Absent ductus venosus: case series from two tertiary centres

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.

An unusual umbilical venous connection to a left posterior intercostal vein

A foetal echocardiogram, in a 27-week foetus referred for cardiomegaly, demonstrated dextrocardia, absence of the ductus venosus, and an unrestricted unusual umbilical venous drainage to a left posterior intercostal vein, which continued to left hemiazygos vein and drained into the coronary sinus. Progressive cardiomegaly led to early delivery. To the best of our knowledge, no case with similar umbilical venous drainage has been previously reported.

Case report of neonatal ductus venosus atresia

INTRODUCTION

In the fetus, the ductus venosus (DV) connects the umbilical vein and the portal veins to the inferior vena cava in order to bypass the high-resistance hepatic vascular network. Via the Eustachian valve, the DV directs umbilical venous blood with the highest oxygen content preferentially towards the myocardium and the brain. An absence (agenesis) or a secondary obliteration of an initially normally developed DV (atresia) is associated with various shunt types and may lead to severe hydrops.

CASE REPORT

A routine check-up of a healthy 34-year-old woman at 27 5/7 wks GA revealed a severe hydrops fetalis with pleural effusions and ascites. After birth at 28 0/7 wks GA, the bilateral pleural effusions needed drainage via thoracic drains. Arterial hypotension was initially treated with volume replacement and dopamine, later on adrenaline and hydrocortisone were added. The initial echocardiography showed normal anatomic structures and normal bi-ventricular function. Despite maximal intensive care treatment, a global respiratory and cardiovascular insufficiency developed. The girl died on fourth day of life. At autopsy, a secondary atresia of the DV was identified, and moreover a pathogenic de novo heterozygous mutation in the KRAS gene was found in the chorion biopsy probe.

DISCUSSION

For all cases of non-haemolytic hydrops fetalis, a prenatal or postnatal sonography with Doppler examination of the venous system and of the heart should be performed. Furthermore, testing for RASopathies should be recommended especially in presence of increased nuchal translucency thickness and polyhydramnios.

First-Trimester Diagnosis of Hypoplastic Left Heart Syndrome: A Case Report

Hypoplastic left heart syndrome (HLHS) comprises a spectrum of left-sided heart anomalies resulting from left outflow or inflow obstruction. Obstruction most often occurs at the levels of the aortic valve and/or mitral valve due to stenosis or atresia. HLHS is a lethal cardiac anomaly if not treated within the first week of life. Knowledge of sonographic features could aid in early detection, which results in better planning and management of pregnancy. This report presents a case in which HLHS was discovered during a routine dating and viability sonogram, performed at 12 weeks’ gestation.

Antenatal intervention for congenital fetal lower urinary tract obstruction (LUTO): a systematic review and meta-analysis

Objective: To evaluate the effectiveness of antenatal intervention for the treatment of congenital lower urinary tract obstruction (LUTO) in improving perinatal survival and postnatal renal function.Methods: Electronic databases were searched from their inception until May 2018. Selection criteria included randomized controlled trials and nonrandomized studies including fetuses with ultrasound evidence of LUTO evaluating antenatal intervention for improving perinatal outcomes. Any type of antenatal bladder drainage technique was analyzed. The primary outcome was perinatal survival. The secondary outcome was postnatal survival with normal renal function. The summary measures were reported as summary odds ratio (OR) with 95% of confidence interval (CI).Results: Ten articles with a total of 355 fetuses were included in the meta-analysis. Inclusion criteria of the selected studies were singleton pregnancy with severe LUTO confirmed on detailed fetal ultrasound examination. Nine studies analyzed the efficacy of vesico-amniotic shunt performed in the second trimester. The overall estimate survival was higher in the vesico-amniotic shunt group compared to the conservative group (OR: 2.54, 95% CI: 1.14-5.67). 64/112 fetuses (57.1%) survived in the vesico-amniotic shunt group compared to 52/134 (38.8%) in the control group. Five studies reported on postnatal renal function between 6 months and 2 years. Rate of good postnatal renal function was higher in the vesico-amniotic shunt group compared to the conservative group (OR: 2.09, 95% CI: 0.74-5.9). Fetal cystoscopy was performed in only two included studies. Overall, 45 fetuses underwent fetal cystoscopy. The perinatal survival was higher in the cystoscopy group compared to the conservative management group (OR: 2.63, 95% CI: 1.07-6.47). Normal renal function was noted in 13/34 fetuses in the cystoscopy group versus 12/61 in the conservative management group at 6 months follow-up (OR: 1.75, 95% CI: 1.05-2.92)Conclusions: Antenatal bladder drainage appears to improve perinatal survival in cases of LUTO.