Fetuses with right aortic arch: a multicenter cohort study and meta-analysis

Prenatal diagnosis and clinical implications of an apparently isolated right aortic arch

OBJECTIVE

To define the associations of a prenatally diagnosed, apparently isolated right aortic arch (RAA) with chromosomal or genetic abnormalities and tracheal compression.

METHODS

This was a retrospective study of apparently isolated RAA assessed by fetal cardiologists and fetal medicine specialists at Kings College Hospital, London between 2000 and 2017.

RESULTS

The search identified 138 cases of apparently isolated RAA. Invasive testing was performed in 75, and chromosomal or genetic anomalies were identified in 16 (22%), and the most common was 22q11 microdeletion. An aberrant left subclavian artery was seen in 51% of cases. Symptoms of a vascular ring were present in 24 of 97 (25%) children who were reviewed after birth. Bronchoscopy was performed in 33 children, and significant tracheal compression was diagnosed in 28, including 18 of 19 symptomatic and 10 of 14 asymptomatic children.

CONCLUSIONS

An apparently isolated RAA is associated with a high incidence of chromosomal or genetic abnormalities and a high incidence of tracheal compression in symptomatic and asymptomatic patients. Prenatal counselling for genetic associations and postnatal airway assessment in the context of the vascular anatomy is recommended.

Fetal cardiac abnormalities: Genetic etiologies to be considered

Congenital heart diseases are a common prenatal finding. The prenatal identification of an associated genetic syndrome or a major extracardiac anomaly helps to understand the etiopathogenic diagnosis. Besides, it also assesses the prognosis, management, and familial recurrence risk while strongly influences parental decision to choose termination of pregnancy or postnatal care. This review article describes the most common genetic diagnoses associated with a prenatal finding of a congenital heart disease and a suggested diagnostic process.

Prenatal echocardiographic assessment of right aortic arch

OBJECTIVES

To report our experience with fetal diagnosis of right aortic arch (RAA) variants based on the ductus arteriosus (DA) anatomy and brachiocephalic vessel branching pattern in relation to the trachea, and to establish whether the echocardiographic 'V-shaped' or 'U-shaped' appearance of the junction between the DA and aortic arch (AA) in the fetal upper mediastinal view is sufficiently accurate for assessment of fetal AA anatomy.

METHODS

This was a retrospective study of pregnancies with a prenatal diagnosis of fetal RAA that had postnatal confirmation of AA anatomy, referred to our tertiary center during 2011-2017. Prenatal and postnatal medical records, including echocardiographic and computed tomography (CT)/magnetic resonance imaging (MRI) scan reports, were reviewed, and cardiac and extracardiac abnormalities and the results of genetic testing were recorded.

RESULTS

Of 55 consecutive pregnancies with a prenatal diagnosis of fetal RAA, six were lost to follow-up, one was terminated and three were excluded due to lack of postnatal confirmation of AA anatomy. Of the remaining 45 pregnancies, AA anatomy was assessed postnatally by CT in 39, by MRI in one and by direct examination at cardiac surgery in five. A U-shaped appearance was found in 37/45 (82.2%) patients, all of which had a complete vascular ring (CVR). Of these 37 patients, on postnatal confirmation, 21 (56.8%) had RAA with Kommerell's diverticulum, left posterior ductus arteriosus (LPDA) and aberrant left subclavian artery (ALSA) (RAA/LPDA/ALSA), 11 (29.7%) had a double AA (DAA), four (10.8%) had RAA with Kommerell's diverticulum, LPDA and mirror-image (MI) branching (RAA/LPDA/MI), and one (2.7%) had RAA with Kommerell's diverticulum, LPDA and aberrant left innominate artery (ALIA) (RAA/LPDA/ALIA). A V-shaped appearance was found in 3/45 (6.7%) patients, all of which had RAA with right DA not forming a CVR and MI branching. In the 5/45 (11.1%) fetuses with neither U- nor V-shaped appearance, RAA with left anterior DA arising from the left innominate artery and MI branching, not forming a CVR, was found. Twelve (26.7%) fetuses had a congenital heart defect (CHD). RAA forming a CVR (U-shaped appearance) was associated with a septal defect in 6/37 (16.2%) fetuses, while RAA not forming a CVR (V-shaped appearance or no U- or V-shaped appearance) was associated with major CHD in 6/8 (75.0%) fetuses.

CONCLUSIONS

In fetuses with RAA, V-shaped appearance of the junction between the DA and AA indicates only that the transverse AA and DA run together on the same side of the thorax (trachea) while a U-shaped appearance is always a sign of a CVR. Among fetuses with a CVR, RAA/LPDA/MI is more frequent than described previously. Finally, RAA forming a CVR is not usually associated with complex CHD, as opposed to RAA not forming a CVR. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Right Aortic Arch: A Quantitative Method of Outcome Prediction

OBJECTIVE

To investigate right aortic arches (RAA) quantitatively and risk-stratify fetuses with RAA prenatally.

METHOD

A total of 143 singleton fetuses were enrolled. Four measurements were studied, including the angle and distance between the aortic arch (AO) and ductal arch (DA), the diameters of the AO and DA, and the distance growth rate (DGR).

RESULT

A significant increase in mean distance was observed in the study group (4.89 ± 1.07 mm) compared to the control group (1.62 ± 0.33 mm, p<.01). The distance increased from the second (1.52 ± 0.35 mm, p<.01, 4.06 ± 0.78 mm, p<.01) to third trimester (1.71 ± 0.29 mm, p<.01, 5.13 ± 1.10 mm, p<.01) in the normal and study groups. Fetuses with abnormalities in addition to RAAs had significantly lower growth rates (12.4 ± 5.2%) than those with an isolated RAA (33.7 ± 12.0%).

CONCLUSION

Parameters, especially DGR, may be clinically significant. DGR may be restricted when an RAA exists with other malformations. Decreasing DGR in fetuses with RAAs suggests the presence of other malformations.

Prenatal Detection, Comorbidities, and Management of Vascular Rings

The 3-vessel and trachea view is now integrated into obstetrical screening and facilitates prenatal detection of vascular rings. We examined trends in prenatal detection, associated cardiac and extracardiac anomalies, and surgical management in this population. We reviewed a population-based cohort of pediatric vascular ring patients diagnosed prenatally and postnatally between 2002 and 2017 in Alberta, Canada. Of 106 cases, 28 (26%) had a prenatal diagnosis. Prenatal detection increased over time: 0/29 from 2002 to 2009, 4/28 (14%) from 2009 to 2011, 7/23 (30%) from 2012 to 2014, and 17/26 (65%) from 2015 to 2017 (p <0.01). The prenatal group more commonly had right aortic arch/left ductus/aberrant left subclavian artery (24/28vs 53/78, p = 0.04) and associated cardiac pathology (18/28vs 33/78, p = 0.05). The rate of genetic anomalies was overall higher than previously reported (34%) and did not differ between groups (11/28vs 25/78, p = 0.48). Those with a prenatal diagnosis were less likely to require cross-sectional imaging (9/28vs 48/78, p <0.01), modifying the vascular ring subtype diagnosis in 2 patients. Surgical intervention was common and did not differ between groups (24/28vs 66/78, p = 0.89). In conclusion, prenatal detection of vascular rings has increased. Despite differences in vascular ring subtype and associated cardiac pathology, the incidence of genetic anomalies and need for surgical intervention is not associated with timing of diagnosis. Genetic counseling should be universally offered. The diagnostic accuracy of echocardiography suggests additional imaging may not be routinely required.

Congenital abnormalities of the aortic arch: revisiting the 1964 Stewart classification

The traditional classification of congenital aortic arch abnormalities was described by James Stewart and colleagues in 1964. Since that time, advances in diagnostic imaging technology have led to better delineation of the vasculature anatomy and the identification of previously unrecognized and unclassified anomalies. In this manuscript, we review the existing literature and propose a series of modifications to the original Stewart classification of congenital aortic arch abnormalities to incorporate this new knowledge. In brief, we propose the following modifications: (1) In Group I, we further divide subgroup B into left arch atretic and right arch atretic; (2) In Group II, we add three more subgroups, including aberrant right innominate artery, "isolated" right innominate artery (RIA), "isolated" right carotid artery with aberrant right subclavian artery; (3) In Groups I, II, and III, we add a subgroup of absence of both ductus arteriosus; and (4) In Group IV, we add three subgroups, including circumflex retro-esophageal aorta arch, persistent V aortic arch, and anomalous origin of pulmonary artery from ascending aorta.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Prenatal diagnosis of congenital heart disease

This review article will guide the reader through the background of prenatal screening for congenital heart disease. The reader will be given insight into the normal screening views, common abnormalities, risk stratification of lesions and also recent advances in prenatal cardiology.

Strategies for Accurate Diagnosis of Fetal Aortic Arch Anomalies: Benefits of Three-Dimensional Sonography With Spatiotemporal Image Correlation and a Novel Algorithm for Volume Analysis

BACKGROUND

Obtaining an accurate diagnosis of fetal aortic arch anomalies is often difficult with traditional two-dimensional (2D) sonography. Thus, the aim of this study was to assess the value of three-dimensional (3D) sonography with spatiotemporal image correlation for diagnosing fetal aortic arch anomalies using a novel algorithm for 3D volume analysis.

METHODS

Two-dimensional and 3D echocardiographic image data from 300 normal fetuses and 30 fetuses with aortic arch anomalies were retrospectively reviewed. Grayscale and high-definition flow imaging data were available for 2D echocardiography. Three-dimensional volumes were acquired in parasagittal views with high-definition flow imaging information. Volume postprocessing was performed using a novel algorithm to obtain 3D tomographic ultrasound imaging slices and color-rendered images. Detection of aortic arch positions, aberrant brachiocephalic patterns, and aortic arch anomalies was compared for 2D and 3D modalities. Postnatal echocardiography was used as the truth standard in assessing aortic anatomy.

RESULTS

In total, four cases of double aortic arch, 21 cases of right aortic arch, one case of retroesophageal aortic arch, and four cases of left aortic arch with aberrant right subclavian arteries were included. Inter- and intraobserver agreement were excellent for 2D and 3D modalities. The 3D modality offered better sensitivity and accuracy compared with 2D imaging for the detection of brachiocephalic anomalies (P < .01) and arch anomalies (P < .01) but comparable sensitivity for arch position. There was no difference in specificity for both modalities.

CONCLUSIONS

The proposed novel algorithm for volume postprocessing ensures that 3D reconstructed images are obtained with high repeatability. The addition of 3D spatiotemporal image correlation to fetal echocardiography may offer a more accurate diagnosis for arch anomalies.

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

We describe a rare case of right aortic arch with bilateral arterial duct and disconnected left pulmonary artery. Prenatal diagnosis allowed to plan delivery at the referral center and to maintain perfusion of the disconnected pulmonary artery through prostaglandin E₁ infusion until surgical reconnection was performed. Early postnatal treatment avoided functional loss of the left lung that would have happened if malformation had not been identified before birth.

Prenatal microarray analysis in right aortic arch-a retrospective cohort study and review of the literature

OBJECTIVE

To examine the risk for clinically significant chromosomal microarray analysis (CMA) findings in fetal right aortic arch (RAA).

METHODS

Data from all CMA analyses performed owing to isolated RAA reported to the Israeli Ministry of Health between January 2013 and September 2016 were evaluated retrospectively. Risk for abnormal CMA findings was compared with two control populations, based on both previously described 9272 pregnancies with normal ultrasound, and on a local cohort of 5541 pregnancies undergoing CMA testing owing to maternal request. In addition, Pubmed database search was conducted for original researches examining this issue.

RESULTS

Of 94 CMA analyses performed owing to isolated RAA, six (6.4%) pathogenic findings were detected (47,XX + 21; 45,X; two 22q11.2 microdeletions; 10p15.3 microdeletion and 16p11.2 duplication). Compared with control groups, an isolated RAA yielded a significantly increased relative risk for abnormal CMA results. Literature search yielded two additional retrospective studies describing microarray testing in RAA and encompassing 57 cases. The overall risk for clinically significant CMA findings was 6.62% (10/151).

CONCLUSIONS

CMA testing is indicated in cases of prenatal isolated RAA, even in the era of advanced sonographic equipment, routine biochemical screening for Down syndrome and available non-invasive prenatal testing.

Congenital anomalies of the aortic arch

Congenital anomalies of the aortic arch include diverse subgroups of malformations that may be clinically silent or may present with severe respiratory or esophageal symptoms especially when associated with complete vascular rings. These anomalies may be isolated or may be associated with other congenital heart diseases. Volume rendered computed tomography (CT) and magnetic resonance angiography (MRA) help in preoperative surgical planning by providing information about the complex relationship of aortic arch and its branches to the trachea and esophagus. Three dimensional capabilities of both computed tomography angiography (CTA) and MRA are helpful in determining evidence of tracheal or esophageal compression or other high-risk features in patients with a complete vascular ring.

Correlation of Symptoms with Bronchoscopic Findings in Children with a Prenatal Diagnosis of a Right Aortic Arch and Left Arterial Duct

A right aortic arch (RAA) with a left arterial duct (LAD) together encircle the trachea and have the potential to cause tracheobronchial compression and published guidelines recommend bronchoscopy in symptomatic patients. The aim of the study was to describe the incidence of tracheal compression in a cohort of prenatally diagnosed RAA and LAD. Retrospective review of clinical course and imaging of prenatal cases of RAA and LAD assessed with flexible bronchoscopy over an 11-year period. 34 cases of prenatally diagnosed RAA with LAD underwent bronchoscopy at median age of 9 months (range 0.4-123) of whom 11 had respiratory symptoms and 23 were asymptomatic. In the neonatal period, three cases demonstrated respiratory symptoms. An aberrant left subclavian artery (ALSA) was identified in 29 cases. Pulsatile tracheal compression was identified in 32/34 (94%) cases and two cases showed normal tracheal appearances. Significant tracheal compression (> 70% occlusion) was present in 25/34 (74%) cases of which 16 were asymptomatic. Significant carinal compression (> 70% occlusion) was identified in 14/34 (42%) cases, an ALSA was observed in 13/14. Surgical relief of a vascular ring has been performed in 27 (79%) cases at a median age of 15 months (range 0.6-128 months). At surgery, a fibrous remnant of an atretic left aortic arch was identified in 11/27 (41%) cases. Significant tracheal compression may be present in infants even without symptoms. If early relief of airway compression is to be achieved to promote normal development of tracheal cartilage, early bronchoscopy should be considered.

Characteristics of prenatally detected right aortic arch cases in a single institution

This study aimed to elucidate the diagnostic process, the associated anomalies and the perinatal outcomes of right aortic arch (RAA) in a group of low-risk patients. The obstetric imaging database and digital patient files were reviewed between January 2015 and June 2016. There were 12 RAA cases detected prenatally. Seven foetuses had an aberrant left subclavian artery and one foetus had mirror image branching. The prevalence of RAA was 1.8 in 1000. Invasive prenatal diagnosis was offered to patients and seven tests were performed. There was one associated cardiac anomaly (8.3%) and one extra-cardiac anomaly (8.3%) in the same foetus which cordocentesis revealed trisomy 21. There were also two 22q11.2 microdeletion cases with isolated RAA with aberrant left subclavian arteries. All patients have given live births except one patient has chosen a termination of pregnancy for 22q11.2 microdeletion. The median follow-up time of the newborns was 21 months. None of the babies required surgery for RAA during follow-up. All the babies are alive, except for the one with trisomy 21, who dead at 5 months due to the surgical complications of an oesophageal atresia operation. Patients with an RAA foetus should be offered for foetal karyotyping and analysis for 22q11.2 microdeletion. When isolated, RAA has usually a good prognosis and rarely requires cardiac surgery. Impact Statement What is already known on this subject? Prenatal diagnosis of RAA should prompt a detailed cardiac and extra-cardiac ultrasound examination. When isolated, RAA is associated with 22q11 deletion and aneuploidies in 4.6% and 5.1%, of cases respectively. What the results of this study add? Our study showed that 28.5% of isolated RAA cases are associated with 22q11.2 microdeletion. Cardiac surgery is rarely required when RAA is an isolated anomaly. What the implications are of these findings for clinical practice and/or further research? Invasive prenatal testing for karyotypes and 22q11.2 microdeletion should be offered to patients with RAA, even in the case of an isolated one. Further larger studies are needed to confirm this finding.

Tetralogy of Fallot With Right Aortic Arch and Retro-Aortic Innominate Vein

Right aortic arch (RAA) and retro-aortic innominate vein are rare vascular anomalies. Diagnosis of these anatomical variations can be achieved using fetal echocardiography, post-natal echocardiography, and computed tomography scan. RAA can form a vascular ring when associated with other vascular anomalies which may compress the trachea and/or esophagus. On the other hand, the existence of retro-aortic innominate vein can influence the clinical decision-making and surgical strategy. We report a rare occurrence of both RAA and retro-aortic innominate vein in a 3 months old girl with a prenatal diagnosis of tetralogy of Fallot and include details of her presentation and successful management.

Utility of fetal cardiac magnetic resonance imaging to assess fetuses with right aortic arch and right ductus arteriosus

OBJECTIVE

To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) to diagnose right aortic arch (RAA) with right ductus arteriosus.

METHODS

This retrospective study included six fetuses with right aortic arch and right ductus arteriosus. The six fetal cases were examined using a 1.5-T magnetic resonance unit. The steady-state free precession (SSFP) and single-shot turbo spin echo (SSTSE) sequences were used to evaluate the fetal heart and airway. The gestational age of the six fetuses ranged from 22 to 35 weeks (mean, 26.5 weeks). The age of the pregnant women ranged from 23 to 40 years (mean 31 years).

RESULTS

Fetal cardiac MRI diagnosed the six fetal cases with RAA with right ductus arteriosus correctly. Among the six fetuses, four were associated with other congenital heart defects. In three of six cases, the diagnoses established using prenatal echocardiography (echo) was correct when compared with postnatal diagnosis.

CONCLUSIONS

Fetal cardiac MRI is a useful complementary tool to assess fetuses with RAA and right ductus arteriosus.

Fetal right aortic arch: associated anomalies, genetic anomalies with chromosomal microarray analysis, and postnatal outcome

OBJECTIVES

The aim of the study was to assess the associated prenatal findings, genetic anomalies with chromosomal microarray analysis (CMA) and postnatal outcome of fetal right aortic arch (RAA).

METHODS

This retrospective study reviewed 92 fetuses diagnosed with RAA and the findings of CMA using Affymetrix CytoScan HD array in our institution between 2013 and 2016.

RESULTS

Postnatal data were not available for six cases, and genetic data were not available for 26 cases. Tetralogy of the Fallot was the most frequently associated anomaly. Among the 60 fetuses with known karyotype, one was 46, X, Yqh+, der(13)t(8;13)(q22.3;q33.2), one was 47, XYY and the remaining were normal. Our study showed that CMA could detect uncertain significant copy number variants in 5.2% of fetal RAA and pathogenic copy number variants in 5.2%, all of which were microdeletion in chromosome 22q11.21. The genetic anomalies, gestational age at delivery and postnatal death were not significantly different between RAA-no intracardiac anomalies and RAA-intracardiac anomalies group. One infant with aberrant left subclavian artery needed to perform a surgery for respiratory symptom.

CONCLUSIONS

A right aortic arch is associated with 22q11.2 deletion syndrome in approximately 5% of cases, and, therefore, prenatal testing, preferably using CMA, should be offered. © 2017 John Wiley & Sons, Ltd.

Multidetector Computed Tomography for Congenital Anomalies of the Aortic Arch: Vascular Rings

The development of multidetector computed tomography has triggered a revolution in the study of the aorta and other large vessels and has replaced angiography in the diagnosis of congenital anomalies of the aortic arch, particularly vascular rings. The major advantage of multidetector computed tomography is that it permits clear 3-dimensional assessment of not only vascular structures, but also airway and esophageal compression. The current update aims to summarize the embryonic development of the aortic arch and the developmental anomalies leading to vascular ring formation and to discuss the current diagnostic and therapeutic role of multidetector computed tomography in this field.