Abnormal continuation of umbilical vein into extra‐hepatic portal vein: Report of three cases

Abstract

Anomalies of the umbilical venous system are perplexing essentially due to dissection errors and vascular connection delineation failure. Continuation of umbilical vein into the extra-hepatic portal vein is classified as group IV umbilical vein anomaly and involves the vitelline vein or its remnants. Despite this categorization most examiners ascribe fetal extra hepatic abdominal vascular abnormality as an umbilical vein anomaly. Since these anomalies involve vitelline vein, the term "umbilical vein anomaly" is inappropriate and should be referred to as "vitelline vein abnormalities". Vitelline vein abnormalities are exceedingly rare and to the best of our knowledge only three cases have been reported prenatally. We report three cases presenting with intrauterine fetal demise and on perinatal autopsy demonstrating aneurysmally dilated group IV umbilical vein anomaly. Review of the literature, embryological basis and clinical implications of persistent vitelline vein and its varix are discussed.

Topographical relationships of the yolk sac remnant and vitelline vessels with the midgut loop in the extra-embryonic coelom of human embryos

“…However, it is difficult to determine whether these thin vessels are actual remnants or develop secondarily as collaterals of the embryonic umbilical vein [19,21,22]. These veins in adults, have sometimes been called umbilical veins [23], resulting in serious confusion between embryonic umbilical and vitelline veins. Most of these adult veins seem to correspond to paraumbilical veins [24,25].…”

Prenatal sonographic diagnosis of a vitelline vein aneurysm

“…While intra‐abdominal umbilical vein varix is the most common one reported in the literature, the extremely low incidence of vitelline vein aneurysm could be related to the lack of accurate prenatal diagnosis. In almost all cases, the diagnosis could only be establihed in the detailed examination at the postpartum period (after delivery or abortion) . At early gestation age, an aneurysm of vitelline vein is often described as umbilical vein varix due to similar appearance and relatively small diameter .…”

Choriovitelline placenta: prenatal sonographic imaging and clinical characteristics

“…Eight cases of persistent VV have been described previously in the literature. In all eight, the definitive diagnosis was made after birth, the presence of a thrombotic mass in the portal system being the main reason for the diagnostic workup. In four of them there was no prenatal diagnosis; three of these cases were diagnosed incidentally at postmortem examination.…”

“…Although persistence of the vitelline veins (VV) has been described, and classified by Blackburn as a type‐IV umbilical system anomaly, literature concerning its clinical significance is scarce. Reports include only eight cases, all diagnosed in the postpartum period: four reported by pediatric surgeons, three by a pathologist after intrauterine fetal death and one by radiologists.…”