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

Combined fetal echocardiographic views improved prenatal differential diagnosis between right aortic arch and double aortic arch: a multicenter research

PURPOSE

Congenital right aortic arch (RAA) and double aortic arch (DAA) were difficult to be diagnosed by traditional fetal echography. However, these two diseases have distinct clinical therapies and long-term outcomes which makes the differential diagnosis of great importance. While fetal screening by traditional fetal echography provides limited information about the branches of the aortic arch. This study aimed to discover and evaluate a novel combination of different echocardiography views in the diagnosis and differentiation of RAA and DAA.

METHODS

From January 2014 to December 2022, a total of 414,686 pregnant women underwent routine ultrasound examinations of the fetus during the second trimester. The scan of the fetal heart included a fetal four-chamber view, The left ventricular outflow tract (LVOT) view, a right ventricular outflow tract (RVOT) view, a three-vessel (3 V) view, and three vessels and trachea (3VT) view. Then the cases diagnosed as RAA or DAA by initial ultrasound screening from two hospitals were divided into the RAA group and the DAA group. Then enter the prenatal diagnosis consultation. All the pregnant women were offered invasive prenatal diagnosis. Genetic tests were fully discussed and decided after genetic counseling. Further ultrasound examination by two more experienced sonographers, in addition to the fetal echocardiogram views, includes further multi-angle scanning of the aortic arch branches with color Doppler flow imaging (CDFI) or high definition flow imaging (HDFI) for further diagnosis, and the reasons for misdiagnosis were analyzed and summarized.

RESULTS

A total of 332 cases were diagnosed with RAA or DAA by initial ultrasound, including RAA group 244 cases and DAA group 88 cases. In the RAA group, the mirror RAA (MRAA) could not be completely diagnosed by 3VT view alone in traditional echocardiography, with accuracy and sensitivity of 88.9% and 72.6%, respectively. In the DAA group, 36 cases were misdiagnosed only by 3VT view alone in traditional echocardiography, with the accuracy and specificity of 88.9% and 86.8%, respectively. However, the accuracy for MRAA or DAA could reach 100% when combined with 3VT and multi-angle scanning of the aortic arch branches. The abnormal detection rate of genetic tests was 10.5% (20/190), excluding the cases who refused the invasive prenatal diagnosis.

CONCLUSION

Combining 3VT and multi-angle scanning of the aortic arch branches With CDFI or HDFI could effectively distinguish RAA variants from DAA. The invasive prenatal diagnosis should be recommended for patients with RAA or DAA, and the accurate prenatal diagnosis was highly valuable in providing appropriate perinatal counseling and prognostic evaluation.

Unusual Vascular Ring in the Fetus

We present the clinical course and echocardiographic and genetic findings of two fetuses with an unusual vascular ring, created by a left aortic arch with a right arterial duct and an aberrant right subclavian artery. One fetus was diagnosed with 22q11.2 microdeletion and the other became symptomatic in infancy. It is important to consider the position of the arterial ductal ligament in patients who present with tracheoesophageal compressive symptoms in the presence of a left aortic arch. These cases also highlight that a vascular ring formed from a left arch may have similar associations to a vascular ring formed by a right aortic arch.

Prenatal diagnosis in fetal right aortic arch using chromosomal microarray analysis and whole exome sequencing: a Chinese single-center retrospective study

BACKGROUND

Right aortic arch (RAA) is a common congenital aortic arch abnormality. Fetuses with RAA frequently have good outcomes after birth. However, chromosomal abnormalities and genetic syndromes suggest poor prognosis for these patients. So far the underlying genetic etiology is still not identified in most RAA patients based on traditional genetic techniques and a problem is still debated whether fetuses with isolated RAA should be referred for CMA. Our study aims to investigate the genetic etiology of fetuses with right aortic arch (RAA) by chromosomal microarray analysis (CMA) and whole exome sequencing (WES) and evaluate the efficacy of CMA in fetal isolated RAA.

RESULTS

Among these 153 fetuses, 99 (64.7%) with isolated RAA and 54 (35.3%) with non-isolated RAA; 25.5% (39/153) with additional intracardiac anomalies (ICA), and 19.0% (29/153) with extracardiac anomalies (ECA). Tetralogy of Fallot (n = 10) and persistent left superior vena cava (n = 11) are the most common ICA and ECA, respectively. CMA detected 15 clinically significant copy number variations (CNVs) in 14 cases (9.2%); microdeletion of 22q11.21 was the most common pathogenic CNVs (7.8%). The chromosomal abnormalities rate was higher in non-isolated RAA and RAA with ICA groups than in isolated RAA group (16.7% vs. 5.1%; 20% vs. 5.1%, both p < 0.05). From five cases further undergoing WES, a diagnostic variant in MTOR gene (c.7255G > A, de novo) was first reported in prenatal, extending the prenatal manifestation of Smith-Kingsmore syndrome (OMIM: 616638); a clinically relevant variant c.3407A > T in STAG2 was identified, being inherited from the healthy mother. Moreover, the premature birth and termination rates were higher in non-isolated RAA group than in isolated RAA group (11.1% vs. 1.0%; 37.0% vs. 2.0%, both p < 0.01).

CONCLUSIONS

We demonstrate that CMA and WES are useful diagnostic tools for fetal RAA, particularly non-isolated RAA, and all fetuses with RAA should be referred for CMA. The data probably aids in prenatal diagnosis and prenatal counseling of fetal RAA.

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 cardiovascular magnetic resonance, postnatal computed tomography 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 three-dimensional (3D) fetal cardiac magnetic resonance (CMR) imaging and postnatal computed tomography (CT)/CMR imaging.

METHODS

Three-dimensional fetal CMR was undertaken in fetuses with suspected DAA over a 6-year period (January 2016-January 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

Thirty-four fetuses with surgically confirmed DAA underwent fetal CMR. The RAA was dominant in 32/34 (94%). Postnatal CT/CMR was undertaken at a median age of 3.3 months (interquartile range 2.0-3.9) demonstrating DAA with patency of both arches in 10/34 (29%), with 7 showing signs of coarctation of the left aortic arch (LAA). The LAA isthmus was not present on CT/CMR in 22/34 (65%), and the transverse arch between left carotid and left subclavian artery was not present in 2 cases.

CONCLUSION

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 the interpretation of postnatal imaging.

Prenatal cardiac findings and 22q11.2 deletion syndrome: Fetal detection and evaluation

Clinical features of 22q11.2 microdeletion syndrome (22q11.2DS) are highly variable between affected individuals and frequently include a subset of conotruncal and aortic arch anomalies. Many are diagnosed with 22q11.2DS when they present as a fetus, newborn or infant with characteristic cardiac findings and subsequently undergo genetic testing. The presence of an aortic arch anomaly with characteristic intracardiac anomalies increases the likelihood that the patient has 22q11.2 DS, but those with an aortic arch anomaly and normal intracardiac anatomy are also at risk. It is particularly important to identify the fetus at risk for 22q11.2DS in order to prepare the expectant parents and plan postnatal care for optimal outcomes. Fetal anatomy scans now readily identify aortic arch anomalies (aberrant right subclavian artery, right sided aortic arch or double aortic arch) in the three-vessel tracheal view. Given the association of 22q11.2DS with aortic arch anomalies with and without intracardiac defects, this review highlights the importance of recognizing the fetus at risk for 22q11.2 deletion syndrome with an aortic arch anomaly and details current methods for genetic testing. To assist in the prenatal diagnosis of 22q11.2DS, this review summarizes the seminal features of 22q11.2DS, its prenatal presentation and current methods for genetic testing.

Post-operative Outcomes for Vascular Rings: A Systematic Review and Meta-analysis

OBJECTIVES

Vascular rings may cause tracheal and/or oesophageal compression. For many patients, symptoms/signs have been present for a long period before diagnosis. However, in the era of prenatal diagnosis, some units advocate universal early surgery. The risks and efficacy of surgery must be known to adequately counsel for the operation. This meta-analysis sought to define the morbidity and mortality associated with surgical correction, and persistent post-operative symptoms.

METHODS

PubMed, Cochrane Library and CINAHL databases were searched for studies that described the outcome of patients undergoing surgery for a double or right aortic arch (DAA or RAA). Non-comparative and random effects model-based meta-analyses were conducted to calculate the pooled rates of mortality, surgical complications, reintervention, and persistent follow-up symptoms.

RESULTS

Nineteen eligible studies were included comprising 18 studies describing outcomes for DAA surgery and 15 for RAA surgery. For DAA surgery, overall mortality rate was 0% [95% confidence interval (CI) 0.0-1.0], post-surgical complication rate 18% [95% CI: 12.0-23.0], prevalence of reintervention 3% [95% CI: 1.0-5.0] and prevalence of symptoms at last follow-up was 33% [95% CI: 17.0-52.0]. For RAA surgery, overall pooled mortality was 0% [95% CI: 0.0-0.0], prevalence of post-surgical complications was 15% [95% CI: 8.0-23.0], reintervention rate was 2% [95% CI: 0.0-4.0], prevalence of symptoms at last follow-up was 40% [95% CI: 26.0-55.0].

CONCLUSIONS

While surgery to correct a vascular ring is safe, the rate of persistent symptoms is high and further strategies must be sought to reduce this burden.

Management of prenatally detected vascular rings: a United Kingdom national survey

OBJECTIVE

To investigate UK variability in prenatal and postnatal management strategy of right aortic arch and double aortic arch (RAA/DAA).

METHODS

Online surveys were sent to senior physicians (consultants) of the National Fetal Cardiology Working Group regarding prenatal diagnosis, counselling, and perinatal management of antenatally diagnosed RAA/DAA and to the British Congenital Cardiovascular Association regarding postnatal management strategies.

RESULTS

There were 28 prenatal and 90 postnatal surveys completed. Prenatally, there was consensus for potential associated chromosomal/genetic anomalies, but there was variation in the risk quoted. Confidence in defining aortic arch morphology was reported by 43% (12/28) of fetal cardiologists. There was variation in what was felt to be possible symptoms/signs of a compressive vascular ring, postnatal investigation, postnatal management, follow-up duration of asymptomatic patients, and indications for surgical intervention.

CONCLUSION

This study has highlighted important areas for future research: improving accuracy of prenatal diagnosis, clarification of potential symptoms, optimal investigation strategies, and indications for surgery.

[Prenatally detected aortic arch anomalies and their consequences after birth]

INTRODUCTION

Aortic arch anomalies are frequently associated with cardiac or extracardiac malformations, chromosomal aberrations and postpartum esophagus/trachea compression.

OBJECTIVE

We aimed to establish the prevalence of associated cardiac and extracardiac malformations, the frequency of chromosomal aberrations in fetuses with the diagnosis of aortic arch anomalies and to assess the pregnancy and the postnatal outcome.

METHOD

Retrospective cohort study of all fetuses with aortic arch anomalies and genetic diagnosis in a tertiary referral obstetric and fetal cardiology centre between 2016 and 2020. Postpartum data were collected within 24 months after birth.

RESULTS

In a cohort of 11.380 pregnant women, the prevalence of aortic arch anomalies was 0.25%. Among 28 cases of right aortic arch anomalies, in 27 fetuses prenatal genetic diagnosis was available. We diagnosed 4 fetuses with mirror-image branching (right sided V-sign) and 23 fetuses with U-sign (4 fetuses with complete double aortic arch). 18 cases (66%) were isolated. Associated anomalies were cardiac in 3 cases and extracardiac in 7 cases (33%). The most frequent cardiac anomaly was tetralogy of Fallot (2/27), the extracardiac anomalies were thymus hypoplasia, single umbilical artery and subclavian artery malformations. In 1 case (3.7%), fluorescent in situ hybridization diagnosed 22q11.2 microdeletion. 75% of fetuses with right sided V-sign were associated with conotruncal malformations. Pregnancy and postpartum outcome were known in 24 pregnancies. Postnatal diagnosis was different from prenatal in 2 cases, the concordance rate was 93%. Isolated cases resulted in live birth in 17/18 pregnancies (93%). The frequency of postpartum trachea/esophagus compression was 42,9% (9 cases) due to vascular ring, in 6 children (28,6%) operation was necessary.

CONCLUSION

Fetal aortic arch anomalies are multidisciplinary diseases to be diagnosed by proper prenatal ultrasound examination. Associated fetal anomalies necessitate extended obstetric and cardiac sonography, invasive prenatal testing should be offered, and thorough postnatal long-term follow-up is recommended. Orv Hetil. 2023; 164(28): 1111-1120.

The Impact of Prenatal Diagnosis on Clinical Outcomes of Isolated Vascular Rings From a Statewide Paediatric Cardiology Tertiary Service

BACKGROUND

Vascular rings, including right aortic arch with aberrant left subclavian artery (RAA-ALSCA), double aortic arch (DAA) and pulmonary artery sling (PAS), are congenital anomalies that may cause airway and oesophageal compression. As prenatal detection has improved, literature comparing clinical outcomes of antenatally versus postnatally diagnosed cases continues to emerge. The aim is to define a statewide tertiary paediatric institution's clinical profile and outcomes of prenatal versus postnatally diagnosed isolated vascular rings.

METHOD

A retrospective single-centre review of isolated RAA-ALSCA, DAA and PAS between 1 January 1999 and 31 December 2020 was conducted. Clinical characteristics, surgical and follow-up information were collected. Antenatal and postnatally diagnosed groups were compared.

RESULTS

Out of 123 cases diagnosed with isolated vascular rings, 98 (79.7%) cases had RAA-ALSCA, 21 (17.1%) with DAA, 4 (3.3%) with PAS. The antenatal detection rate was 73.6% in the past decade; 20.3% had a genetic disorder, of which 48% had 22q11.21 microdeletion. Of prenatally diagnosed cases, 31.3% developed symptoms, commonly stridor and dysphagia, at a median age of 2.0 months (IQR 0.0-3.0), compared to a median age of diagnosis for the postnatal cohort of 9 months (IQR 1.0-40.7). Postnatally diagnosed cases were more likely to present with symptoms, primarily respiratory distress, than prenatally diagnosed cases (p=0.006). Fifty-nine (59) cases (50% antenatally diagnosed) required vascular ring division; 6.8% had residual symptoms following surgery.

DISCUSSION

Antenatal diagnosis has improved and leads to better parental awareness and more timely, appropriate intervention. Postnatally diagnosed patients were older, more likely to be symptomatic, underwent more investigations and were commenced on more medications for symptom management prior to diagnosis. One in five cases of isolated vascular ring anomalies carried a genetic diagnosis, which has important implications on prenatal counselling and genetic testing.

Prenatal Diagnosis of the Right Aortic Arch: Change in Detection Rate, the Status of Associated Anomalies, and Perinatal Outcomes in 137 Fetuses

To evaluate prenatal findings of the right aortic arch (RAA), associated cardiac, extracardiac, and genetic anomalies, its perinatal outcomes and the need for postnatal interventions in cases of isolated RAA with a view to facilitating appropriate counseling. This was a multicenter, cohort study, that was undertaken in two international major cardiac centers between 2009 and 2020. The study subjects were prenatally diagnosed RAA cases with and without other structural cardiac defects. A RAA was identified in 137 fetuses. There were 84 cases of isolated RAA. Associations with additional intracardiac malformations were found in 53 (38.7%) cases. An extracardiac anomaly was observed in 26/137 (18.9%) fetuses, 11/84 (13.0%) fetuses with isolated RAA, and 15/53 (28.3%) fetuses with an additional intracardiac anomaly. The incidence of extracardiac and chromosomal anomalies was significantly higher in cases of RAA with abnormal intracardiac anatomy (28.3-18.8%, respectively), compared with RAA with normal intracardiac anatomy (13.0-5.9%, respectively) (p < 0.05). 22q11.2 microdeletion was found higher in RAA with CHD (4/18 fetuses) than isolated RAA (2/24 fetuses) (22.2% vs. 8.3% respectively). ALSA was present in 19.3% of cases. ALSA was more frequently observed in cases of isolated RAA (23.6%), than in RAA with structural CHD (7.6%) (p < 0.05). The pregnancy was interrupted in six fetuses, and one died in utero. The mortality rate was higher in fetuses with intracardiac anomaly than RAA without cardiac anomaly (11/49 (22.4%) vs. 2/81 (2.4%). Vascular ring formation was revealed in 21/98 cases. The RAA caused symptoms of a vascular ring in only one patient (0.7%) requiring surgery in the follow-up. Overall survival after initial diagnosis in the total cohort was 85.4% with 38 of 53 (71%) RAA with CHD cases and 79 of 84 (94.0%) isolated RAA cases. Chromosomal and extracardiac anomalies are lower in isolated RAA but not negligible hence amniocentesis should be routinely offered in all cases. The requirement for postnatal intervention in the immediate neonatal period is remote, therefore delivery of these fetuses need not be undertaken at a cardiac or surgical center.

Chromosomal Microarray Analysis in Fetuses Detected with Isolated Cardiovascular Malformation: A Multicenter Study, Systematic Review of the Literature and Meta-Analysis

Cardiovascular malformations (CVM) represent the most common structural anomalies, occurring in 0.7% of live births. The CVM prenatal suspicion should prompt an accurate investigation with fetal echocardiography and the assessment through genetic counseling and testing. In particular, chromosomal microarray analysis (CMA) allows the identification of copy number variations. We performed a systematic review and meta-analysis of the literature, studying the incremental diagnostic yield of CMA in fetal isolated CVM, scoring yields for each category of heart disease, with the aim of guiding genetic counseling and prenatal management. At the same time, we report 59 fetuses with isolated CVM with normal karyotype who underwent CMA. The incremental CMA diagnostic yield in fetuses with isolated CVM was 5.79% (CI 5.54–6.04), with conotruncal malformations showing the higher detection rate (15.93%). The yields for ventricular septal defects and aberrant right subclavian artery were the lowest (2.64% and 0.66%). Other CVM ranged from 4.42% to 6.67%. In the retrospective cohort, the diagnostic yield was consistent with literature data, with an overall CMA diagnostic yield of 3.38%. CMA in the prenatal setting was confirmed as a valuable tool for investigating the causes of fetal cardiovascular malformations.

Contemporary surgical outcome and symptomatic relief following vascular ring surgery in children: effect of prenatal diagnosis

OBJECTIVES

Our goal was to describe postoperative complications and outcomes in a large contemporary cohort of children with an isolated double aortic arch (DAA) or a right aortic arch (RAA) with left arterial ligament and to assess the impact of foetal diagnosis on outcomes.

METHODS

We performed a retrospective analysis of all patients who underwent surgery for DAA or RAA with left arterial ligament between 2005 and 2019.

RESULTS

A total of 132 children were operated on for a DAA (n = 77) or a RAA (n = 55). Prenatal diagnosis was made in 100/132 (75.8%). Median age at surgery for DAA was 5.0 (1.7-13.3) months and for RAA was 13.9 (6.4-20.1) months. There was no difference in the age at surgery between the prenatal and postnatal cases (8.6 [4.0-15.6] vs 5.4 months [1.8-17.7]; P = 0.37). No surgical deaths occurred. Vocal cord palsy was the most common complication, occurring in 12/132 (9%): of these, 11 resolved spontaneously and 1 required a temporary tracheostomy. Logistic regression demonstrated that older age at operation was the only predictor for a postoperative complication (P = 0.02). Overall, 21/67 (31%) of prenatally detected, symptomatic cases reported residual symptoms/signs 1 year after surgery compared to 18/28 (64%) of postnatally detected cases. Postnatal diagnosis was associated with persistent postoperative symptoms/signs [P = 0.006, odds ratio = 3.9 (95% confidence interval 1.5-9.4)].

CONCLUSIONS

Surgery to relieve a vascular ring resolves trache-oesophageal compressive symptoms in most cases, but parents/patients should be aware that symptoms/signs may persist in the first postoperative year despite effective release of the vascular ring. Earlier surgery and prenatal diagnosis may improve outcomes.

Fetal echocardiographic markers to differentiate between a right and double aortic arch

OBJECTIVES

To describe the fetal echocardiographic features of a double aortic arch (DAA) and secondly, to assess the performance of these features to differentiate between a right aortic arch with left duct (RAA-LD) in a blinded cohort of vascular rings.

METHODS

Review of records to identify surgically confirmed cases of DAA diagnosed prenatally from 2014 to 2018 (cohort-A). Prenatal echocardiograms were reviewed and the segments of the aortic arches anterior and posterior to the trachea, aortic isthmuses and the presence/absence of the Z-sign were described. The utility of these markers were assessed in a separate cohort (B) of fetuses with surgically confirmed cases of DAA or RAA-LD.

RESULTS

Cohort-A comprised 34 cases with DAA; there was a dominant RAA in 32/34 (94%) and balanced left aortic arch (LAA) and RAA in two cases. The proximal LAA was seen in 29/34 (85%), distal LAA in 15/34 (44%) and the LAA aortic isthmus in 4/34 (12%). The "Z" configuration was present in 29/34 (85%) cases. The most predictive marker for DAA in cohort-B was the Z-sign (sensitivity: 100%, specificity: 81%).

CONCLUSION

The "Z" sign is a useful differentiator between RAA-LD and DAA. The absence of visualization of the left aortic isthmus does not preclude the presence of a DAA.

Prenatal diagnosis and postnatal outcomes of right aortic arch anomalies

PURPOSE

To give a report on the experience of our tertiary perinatology clinic on the pre- and postnatal management of the right aortic arch (RAA) by evaluating the patients as isolated and non-isolated RAA.

MATERIALS AND METHODS

Patients referred to our perinatology clinic for fetal echocardiography were evaluated retrospectively. They were assessed in two groups: isolated RAA and non-isolated RAA. The isolated RAA group consisted of patients without any additional cardiac or extracardiac anomalies. According to our routine practice, all patients received detailed prenatal ultrasonography following fetal echocardiography and genetic counseling.

RESULTS

A total of 60 patients were evaluated. 38 patients (63.3%) presented with additional cardiac anomalies. 21.7% had extracardiac anomalies, including 16.7% who also had cardiac anomalies. In 2 patients (3.7%) 22q11.2 microdeletion, in 2 patients (3.7%) trisomy 21, in 1 patient (1.9%) trisomy 13 and in 1 patient (1.9%) 20p12.1p11.23 (a deletion of 2880 kbp) were reported. The most common cardiac anomaly associated with RAA was Tetralogy of Fallot (25%). Fetal growth restriction was reported in 8.3% of the cases. 18 patients had isolated RAA. 16 out of the 18 patients had normal genetic analysis. 2 of them (11.11%) presented with a 22q11.2 microdeletion.

CONCLUSION

A single-center experience on the diagnosis and management of RAA has been reported in this study. The results indicate that a prenatal cardiac evaluation in 3VV is of utmost importance in all pregnancies to detect RAA and refer these patients to the appropriate perinatology clinics for further evaluation and care.

Prenatal incidence of isolated right aortic arch and double aortic arch

OBJECTIVE

To define the incidence of variants of aortic arch sidedness in fetuses undergoing routine first trimester ultrasound examination.

METHODS

The data for this study were derived from prospective routine ultrasound examination at 11+0 to 13+6 weeks' gestation in singleton pregnancies examined in a local population between January 2014 and March 2018. We examined the incidence of isolated right aortic arch (RAA) and double aortic arch (DAA) in the local, screened population and compared the groups with and without these abnormalities.

RESULTS

The study population of 33,202 pregnancies included 18 (5.4 per 10,000) cases with isolated RAA and 5 (1.5 per 10,000) with DAA. In the group with isolated RAA or DAA, compared to those without, the median maternal age was higher and the incidence of conceptions from in vitro fertilization (IVF) was eight-fold higher. The prevalence of 22q11microdeletion was 5% in patients with RAA from this local population.

CONCLUSIONS

The incidence of isolated RAA and DAA in a local population undergoing routine first-trimester ultrasound examination is 2-3-fold higher than that reported in postnatal studies and the risk for these abnormalities is substantially increased in fetuses conceived by IVF.

Chromosomal Microarray Analysis for the Fetuses with Aortic Arch Abnormalities and Normal Karyotype

Background

Aortic arch abnormalities (AAA) are abnormal embryologic developments of the aorta and its branches. Their outcomes often depend on their association with other congenital diseases and genetic testing results.

Objective

This study aimed to evaluate the yield of chromosomal microarray analysis (CMA) in fetuses with different patterns of AAA and normal karyotype.

Methods

Data from 158 pregnancies referred for prenatal CMA testing due to fetal AAA were obtained between April 2016 and April 2019. Fetuses with isolated AAA, AAA accompanied by soft ultrasound markers, and AAA with other ultrasound malformations were classified into groups A, B, and C, respectively. Cases with detectable karyotype aberrations were excluded from the study.

Results

Twenty cases (12.7%) of submicroscopic anomalies were detected in 158 cases with normal karyotype, comprising 16 cases (10.1%) of clinically significant variants, two cases (1.3%) of variants of unknown significance, and two variants (1.3%) that were likely benign. Microdeletion of 22q11.2 accounted for 25% (4/16) of the clinically significant variants. The overall incremental yields by CMA in group A, group B, and group C were 1.8%, 2.3%, and 24.1%, respectively. Except for double aortic arch, the incremental yield of clinical significant findings for each type of AAA in group C was much higher than that in group A and group B. In group A, a clinically significant variant was only detected in one fetus with right aortic arch (RAA) (1.8%, 1/57).

Conclusions

In addition to 22q11.2 microdeletion, many other clinically significant submicroscopic variants are present in fetuses with AAA, especially in fetuses with other ultrasound malformations. Although CMA is always recommended in the presence of any malformation in many countries, our results suggest insufficient evidence to recommend CMA in fetuses with isolated AAA, except for isolated RAA.

The Differential Diagnosis of Double Aortic Arch and Right Aortic Arch with Mirror-Image Branches in the Fetus: A Potential Novel Method

The objective of this study was to explore a new method for the differential diagnosis between fetal double aortic arch (DAA) and right aortic arch with mirror-image branches (RAA-MB). Clinical data and prenatal echocardiographic features of the DAA (n = 22) and RAA-MB (n = 65) confirmed by postnatal or autopsy findings were analyzed retrospectively. The angles between the two aortic arches in the DAA group and between the right aortic arch and the mirror branch were measured. The differences between the two groups and differential diagnosis value of the angles were compared and analyzed based on the receiver operating characteristic curve. The proportion of left-sided ductal arteriosus (100%) was higher in the DAA group than that (32.3%) in the RAA-MB group, (P < 0.05). The proportion of conotruncal anomalies is higher in the RAA-MB group (64.6%) than in the DAA group (18.2%) (P < 0.05). There was a significant difference in the angles between the groups (DAA: 50.3° ± 8.3° vs. RAA-MB: 82.9° ± 13.8°) (P < 0.01). When the cutoff value was 62.8°, the sensitivity and specificity of the differential diagnosis were 95.5% and 96.9%, respectively. Distinguishing the angle measurement between DAA and RAA-MB is helpful in prenatal prognosis. We recommend a cutoff value of 62.8°.

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 impact of a prenatally diagnosed double aortic arch

BACKGROUND

A double aortic arch (DAA) is increasingly identified before birth; however, there are no published data describing the postnatal outcome of a large prenatal cohort.

OBJECTIVE

To describe the associations, symptoms and impact of prenatally diagnosed DAA.

METHODS

Retrospective review of consecutive cases seen at two fetal cardiology units from 2014 to 2019. Clinical records including symptoms and assessment of tracheobronchial compression using flexible bronchoscopy were reviewed. Moderate-severe tracheal compression was defined as >75% occlusion of the lumen.

RESULTS

There were 50 cases identified prenatally and 48 with postnatal follow-up. Array comparative genomic hybridisation (aCGH) was abnormal in 2/50 (4%), aCGH was normal in 33/50 (66%) and of those reviewed after birth, 13 were phenotypically normal. After birth, there was a complete DAA with patency of both arches in 8/48 (17%) and in 40/48 (83%) there was a segment of the left arch which was a non-patent, ligamentous connection.Stridor was present in 6/48 (13%) on the day of birth. Tracheo-oesophageal compressive symptoms/signs were present in 31/48 (65%) patients at median age of 59 days (IQR 9-182 days). Tracheal/carinal compression was present in 40/45 (88%) cases. Seven of 17 (41%) asymptomatic cases demonstrated moderate-severe tracheal compression. All morphologies of DAA caused symptoms and morphology type was not predictive of significant tracheal compression (p=0.3).

CONCLUSIONS

Genetic testing should be offered following detection of double aortic arch. Early signs of tracheal compression are common and therefore delivery where onsite neonatal support is available is recommended. Significant tracheal compression may be present even in the absence of symptoms.

Prenatal diagnosis of complete vascular ring using high-definition flow render mode and spatiotemporal image correlation

Vascular rings (VRs) are defined as congenital abnormalities of the aortic arch and its branches. VR can form a ring that may compress the esophagus and trachea, which likely result in feeding difficulties and respiratory distress. Physicians performing fetal echocardiography are knowledgeable about VRS and can provide this information to pediatric cardiothoracic surgeons. However, VRs are rare and can be missed. The three vessels and trachea (3VT) view used to diagnose VRs has been reported in the literature multiple times but in a small series. We diagnosed three cases of VRs using high-definition (HD) flow render mode and spatiotemporal image correlation (STIC). The composition of the VRs and vessel connections were shown more intuitively. This article reports our experience of the following related cases. In addition, postnatal imaging features of VRs were also evaluated.

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.

22q11.2 deletion syndrome and congenital heart disease

The 22q11.2 deletion syndrome has an estimated prevalence of 1 in 4-6,000 livebirths. The phenotype varies widely; the most common features include: facial dysmorphia, hypocalcemia, palate and speech disorders, feeding and gastrointestinal disorders, immunodeficiency, recurrent infections, neurodevelopmental and psychiatric disorders, and congenital heart disease. Approximately 60-80% of patients have a cardiac malformation most commonly including a subset of conotruncal defects (tetralogy of Fallot, truncus arteriosus, interrupted aortic arch type B), conoventricular and/or atrial septal defects, and aortic arch anomalies. Cardiac patients with a 22q11.2 deletion do not generally experience higher mortality upon surgical intervention but suffer more peri-operative complications than their non-syndromic counterparts. New guidelines suggest screening for a 22q11.2 deletion in the patient with tetralogy of Fallot, truncus arteriosus, interrupted aortic arch type B, conoventricular septal defects as well as those with an isolated aortic arch anomaly. Early identification of a 22q11.2 deletion in the neonate or infant when other syndromic features may not be apparent allows for timely parental screening for reproductive counseling and anticipatory evaluation of cardiac and noncardiac features. Screening the at-risk child or adult allows for important age-specific clinical, neurodevelopmental, psychiatric, and reproductive issues to be addressed.

Incidence of chromosomal anomalies in fetuses with isolated right aortic arch: A meta-analysis

OBJECTIVE

Right aortic arch (RAA) can be associated with chromosomal anomalies. However, the incidence of chromosomal anomalies when RAA is isolated (iRAA), ie, not associated with intracardiac anomalies, varies between different studies (0%-28.5%). We have performed a meta-analysis to allow a more accurate prenatal counselling.

METHODS

We searched PubMed, Embase, and Web of Science for articles related to chromosomal anomalies among iRAA fetuses until April 2019. A total of 22 relevant studies, including 670 fetuses, were selected in the final meta-analysis.

RESULTS

The results revealed that the overall rates of chromosomal anomalies and 22q11.2 deletion in iRAA fetuses were 7.5% (95% confidence interval [CI], 4.7%-10.8%) and 4.3% (95% CI, 2.6%-6.4%), respectively, while the rates were lower in iRAA without extracardiac anomalies, 4.7% (95% CI, 1.1%-10.8%) and 2.4% (95% CI, 0.5%-5.7%). The rate of chromosomal or copy number variants including 22q11.2 deletion identified by chromosomal microarray analysis (CMA) in iRAA fetuses was 8.2% (95% CI, 5.0%-12.1%) and 3.7% (95% CI, 1.7%-6.6%), respectively, compared with 5.1% (95% CI, 2.5%-8.4%) and 2.4% (95% CI, 0.7%-5.1%) identified by traditional karyotyping.

CONCLUSIONS

A considerable proportion of iRAA cases have associated chromosomal anomalies and prevalence of associated 22q11.2 deletion, and CMA is recommended if invasive prenatal testing is performed.