Ultrasound of the fetal veins part 1: the intrahepatic venous system

Agenesis of the ductus venosus and fetal growth restriction: Is there a relation? A tertiary care center experience and systematic review of the literature

An update on the antenatal diagnosis of agenesis of ductus venosus (ADV) by differentiating the various possible types of shunts, focusing on the associated fetal anomalies, and predicting neonatal outcomes. This study reviewed the experience of two tertiary referral centers and literature. An unfavorable outcome was detected in preterm fetuses (p = 0.017), fetuses with a genetic anomaly (p = 0.046) or other associated malformations (p < 0.001). 71% of ADVs with other anomalies had an extrahepatic ADV (p = 0.002). 76% of fetuses with Fetal Growth Restriction (FGR) had an extrahepatic ADV (p = 0.025). ADV may negatively influence fetal growth in cases with extrahepatic vein drainage.

Absence of Ductus Venosus: A Comparison of 2 Distinctive Fetal Autopsy Cases and Embryologic Perspectives

In fetal circulation, oxygenated blood from the placenta flows through the umbilical vein into the ductus venosus (DV), then enters the inferior vena cava, and subsequently reaches the right atrium of the heart. The DV serves as a shunt, allowing this oxygen-rich blood to bypass the liver. The absence of the DV (ADV), also known as agenesis of the DV, is a rare congenital anomaly. Without a DV, blood from the umbilical vein must follow alternative routes to the heart. In ADV cases, blood from the umbilical vein must follow 1 of 2 primary drainage patterns: either an extrahepatic shunt or an intrahepatic shunt. This report details the antenatal ultrasound and postmortem findings of 2 fetuses diagnosed with ADV by prenatal imaging studies. The first case involved a fetus with a persistent right umbilical vein connected directly to the suprahepatic IVC, accompanied by early obliteration of the left umbilical vein and true agenesis of the DV. This fetus also had additional congenital anomalies. In contrast, the second case involved a fetus with a normal left umbilical vein that entered the liver. However, despite an ultrasound diagnosis of "absence" of the DV, a DV was present, though markedly hypoplastic and probably minimally functional or non-functional. In this case, blood from the umbilical vein likely followed an alternate intrahepatic route through the portal and hepatic veins, before reaching the heart (intrahepatic shunt). These contrasting cases emphasize the heterogeneity of vascular anomalies and embryologic origins captured by the term "ADV." Additionally, the terminology of "absence" or "agenesis" may be misleading in some purported ADV cases. Specifically, in the second case, the DV was not absent; it was markedly hypoplastic instead. This also appears to be the first reported case of a hypoplastic DV in a fetus. Both cases underscore the importance of effective collaboration and clear communication between maternal-fetal medicine specialists and pathologists.

Intrahepatic portosystemic shunts, from prenatal diagnosis to postnatal outcome: a retrospective study

OBJECTIVE

Congenital intrahepatic portosystemic shunts (IHPSS) are rare vascular malformations resulting in blood bypassing the liver to the systemic circulation. Previous studies included symptomatic patients diagnosed postnatally, but the outcome of IHPSS diagnosed prenatally is rarely reported. We present a cohort of children prenatally diagnosed with IHPSS and report their natural course and outcome.

METHODS AND DESIGN

This was a retrospective study of all fetal cases diagnosed by ultrasound with IHPSS between 2006 and 2019 at a single tertiary centre which were prospectively followed up at the paediatric gastroenterology unit. The postnatal outcome was compared between patients with a single versus multiple intrahepatic shunts.

RESULTS

Twenty-six patients (70.3% boys) were included in the study, of them, eight (30.8%) patients had multiple intrahepatic shunts. The median gestational age at diagnosis was 29.5 weeks. Growth restriction affected 77% of the cohort. Postnatally, spontaneous shunt closure occurred in 96% of patients at a median age of 7.5 months (IQR 2.2-20 months). Failure to thrive (FTT) and mild developmental delay were observed in eight (30.8%) and seven (26.9%) patients, respectively. FTT was significantly more prevalent in patients with multiple shunts compared with patients with a single shunt (62.5% vs 16.7%, p=0.02); however, the rate of shunt closure and age at time of closure were similar between these groups. All patients survived with limited to no sequelae.

CONCLUSIONS

IHPSS usually close spontaneously by 2 years of age. Children with prenatally detected IHPSS may develop FTT and mild developmental delay. Close surveillance at a paediatric gastroenterology unit may be beneficial.

Persistent Left Superior Vena Cava: Why is Prenatal Diagnosis Important?

ObjectiveTo investigate fetal anomalies and pregnancy outcomes in pregnancies with persistent left superior vena cava (PLSVC) to provide assistance in prenatal counseling.MethodsCases diagnosed with PLSVC between January 2015 and January 2020 were obtained from the hospital's electronic system and were analyzed retrospectively.ResultsTwenty-seven cases were analyzed. The prevalence of PLSVC among congenital heart diseases (CHD) was 6.9%. Conotruncal anomalies and renal anomalies were the most common accompanying cardiac and extracardiac anomalies, respectively. Chromosomal abnormality was detected in one fetus.In the postpartum period coarctation of aorta (CoA) was found in one fetus.ConclusionsWhen PLSVC is detected during prenatal ultrasonography, fetal anatomy should be carefully examined because of the anomalies that may accompany it. Prenatal genetic counseling should be given especially to cases with additional anomalies. In isolated cases, cardiac anatomy should be evaluated with repeated echocardiography because of the risk of CoA.

Ductus Venosus Agenesis and Portal System Anomalies-Association and Outcome

To evaluate the prenatal diagnosis of agenesis of ductus venosus (ADV) and portal venous system (PVS) anomalies and describe the outcome of these cases, either isolated or associated. We evaluated the intrahepatic vascular system regarding the presence of normal umbilical drainage and PVS characteristics in the second and third trimester of pregnancy. The associated anomalies and umbilical venous drainage were noted. Follow-up was performed at six months follow-up. Ultrasonography was performed in 3517 cases. A total of 19 cases were prenatally diagnosed: 18 ADV cases, seven abnormal PVS cases, and six associations of the two anomalies. We noted an incidence of 5.1‱ and 1.9‱ for ADV and PVS anomalies, respectively. Out of the 18 ADV cases, 27.7% were isolated. Five cases (26.3%) presented genetic anomalies. PVS anomalies were found in 33.3% of the ADV cases. ADV was present in 85.7% of the PVS anomalies. DV and PVS abnormalities were found with a higher than reported frequency. Normal DV is involved in the normal development of the PVS. Additional fetal anomalies are the best predictor for the outcome of ADV cases. Evaluation of PVS represents a powerful predictor for ADV cases and addresses the long-term prognosis.

Ultrasound Pitfalls in a Complex Fetal Cardiac Malformation—Case Report of a New Arteriovenous Central Communication

Cardiac and cardiovascular malformations are of real interest in terms of definition, epidemiology, and means of early diagnosis by imaging. Although ultrasound examination reaches exceptional performance nowadays, unusual pathologies are still exposed to the risk of either incorrect acquired image or misinterpretation by the specialist in a routine scan. Herein, we present a case of a 20-week-old fetus (from an apparently low-risk pregnancy) with complex cardiac and vascular abnormalities, including an arteriovenous malformation along with ventricular septal defect, ductal coarctation of the aorta, aneurysm of a brachiocephalic vein, and dilation of the entire neck and upper mediastinum venous system, and the limitations that were encountered in the process of diagnosis and management of the case.

A new classification of congenital abnormalities of UPVS: sonographic appearances, screening strategy and clinical significance

The umbilical–portal venous system (UPVS) plays an important role in embryonic development, as well as a significant blood circulation system to ensure the normal blood supply of fetal heart and brain and other vital organs. Congenital anomalies of UPVS contain many subtypes with a broad spectrum of manifestations and prognoses. Furthermore, because of fetal small lumen of UPVS, the sonographic evaluation remains difficult in utero. Appreciation of normal embryology and anatomy of UPVS is essential to an understanding of sonographic characteristics of anomalies of UPVS and fetal sequential changes. Through reviewing previous references and our experience with congenital abnormalities of UPVS, a new comprehensive classification is proposed. The new classification identifies three types of congenital abnormalities of UPVS based on morphological abnormalities and shunts. The embryology and etiology, sonographic, clinical and prognostic characteristics of each subtype of the new classification are described in detail. Knowledge of congenital abnormalities of UPVS can give sonographers a clue and aid prenatal sonographic diagnosis. The purpose of this article is to help the sonographers to understand the new classification of congenital abnormalities of UPVS, master the sonographic characteristics of each subtype and prenatal ultrasonographic screening strategy, and guide subsequent appropriate counseling and management.

Prenatal diagnosis of abnormality of the umbilical portal DV complex: difficulty in universal classification due to various alternative routes in hepatic circulation for placental drainage

OBJECTIVE

To review our experience with fetal abnormality of the umbilical-portal-DV complex and to discuss the new classification system for umbilical portal systemic venous shunts (UPSVS) according to our cases.

METHODS

This study was a retrospective analysis of fetuses with a prenatal diagnosis of abnormality of the umbilical-portal-DV complex. The integrity of the fetal umbilical-portal ductus venosus complex and the hepatic venous system were evaluated using two-dimensional color Doppler sonography. The origin of the shunt, the location of the drainage, and the presence or absence of intrahepatic portal venous system and DV were noted.

RESULTS

35 cases of abnormality of the umbilical-portal-DV complex were identified. Agenesis of ductus venous was detected in 33 of them. Based on the abnormality of the umbilical-portal-DV complex, we divided the cases into five groups. Group 1, ductus venosus agenesis with normal hepatic venous anatomy (n = 11); Group 2 downward displacement of the umbilical-portal-DV complex (n = 13); Group 3, umbilical-systemic shunt (n = 5); Group 4, intrahepatic portosystemic shunt (n = 4), Group 5, hepatic arteriovenous malformation (n = 2). Three different intrahepatic portosystemic shunt and one different downward displacement of the umbilical-portal-DV complex cases were detected.

CONCLUSIONS

Disruption of the normal anatomy of the umbilical-portal-DV complex causes various alternative pathway of the placental drainage. This illustrates highlights the challenge of creating a universal classification.

Ultrasonic detection of fetal persistent right umbilical vein and incidence and significance of concomitant anomalies

BACKGROUND

Persistent right umbilical vein (PRUV) is characterized by atresia of the left umbilical vein while the right umbilical vein remains open. Given the limited sample size of most studies, the incidence of PRUV and the status of concomitant anomalies may not be fully reflected. Thus, we studied the incidence of fetal PRUV and its concomitant anomalies on a larger scale using our hospital database. This study hoped to address the following questions: Does PRUV increase the risk of fetal anomalies? If the PRUV fetus also has a single umbilical artery (SUA), does the risk of fetal anomaly increase further? What is the positive predictive value of PRUV for fetal anomalies?

METHODS

This retrospective study analyzed 756 cases of fetal PRUV at our hospital from January 2007 to April 2017. Prenatal ultrasound and color Doppler images were assessed. All PRUV fetuses underwent echocardiography and detailed ultrasound examinations of other systems. Newborn status was obtained via the database or by telephone follow-up.

RESULTS

A total of 435,428 pregnant women underwent prenatal ultrasonography at 16-40 weeks, the incidence of fetal PRUV was 0.17%, and 102 fetuses (13.5%) developed other anomalies. Two complicated cases had trisomy 18. PRUV was associated with a higher incidence of fetal anomalies. When fetal anomalies were classified by body systems, PRUV was associated with a higher incidence of cardiovascular, nervous, urinary, skeletal, digestive, and respiratory system anomalies. The positive predictive values of a PRUV for any fetal anomalies and cardiovascular anomalies were 13.5% (95%CI, 11.2-16.2%) and 5.4% (95%CI, 4.0-7.3%), respectively. SUA further increases the risk of PRUV fetuses with other anomalies and cardiovascular anomalies.

CONCLUSIONS

Detailed prenatal ultrasonography and echocardiography should be performed in fetuses with PRUV to rule out anomalies in other systems. When the PRUV is combined with SUA, echocardiography is particularly important. Fetuses with complicated PRUV should undergo chromosomal examination. Although isolated fetal PRUV prognosis is good, complicated PRUV prognosis depends on the type and severity of the concomitant anomalies.

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

INTRODUCTION

The purpose of this study was to describe the echographic features and perinatal outcomes of fetuses with absence of ductus venosus.

MATERIAL AND METHODS

Retrospective review of 10 cases with absence of ductus venosus diagnosed by prenatal ultrasonography between January 2014 and February 2016 at a single referral center. Prenatal findings, umbilical shunting type, perinatal outcomes, and autopsy reports were reviewed.

RESULTS

A total of 11 491 fetuses underwent a first- and second-trimester screening during the study period. Ten cases of absence of ductus venosus were diagnosed. All of the fetuses presented an extrahepatic shunt: three fetuses from the umbilical vein to the right atrium and the seven remaining fetuses from the umbilical vein to the inferior vena cava. Major structural defects and fetal effusions were detected in six fetuses. There were two cases of chromosomal abnormalities. Five patients underwent legal termination of pregnancy and five decided to carry to term. In two of these, the absence of ductus venosus anomaly was isolated and had a normal outcome. In the remaining three cases, a follow up of the children showed a variety of adverse outcomes.

CONCLUSIONS

The absence of ductus venosus is associated with high rates of adverse perinatal outcomes. The prognosis for this group of anomalies depends on the additional findings with targeted ultrasound. This pathology should lead to a detailed anatomical study and affected fetuses should be closely monitored for signs of congestive heart failure.

Intrathymic and other anomalous courses of the left brachiocephalic vein in the fetus

OBJECTIVE

The left brachiocephalic vein (LBCV), or innominate vein, connects the left jugular vein to the right superior vena cava. Its course is posterior to the thymus and directly anterior and superior to the aortic arch. Pediatric and adult cardiology studies have reported on the subaortic or retrotracheal courses of the LBCV and the presence of double LBCV. We observed recently in the fetus that the LBCV may have a course through the thymus (intrathymic) or be absent in the presence of a left superior vena cava. The aim of this study was to report the prevalence of isolated intrathymic and absent LBCV in normal fetuses undergoing second-trimester ultrasound screening, as well as the prevalence of other courses in association with cardiac anomalies.

METHODS

In the prospective part of this study, consecutive second-trimester ultrasound examinations were evaluated to assess the presence and course of the fetal LBCV. In the retrospective case-control part of this study, the databases of two fetal medicine centers were reviewed for cardiac anomalies and the pattern and prevalence of anomalous courses of the LBCV were reported.

RESULTS

One thousand four hundred and eighteen consecutive fetuses were examined prospectively. An intrathymic course of the LBCV with a typical bent shape was found in 1.76% (1 : 57) of cases and the absence of a LBCV in association with a persistent left superior vena cava (LSVC) was found in 0.28% (1 : 350). All fetuses with an isolated intrathymic course or absence of the LBCV had a normal outcome. Over a period of 4.5 years, a total of 1544 fetuses with cardiac malformations were reviewed at two centers. Among these, an anomalous course of the LBCV was noted in eight (0.5%) cases: six subaortic, one retrotracheal and one double LBCV.

CONCLUSION

An intrathymic LBCV is a common condition and appears to be a normal variant in the fetus. The prevalence of a LSVC in our screening population was similar to that reported in previous studies. Anomalous courses of the LBCV are seen occasionally in cases with cardiac malformation. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

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

We describe a case of a fetus with an ectopic connection of the ductus venosus to a dilated coronary sinus that was diagnosed at ShengJing Hospital of China Medical University. A dilated coronary sinus was initially detected with prenatal echocardiography. Neither a persistent left superior vena cava nor an anomalous pulmonary venous connection was present. After comprehensive examination, we discovered that the ductus venosus had an abnormal course draining into the coronary sinus. The postnatal outcome of this fetus was good. Once a dilated coronary sinus is confirmed, further ultrasound evaluation should be performed to search for a potential cause.

Sonographic Assessment of the Umbilical Cord

The umbilical cord (UC) is a vital connection between fetus and placenta. It constitutes a stable connection to the fetomaternal interface, while allowing the fetal mobility that is of great importance for fetal development in general and fetal neuromotor development in particular. This combination of mechanical stability and flexibility is due to the architecture of the UC. There is however a range of umbilical cord complications that may be life threatening to the fetus and these too can be explained to a large extent by the cord's structural characteristics. This review article discusses clinically relevant aspects of UC ultrasound.