Prenatal diagnosis of right aortic arch: associated anomalies and fetal prognosis according to different subtypes.

OBJECTIVES: Right aortic arch (RAA) is a rare anomaly with an incidence of 0.1 % in the adult population and low-risk fetuses. Our aim in this study was to evaluate associated anomalies and conditions according to subtypes. METHODS: This was a retrospective study examining consecutive pregnancies diagnosed with RAA in our hospital between 2018 and 2022. Fetuses with RAA were divided into three groups, RAA with right-sided ductus arteriosus (RAA-RDA), RAA with left-sided ductus arteriosus (RAA-LDA), and RAA with a double aortic arch (RAA-DAA). RESULTS: A total of 81 fetuses were diagnosed as having RAA during the study period. The rate of cardiac anomalies (82.8 %) in the RAA-RDA group was higher than in the RAA-LDA (17.6 %) and RAA-DAA (22.2 %) groups (p<0.001). No statistically significant difference was found between the groups in terms of maternal age, diagnosis week, pregnancy outcome, extracardiac anomalies, and genetic anomalies. Three (8 %) of 36 fetuses with isolated RAA who resulted in live birth developed symptoms related to the vascular ring, and one (2.7 %) newborn with RAA-DAA underwent surgery. CONCLUSIONS: The incidence of cardiac anomalies is high in fetuses with RAA-RDA. Ultrasound examinations should be performed for cardiac anomalies and additional structural anomalies. Vascular ring formation is a rare but important complication due to compression risk to the trachea and esophagus.

Narrowing Down the Symptomatology of Isolated Vascular Rings in Children.

Vascular rings may cause respiratory or gastrointestinal symptoms due to compression of the trachea and/or esophagus. Advances in imaging have enabled early detection in asymptomatic patients posing new management dilemmas. Surgery is expected to relieve symptoms, although this has not been well studied. We sought to evaluate the presence and pattern of symptoms associated with vascular rings before surgical intervention and to detail symptom resolution after surgery. A 10-year retrospective review of patients diagnosed with an isolated vascular ring was performed between January 2010 and December 2019. 100 patients were identified; 35 double aortic arch (DAA) and 65 right aortic arch and left ligamentum arteriosum (RALL). 73 patients were symptomatic on presentation; 47 had respiratory, 5 had gastrointestinal, and 21 had both types of symptoms. Surgical repair was performed in 75 patients; 74 were symptomatic. Respiratory symptoms were more likely in patients with preoperative tracheal narrowing (p < 0.001). Moderate-severe respiratory symptoms led to surgery in RALL patients (OR 10.6, p = 0.0001). DAA patients were more likely to undergo surgery (p < 0.001) irrespective of symptom severity. At a median post-surgical follow-up of 4 months, there was a significant reduction in symptom burden (p < 0.001), except for asthma symptoms (p = 0.131). Symptom resolution was not dependent on the vascular ring anatomy (p = 0.331) or the age at operation (p = 0.158). Vascular rings are typically accompanied by respiratory symptoms and less commonly GI symptoms, both of which resolve in most patients after surgery. Those who present predominantly with asthma-like symptoms may not achieve resolution after surgery.

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

OBJECTIVES: To evaluate the prenatal characteristics of double aortic arch (DAA), assess the relative size of the arches and their growth during pregnancy, describe associated cardiac, extracardiac and chromosomal/genetic abnormalities and review postnatal presentation and clinical outcome. METHODS: This was a retrospective cohort study of all fetuses with a confirmed diagnosis of DAA seen in five specialized referral centers in London, UK, between October 2012 and November 2019. Cases were identified from the hospitals' fetal databases. Fetal echocardiographic findings, intracardiac and extracardiac abnormalities, genetic defects, computed tomography (CT) findings and postnatal clinical presentation and outcome were evaluated. RESULTS: A total of 79 fetuses with DAA were included. Of those assessed postnatally, 48.6% had an atretic left aortic arch (LAA), while 5.1% had an atretic LAA at the first fetal scan and were misdiagnosed antenatally with right aortic arch (RAA). The LAA was atretic in 55.8% of those who underwent CT. DAA was an isolated abnormality in 91.1% of cases; 8.9% of patients had an additional intracardiac abnormality and 2.5% had both intra- and extracardiac abnormalities. Among the 52 cases that underwent genetic testing, 11.5% had genetic abnormalities and, specifically, the 22q11 microdeletion was identified in 3.8% of patients. At a median follow-up of 993.5 days, 42.5% of patients had developed symptoms of tracheoesophageal compression (5.5% during the first month after birth) and 56.2% had undergone intervention. Statistical analysis using the χ-square test showed no significant relationship between morphology of DAA (patency of both aortic arches vs atretic LAA) and the need for intervention (P = 0.134), development of vascular ring symptoms (P = 0.350) or evidence of airway compression on CT (P = 0.193). CONCLUSIONS: Most cases of DAA can be diagnosed easily at midgestation, as typically both arches are patent with a dominant RAA at this stage. However, we found that the LAA had become atretic in approximately half of the cases postnatally, supporting the theory of differential growth of the arches during pregnancy. DAA is usually an isolated abnormality; however, thorough assessment is required to exclude associated intra- and extracardiac anomalies and to determine the need for invasive prenatal genetic testing. Postnatally, early clinical assessment is needed and CT scan should be considered, irrespective of the presence of symptoms. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Short-term outcome after the prenatal diagnosis of right aortic arch.

OBJECTIVES: To determine the proportion of children that require surgery in the first year of life and thereafter in order to improve the counseling of parents with a fetus with a right aortic arch (RAA). METHODS: Fetuses diagnosed with isolated RAA, defined as the absence of intra- or extracardiac anomalies, between 2007 and 2021 were extracted from the prospective registry PRECOR. RESULTS: In total, 110 fetuses were included, 92 with a prenatal diagnosis of RAA and 18 with double aortic arch (DAA). The prevalence of 22q11 deletion syndrome was 5.5%. Six pregnancies were terminated and five cases were false-positive; therefore, the follow-up consisted of 99 neonates. Surgery was performed in 10 infants (10%) in the first year of life. In total, 25 (25%) children had surgery at a mean age of 17 months. Eight of these 25 (32%) had a DAA. Only one child, with a DAA, required surgery in the first week of life due to obstructive stridor. CONCLUSIONS: Children with a prenatally diagnosed RAA are at a low risk of acute respiratory postnatal problems. Delivery in a hospital with neonatal intensive care and pediatric cardiothoracic facilities seems only indicated in cases with suspected DAA. Expectant parents should be informed that presently 25% of the children need elective surgery and only incidentally due to acute respiratory distress.

Right cervical aortic arch associated with anomaly of epiaortic vessels and haemodynamically significant obstruction between ascending and descending aorta. Extra-anatomic bypass graft between ascending and descending aorta and long-term follow-up.

Right cervical aortic arch is a rare malformation in which a right-sided aortic arch is unusually long, forms a loop, descends, and crosses behind the oesophagus to continue as a left descending aorta. We present a case of right cervical aortic arch associated with anomaly of epiaortic vessels and aortic obstruction, surgically treated with extra-anatomic bypass graft between ascending and descending aorta.

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.

Descending aortic translocation for left aortic arch with right descending aorta and coarctation of the aorta.

Left aortic arch with right descending aorta associated with coarctation of the aorta is a rare congenital cardiac anomaly. Conventional aortic arch repair in this condition may cause airway compression by the abnormally coursing descending aorta. We present the case of a neonate with this anomaly who underwent successful descending aortic translocation to prevent postoperative left main bronchial stenosis.

Recognising ligamentous atresia in double aortic arch.

Ligamentous atresia of the left side of a double arch distal to the left subclavian artery is a rare form of vascular ring, which can easily be confused, on transthoracic echocardiography, with the right-sided aortic arch when there is mirror-imaged branching. Because of its rapid acquisition, computed tomographic angiography with three-dimensional reconstruction has now become the modality of choice for accurate diagnosis of the various forms of double aortic arch. It can be performed without sedation in any age group, including neonates. It provides excellent visualisation of the aortic arch and its branching pattern, thus permitting accurate diagnosis and surgical planning. We present a case series of six children with this rare vascular ring assessed using CT, highlighting their outcomes.

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.

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 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.

Airway obstruction in children with complex conotruncal cardiac anomalies.

The incidence of airway obstruction in patients with complex CHD other than vascular rings and absent pulmonary valve syndrome is unknown. We reviewed pre-operative CT and clinical data of children with conotruncal abnormalities to assess for airway obstruction. Airway obstruction was common (41% of patients), often moderate to severe, of diverse aetiology, and most commonly associated with a right aortic arch. Patients with airway obstruction showed a trend towards a higher mortality rate. Patients with complex conotruncal abnormalities should be assessed for airway obstruction as it may help predict the need for additional interventions and assist with prognostication.

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°.

How best to describe the pharyngeal arch arteries when the fifth arch does not exist?

In the accompanying article appearing in this issue of the Journal, Prabhu and his colleagues, from Bengalaru in India, describe their experience with patients having a right aortic arch. They discuss the fact that the anomalous arrangements they encountered can all be interpreted on the basis of the hypothetical double arch proposed by Edwards. They point to the fact that interpretation of the developmental changes underscoring the production of the double arch is currently confused by reference to the so-called Rathke diagram, in which six sets of arteries are shown extending through the mesenchyme of the pharyngeal arches. As the authors point out, Graham and his associates have now shown that the alleged fifth set of pharyngeal arches do not exist. Based on our own observations, we endorse this statement. It means that new explanations must now be provided for the lesions previously described on the basis of persistence of the alleged artery of the fifth pharyngeal arch. We have previously claimed to have observed such an artery in a human fetus. We now believe, on the basis of our latest findings, that our earlier observation is better explained on the basis of presence of a collateral channel. We suggest that the so-called "fifth arch arteries" are themselves then best explained either on the basis of existence of such collateral channels, or remodelling of the aortic sac, which is the manifold, during development, that gives rise to the pharyngeal arch arteries.

The aortic arch in tetralogy of Fallot: types of branching and clinical implications.

INTRODUCTION: Tetralogy of Fallot is the most common form of cyanotic CHD, with an incidence of 421 cases per million live births, constituting around 10% of CHD. Variations in aortic arch anatomy associated with tetralogy of Fallot, other than the incidence of right aortic arch (13-34%), are not frequently reported. A comprehensive analysis of a large number of tetralogy of Fallot cases is required to arrive at a compendious description of aortic arch anatomy. MATERIALS AND METHODS: All patients with a diagnosis of tetralogy of Fallot who had CT or MRI either pre or post procedures between 1 January 2010 and 31 December 2019 at our hospital were included in the study. Using radiology consultants' reports and analysis of individual images, we identified the various morphological patterns of aortic arches prevalent in these patients. RESULT: Out of 2684 patients who met the inclusion criteria, 1983 patients had left aortic arch (73.9%), 688 patients had right aortic arch (25.7%), four patients had cervical aortic arch (0.15%), eight patients had double aortic arch (0.3%), one patient had an aorto-pulmonary window (0.04%), and none of the patients had interrupted aortic arch. Sub-classification and clinical implications of the arch variations are described. CONCLUSION: Up to 10% of tetralogy of Fallot patients may have significant anatomical variations of aortic arch that would necessitate changes or additional steps in their surgical or interventional procedures.

Right aortic arch with an aberrant left subclavian artery: sonographic features by HDlive Flow imaging.

The right aortic arch is a congenital vascular anomaly, which may form a vascular ring. However, prenatal identification of the branching pattern of brachiocephalic vessels is often limited. In this paper, we clearly demonstrated the branching pattern of brachiocephalic vessels in a case of right aortic arch with an aberrant left subclavian artery using HDlive Flow imaging.

Reduced maternal vitamin A status increases the incidence of normal aortic arch variants.

While common in the general population, the developmental origins of "normal" anatomic variants of the aortic arch remain unknown. Aortic arch development begins with the establishment of the second heart field (SHF) that contributes to the pharyngeal arch arteries (PAAs). The PAAs remodel during subsequent development to form the mature aortic arch and arch vessels. Retinoic acid signaling involving the biologically active metabolite of vitamin A, plays a key role in multiple steps of this process. Recent work from our laboratory indicates that the E3 ubiquitin ligase Hectd1 is required for full activation of retinoic acid signaling during cardiac development. Furthermore, our study suggested that mild alterations in retinoic acid signaling combined with reduced gene dosage of Hectd1, results in a benign aortic arch variant where the transverse aortic arch is shortened between the brachiocephalic and left common carotid arteries. These abnormalities are preceded by hypoplasia of the fourth PAA. To further explore this interaction, we investigate whether reduced maternal dietary vitamin A intake can similarly influence aortic arch development. Our findings indicate that the incidence of hypoplastic fourth PAAs, as well as the incidence of shortened transverse arch are increased with reduced maternal vitamin A intake during pregnancy. These studies provide new insights as to the developmental origins of these benign aortic arch variants.

Antenatal Detection of Treatable Critical Congenital Heart Disease Is Associated with Lower Morbidity and Mortality.

OBJECTIVE: To establish the impact that timing of diagnosis and place of birth have on neonatal outcomes in those with readily treatable critical congenital heart disease. STUDY DESIGN: This was a population-based study with a complete national cohort of live-born infants with transposition of the great arteries and aortic arch obstruction in New Zealand between 2006 and 2014. Timing of diagnosis, place of birth, survival to surgery, in-hospital events, and neonatal mortality were reviewed. Live births with a gestation of ≥35 weeks and without associated major extracardiac anomalies were included for analysis. RESULTS: A total of 166 live-born infants with transposition of the great arteries and 87 with aortic arch obstruction were included. Antenatal detection increased from 32% in the first 3 years to 47% in the last 3 years (P = .05). During the same period, neonatal mortality decreased from 9% to 1% (P = .02). No deaths occurred after surgical intervention. An antenatal diagnosis was associated with decreased mortality (1/97 [1%] vs 11/156 [7%]; P = .03) and birth outside the surgical center was associated with increased risk of mortality (11/147 [7%] vs 1/106 [1%]; P = .02). Those with an antenatal diagnosis required fewer hours of mechanical ventilation (P = .02) and had shorter durations of hospital stay (P = .05) compared with those diagnosed >48 hours after birth. CONCLUSIONS: The mortality risk for transposition of the great arteries and critical aortic arch obstruction is greatest before cardiac surgery. Improved antenatal detection allowing delivery at a surgical center is associated with reduced mortality.

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.

The python aortic arch.

Aortic arch anomalies are rare congenital cardiovascular malformations. We present a case of a 9-year-old asymptomatic boy with an unusual, unknown arch anomaly.