Impact of prenatal diagnosis of ductal origin of the left pulmonary artery

A 25-year-old healthy primigravida, who had a consanguineous partner, was referred for fetal echocardiography at the 22nd week of gestation. Based on an abnormal three-vessel view at the 20weeks anomaly scan in a first-level center, a non-specified congenital heart defect was suspected. First-trimester prenatal screening (nuchal translucency measurement) was not performed. The family history was negative for congenital heart defects. Echocardiography revealed visceroatrial situs solitus with normal systemic and pulmonary venous connections and normal intracardiac anatomy. The ascending aorta had a normal size (3.7mm), however, a right aortic arch (RAA) was present. A left patent ductus arteriosus (PDA) was running from the brachiocephalic artery connecting end-to-end with the left pulmonary artery (LPA) (Figure 1a and b). The usual pulmonary arterial bifurcation was not present. The main PA had a normal size (4.8mm) and continued into the right PA (RPA), but was not connected to the LPA (Figure 2). A right-sided PDA connected the right RPA with the RAA. Amniocentesis for karyotyping and analysis of 22q11 deletion was offered but declined by the parents. Follow-up scans supported the suspected diagnosis. At 37 + 3weeks, a boy of 3760 g was born after an uncomplicated delivery. The physical examination and arterial oxygen saturation were normal. Echocardiography confirmed the diagnosis of non-confluent pulmonary arteries, distal ductal origin of the LPA from the long left-sided PDA running from the brachiocephalic artery, and a RAA with a right-sided PDA. Genetic testing did not disclose any abnormalities; among others, a possible 22q11 microdeletion was excluded. On day 3, echocardiography demonstrated constriction of both right-sided and left-sided PDA. To prevent occlusion of the LPA, prostaglandin E1 infusion was started, leading to reopening of both PDAs. With the intention to postpone the surgical reconstruction of the pulmonary bifurcation, stenting of the left PDA (Stent PRO-Kinetic 3.0 × 15mm.) was performed. The right-sided PDA closed spontaneously several days later. A successful surgical reconstruction of the PA bifurcation has been performed at the age of 5months. Distal ductal origin of one or both pulmonary arteries is an uncommon congenital cardiovascular anomaly. This condition is associated with many types of congenital heart disease. The most frequent associations are with tetralogy of Fallot, tetralogy with absent pulmonary valve syndrome, pulmonary atresia and ventricular septal defect, or visceroatrial heterotaxia. Rarely isolated non-confluent pulmonary arteries have been described. Sotomora and Edwards were the first to describe the patency of a PA in a series of autopsies on deceased patients presumed to have one absent PA by echocardiography or angiography. Later, it was postulated that flow disturbance in the early embryo could be the cause of regression of the proximal right or left sixth aortic arch, resulting in ductal origin of the RPA or LPA, respectively. Apostolopoulou et al. found evidence for this theory by depicting the progressive cessation of antegrade blood flow to the absent PA due to closure of the ductus arteriosus in the first days after birth. Closure of the arterial duct isolates the ipsilateral PA and lung, often causing significant morbidity. This condition, after closure of the duct, is also described as unilateral absence of the pulmonary artery. In a review of the literature, 108 patients with unilateral absence of the PA without associated cardiac anomalies were described. The median age of these patients at presentation was 14 years, 12% were infants <1 year of age. Fourteen patients were asymptomatic, but most patients presented with symptoms like chest pain, pleural effusion, recurrent pulmonary infections, dyspnea, exercise