Ultrasound of the Fetal Veins Part 1: The Intrahepatic Venous System

Abstract

Advances in high-resolution ultrasound combined with color Doppler and three-dimensional (3 D) rendering have contributed to an increasing understanding of the fetal venous circulation in recent years. Still the sonographic evaluation of the venous system in the fetus remains difficult. This article reviews the normal and abnormal intrahepatic venous system. Normal anatomy and abnormal findings of the umbilical vein (UV), the ductus venosus (DV), portal veins, hepatic veins and the inferior vena cava are demonstrated by grayscale, color Doppler and 3D ultrasound and explained by numerous schemes. Typical variants and abnormalities such as agenesis of the DV and portal venous system, persistence of the right UV, UV varix are explained and the clinical value of normal and abnormal Doppler findings in the DV is discussed. Many of these abnormal findings can be detected by a targeted examination of the intrahepatic vasculature with means of color Doppler.

Abnormal Connection of the Ductus Venosus to a Dilated Coronary Sinus Imaged by Prenatal Echocardiography: Case Report

“…Some typical congenital intrahepatic venous system anomalies include agenesis or abnormal connection of the DV, total and partial agenesis of the portal system, arteriovenous communications, interruption of the intrahepatic portion of the inferior vena cava (IVC) with an azygous continuity, and partial or total infradiaphragmatic anomalous pulmonary venous return with drainage into the IVC or the portal system . In this case, the DV drained abnormally into a dilated CS, which has rarely been reported.…”

Echographic features and perinatal outcomes in fetuses with congenital absence of ductus venosus

“…The association with other abnormalities may be the most important prognosis factor in ADV. In this large group of venous system anomalies, there is an increase in the risk of fetal death, associated anomalies, aneuploidy (trisomies 21, 13 and 18), monogenic disorders (typically Noonan syndrome) or other syndromic conditions . The absence of a normal connection between the umbilical vein and the fetal venous system, particularly of a direct connection into the inferior vena cava, increases the risk of aneuploidy such as trisomy 21 , trisomy 18 or other alterations.…”

“…During the last decades, the fetal venous system has been the subject of intense research because of its importance in fetal circulation, transporting oxygenated blood from the placenta to the fetal heart. The development of high‐resolution ultrasonographic probes, the routine use of color Doppler and the introduction of bidirectional power Doppler have allowed for a better understanding of the fetal venous system, its normal physiology and the circulatory changes that may occur in anomalous circumstances .…”

“…Absence of the ductus venosus (ADV) is not a single anomaly, but rather a group of anomalies with the common characteristic of an abnormality or absence of a connection between the umbilical vein–portal sinus and the inferior vena cava at its insertion into the heart . This is a rare condition for which the true prevalence is unknown ; some authors estimate that it affects six out of every 1000 fetuses . There is a failure in the development of this “critical anastomosis” and, as there is no connection between the umbilical vein and the ductus venosus, the blood from the umbilical vein goes into the fetal heart through an aberrant vessel .…”

Ultrasonic Detection of Fetal Persistent Right Umbilical Vein and Incidence and Significance of Concomitant Anomalies

“…The segment of the left umbilical vein proximal to the heart, that is, the left umbilical vein between the liver and the sinus venosus, also degenerates, and the left umbilical vein from the umbilicus to the liver remains, which communicates with the umbilical vein in the umbilical cord, returning blood from the placenta to the inferior vena cava through the ductus venosus formed through the liver. [2][3][4][5] As a result, PRUV occurs if the left umbilical vein atrophies and degenerates and the right umbilical vein is retained. 6 PRUV can be diagnosed during prenatal ultrasonography by examination of the transverse section of the fetal abdomen.…”