Two anatomical types of CPSS are currently classified as intrahepatic, the portohepatic shunts and the patent ductus venosus.

Porto-hepatic shunts consist of direct communications between one or several portal branches and one or several hepatic veins.

Patent Ductus Venosus is the abnormal patency of the ductus venosus that is a physiological connection between the intrahepatic left portal vein and hepatic vein during pregnancy and that normally closes spontaneously after birth. In case of malformation, the Ductus venosus remains patent.