Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

Abstract

BackgroundA 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.Methods10 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.ResultsIn group A, all pigs developed continuous expanding AAA's with a mean increase in AP-diameter to 16.26 ± 0.93 mm equivalent to a 57% increase. In group B the AP-diameters increased to 11.33 ± 0.13 mm 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.ConclusionIn 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.

Animal Models Used to Explore Abdominal Aortic Aneurysms: A Systematic Review

“…41 Kloster et al recently reported a continuously expanding AAA over 28 days in a porcine model. 42 They performed elastase infusion followed by angioplasty and cuff placement proximal to the AAA (Fig. 4).…”

Induction of autoimmune abdominal aortic aneurysm in pigs - A novel large animal model

“…This substantial AP-diameter increase is far beyond what can be attributed to normal increase in body weight of the pigs as shown by the control pigs in our recent study by Kloster et al. [8] This study was performed at the same institution using pigs from the same herd and at the same age as in our study. Kloster et al.…”

Experimental Models in Abdominal Aortic Aneurysm

“…It is percutaneously performed and whole side branches of aorta are preserved. It results with moderate degree of dilatation [2].…”

“…Most important advantage of this model is preservation of lumbar arteries. Disadvantages are requirement of laparotomy, occurrence of retroperitoneal fibrosis and aneurysm extension limited at proximal [2]. Turbulent flow in this model provides appropriate hemodynamic effect for damaging intercellular matrix after protective barriers like tunica intima and lamina elastic interna are weakened by elastase and effect of balloon; rather than creating aneurysm alone [45].…”

“…It has firstly been incidentally observed by Ponseti IV et al in 1952 that medial necrosis, dissection and aneurysm formation occurred after a special diet. Abdominal aortic aneurysm has been created with different techniques in many different models, its pathophysiology and drugs for preventing aneurysm formation have been investigated [2].…”