Transjugular intrahepatic portosystemic shunt (TIPSS) is considered a valid therapeutic option for the treatment of portal hypertension and its complications. The guidelines for this procedure have already been established on the basis of the normal vascular anatomy and of various technical radiological aspects. In some few rare cases, diagnosis of a congenital vascular anomaly can be made accidentally by interventional radiologists, making the procedure of the TIPSS placement extremely difficult or in some cases technically impossible. This report describes a rare vascular malformation characterized by the absence of the right superior vena cava and persistence of the left superior vena cava in a patient with a diagnosis of advanced liver cirrhosis who needed a TIPSS placement in order to control refractory ascites.