Membranous obstruction of the inferior vena cava associated with intrahepatic portosystemic shunt.

Two cases of membranous obstruction of the IVC at hepatic portion associated with intrahepatic portosystemic shunts, which presumably represent the persistent vitelline sinusoids, are presented. The association of these two conditions has not been previously reported and may support the congenital etiology of the membranous obstruction of the IVC. The caval membrane was successfully dilated percutaneously with a balloon catheter in each case.