Persistent Right-Sided Umbilical Vein and Azygos Continuity associated with Ophthalmological and Pulmonary Malformations. Prenatal Diagnosis of an Exceptional Case

Abstract

We report on the case of a fetus in whom a prenatal ultrasound performed at 22 weeks of gestation allowed the diagnosis of a double anomaly of the systemic venous return, with a persistent right umbilical vein and the agenesis of the inferior vena cava with azygos continuity.The fetus showed also a large umbilical hernia and a right sided microphtalmia. Fetal growth was normal. Genetic anomalies were excluded by karyotype and CGH array. Cesarean section was performed at 39 weeks of gestational age for breech presentation. The neonate adapted well. Post-natal examination confirmed pre-natal diagnosis. Thoraco-abdominal CT-scan performed at 8 days of age showed additional right upper lobe bronchial atresia with relative hypoplasia of the right pulmonary artery and right hepatic lobe hypotrophy. It also showed a short segmental infra diaphragmatic aplasia of the vena cava with dilation of the azygos vein running along the homolateral diaphragmatic coupola that drained into superior vena cava and malposition of the mesenterial vessels without any intestinal malrotation. Anomalies of the fetal cardinals and umbilical veins are the result of early abnormal venous system development in the embryo, the etiology of which is unknown. Usually, abnormal systemic venous return only affects one vessel. The presence of a double anomaly as described in this case is exceptional.A persistent right umbilical vein is reported in 0.2 to 0.4% of antenatal screening. The variant with intrahepatic transition is the most frequent and isolated form. The exceptional, form with hepatic bypass, is commonly part of a polymalformative syndrome. Agenesis of the inferior vena cava (IVC) with azygos continuity is a rare anomaly (0,2-3% of antenatal screening). Its significance relates to its frequent association with complex congenital heart diseases. The prognosis of anomalies of cardinals and umbilical veins depends on the presence of associated cardiac and extra cardiac malformations that might impact prenatal counseling and parental decision to continue or interrupt pregnancy. Careful repeated pre and post-natal evaluation is necessary to exclude polymalformative syndrome despite of normal molecular genetic examination.