Double aortic arch: implications of antenatal diagnosis, differential growth of arches during pregnancy, associated abnormalities and postnatal outcome

Implications of right aortic arch prenatal diagnosis: the multicentric nationwide ARCADE cohort

OBJECTIVES

This study aims to describe the various presentations of the prenatally diagnosed isolated right aortic arch (RAA), that is, without associated congenital heart defect and to evaluate the impact of prenatal diagnosis of isolated RAA in terms of postnatal outcome.

METHOD

In this multicentric retrospective study, from 2010 to 2019, all live births with a prenatal ultrasound diagnosis of isolated RAA were included, with a 1-year postnatal follow-up. The concordance between the different diagnostic steps (prenatal ultrasound, postnatal ultrasound and postnatal CT scan) was evaluated using Gwet's AC1 coefficient.

RESULTS

A total of 309 cases of prenatally diagnosed RAA were analysed, most of which had a left ductus arteriosus (83%). The concordance between prenatal and postnatal ultrasound diagnosis was excellent regarding the RAA type (AC1=0.97, 95% CI=(0.94 to 0.99)). The rare discrepancies mainly involved non-diagnosed or misdiagnosed double aortic arch (2%). CT scan was performed in 108 neonates (35%) and the concordance between prenatal ultrasound and postnatal CT scan was good regarding the RAA diagnosis (AC1=0.80, 95% CI=(0.69 to 0.90)) but poor regarding the distribution of brachiocephalic vessels (AC1=0.21, 95% CI=(0.06 to 0.36)). An associated genetic anomaly was sought for in half of the cases and identified in 4% of the cohort. During the first year of life, 50 (18%) infants presented with vascular ring symptoms and 24 (8%) underwent aortic arch surgery.

CONCLUSION

This multicentric nationwide cohort of 309 prenatally diagnosed isolated RAA demonstrated the reliability of prenatal screening, highlighted the rare cases of discrepancies between prenatal and postnatal diagnosis and underlined the value of CT scan to improve the postnatal follow-up.

TRIAL REGISTRATION NUMBER

NCT04029064.

Double Aortic Arch: A Comparison of Fetal CMR, Postnatal CT and Surgical Findings

BACKGROUND

In double aortic arch (DAA) one of the arches can demonstrate atretic portions postnatally, leading to diagnostic uncertainty due to overlap with isolated right aortic arch (RAA) variants. The main objective of this study is to demonstrate the morphological evolution of different DAA phenotypes from prenatal to postnatal life using 3D fetal cardiac magnetic resonance imaging (CMR) and postnatal CT/CMR imaging.

METHODS

3D fetal CMR was undertaken in fetuses with suspected DAA over a six-year period (Jan 2016 - Jan 2022). All cases with surgical confirmation of DAA were retrospectively studied and morphology on fetal CMR was compared to postnatal CT/CMR and surgical findings.

RESULTS

32 fetuses with surgically confirmed DAA underwent fetal CMR. All demonstrated a complete DAA with left-sided arterial duct. The RAA was dominant in 30/32 (94%). Postnatal CT/CMR was undertaken at median age of 3.3months (IQR 2.0-3.9) demonstrating DAA with patency of both arches in 9/32 (28%), with 6 showing signs of coarctation of the left aortic arch (LAA). The LAA isthmus was not present on CT/CMR in 22/32(69%), the transverse arch between left carotid and left subclavian artery was not present in 1 case.

CONCLUSIONS

Fetal CMR provides novel insights into perinatal evolution of DAA. The smaller LAA can develop coarctation or atresia related to postnatal constriction of the arterial duct, making diagnosis of DAA challenging with contrast-enhanced CT/CMR. This highlights the potentially important role for prenatal 3D vascular imaging and might improve intepretation of postnatal imaging.

Three- and Four-Dimensional Imaging of Ductus Arteriosus in Fetuses With Pulmonary Atresia and Aortic Arch Abnormalities

Advances in fetal echocardiography including newer techniques like 4D spatio-temporal image correlation technology has improved our understanding of fetal cardiac and extracardiac abnormalities. High resolution ultrasound combined with color Doppler and 3D rendering have contributed to an improved understanding of the fetal vascular system and its anomalies. This pictorial essay including ultrasound images and videos alongside their respective clay models, provides precise information of duct anatomy in fetuses with pulmonary atresia and aortic arch abnormalities.