diameter to 16.26±0.93mm equivalent to a 57% increase. In group B the AP-diameters increased to 11.33±0.13mm equivalent to 9.3% which was significantly less than in group A (p<0.001). In group A, a significant negative association between the preoperative weight and the resulting AP-diameters was found. Histology shoved more or less complete resolution of the elastic tissue in the tunica media in group A. The most frequent complication was a neurological deficit in the lower limbs. Conclusion: In pigs it's possible to induce continuous expanding AAA's based upon proteolytic degradation and pathological flow, resembling the real life dynamics of human aneurysms. Because the lumbars are preserved, it's also a potential model for further studies of novel endovascular devices and their complications.
Kloster, B. O., Lund, L., & Lindholt, J. S. (2015). Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model. Annals of Medicine and Surgery, 4(1), 30–35. https://doi.org/10.1016/j.amsu.2014.10.001