Right aortic arch with bilateral arterial duct and nonconfluent pulmonary arteries without associated cardiac defects: Prenatal diagnosis and successful postnatal treatment

Prenatal Diagnosis of Anomalous Origin of the Left Pulmonary Artery in Fetus with a Right-Sided Aortic Arch: Case Report and Review of the Literature

INTRODUCTION

Anomalous origin of the left pulmonary artery (AOLPA) is an exceptionally rare congenital malformation, requiring particular care to be detected during fetal echocardiography.

CASE PRESENTATION

A 30-year-old woman, gravida 1, para 0, was referred for a mid-trimester anomaly scan. The three-vessel tracheal view in fetal echocardiographic examination led to the prenatal detection of an AOLPA in the presence of a right-sided aortic arch. Additionally, a bilateral arterial duct and the ductal origin of the left pulmonary artery (LPA) were detected postnatally. Prenatal diagnosis enabled the scheduling of the delivery in a tertiary perinatal center, immediate postnatal treatment with prostaglandin E1 to avoid obstruction of the isolated LPA, as well as surgical repair of the anomaly.

CONCLUSION

The rareness of the disease led to only sporadically published cases of prenatal diagnosis of AOLPA. However, early detection makes prenatal diagnosis crucial regarding the infants' outcome. This case report underlines the importance of a meticulous examination of the bifurcation of the pulmonary trunk during fetal echocardiography.

INTRODUCTION

Anomalous origin of the left pulmonary artery (AOLPA) is an exceptionally rare congenital malformation, requiring particular care to be detected during fetal echocardiography.

CASE PRESENTATION

A 30-year-old woman, gravida 1, para 0, was referred for a mid-trimester anomaly scan. The three-vessel tracheal view in fetal echocardiographic examination led to the prenatal detection of an AOLPA in the presence of a right-sided aortic arch. Additionally, a bilateral arterial duct and the ductal origin of the left pulmonary artery (LPA) were detected postnatally. Prenatal diagnosis enabled the scheduling of the delivery in a tertiary perinatal center, immediate postnatal treatment with prostaglandin E1 to avoid obstruction of the isolated LPA, as well as surgical repair of the anomaly.

CONCLUSION

The rareness of the disease led to only sporadically published cases of prenatal diagnosis of AOLPA. However, early detection makes prenatal diagnosis crucial regarding the infants' outcome. This case report underlines the importance of a meticulous examination of the bifurcation of the pulmonary trunk during fetal echocardiography.

Case report: the 'vanished' left pulmonary artery

Background

We report a case of isolated ductal origin of pulmonary artery (DOPA) diagnosed in an asymptomatic newborn. The primary aim of this case is to highlight the need to investigate for DOPA in patients diagnosed with an 'absent branch pulmonary artery'.

Case summary

Our patient was an asymptomatic newborn infant, with normal intracardiac anatomy. He was initially diagnosed post-natally with 'absent left pulmonary artery' (LPA), though the LPA was seen in antenatal scans. He underwent angiography and was re-diagnosed with bilateral arterial ducts, with ductal origin of the LPA from the left arterial duct. The LPA was salvaged by first stenting the left arterial duct on Day 11 of life, with subsequent surgery to connect the LPA to the main pulmonary artery at 4.5 months old. The patient had an uneventful recovery after the surgery.

Discussion

Ductal origin of pulmonary artery is a rare vascular anomaly characterized by continuity of the left or right pulmonary artery (PA) with the distal end of the arterial duct, and discontinuity with the main PA. It is commonly misdiagnosed as pulmonary artery agenesis when the patent arterial duct constricts, with cessation of blood flow into the affected pulmonary artery. A high index of suspicion is necessary for diagnosis of DOPA. Once diagnosed, this lesion is clearly amenable to intervention, with benefits from unifocalization, to prevent late onset pulmonary hypertension or cardiac failure.

The multiform sonographic spectrum of arterial duct in right aortic arch

To study the different characteristics of arterial duct (AD) in a series of prenatally detected right aortic arch (RAA). Out of 832 congenital heart diseases (CHD) referred to a tertiary center, 98 cases had RAA. Based on anatomical landmarks we identified 7 types of AD: type 1 left-sided, transverse; type 2 left-sided, vertical; type 3 from the underside of aortic arch (AA), vertical; type 4 right-sided, mirror-image “V”, transverse; type 5 right-sided, “H” shaped, transverse; type 6 bilateral; type 7 absent or unidentifiable. For each type of AD the incidence of associated major CHD was calculated and chi-square test was applied to verify the null hypothesis with significance level of p < 0.05. Type 1 occurred in 43% of cases including 4 with CHD and no cases with pulmonary outflow obstruction (POO). Symptoms of vascular ring were present in 41% of survivors. Type 2, 3 and 7 AD were associated with tetralogy of Fallot (TOF) or equivalents. No type 5 AD with CHD had POO and 3 isolated cases had asymptomatic hypoplasia of left pulmonary artery (LPA). Two type 6 AD had disconnection of LPA. Type 1 occurred more often as an isolated finding (p < 0.001), whereas types 2 (p = 0.0026), 3 (p = 0.0045), 4 (p = 0.0325) and 7 (p = 0.0001) were frequently associated with major CHD. In RAA, type 1 (U-shaped) is usually an isolated finding (p < 0.001) which includes all symptomatic vascular rings. POO is always present when the AD is vertical or absent but not when it lies on a transverse plane. Bilateral AD is rare and brings the risk of functionary loss of left lung if not identified.

Postnatal Outcome and Associated Anomalies of Prenatally Diagnosed Right Aortic Arch with Concomitant Right Ductal Arch: A Systematic Review and Meta-Analysis

Right aortic arch presents a reported incidence of 0.1% of the general population; the aim of our study was to evaluate the risk of associated intracardiac (ICA), extracardiac (ECA), or chromosomal abnormalities in fetuses with right aortic arch (RAA) and concomitant right ductal arch (RDA). A systematic review of the literature selected 18 studies including 60 cases of RAA/RDA. A meta-analysis with a random effect model calculated for each outcome the pooled crude proportion of associated abnormal outcomes in cases of RAA/RDA and the pooled proportions and odds ratios in RAA with LDA or RDA. Quality assessment of the included studies was achieved using the NIH quality assessment tool for case series studies. RAA/RDA presents risk of associated conotruncal CHDs of about 30% and risk of 22q11 microdeletion in the region of 1%. Two-thirds of 22q11 microdeletions had concomitant thymic hypoplasia and no other chromosomal defects were described. Risks for ICA, ECA, 22q11 microdeletion, and aberrant left subclavian artery are not substantially different in RAA with right or left arterial duct. RAA increases the risk of associated cardiac defects regardless of laterality of the ductal arch. In isolated RDA/RAA cases, absolute risks of extracardiac associated problems or surgery are rather low, we would therefore recommend reassurance, particularly when the thymus and karyotype are normal.