Congenital membranous obstruction of the inferior vena cava.

Congenital membranous obstruction of the inferior vena cava is a rare phenomenon resulting from failure of anastomosis between the right subcardinal vein and the liver. A case is reported in which the presenting symtpom was bleeding from esophageal varices. Cirrhosis was present and other signs of vena caval obstruction were minimal. The diagnosis was made only after an ineffective mesenterico-caval shunt had been performed. Venacavography or pressure measurements in the inferior vena cava are mandatory before attempting a porta-systemic shunt operation.