THE umbilical vein has been supposed to undergo thrombosis and fibrosis in the postnatal period.1,2 Despite this, it has been shown that the adult umbilical vein can be cannulated in a superficial position in the upper abdomen, and through it direct access to the portal venous system can be obtained.3 If the umbilical vein had become fibrosed and obliterated in infancy, it should not be possible to cannulate it easily in the adult.
This study was undertaken to determine the gross and histologic structure of the normal adult umbilical vein, its possible relationships to surface landmarks and to the liver, and whether cannulation involved catheter placement in a true lumen or in a false passage.
Forty dissections were done in unselected male cadavers. Although minimal cirrhosis was present in a few cases, none had had clinically recognized portal hypertension or esophageal varices and none had major abnormalities
Braastad FW, Condon RE, Gyorkey F. The Umbilical VeinSurgical Anatomy in the Normal Adult. Arch Surg. 1967;95(6):948-955. doi:10.1001/archsurg.1967.01330180096018