Portosystemic shunts, which develop in patients with portal hypertension, are classified as two types based on their location: extrahepatic portosystemic shunts and transhepatic portosystemic shunts. The extrahepatic portosystemic shunts are well known and include esophageal varices and splenorenal shunts. Except for descriptions of the paraumbilical vein, little information has been published in imaging literature regarding the CT appearance of transhepatic portosystemic shunts.
In 1883, Sappey [1] described the accessory portal veins in the suspensory ligament, such as the vessels located at the falciform ligament through which the anterior parietal veins communicate with the left branch of the portal vein. These vessels play a role in the origin of transhepatic portosystemic shunts.
CT during arterial portography (CTAP) can selectively opacify the portal venous system and show tiny portosystemic shunts outside the liver such as the veins of Retzius [2]. In this pictorial essay, we describe the transhepatic portosystemic shunts classified by anatomic location mainly on the basis of the CTAP appearance.