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.

Variations in the Evaluation and Management of Vascular Rings: A Survey of American Clinicians.

Vascular rings are arterial malformations that lead to the compression of the trachea and/or esophagus. While "tight" rings often produce symptoms and require surgery, "loose" rings rarely produce symptoms. Given advances in fetal echocardiography, this diagnosis is now more often made prenatally. This poses a new conundrum in the management of asymptomatic patients, leading to practice variation and creating a target for clinical system improvement. Hence, we conducted this survey aiming to demonstrate the practice variation existing in current evaluation and management of these patients. An anonymous web-based survey was distributed to several listservs for pediatric cardiologists and pediatric cardiothoracic surgeons. Survey questions targeted respondent practice characteristics, testing obtained, and indications for testing or surgical referral. In total 61 responses were received, predominantly from pediatric cardiologists (95%) in the United States (97%). About 60% of clinicians reported frequently diagnosing patients with vascular rings by fetal echocardiogram, with only about 20% diagnosing them frequently on evaluation of symptoms. Computed tomography angiography and echocardiogram were the most common imaging modalities employed. Most clinicians obtained cross-sectional imaging at the time of diagnosis and referred to surgery once patients had at least occasional symptoms. Respondents demonstrated a low degree of agreement (Krippendorf's alpha 0.48). Few statistically significant patterns were identified between respondents based on their practice characteristics. This study identified significant variation between clinicians regarding the evaluation and management of vascular rings. Further research or expert opinions may help to standardize practice, saving costs and improving the quality of care for affected patients.

Utility of the Angle between the Right Aortic Arch and First Branch for Detecting Double Aortic Arch via Fetal Echocardiography.

INTRODUCTION: The presence of a double aortic arch (DAA) is manifested by compressive symptoms, requiring surgery. DAA cases are classified as either complete or incomplete type. DAA and a right aortic arch with mirror image branching (mRAA) have a similar configuration to the first branch artery. The first branch of the mRAA is the left brachiocephalic artery, which appears to be the same as that of an incomplete DAA due to blood flow interruption. The present retrospective study aimed to evaluate the differences between DAA and mRAA by fetal echocardiography. METHODS: This single retrospective cohort study included all patients diagnosed with complete DAA, incomplete DAA, or mRAA at our facility between 2010 and 2022. The patients were diagnosed with complete DAA, incomplete DAA, or mRAA after birth and remaining fetal echocardiograms. The patients were divided into the DAA (complete DAA: n = 4, incomplete DAA: n = 3) and mRAA (n = 4) groups. The following three outcomes were compared: (1) angle between the right aortic arch and first branch (RF angle), (2) ratio of height to width of the region bounded by the aortic arch, first branch of the aortic arch, and descending aorta, and (3) maximum tracheal diameter on a three-vessel trachea view. RESULTS: The incomplete DAA cases were difficult to diagnose via fetal echocardiography. On fetal echocardiography, the RF angle was significantly steeper in the DAA group than in the mRAA group (median 57° [36°-69°] vs. 75° [62°-94°]; p < 0.05). The DAA and RAA groups showed no significant differences in the ratio of height to width of the region bounded by the aortic arch, first branch of the aortic arch, and descending aorta (median 0.57 [0.17-0.68] vs. 0.73 [0.56-1.0]) and maximum tracheal diameter (median 2.5 [1.4-3.3] vs. 3.2 [2.8-3.5] mm). The cut-off value for the presence of DAA was an RF angle <71°. CONCLUSION: The DAA group (complete and incomplete DAA) had a significantly steeper RF angle than the mRAA group. Therefore, RF angle measurement could improve the fetal diagnosis and postnatal prognosis of DAA.

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.

The prenatal diagnosis and prognosis of fetal right aortic arch and double aortic arch malformation: A single-center study.

AIM: This study aimed to characterize the pathological types, diagnosis, chromosomal abnormalities, and postnatal clinical manifestations of right and double aortic arch malformations in fetuses. METHODS: In this retrospective study, all fetuses diagnosed with right or double aortic arch anomalies for whom conventional two-dimensional echocardiography combined with spatio-temporal image correlation was performed at our tertiary referral center between December 2012 and December 2021 were included. RESULTS: In total, 234 fetuses with aortic arch abnormalities were identified. Forty-one cases lost to follow-up. One hundred ninety-three cases were included in this study. One hundred eighty-seven cases with right aortic arch. Six cases with double aortic arch. Most cases of right aortic arch with aberrant left subclavian artery (77/101, 76.2%) were isolated lesions, whereas most of those with mirror-image branching (45/75, 60%) were associated with intracardiac or extracardiac anomalies. Chromosomal abnormalities were screened prenatally in 113 fetuses with right aortic arch, among whom three with aberrant left subclavian artery (3/63, 4.8%) and eight with mirror-image branching (8/50, 16%) had chromosome anomalies (p < 0.05). Furthermore, three cases had microdeletion 22q11.2 and these were significantly associated with intracardiac malformations. CONCLUSIONS: Most cases of isolated right aortic arch do not present with clinical symptoms except isolated left subclavian artery and isolated left brachiocephalic trunk. In addition, the risk of chromosomal abnormalities in patients with isolated right aortic arch is very low. We recommend that pregnant women should be informed of the risks and benefits of undergoing invasive prenatal chromosomal detection.

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.

Computed tomographic features of double aortic arch in six dogs.

Double aortic arch (DAA) is a rare, congenital anomaly in small animals, resulting in a complete vascular ring encircling the esophagus and trachea, and subsequent compression of these organs. Few studies have reported utilizing CT angiography (CTA) for diagnosing DAA in dogs; thus, the imaging features are currently lacking in the literature. The objectives of this retrospective, multicenter, descriptive case series were to report the clinical and CTA characteristics of DAA in surgically treated cases. Medical records and CTA images were reviewed. Six juvenile dogs met the inclusion criteria (median age: 4.2 months; range: 2-5 months). The most common clinical signs included chronic regurgitation (100%), decreased body condition (67%), and coughing (50%). Common CTA features of DAA included a dominant left aortic arch (median diameter: 8.1 mm) and minor right aortic arch (median diameter: 4.3 mm; 83%), an aberrant right subclavian artery arising directly from the right aortic arch (83%), segmental esophageal constriction (100%), and variable degrees of dilation cranial to the heart base, and marked tracheal luminal compression (median percent change: -55%; 100%) and leftward curvature of the trachea at the level of the bifurcation of the aortic arches (100%). All dogs underwent successful surgical correction with only minor postoperative complications. Due to the similarity of clinical and imaging characteristics described to that of other forms of vascular ring anomalies (VRA), CTA is vital for the specific diagnosis of DAA in dogs.

Congenital Aortic Vascular Ring: In-Utero Sonographic Assessment of Tracheal Patency and Postnatal Outcome.

OBJECTIVE: Congenital aortic vascular ring may present after birth with variable degrees of respiratory distress due to tracheal compression. The aim of this study was to prospectively evaluate in utero tracheal patency in correlation with postnatal outcome. METHODS: During an eight-year period, fetuses with aortic arch abnormality encircling the trachea and forming a complete ring were recruited for the study. Tracheal patency was classified as: no compression, partial compression, or complete compression. Postnatal MRI/CTangio studies were performed and outcome data was retrospectively analyzed from the medical records. RESULTS: Among the 46 fetuses recruited to the study, 38 had right aortic arch (RAA), and 8 presented with double aortic arch (DAA). In the RAA group 35 (92.1 %) of the fetuses presented no compression and 34 (97.1 %) of them were asymptomatic in the long-term follow-up. Three fetuses (7.9 %) in this group presented in utero compression: one was terminated at 16 weeks of gestation due to associated ominous findings, and the other two had mild respiratory symptoms around 12 months of age and underwent surgery with a good outcome. In the DAA group, all fetuses presented in utero with tracheal compression. Seven showed partial and one complete compression. Among the seven with partial compression, six were symptomatic and underwent surgery. The case with severe airway occlusion had emergency tube insertion in the delivery room and underwent surgery at 7 days but died from severe respiratory complications. CONCLUSION: This is the first study to evaluate in utero tracheal patency in cases with vascular ring. It allows better prenatal and postnatal workup and follow-up including potentially life-threatening respiratory failure.

Double aortic arch: an elusive diagnosis in a child with CHD.

An 18-month-old male with pulmonary atresia and ventricular septal defect presented with stridor after neonatal systemic-to-pulmonary artery shunt surgery, that persisted on follow-up. CT angiography revealed a vascular ring with balanced double aortic arch.

Frozen Elephant Trunk to Exclude the Kommerell Diverticulum Associated with Double Aortic Arch in Adult Redo Patient.

Kommerell diverticulum can be associated to several types of vascular rings, including double aortic arch. Surgical indications for vascular rings and Kommerell diverticulum include bulging symptoms onto trachea and esophagus too. Moreover, the aneurysmal enlargement over time can eventually cause acute aortic syndromes. Management of this pathology in adulthood is challenging and many techniques have been proposed, notably hybrid solutions. Herein, we report the case of a patient, who underwent redo surgery with frozen elephant trunk technique, caused by persisting symptoms after a previous operation of vascular ring interruption.

Vascular Rings With Tracheoesophageal Compression: Management Considerations.

Our series of vascular ring patients treated at Ann & Robert H. Lurie Children's Hospital of Chicago has now exceeded 450 patients (see Central Picture). The recommendations from this review are based on our experience with those patients. Since 1990, we have used preoperative cross-sectional imaging in all vascular ring patients. This has led us to refine our operative strategies and carefully tailor the operation to the individual's unique anatomy. In particular for right aortic arch patients, we now address the Kommerell diverticulum in most cases and carefully consider Kommerell diverticulum resection with left subclavian artery transfer. In double aortic arch patients, we also look for a Kommerell diverticulum and resect the diverticulum if present. This will decrease the number of patients presenting for a reoperation after initial vascular ring surgery. Since 1947, we have operated on 217 patients with a right aortic arch. The median age is 1.5 years. Since 2006, 47 out of 111 patients have had Kommerell diverticulum resection and left subclavian artery transfer to the left carotid artery. Mean length of stay is 4.5 days. In the same time period, 187 patients have been treated for a double aortic arch. The median age is 1 year. Twelve of these patients also had resection of a Kommerell diverticulum. The mean length of stay in this group was 3 days. Advanced preoperative cross-sectional imaging leads to precise operative techniques tailored to the unique anatomy of each vascular ring patient.

Congenital vascular ring.

A vascular ring is a rare congenital cardiovascular anomaly, which encircles and compresses the trachea or esophagus, or both. In this review we discuss the pathophysiology, theoretical embryopathogenesis, diagnostic modalities, and surgical treatment of the different types of vascular ring. Knowledge of the normal embryonic development of the aortic arch and related structures is important for understanding and classifying the various forms of vascular ring. The development of a vascular ring begins with the embryonic aortic arch system. The persistence, involution, or regression of the arches determines the multiple variations of vascular ring. With the development of new technologies, multi-detector computed tomography (MDCT) has become a good diagnostic modality for pre- and postoperative evaluation. MDCT provides an excellent image of aortic arch abnormalities and the related anatomy, as well as the tracheal pathology. For patients with symptoms, surgical division of the vascular ring usually achieves excellent outcomes with marked resolution of symptoms and a low risk of morbidity and mortality. Symptomatic vascular rings require early surgical intervention to prevent prolonged vascular compression of the airway and serious complications.

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.

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.

Assessment of Suspected Vascular Rings and Slings and/or Airway Pathologies Using Magnetic Resonance Imaging Rather Than Computed Tomography.

BACKGROUND: Congenital cardiovascular malformations (CCVM) may cause infrequently airway pathologies (AP) in children and are of prognostic and therapeutic relevance. While computed tomography (CT) is considered first-line imaging modality in many centres, we started using magnetic resonance imaging (MRI) more and more in the last years to detect CCVM and AP to avoid radiation in this patient group. OBJECTIVE: The aim of this retrospective study was to determine and to compare the diagnostic accuracy of CT and MRI when used to detect CCVM and/or AP. METHODS: All patients suspected to have CCVM and/or AP and examined either by CT or MRI between 2000 and 2013 in our hospital were included. Extension and type of CCVM, as well as their relationship to esophagus, trachea or bronchi were assessed and related to findings of tracheobronchoscopy, cardiac catheterization or surgery if available. RESULTS: One hundred six patients (median [range] 4 years [2 days to 66 years]) were examined by CT (n = 27) or MRI (n = 79). In 78 patients (74%), CCVM and/or AP were found with either of the imaging methods. CCVM were found in 63 subjects. Forty-six of 63 subjects had both, CCVM and AP. The presence of CCVM was always detected correctly by CT or MRI, although both techniques had a weakness detecting atretic segments directly. AP (n = 61) were correctly diagnosed in all patients not intubated for artificial ventilation by CT (n = 17) and in all but 2 patients by MRI (39 out of 41). CONCLUSIONS: MRI is sensitive to detect CCVM associated with AP equally to CT without any radiation exposure.

An In-depth Perspective of Aortic Arch Branching in Fetal Vascular Rings Using Spatiotemporal Image Correlation Combined With High-definition Flow Imaging: Report of 4 Cases.

On the basis of 2-dimensional fetal echocardiographic findings, we investigated 4 different fetal vascular ring cases using spatiotemporal image correlation (STIC) combined with high-definition (HD) flow imaging. An in-depth 3-dimensional perspective of aortic arch branching (ie, the brachiocephalic arteries) was created by application of glass body and HDlive flow rendering algorithms (GE Healthcare, Zipf, Austria). Additionally, complete (U- or O-shaped) or incomplete (C-shaped) vascular rings were clearly differentiated in utero, and articulations around the trachea and esophagus were more easily imaged. In conclusion, spatiotemporal image correlation combined with HD flow imaging could classify fetal vascular rings with accuracy and facilitate decision making during postnatal management.

Two Cases of a Prenatally Diagnosed Double Aortic Arch with Postnatal Obliteration of the Distal Left Aortic Arch.

We report two cases of prenatally diagnosed double aortic arch with dominant right arch and a left-sided ductus arteriosus, consistent with a complete vascular ring. Postnatal transthoracic echocardiogram and cardiac magnetic resonance imaging demonstrated a spontaneous closure of the ductus arteriosus and obliteration of the left aortic arch distal to the origin of the left subclavian artery in both cases. Spontaneous closure of the ductus arteriosus involving extended ductal tissue in the left aortic arch likely led to obliteration of the distal left arch after birth. One patient presented with recurrent symptoms suggestive of dysphagia and underwent a successful surgical repair of the vascular ring with resolution of symptoms. The other patient has been asymptomatic and is 4 years old at the time of this report.

Atretic anomalous left subclavian artery as part of an unusual vascular ring.

In this report, a unique case of a symptomatic vascular ring formed by right aortic arch, aberrant left subclavian artery, and left ligamentum arteriosus in which there is atresia of the proximal left subclavian artery is described. Imaging modalities were non-diagnostic and the patient was sent to surgery based on strong clinical suspicion. Her anatomy was delineated in the operating room and the ring was successfully repaired.

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.