Infrahepatic caudal/inferior vena cava interruption with azygos/hemiazygos continuation. Vascular anomaly in swine

Background. Swine are commonly used as a model to study congenital cardiovascular defects that occur in humans and these models have been both spontaneous and experimentally induced. Ventricular septal defect, patent ductus arteriosus, and atrial septal defect (ASD) are examples of experimentally induced models. Absence of caudal/ inferior vena cava (CVC/IVC) with azygos/hemiazygos continuation is an uncommon vascular anomaly.Case report. The vascular anomaly presented in this case report was an incidental finding on a pig that was evaluated for experimental percutaneous atrial septal defect creation and its closure using a percutaneous femoral vein approach. Absence of CVC/IVC was confirmed by venography and necropsy.Conclusions. To the best of the investigators knowledge, this is the first report of absence of CVC/IVC with azygos/hemiazygos continuation in the swine.