The angiographic anatomy of the portal venous system in the neonatal dog

The angiographic anatomy of the portal venous system in 50 dead, neonatal L abrador/Retriever type puppies is described. Angiography was performed by t he injection of radioopaque contrast media through a catheter placed within the umbilical vein. In 49 pups the ductus venosus was a straight vessel ar ising from the left main portal vein and terminating in an ampulla into whi ch the left hepatic and left phrenic veins entered prior to the ampulla ent ering the caudal vena cava. The diameter of the ductus venosus was signific antly narrower (P < 0.001) in pups born alive (n = 10) when compared to sti llborn individuals (n = 39). No discreet narrowing of the ductus venosus in dicating a sphincter was found, with closure appearing to be uniform along the vessel's length. A well-developed, patent portal venous system was pres ent in the majority of individuals. One pup showed variation from the other s studied having a vascular connection between the portal sinus and the ven a cava within the liver. This may represent a normal variant of the ductus venosus, or may be an anatomical abnormality leading to the development of an intrahepatic portosystemic shunt. If this was an intrahepatic shunt, no concurrent ductus venosus was present.