Umbilical vein
The umbilical vein is a blood vessel present during fetal development that carries oxygenated blood from the placenta to the growing fetus.
Closure
Within a week of birth, the infant's umbilical vein is completely obliterated and is replaced by a fibrous cord called the round ligament of the liver (also called the ligamentum teres hepatis, from the Latin meaning the same). It extends from the umbilicus to the transverse fissure, where it joins with the ligamentum venosum to separate the left and right lobes of the liver.
Closure of the umbilical vein usually occurs after the umbilical arteries have closed. This prolongs the communication between the placenta and fetal heart, allowing for a sort of autotransfusion of remaining blood from the placenta to the fetus.
Recanalization
Under extreme pressure, the round ligament may reopen to allow the passage of blood. Such recanalization is common in patients with cirrhosis and portal hypertension. Patients with cirrhosis experience rapid growth of scar tissue in and around the liver, often functionally obstructing nearby vessels. Vessel occlusion increases vascular resistance and therefore leads to hypertension. In portal hypertension, the vessels surrounding the liver are subjected to abnormally high blood pressure—so high, in fact, that the force of the blood pressing against the round ligament is sufficient to recanalize the structure.
Catheterization
A newborn baby has a patent umbilical vein for at least a few months. This umbilical vein may be catheterised for ready intravenous access. It may be used as a site for regular transfusion in cases of erythroblastosis or hemolytic disease.
Translation of "Umbilical vein"
German: Nabelvene, Japanese: 臍帯静脈, Polish: Żyła pępkowa.
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