Abdominal aortic aneurysm model in swine with bovine pericardium patch

BACKGROUND: Aneurysm repair using endovascular techniques has grown in importance as materials have improved. Studies of endovascular prostheses require experimental models that reproduce anatomic and pathophysiological characteristics of human aneurysms. OBJECTIVES: To describe a porcine model of abdominal aortic aneurysm. METHODS: This prospective cohort study used eleven Large White female pigs with a mean age of 12 weeks in two study phases. In phase I, the aneurysm was produced with a bovine pericardium patch by retroperitoneal surgery conducted under general anesthesia. In phase II, 15 days later, the animals underwent arteriography and were then euthanized before specimens were removed for histological analysis. RESULTS: Formation of parietal thrombus was observed in all animals. Microscopic analysis showed calcifications around thrombus in 82% of the animals. There was lymphoplasmacytic infiltration in the graft and adjacent area, with fibrosis in nine animals. Three pigs had substantial myointimal thickening, and eight had microcalcifications. Mortality was zero, and there were no ruptures, ischemia, or surgery site infections. CONCLUSIONS: This is a unique model, using inexpensive, biocompatible material. Bovine pericardium is easy for the surgeon to handle and has very similar characteristics to autologous tissue in terms of integration with the cell wall.