Animal Model for Pericardium Patch Thoracoabdominal Aortic Aneurysm: Step by Step

Abstract

Objectives: We aimed to improve previously described methods for confection of thoracoabdominal aortic aneurysms (TAAA) in porcine animal models, reducing surgical procedure time and specimen mortality. Methods: A total of 18 swine underwent a surgical procedure in order to confect a TAAA. All anesthetic precautions were taken. All the procedures were carried out via laparotomy and retroperitoneal access. An autologous peritoneum patch was used to make the aneurysm in 2 animals, and a bovine pericardium patch in 16. All the animals were followed up post-operatively, and were re-approached after 4 weeks for analysis of the aneurysm sac. The models that did not die in the post-operative period were euthanized under institutional recommendations Results: All the animals underwent laparotomy with retroperitoneal access. Two were submitted to an autologous peritoneum patch and 16 to a bovine pericardium patch. Three models underwent single suprarenal clamping; while 15 underwent sequential clamping. There were no differences in surgical time (p 0.207) or total clamping time (p 0.276) between groups. There was a higher mortality rate after 4 weeks in models submitted to single clamping (100%) compared to sequential clamping (26.7%) (p 0.0017). Conclusion: The experimental model of a thoracoabdominal bovine pericardium aneurysm which uses a sequential clamping technique, provides a stable and reliable platform with consistent anatomy and patency for up to four weeks. This model can be extremely valuable for assessing new endovascular therapy options in living organisms