Umbilical vein variations: review of the literature and a case report of a persistent right umbilical vein.

A case of a ligamentum teres formed from an obliterated right umbilical vein is described. It passed to the right branch of the portal vein. The quadrate and left lobes of the liver were not separated by the usual fissure. Very few cases of anomalous umbilical veins or persistent right umbilical veins have been recorded. Of these, several have been recorded only in the umbilical cord, while in others the persistent right umbilical vein has been found intra-abdominally, in an extrahepatic position, and passing directly to the right atrium or to the inferior vena cava. Its presence is generally associated with severe congenital abnormalities, in contrast with the present case. In view of the high incidence of congenital defects associated with aberrant or accessory umbilical veins, when these are detected either in the umbilical cord or in the abdomen by umbilical phlebography, it is suggested that the patient should be carefully investigated for other congenital abnormalities.