Extrahepatic vitelline vein aneurysm: prenatal diagnosis and follow up.

Umbilical vein varix is a well-described prenatal anomaly in which the prognosis remains unclear. We describe a very rare venous malformation that mimicked an umbilical vein varix consisting of a persistent vitelline vein. From 2003 to 2010, three patients were referred starting at 20 weeks gestation to our prenatal centers for an umbilical vein varix diagnosis. Fetal follow up was unremarkable, with the exception of the dilated vein size (mean: 35 mm at 33 weeks gestation). After birth, the three children presented with thrombosis from the aneurysmal sac to the portal trunk. All the children underwent surgical thrombectomy and resection of the aneurysmal sac after birth. Operative findings showed no umbilical vein but an abnormal dilated and thrombosed vein coming from the umbilicus to the portal vein following the right vitelline vein trajectory. One child was treated with systemic heparin. Median follow up is 5.6 years. Currently, one patient has a normal portal flow. The other two have persistent portal vein thrombosis with portal cavernoma and portal hypertension. This malformation is rare and should be considered in cases of early diagnosed umbilical vein varix whose diameter is greater than 20mm. We advocate an early surgical thrombectomy with heparinization to prevent portal vein thrombosis.