Aberrant right subclavian artery at 16 to 23 + 6 weeks of gestation: a marker for chromosomal abnormality

Diagnostic yield of chromosomal microarray to examine the genetic factors associated with fetal aberrant right subclavian artery

PURPOSE

The primary objective was to find the risk factors that increase the probability of chromosomal abnormalities in fetal aberrant right subclavian artery (ARSA). Secondary objectives were to assess the factors which impact the adverse pregnancy outcomes in ARSA fetuses.

METHODS

This retrospective study included a total of 104 pregnant women whose fetuses were diagnosed with ARSA from January 2020 to July 2024, with subsequent chromosomal microarray analysis (CMA) performed.

RESULTS

Among the 104 cases of ARSA in this study, 46 (44.2%) were classified as isolated ARSA and 58 (55.8%) as non-isolated ARSA. Classification of non-isolated ARSA based on ultrasound soft marker abnormalities and structural abnormalities showed that an increase in the number of combined ultrasound soft marker abnormalities was associated with increased fetal chromosomal abnormalities and pathogenicity. In fetuses with structural abnormalities and ultrasonographic soft markers, they have more microarray abnormalities and higher pathogenicity compared to ARSA with only a single soft marker. The chromosomal abnormalities in ARSA fetuses predominantly manifest as trisomy 21, partial segmental microduplications, and microdeletions. Logistic regression analysis indicated that the presence of ultrasonographic soft marker abnormalities alongside ARSA serves as a risk factor for adverse pregnancy outcomes in ARSA fetuses.

CONCLUSION

In contrast to isolated ARSA, chromosomal disorders indicate a significant risk in ARSA accompanied by ultrasound abnormalities, and the risk is closely related to the number of ultrasonographic soft marker abnormalities. In addition, the combination of ultrasonographic soft marker abnormalities was a risk factor for adverse pregnancy outcomes in ARSA, while maternal age, structural abnormalities, polyhydramnios, and intrauterine growth restriction were not associated with it.

The "full rectangle" sign: a novel method for ultrasonographic diagnosis of fetal aberrant right subclavian artery

OBJECTIVE

To evaluate the feasibility and accuracy of a novel ultrasonographic screening method for an aberrant right subclavian artery (ARSA) using the novel "full rectangle" method.

METHODS

This prospective study was conducted at a tertiary care center, September 2022 to February 2023. The study included unselected pregnant women at 14-38 weeks of gestation referred for routine or targeted anomaly scans. All participants underwent scanning by two experienced sonographers to ascertain the presence or absence of aberrant right subclavian artery (ARSA) using both conventional and novel "full rectangle sign" methods for validation purposes. This is a novel screening method for ARSA that demonstrates the retro-tracheal course at the level of the supra-aortic vessels, forming what we term the "full rectangle sign".

RESULTS

A cohort of 138 patients was enrolled. The "full rectangle" sign was discerned in 6 fetuses with ARSA (4.3%), while the typical three-sided figure of the right subclavian artery was demonstrated in the remaining 132 fetuses (95.7%). The novel method demonstrated 100% feasibility and complete concordance with the conventional method.

CONCLUSION

The study results indicate that the full rectangle sign serves as an effective and dependable screening tool for identifying ARSA. It offers the advantage of a clear, unobstructed view at a level unaffected by sternum shadowing and eliminates confusion with the azygous vein.

Aberrant right subclavian artery: the importance of distinguishing between isolated and non-isolated cases in prenatal diagnosis and clinical management

OBJECTIVES

This study aimed to evaluate the association of aberrant right subclavian artery (ARSA) with genetic abnormalities and postnatal symptomatology, by comparing isolated and non-isolated ARSA cases.

METHODS

Retrospective, descriptive and comparative study involving fetuses diagnosed with ARSA during routine fetal ultrasound scans, between 19 and 40 weeks, in a tertiary referral university hospital in Barcelona from January 2007 to December 2023.

RESULTS

Out of 154 fetuses diagnosed with ARSA, 75.3 % (116) were classified as isolated cases, while 24.7 % (38) had associated structural anomalies. Non-invasive prenatal testing with cell-free DNA was performed in 27.3 % (42) of cases, yielding low-risk results in 96.6 %, with only one case of trisomy 21 detected. Genetic evaluation was pursued in 15.6 % (24) of cases, revealing abnormalities in three fetuses: one with trisomy 21 and two with 22q11 deletion. All affected fetuses had associated structural defects. Overall, 151 fetuses survived after birth, there were two terminations of pregnancy and one stillbirth. Mild symptoms at birth were observed in 1.9 % (3) of newborns, all from the non-isolated ARSA group.

CONCLUSIONS

These findings emphasize the significance of distinguishing between isolated and non-isolated ARSA cases in prenatal diagnosis and clinical management, suggesting that isolated ARSA may be considered a normal vascular variation.

Comprehensive Analysis of the Aberrant Right Subclavian Artery: A Perspective from a Single Institute

Background/Objectives: This study aimed to provide a descriptive review of fetal aberrant right subclavian artery (ARSA), with a discussion of the genomic and structural anatomy and perinatal prognosis in our hospital's obstetric department. Methods: In total, 3266 fetal level II sonographies were performed between January 2020 and June 2023. The 21 cases diagnosed with ARSA were included in this study. Obstetric ultrasound screening, noninvasive prenatal screening, and fetal karyotyping were performed. Fetal echocardiograms, postnatal information, and follow-up data were recorded. Results: In our dataset of 3266 cases, the overall incidence rate of ARSA was 0.6%. Of the 21 fetuses with ARSA, no abnormalities were detected in either prenatal or genetic tests, and no chromosomal anomalies were identified. Conclusions: Our study provides informative insights into ARSA, emphasizing the need for a comprehensive evaluation of its structural and genetic aspects. The findings of this study prompt further exploration, especially regarding the increasing incidence of ARSA and the potential role of advanced genetic analyses in enhancing diagnostic precision and fetal prognostic evaluation.

Aberrant right subclavian artery in the absence of other prenatal ultrasound findings: Should we still be concerned?

OBJECTIVE

To analyze the value of prenatal diagnostic genetic testing in cases with isolated aberrant right subclavian artery (ARSA).

METHODS

This is a retrospective cohort study, conducted between January 2015-January 2022 in a fetal medicine center. Women who had an ultrasound scan and diagnosed with fetal ARSA were included. Ultrasonographic characteristics, genetic, obstetric, and neonatal outcomes were collected and analyzed.

RESULTS

A total of 240 fetuses with ARSA were identified and included to the analysis. Eighty-two of the group had isolated ARSA (34.2%, 82/240), 57 had additional soft markers (23.8%, 57/240) and 101 had additional major ultrasonographic abnormalities (42.1%, 101/240). Genetic results were available in 196 cases (81.7%, 196/240). Seventy-four of isolated ARSA cases underwent genetic testing (90.2%, 74/82). A chromosomal abnormality was present in 60 cases; 54 (22.5%, 54/240) aneuploidies and 6 (2.5%, 6/240) copy number variants. Five (6.1%) of the isolated ARSA cases had chromosomal abnormalities. All of these five cases had prenatal genetic testing due to high-risk aneuploidy screening fetuses who had ARSA with at least one additional anomaly had the highest chromosomal abnormality rate (38.6%, 39/101). Seventy-seven of isolated ARSA cases were liveborn (93.9%, 77/82).

CONCLUSION

Our results supports the evidence from the literature that isolated ARSA confers a very low-risk for aneuploidy, if the aneuploidy screening tests are low-risk. Also, chromosomal microarray analysis did not yield any extra information in isolated ARSA.

Postnatal outcome of fetal aberrant right subclavian artery: a single center study

PURPOSE

This study aims to explore the correlation between fetal aberrant right subclavian artery (ARSA) and chromosomal disorders, with a specific focus on Down syndrome and DiGeorge syndrome.

METHODS

From November 2017 to February 2020, we conducted fetal anomaly screening and assessed the fetal heart in 8494 at our institution. The right subclavian artery tracing was assessed using Doppler ultrasonography following the 3-vessel and tracheal views (3VTV) in the fetal heart scan.

RESULTS

ARSA was found in 31 fetuses, which accounts for 0.36% of the total of 8494 fetuses. 96.8% of fetuses with ARSA were found to have normal chromosomal analysis. We identified only one case of trisomy 21 as the chromosomal condition present. In 80% of the identified ARSA, there were no additional associated findings.

CONCLUSION

ARSA is a rare condition that often does not manifest any concomitant abnormalities. The majority of ARSA instances identified in the second trimester are euploid. If ARSA is the only sonographic finding during fetal anomaly screening and there are no maternal or laboratory risk factors, further evaluation with non-invasive diagnostics may be recommended. Non-invasive genetic testing may be used for additional investigation.

Associated congenital anomalies and genetic anomalies in fetuses with isolated and non-isolated aberrant right subclavian artery

OBJECTIVE

This study's aim was to determine the prevalence of chromosomal anomalies in fetuses with isolated and non-isolated aberrant right subclavian artery (ARSA) and to evaluate its association with other congenital anomalies.

METHODS

From September 2018 to October 2021, 668 ARSA cases were diagnosed by prenatal ultrasound in our hospital; cases with missed visits and a lack of chromosomal findings were excluded and 363 cases were eligible for enrollment. General information, ultrasound presentation, chromosomal findings and pregnancy outcomes were retrospectively analyzed.

RESULTS

Among the 363 cases, 296 were isolated, and 67 were associated with structural abnormalities or soft marker abnormalities. The proportion of fetuses with chromosomal abnormalities in the isolated ARSA group was significantly lower than that in the non-isolated ARSA group (p < .001). In the non-isolated ARSA group, 22 cases were combined with other soft marker abnormalities and 45 cases were combined with structural abnormalities. The most frequent structural abnormality coexisting with ARSA was cardiac malformations (38.81%).

CONCLUSION

The most common combined malformation in ARSA is intracardiac malformation. Isolated ARSA has a low risk of chromosomal abnormalities, so invasive chromosomal testing is not recommended. Non-isolated ARSA has a high incidence of chromosomal abnormalities, so early karyotyping should be recommended.

Isolated aberrant right subclavian artery: an underlying clue for genetic anomalies

OBJECTIVE

Aberrant right subclavian artery (ARSA) is known to be associated with specific chromosomal abnormalities. However, there is no agreement regarding clinical decisions related to isolated ARSA. This study evaluated the association between ARSA and genetic abnormalities to provide evidence for prenatal consultation and the postpartum management of isolated ARSA.

METHODS

This single-center cross-sectional study involved fetuses diagnosed with ARSA between January 2014 and May 2021. A range of data was recorded for each patient, including screening ultrasound, fetal echocardiograms, genetic results, postnatal information, and follow-up records.

RESULTS

ARSA was detected in 151 fetuses, of which 136 were considered isolated cases. The remaining 9.9% (15/151) of cases had cardiac and/or extracardiac abnormalities or soft markers. Data from karyotype analysis and chromosomal microarray analysis (CMA) were available for 56 and 33 (out of 56) fetuses, respectively. Genetic abnormalities were detected in 10.7% of fetuses (6/56). Of these, 4.4% (2/45) and 36.4% (4/11) were associated with isolated and non-isolated ARSA, respectively, with a significant difference between these two groups regarding the frequency of genetic abnormality (p = 0.011). The analysis detected Klinefelter Syndrome (47, XXY) and 16p11.2 microdeletion in two isolated cases. One case each of trisomy 21 and 22q11.2 deletion, and another case of 47, XXY, were detected in fetuses with cardiac anomalies. Partial 5q deletion was found in a fetus with extracardiac malformations. In total, 141 of the fetuses survived after birth; termination of pregnancy was performed for 10 fetuses; only two fetuses had mild symptoms of dysphagia.

CONCLUSION

ARSA may be an underlying ultrasonic clue for genetic anomalies even in isolated ARSA. Fetuses with isolated ARSA cannot be ruled out for invasive antenatal diagnosis.

Prevalence and Complications of Aberrant Subclavian Artery in Patients With Heritable and Nonheritable Arteriopathies

BACKGROUND

An aberrant subclavian artery (ASA) (or lusoria) is the most common congenital anomaly of the aortic arch (0.5%-2.2%; female-to-male ratio 2:1 to 3:1). ASA can become aneurysmal and result in dissection, involving Kommerell's diverticulum when present and the aorta. Data of its significance in genetic arteriopathies are not available.

OBJECTIVES

The purpose of this study was to assess the prevalence and complications of ASA in gene-positive and -negative nonatherosclerotic arteriopathies.

MATERIALS

The series includes 1,418 consecutive patients with gene-positive (n = 854) and gene-negative arteriopathies (n = 564) diagnosed as part of institutional work-up for nonatherosclerotic syndromic and nonsyndromic arteriopathies. Comprehensive evaluation includes genetic counseling, next-generation sequencing multigene testing, cardiovascular and multidisciplinary assessment, and whole-body computed tomography angiography.

RESULTS

ASA was found in 34 of 1,418 cases (2.4%), with a similar prevalence in gene-positive (n = 21 of 854, 2.5%) and gene-negative (n = 13 of 564, 2.3%) arteriopathies. Of the former 21 patients, 14 had Marfan syndrome, 5 had Loeys-Dietz syndrome, 1 had type-IV Ehlers-Danlos syndrome, and 1 had periventricular heterotopia type 1. ASA did not segregate with genetic defects. Dissection occurred in 5 of 21 patients with genetic arteriopathies (23.8%; 2 Marfan syndrome and 3 Loeys-Dietz syndrome), all with associated Kommerell's diverticulum. No dissections occurred in gene-negative patients. At baseline, none of the 5 patients with ASA dissection fulfilled criteria for elective repair according to guidelines.

CONCLUSIONS

The risk of complications of ASA is higher in patients with genetic arteriopathies and is difficult to predict. In these diseases, imaging of the supra-aortic trunks should enter baseline investigations. Determination of precise indications for repair can prevent unexpected acute events such as those described.

Prenatal genetic analysis of fetal aberrant right subclavian artery with or without additional ultrasound anomalies in a third level referral center

To evaluate the correlation between chromosomal abnormalities and fetal aberrant right subclavian artery (ARSA) with or without additional ultrasound anomalies (UAs). A total of 340 fetuses diagnosed with ARSA by ultrasound between December, 2015, and July, 2021, were included. All cases were subdivided into three groups: (A) 121 (35.6%) cases with isolated ARSA, (B) 91 (26.8%) cases with soft markers, and (C) 128 (37.6%) cases complicated with other UAs. Invasive testing was performed via amniotic fluid or cord blood karyotyping and chromosomal microarray analysis (CMA) in parallel, and pregnancy outcomes were followed. Karyotype abnormalities were identified in 18/340 (5.3%) patients. Karyotype abnormalities in Groups A, B, and C were 0/121 (0.0%), 7/91 (7.7%), and 11/128 (8.6%), respectively. CMA abnormalities with clinically significant variants were detected in 37/340 (10.9%) cases, of which 22q11.2 deletion syndrome and trisomy 21 accounted for 48.6% (18/37). The overall abnormal CMA with clinically significant variant detection rates in Groups A, B, and C were 3/121(2.5%), 13/91 (14.3%), and 21/128 (16.4%), respectively. There were significant difference in clinically significant CMA anomalies detection rate between Groups A and C (p < 0.05), as well as Groups A and B (p < 0.05). Comparing CMA to karyotyping showed a clinically significant incremental yield in Group C (7.8%, 10/128) compared to Groups A (2.5%, 3/121) and B (6.6%, 6/91) (p > 0.05). Fetal ARSA with additional UAs, concurred with cardiac and extra-cardiac anomalies, constitutes a high-risk factor for chromosomal aberrations, especially for pathogenic or likely pathogenic copy number variants.

Aberrant right subclavian artery: embryology, prenatal diagnosis and clinical significance

Introduction

The right subclavian artery normally arises as the first vessel from the brachiocephalic trunk. An aberrant right subclavian artery (ARSA) arises directly from the aortic arch and crosses behind the trachea towards the right arm. This variant occurs in approximately 1-2% of the population; however, the frequency increases in individuals with chromosomal abnormalities such as trisomy 21 and 22q11.2 microdeletion. Prenatal identification of ARSA therefore has a role in screening for such conditions.

Methods

Databases were searched for studies reporting the prenatal ultrasound evaluation of ARSA and its frequency in normal fetuses and in those with chromosomal abnormalities.

Results

A total of 23 studies were evaluated. Feasibility for the ultrasound evaluation of ARSA was 85-95%. The sonographic detection of ARSA is best in the three-vessel trachea view; however, sagittal and coronal imaging of the aortic arch may be useful. ARSA in isolation was not found to be associated with chromosomal abnormalities. The prevalence of ARSA in chromosomally abnormal fetuses was up to 24-fold higher than in normal fetuses, but the majority of chromosomally abnormal fetuses with ARSA had additional abnormal ultrasound findings, particularly cardiac abnormalities.

Conclusions

The prenatal detection of ARSA is a clinically useful prenatal marker for chromosomal abnormalities. In isolation, it is unlikely to be associated with pathogenic genetic variants. The ultrasound diagnosis of ARSA should prompt meticulous assessment of associated abnormalities. Invasive diagnostic testing should be offered to patients with non-isolated ARSA or in the presence of non-reassuring screening results or other risk factors.

Prenatal diagnosis of aberrant right subclavian artery: a literature review

The primary aim of this review is to estimate the prevalence of ARSA both in euploid fetuses as well as in fetuses with Down Syndrome. Secondary objectives were to estimate the association of ARSA with cardiac anomalies and chromosomal defects, especially trisomy 21 and 22q11 deletion (DiGeorge Syndrome). The incidence of ARSA in normal population varies from 0.35% to 3.5%, based on different studies. Since the first reported association between ARSA and trisomy 21 in 2015 until today, several studies have emerged to confirm different degrees of this correlation. Indeed, ARSA appears to be a clinically useful prenatal ultrasound marker for trisomy 21. Particularly, most recent studies concluded that ARSA as a non-isolated finding can be used as screening for Down syndrome. However, when ARSA is an isolated finding, various studies proved that there is no significant correlation with Down syndrome. Apart from these, ARSA appears to be associated with other chromosomal abnormalities, such as 22q11 deletion, cardiac defects and other morphological anomalies. As a conclusion ARSA should be characterized as isolated or non-isolated, as the non - isolated ARSA appears to be a clinically useful marker of Down syndrome and thus, additional testing is required when diagnosed.

Fetal Aberrant Right Subclavian Artery: Associated Anomalies, Genetic Etiology, and Postnatal Outcomes in a Retrospective Cohort Study

BACKGROUND

Aberrant right subclavian artery (ARSA) is becoming increasingly common in fetuses. However, there are relatively fewer studies regarding the genetic etiology of ARSA. We performed a genetic analysis of fetuses with ARSA and followed up on the pregnancy outcomes to evaluate the prognosis of the fetuses, providing information for prenatal and eugenic consultations.

METHODS

This retrospective study included 112 pregnant females whose fetuses were diagnosed with ARSA from December 2016 to February 2021. Fetal karyotype analysis and single-nucleotide polymorphism (SNP) array were performed.

RESULTS

The 112 fetuses were divided into two groups: the isolated ARSA group (n = 48, 42.9%) and the non-isolated ARSA group (ARSA with other ultrasound abnormalities, n = 64, 57.1%). The total rate of pathogenic copy number variation (CNV) observed using karyotype analysis (3/8) and SNP array (5/8) was 7.1% (8/112). The rates of pathogenic CNV in the isolated and non-isolated ARSA groups were 4.2% (2/48) and 9.4% (6/64), respectively. No significant difference was observed between the two groups (P = 0.463). The results of genetic analysis influenced the parents' decision to terminate the pregnancy. During the follow-up examination, fetuses with ARSA without pathogenic CNV were found to have normal growth and development after birth.

CONCLUSION

Fetuses with isolated ARSA have a low probability of being diagnosed with pathogenic CNV. However, when ARSA is complicated with other ultrasound abnormalities, the risk of pathogenic CNV remarkably increases. Prenatal genetic counseling and SNP-array should be recommended for better assessment of fetal prognosis.

Aberrant right subclavian artery as soft marker in the diagnosis of trisomy 21 during the first trimester of pregnancy

Purpose

Aberrant right subclavian artery is an anatomical variation with a prevalence of around 0.5–1.5% of the general population, being more frequently found among people with chromosomopathies, especially, trisomy 21. Despite being an anatomical finding, and thus, constant through the whole pregnancy, its value in the diagnosis of aneuploidies during the first trimester of pregnancy has been little studied. The aim of this study is to evaluate the reliability of the first-trimester ultrasound in the diagnosis of ARSA and its utility in the early diagnosis of aneuploidies.

Methods

This was a descriptive, observational, cross-sectional study that included all fetuses with sonographic diagnosis of ARSA between 2011 and 2018.

Results

There were 257 cases of ARSA diagnosed. The first-trimester ultrasound showed the following results in the detection of ARSA: sensitivity of 68% (CI 95% 60.8%–74.5%), specificity of 99.9% (CI 95% 99.9%–100%), positive predictive value of 93.7% (CI 95% 88.1%–96.8%), and negative predictive value of 99.6% (CI 95% 99.5%–99.7%). Due to the presence of ARSA, two cases of trisomy 21, that would have been missed in the first trimester, were diagnosed, using ARSA as a soft marker and modifying the risk obtained by the combined screening as part of the genetic sonogram of the first trimester.

Conclusions

ARSA visualization during the first-trimester ultrasound is trustworthy and it can improve the detection of trisomy 21 in some cases of aneuploidy missed during the combined screening of the first trimester.

Should isolated aberrant right subclavian artery be ignored in the antenatal period? A management dilemma

Objective:

To investigate the frequency and types of chromosomal abnormalities in fetuses with the aberrant right subclavian artery (ARSA) and to evaluate its association with other ultrasonographic findings.

Materials and Methods:

In all, 11,666 fetal anatomic surveys were performed between March 2014 and March 2020. The cases diagnosed as ARSA were examined. Accompanying ultrasound findings and chromosomal abnormalities were collected.

Results:

ARSA was detected in 140 fetuses (1.2%). The ARSA appeared isolated in 47.1% (66/140) of cases and the remaining 52.9% (74/140) of cases were associated with cardiac or extracardiac malformations and soft markers. Chromosomal abnormalities were detected in 17.8% (25/140) of all cases. Trisomy 21 was the most common chromosomal anomaly with a prevalence of 11.4% (16/140). The corresponding rate was 3% (2/66) and 18.9% (14/74) for isolated and non-isolated ARSA, respectively. DiGeorge syndrome was detected in 3% (n=2) and Turner syndrome was in 3% (n=2) of the isolated group. ARSA was not an isolated finding in any of the 4 fetuses with trisomy 18.

Conclusion:

Isolated ARSA may be the only antenatal predictor of trisomy 21 or other chromosomal anomalies, including DiGeorge or Turner syndrome. Hence, visualization of the right subclavian artery should be a part of the fetal anatomic survey and genetic analysis should be recommended even in the absence of associated findings.

Prenatal Diagnosis of Aberrant Right Subclavian Artery: Association with Genetic Abnormalities

OBJECTIVE

 The objective of the present study was to determine the frequency of malformations and chromosomal abnormalities in a population of fetuses with an aberrant right subclavian artery (ARSA).

METHODS

 This is a 6-year retrospective study of fetuses with a prenatal diagnosis of ARSA conducted during the period between September 2013 and June 2019 at a fetal medicine unit. Data were collected from ultrasound, fetal echocardiograms, genetic studies, and neonatal records.

RESULTS

 An ARSA was diagnosed in 22 fetuses. An ARSA was an isolated finding in 18 out of 22 cases (82%). Associated abnormal sonographic findings were found in 4 cases. All cases underwent invasive testing. In 1 of the cases, a chromosomal abnormality was detected (mos 45,X [13]/46,X,e(X) (p22.1q22.1)). No cases of congenital heart disease were found in any of these fetuses. There were two cases in which the postnatal evaluation revealed a malformation: one case of hypospadias and 1 case of cleft palate.

CONCLUSION

 The presence of an isolated ARSA is benign and is not associated with chromosomal abnormalities. The finding of ARSA, however, warrants a detailed fetal ultrasound in order to exclude major fetal abnormalities and other soft markers.

Aberrant right subclavian artery: the association with chromosomal defects and the related post-natal outcomes in a third level referral centre

Aberrant right subclavian artery (ARSA) is the most common embryologic abnormality of the aortic arch. The presence of ARSA has been previously associated with an increased risk of Down syndrome. ARSA at birth may be associated with dysphagia, respiratory distress and stridor and there is no clear evidence-based management. The aim of this study was to describe the associations with chromosomal abnormalities and the postnatal outcome of fetuses diagnosed with ARSA. We analysed fetuses diagnosed antenatally with ARSA between January 2013 and September 2019 in the fetal echocardiography unit of the Hospital Monaldi, University 'Vanvitelli' of Naples, Italy. The results showed fifty fetuses diagnosed with ARSA, all confirmed after birth. The ARSA was an isolated finding in 46 fetuses (92%), while in 4 fetuses the ARSA was associated with other cardiac and/or extra-cardiac anomalies. Only one fetus was diagnosed with trisomy 21 (2%). In this fetus the ARSA was the only ultrasound anomaly identified. There were no cases necessitating referral due to the presence of compression symptoms at birth. The presence of ARSA was associated with trisomy 21 in the 2% of cases in our series and there were no neonatal complications due to airway compression at birth.IMPACT STATEMENTWhat is already known on this subject? Aberrant right subclavian artery (ARSA) is the most common embryologic abnormality of the aortich arch. ARSA at birth could be associated with dysphagia, respiratory distress and stridor and no evidence-based management of these fetuses has been described yet. The presence of ARSA has been previously associated with an increased risk of Down syndrome.What do the results of this study add? This study confirms known data on association with chromosomal defects and provides some original data on the absence of symptomatology due to tracheal compression with a postnatal follow-up up to three years of age.What are the implications of these findings for clinical practice and/or further research? Our findings suggest that in cases with adequate prenatal assessment performed by experienced clinicians, delivery can safely take place at local hospitals, with no need of referral soon after birth. The use of transthoracic echocardiography to confirm the diagnoses of ARSA after birth and to plan the next follow-up appointments can be supported.

Prenatal chromosomal microarray analysis in 2466 fetuses with ultrasonographic soft markers: a prospective cohort study

BACKGROUND

Soft markers are nonspecific findings detected by ultrasonography during the second trimester that are often transient and nonpathologic but may imply an increased risk of underlying fetal aneuploidy. However, large-scale prospectively stratified studies focusing on the prevalence of chromosomal aberrations, including copy number variants, in fetuses with different types of isolated soft markers have rarely been published in the literature.

OBJECTIVE

This study aimed to investigate clinical outcomes in fetuses with isolated soft markers by single nucleotide polymorphism array with long-term follow-up and to propose a diagnostic algorithm based on specific types of soft markers.

STUDY DESIGN

The prevalence of fetal isolated soft markers was 13.2% (7869 of 59,503). A total of 2466 fetuses with ultrasonographic soft markers during the second trimester, which were subjected to single nucleotide polymorphism array with long-term follow-up, were selected in this prospective study over a 5-year period. Soft markers were categorized into 12 groups. The demographic profile and chromosomal microarray analysis detection results were analyzed and compared among different groups.

RESULTS

The overall prevalence of chromosomal aberrations in fetuses with soft markers was 4.3% (107 of 2466), which comprised 40.2% with numeric chromosomal abnormalities, 48.6% with pathogenic copy number variants, and 11.2% with likely pathogenic copy number variants. The incidence of numeric chromosomal abnormalities was significantly higher in multiple soft markers (5.5% vs 1.5%; P=.001) and the thickened nuchal fold group (8.3% vs 1.7%; P=.024). Meanwhile, the incidence of pathogenic copy number variants was significantly higher in multiple soft markers (5.5% vs 2.4%; P=.046) and the short femur length group (6.6% vs 2.2%; P<.0001). The incidences of pathogenic copy number variants in fetuses with isolated echogenic intracardiac focus, enlarged cisterna magna, choroid plexus cysts, echogenic bowel, or single umbilical artery were lower than 1.5%. The normal infant rate in fetuses without chromosomal aberrations was 91.7%; however, it was significantly lower in the mild ventriculomegaly (86.2% vs 93.0%; P<.0001) and short femur length groups (71.4% vs 93.6%; P<.0001).

CONCLUSION

The potential chromosomal aberrations and clinical prognoses varied widely among different types of isolated soft markers. Pathogenic copy number variants are more often present in specific soft markers, especially when multiple soft markers are found. Thus, a specific soft marker type-based prenatal genetic testing algorithm was proposed.

Tracheal anomalies associated with Down syndrome: A systematic review

INTRODUCTION

Airway anomalies are accountable for a substantial part of morbidity and mortality in children with Down syndrome (DS). Although tracheal anomalies occur more often in DS children, a structured overview on the topic is lacking. We systematically reviewed the characteristics of tracheal anomalies in DS children.

METHODS

A MEDLINE and EMBASE search for DS and tracheal anomalies was performed. Tracheal anomalies included tracheal stenosis, complete tracheal ring deformity (CTRD), tracheal bronchus, tracheomalacia, tracheal web, tracheal agenesis or atresia, laryngotracheoesophageal cleft type 3 or 4, trachea sleeve, and absent tracheal rings.

RESULTS

Fifty-nine articles were included. The trachea of DS children is significantly smaller than non-DS children. Tracheomalacia and tracheal bronchus are seen significantly more often in DS children. Furthermore, tracheal stenosis, CTRD, and tracheal compression by vascular structures are seen regularly in children with DS. These findings are reflected by the significantly higher frequency of tracheostomy and tracheoplasty performed in DS children.

CONCLUSION

In children with DS, tracheal anomalies occur more frequently and tracheal surgery is performed more frequently than in non-DS children. When complaints indicative of tracheal airway obstruction like biphasic stridor, dyspnea, or wheezing are present in children with DS, diagnostic rigid laryngotracheobronchoscopy with special attention to the trachea is indicated. Furthermore, imaging studies (computed tomography, magnetic resonance imaging, and ultrasound) play an important role in the workup of DS children with airway symptoms. Management depends on the type, number, and extent of tracheal anomalies. Surgical treatment seems to be the mainstay in severe cases.

Anatomical Variations of the Aortic Arch: A Computerized Tomography-Based Study

Introduction

Despite adequate preparation and meticulous pre-operative assessment, variations of the vascular anatomy of the aortic arch may lead to clinical dilemmas. In the present era, with the easy availability of imaging facilities, various anatomical variations can be found out prior to an interventional procedure. However, there are many countries including India where such facilities may still be not widely available. The purpose of this study was to assess the prevalence of these anatomical variants in patients undergoing Computerised Tomography (CT) chest with contrast.

Methods

This observational study involved patients who underwent CT chest with contrast as part of various clinical indications during a three-year period in a tertiary care centre in South India. Variations of the aortic arch and its branching pattern were studied in 4,000 chest CT images of patients referred to the radiology department. 

Results

A total of 4,000 patients underwent CT chest with contrast during the study period. Twenty-seven variations were observed in these patients. They included aberrant right subclavian artery in seven patients, bovine arch in one patient, bovine origin of left vertebral artery from arch in one patient, bronchial artery of anomalous origin from arch in one patient, double aortic arch in one patient, and right-sided aortic arch in 16 patients. 

Conclusion

The variant anatomy of the aortic arch has tremendous clinical significance, especially from the surgical standpoint. Anatomical variants can also cause difficulty during catheterization while performing endovascular interventions. Given the prevalence demonstrated in our study, imaging may be indicated prior to any procedure involving vascular access in order to prevent unwanted complications. 

PRENATAL IDENTIFICATION OF ABERRANT RIGHT SUBCLAVIAN ARTERY IN ISOLATION: THE NEED FOR FURTHER GENETIC WORK-UP?

The objective of this study was to evaluate the association between aberrant right subclavian artery (ARSA) and chromosomal abnormalities. The study included 5211 women having attended our unit for fetal anatomic screening and fetal echocardiography from August 2016 until February 2019. After diagnosing ARSA, prenatal invasive testing was discussed with the patients. ARSA affected fetus was determined in 57 cases; of these, there were 38 cases of isolated ARSA and 19 cases of non-isolated ARSA but associated with soft markers and fetal anomalies. Nineteen patients underwent amniocentesis; Down syndrome was determined in two women, both of them from the non-isolated ARSA group, with fetal hydrops, atrioventricular septal defect and esophageal atresia. Fifteen of 38 patients who declined prenatal diagnostic testing, accepted karyotype analysis after delivery and none of these 15 cases had chromosomal abnormalities. Identification of ARSA should be followed by detailed ultrasound examination to ensure that there are no accompanying soft markers and/or structural defects. Isolated ARSA may not be an indication for karyotype analysis or 22q11.2 microdeletions. Non-ARSA implies a strong predictor of aneuploidy, and when additional findings are detected, invasive testing should be offered to the parents. The association between isolated ARSA and genetic disease should be evaluated in large powered prospective studies.

Is it useful to evaluate the presence of aberrant right subclavian artery in prenatal diagnosis ultrasounds?

AIM

Analyze if the evaluation of aberrant right subclavian artery in the prenatal echography has improved the detection of chromosomal, genetic and/or morphological abnormalities in our population.

METHODS

Descriptive, observational, cross-sectional study of the cases of aberrant right subclavian artery diagnosed in our Prenatal Diagnosis Unit between January of 2011 and December of 2018.

RESULTS

Two hundred and fifty-seven cases of aberrant right subclavian artery were diagnosed and among them, 179 were considered isolated cases and thus were confirmed after birth. The detection of aberrant right subclavian artery did not improve itself neither the diagnosis of trisomy 21 in the second trimester of pregnancy nor other chromosomal or genetic abnormalities, including the not isolated cases. There were two cases of trisomy 21 diagnosed in the second trimester that presented major sonographic disorders and an inadequate examination during the first trimester. When aberrant right subclavian artery was associated with soft markers of aneuploidy in the second trimester, any case was a trisomy 21. Aberrant right subclavian artery seems to be associated with some minor and major heart defects, especially ventriculoseptal defect and aneurismatic ductus, and in some cases, also with clubfeet.

CONCLUSION

When an adequate screening of aneuploidies and a thorough ultrasound have been performed during the first trimester, aberrant right subclavian artery hardly helps to perform other diagnosis in the second trimester.

The “No ARSA” Sign: A Novel Method of Prenatal Screening for Aberrant Right Subclavian Artery

An aberrant right subclavian artery (ARSA) can be overlooked by the conventional method as described by Chaoui et al., due to acoustic shadowing. The aim of this study was to evaluate the feasibility and accuracy of a novel screening method for ARSA by demonstrating the brachiocephalic artery bifurcation, referred to as the “No ARSA” sign. A prospective study conducted at a tertiary care center between 2018 and 2019 included unselected pregnant patients at a median gestational age of 15.1 (14.2–22.1; IQR (inter-quartile range)) weeks, who had been referred for a routine or targeted anomaly scan. All participants were scanned for the presence or absence of ARSA using both the conventional and the novel “No ARSA” methods for validation purposes. A total of 226 unselected patients were enrolled in the study. The “No ARSA” sign was visualized in 218 fetuses (96.5%). In the remaining 8 cases (3.5%), the “No ARSA” sign was not demonstrated. In these fetuses, an ARSA was visualized by the conventional method. The new method exhibited 100% feasibility and was in complete agreement with the conventional method. Intra- and inter-observer agreement was excellent (κ = 1). The results of the study suggest that the “No ARSA” sign is an efficient and reliable screening tool for ARSA.

Microarray analysis has no additional value in fetal aberrant right subclavian artery: description of 268 pregnancies and systematic literature review

OBJECTIVES

Fetal aberrant right subclavian artery (ARSA) is a relatively common sonographic finding. Several studies have reported a significant association between ARSA and Down syndrome, as well as 22q11.2 microdeletion. The objective of this study was to assess the risk of abnormal chromosomal microarray analysis (CMA) findings in a large cohort of pregnancies with fetal ARSA as an isolated, as well as a non-isolated, sonographic anomaly. A secondary objective was to review the literature, examining the frequency of chromosomal microarray aberrations in fetuses with isolated ARSA.

METHODS

Data from all pregnancies referred for invasive testing and CMA due to sonographic diagnosis of fetal ARSA, between 2013 and 2017, were obtained retrospectively from the computerized database of the Israeli Ministry of Health. The rate of clinically significant CMA findings in these fetuses was compared to that in a local control population of 2752 low-risk pregnancies with normal ultrasound and serum screening results. In addition, a literature search was conducted in PubMed, from inception to February 2018, of original studies in the English language describing the frequency and nature of microscopic and submicroscopic aberrations in fetuses with isolated ARSA.

RESULTS

Of 246 pregnancies with isolated ARSA that underwent CMA analysis, a clinically significant finding was detected in one (0.4%) pregnancy (trisomy 21). This rate did not differ significantly from that in the control population (P = 0.1574). Of 22 fetuses with non-isolated ARSA, one (4.5%) additional case of trisomy 21 was noted. The frequency of trisomy 21 in this cohort also did not differ from that in the control population (relative risk, 5.5 (95% CI, 0.8-37.6)). The literature search yielded 13 additional relevant papers, encompassing 333 cases of isolated ARSA. Of 579 cases overall (including those of the present study), 13 (2.2%) cases of trisomy 21 were detected, with no cases of 22q11.2 microdeletion.

CONCLUSION

While an association may exist between non-isolated ARSA and Down syndrome, isolated ARSA might better serve as a soft marker for Down syndrome, rather than a routine indication for invasive prenatal testing. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Anomalous Origin of the Right Vertebral Artery from the Right Common Carotid Artery

The anomalous origin of the right vertebral artery (VA) from the right common carotid artery (CCA) is a rare vascular anomaly, which is usually clinically asymptomatic and found incidentally during angiographic examinations. This anomaly is invariably associated with an aberrant right subclavian artery (RSCA). Approximately 31 cases have been reported in the literature. We present a case of a right VA originating from the right CCA in a patient with Down syndrome and discuss the imaging findings, embryological etiology of the anomaly, as well as its implications for endovascular/surgical treatment.

Incidence of an Aberrant Right Subclavian Artery on Second-Trimester Sonography in an Unselected Population

OBJECTIVES

The aim of this study was to assess the incidence of an aberrant right subclavian artery (ARSA) among an unselected population during second-trimester sonography and to review the importance of this conotruncal variant as a marker of Down syndrome.

METHODS

The presence or absence of an ARSA was assessed in an unselected population of 1913 second-trimester fetuses.

RESULTS

Among the 1913 patients, an ARSA was detected in 20 fetuses (1.04%), all with a normal karyotype. Thirteen of 20 fetuses had an isolated ARSA, and 7 of them were nonisolated. Associated abnormal sonographic findings were an intracardiac echogenic focus (n = 3), a choroid plexus cyst (n = 1), pyelectasis (n = 1) and tetralogy of Fallot (n = 2). One of the cases of tetralogy of Fallot was also associated with a persistent left superior vena cava, a persistent right umbilical vein, hydrocephalus, rhombencephalosynapsis, and unilateral renal agenesis. There were only 2 fetuses with Down syndrome in this group, and both of them had a normal origin of the right subclavian artery.

CONCLUSIONS

In an unselected population, an ARSA may be seen less frequently than in a high-risk population and may not be related to Down syndrome. An isolated ARSA is not a sufficient indication for karyotype analysis; it can be managed with noninvasive prenatal testing rather than invasive testing.

Aberrant Right Subclavian Artery: Correlation Between Fetal and Neonatal Abnormalities and Abnormal Genetic Screening or Testing

OBJECTIVES

To determine whether fetuses with an isolated aberrant course of the right subclavian artery (ARSA) have increased risk for chromosomal abnormalities, including trisomy 21 or 22q11 deletion.

METHODS

We performed a retrospective chart review of all fetuses with antenatally diagnosed ARSA. Data were collected from fetal anatomic surveys, fetal echocardiograms, noninvasive trisomy 21 screening programs, invasive genetic studies, and neonatal records.

RESULTS

Seventy-nine fetuses with ARSA were identified at 20.3 ± 3.8 weeks' gestation. Forty-eight fetuses underwent chromosomal evaluation. Of those, seven had trisomy 21. Four other fetuses had unusual karyotype abnormalities. All fetuses with genetic anomalies had additional aberrant ultrasound findings. There were three spontaneous fetal deaths (trisomy 21-2 and Wolf-Hirshhorn-1). Nine pregnancies were terminated because of abnormalities and one died as a result of hypoplastic left heart syndrome. No neonate was found or suspected to have 22q11.2 deletion. The ARSA was isolated in 43 fetuses; all had unremarkable neonatal outcomes, and none were readmitted within 6 months after discharge.

CONCLUSIONS

As an apparently isolated finding, ARSA is benign and not associated with trisomy 21 or 22q11.2 deletion. The finding of ARSA, however, warrants a detailed fetal ultrasound. All fetuses with ARSA and genetic anomalies had additional ultrasound findings.

Chromosomal microarray analysis in fetuses with aberrant right subclavian artery

OBJECTIVE

To evaluate the association between aberrant right subclavian artery (ARSA), with or without additional risk factors for aneuploidy or ultrasound abnormality, and results of chromosomal microarray analysis (CMA).

METHODS

This was a multicenter study of fetuses diagnosed with ARSA that underwent genetic analysis by CMA, all samples being analyzed in the same laboratory. Clinical investigation included nuchal translucency measurement, first- and second-trimester maternal serum screening, early and late second-trimester fetal anatomy scans and fetal echocardiography. Comparative genomic hybridization microarray analysis or single-nucleotide polymorphism array technology was used for CMA of DNA samples obtained from amniotic fluid.

RESULTS

CMA results were available for 63 fetuses with ARSA. In 36 fetuses, ARSA was an isolated finding, and no pathogenic variant was found. Additional ultrasound findings and/or risk factors for aneuploidy were present in 27 fetuses, five of which had pathogenic CMA results. Of these five, trisomy 21 was detected in a fetus with echogenic intracardiac focus (EIF), 22q11 deletion was detected in a fetus with EIF and an increased risk of trisomy 21 of 1:230 from maternal serum screening, 22q11 duplication was detected in a fetus with hypoplastic right kidney and choroid plexus cyst and 22q11 deletion was detected in a fetus with right aortic arch and clubfoot. The fifth fetus had increased nuchal translucency thickness (4 mm) and a ventricular septal defect, and CMA identified both 22q11 deletion and 1q21 duplication.

CONCLUSIONS

In fetuses with isolated ARSA, an invasive procedure for CMA is not indicated. However, CMA is recommended when additional ultrasound abnormalities or risk factors for aneuploidy are observed. The chromosomal findings in four of the five cases with an abnormal CMA result in our study would not have been detected by standard fetal chromosomal testing. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal diagnosis of aberrant right subclavian artery in an unselected population

Purpose

The purpose of this study was to determine the frequency of aberrant right subclavian artery (ARSA) among unselected fetuses and to evaluate its association with chromosomal abnormalities and other congenital anomalies.

Methods

In all, 7,547 fetuses (gestational age, 20 to 34 weeks) were examined using routine antenatal sonography at our institution between April 2014 and September 2015. The right subclavian artery was assessed using grayscale and color Doppler ultrasonography in the transverse 3-vessel and tracheal view, and confirmed in the coronal plane.

Results

ARSA was found in 28 fetuses (0.4%). Further, 27 of these 28 fetuses were euploid (96.4%). Trisomy 18 was the only chromosomal anomaly (3.6%) found in the study sample. ARSA was an isolated finding in 23 of the 28 cases (82.1%). In the remaining three cases (10.7%), ARSA was accompanied with extracardiac anomalies. Other cardiac defects were present in three cases (10.7%).

Conclusion

Isolated ARSA does not seem to be associated with a significantly increased risk of aneuploidy. However, the possibility of fetal karyotyping, which is a more invasive procedure, should be discussed in the light of the overall risk of the fetus.

Fetal Aortic Arch Anomalies: Key Sonographic Views for Their Differential Diagnosis and Clinical Implications Using the Cardiovascular System Sonographic Evaluation Protocol

Aortic arch anomalies are present in 1% to 2% of the general population and are commonly associated with congenital heart disease, chromosomal defects, and tracheaesophageal compression in postnatal life. The sonographically based detection of aortic arch anomalies lies in the 3-vessel and trachea view. Although highly sensitive, this view alone does not allow identification of the aortic arch branching pattern, which prevents an accurate diagnosis. The systematic addition of a subclavian artery view as part of a standardized procedure may be useful in the differential diagnosis of these conditions. We describe the sonographic assessment of fetal aortic arch anomalies by combining 2 fetal transverse views: the 3-vessel and trachea view and the subclavian artery view, which are included in the cardiovascular system sonographic evaluation protocol. We also review the sonographic findings and the clinical implications of fetal aortic arch anomalies.

Prenatal Associated Features in Fetuses Diagnosed with an Aberrant Right Subclavian Artery

Objective: The objective of this study was to determine the frequency and the nature of associated anomalies, especially malformations and chromosome abnormalities, in a population of fetuses with an aberrant right subclavian artery (ARSA). Materials and Methods: This is a 7-year descriptive study. All patients whose fetus had an ARSA diagnosed by ultrasound performed during the 1st, 2nd, or 3rd trimester of pregnancy were included, regardless of their risk of chromosomal abnormalities. Results: Between May 2007 and April 2014, an ARSA was diagnosed in 120 fetuses. The outcome was found in 108 cases (90%). ARSA was an isolated finding in 54/108 cases (50%). In 20% (22/108) of the fetuses, chromosomal abnormalities were detected. No chromosomal abnormalities were found in fetuses with an isolated ARSA. 82% (18/22) of chromosomal abnormalities were usual, such as trisomies 21 and 18, monosomy X, and 22q11.2 deletion. 21% (23/108) of the fetuses presenting an ARSA were associated with having a congenital heart disease. Conclusion: The presence of an isolated ARSA is a condition rarely associated with a chromosomal abnormality. The decision to perform an invasive karyotyping procedure under such circumstances or not may be made according to the principle of parental autonomy after extensive counselling and mostly a thorough assessment of the fetus.

An Anomalous Right Subclavian Artery with a Retrotracheal Course: A Case Report

An aberrant right subclavian artery arising as the last vessel of the arch of aorta is an uncommon anatomic anomaly with prevalence reported between 0.2% and 2.0%. In 80% of the cases the aberrant right subclavian artery takes a retro-oesophageal course to the right upper limb. During routine dissection of cadavers for teaching undergraduate medical students an anomalous retrotracheal right subclavian artery which is a very rare vascular anomaly was encountered in a 35-year-old male cadaver. The artery arose as the last branch of the arch of aorta and coursed to the right between the trachea and oesophagus. The presence of this vascular anomaly could be an unusual cause of dysphagia and breathing difficulty. The clinical significance and embryological aspects of this vascular variant is discussed in this paper.

Aberrant right subclavian artery in fetuses with Down syndrome: a systematic review and meta-analysis

OBJECTIVES

The primary objective was to estimate the prevalence of aberrant right subclavian artery (ARSA) in fetuses with Down syndrome. Secondary objectives were to assess the prevalence of ARSA in euploid fetuses, the feasibility of ultrasound evaluation of the right subclavian artery (RSA) in the first and second trimesters of pregnancy, the performance of ARSA in screening for trisomy 21 and its association with other abnormalities.

METHODS

Web-based databases (PubMed, EMBASE and MEDLINE) were searched up to July 2014. The STROBE, PRISMA and QUIPS instruments were used to assess all included studies and for reporting of methodology, results and conclusions. Original studies that reported prenatal ultrasound evaluation of ARSA, assessment of its prevalence in Down-syndrome and euploid fetuses, feasibility of ultrasound evaluation of the RSA in the first and second trimesters of pregnancy and correlation of ARSA with other abnormalities were included, excluding duplications and case reports. Collected data were summarized to estimate prevalence and feasibility. A meta-analysis was performed pooling the study-specific positive and negative likelihood ratios (LR+ and LR-), detection rates and false-positive rates for trisomy 21.

RESULTS

Prevalence of ARSA in Down-syndrome fetuses was 23.6% (95% CI, 19.4-27.9%), whereas in euploid fetuses it was 1.02% (95% CI, 0.86-1.10%). Ultrasound evaluation of the RSA course and origin in the first and second trimesters of pregnancy was feasible in 85% and 98% of cases (first and second trimester, respectively) and it was directly related to sonographic experience and fetal crown-rump length and inversely related to maternal body mass index. In more than 20% of fetuses with ARSA there was an association with other abnormalities but ARSA seemed to be an independent marker of trisomy 21. The meta-analysis showed that ARSA is a significant risk factor for Down syndrome (pooled LR+ = 26.93, 95% CI, 19.36-37.47, P for effect < 0.001, P for Q = 0.3, I(2) = 17.3%), whereas normal RSA is a significant protective marker (pooled LR- = 0.71, 95% CI, 0.51-0.99, P for effect = 0.043, P for Q = 0.9, I(2) = 0%).

CONCLUSIONS

ARSA appears to be a clinically useful prenatal ultrasound marker of Down syndrome. Additional testing when ARSA is diagnosed should involve evaluation of all risk factors by applying a mathematical model. There is insufficient evidence to recommend fetal karyotyping in cases with isolated ARSA. If the background risk is higher or additional markers are present, full fetal karyotyping is advisable, including analysis for 22q11 microdeletion.

Cardiovascular System Sonographic Evaluation Algorithm: A New Sonographic Algorithm for Evaluation of the Fetal Cardiovascular System in the Second Trimester

OBJECTIVES

To evaluate the reproducibility and feasibility of the new cardiovascular system sonographic evaluation algorithm for studying the extended fetal cardiovascular system, including the portal, thymic, and supra-aortic areas, in the second trimester of pregnancy (19-22 weeks).

METHODS

We performed a cross-sectional study of pregnant women with healthy fetuses (singleton and twin pregnancies) attending our center from March to August 2011. The extended fetal cardiovascular system was evaluated by following the new algorithm, a sequential acquisition of axial views comprising the following (caudal to cranial): I, portal sinus; II, ductus venosus; III, hepatic veins; IV, 4-chamber view; V, left ventricular outflow tract; VI, right ventricular outflow tract; VII, 3-vessel and trachea view; VIII, thy-box; and IX, subclavian arteries. Interobserver agreement on the feasibility and exploration time was estimated in a subgroup of patients. The feasibility and exploration time were determined for the main cohort. Maternal, fetal, and sonographic factors affecting both features were evaluated.

RESULTS

Interobserver agreement was excellent for all views except view VIII; the difference in the mean exploration time between observers was 1.5 minutes (95% confidence interval, 0.7-2.1 minutes; P < .05). In 184 fetuses (mean gestational age ± SD, 20 ± 0.6 weeks), the feasibility of all views was close to 99% except view VIII (88.7%). The complete feasibility of the algorithm was 81.5%. The mean exploration time was 5.6 ± 4.2 minutes. Only the occiput anterior fetal position was associated with a lower frequency of visualization and a longer exploration time (P < .05).

CONCLUSIONS

The cardiovascular system sonographic evaluation algorithm is a reproducible and feasible approach for exploration of the extended fetal cardiovascular system in a second-trimester scan. It can be used to explore these areas in normal and abnormal conditions and provides an integrated image of extended fetal cardiovascular anatomy.

Second-trimester fetal aberrant right subclavian artery: original study, systematic review and meta-analysis of performance in detection of Down syndrome

OBJECTIVES

First, to estimate the prevalence of fetal aberrant right subclavian artery (ARSA) in our population and its association with Down syndrome. Second, to determine the feasibility of ultrasound to visualize ARSA in the three planes. Finally, to carry out a systematic review of the literature on the performance of second-trimester ARSA to identify fetuses with Down syndrome.

METHODS

ARSA was assessed by ultrasound in the axial plane and confirmed in the longitudinal and coronal planes during the second half of pregnancy in women attending our unit (from February 2011 to December 2012). A search of diagnostic tests for the assessment of ARSA was carried out in international databases. Relevant studies were subjected to a critical reading, and meta-analysis was performed with Meta-DiSc.

RESULTS

Of the 8781 fetuses in our population (mean gestational age: 24 ± 5.4 weeks), 22 had Down syndrome. ARSA was detected in the axial view in 60 cases (0.7%) and confirmed in the coronal view in 96.7% and in the longitudinal view in 6.7% (P < 0.001). Seven cases with ARSA had Down syndrome and all were in the non-isolated-ARSA group. The estimates of positive likelihood ratio (LR) were 0 for isolated ARSA and 199 (95% CI, 88.9-445.2) for non-isolated ARSA. In the systematic review, six studies were selected for quantitative synthesis. The pooled estimates of positive and negative LRs for global ARSA were, respectively, 35.3 (95% CI, 24.4-51.1) and 0.75 (95% CI, 0.64-0.87). For isolated ARSA, the positive and negative LRs were 0 (95% CI, 0.0-14.7) and 0.98 (95% CI, 0.94-1.02), respectively.

CONCLUSIONS

The prevalence of ARSA seems close to 1%. The coronal plane is the most suitable for its confirmation after detection in the axial plane. Detection of isolated or non-isolated ARSA should guide decisions about karyotyping given that isolated ARSA shows a weak association with Down syndrome.

[Aberrant right subclavian artery in children examined at the National Institute of Cardiology Ignacio Chavez (1992-2012)]

OBJECTIVES

Congenital vascular malformations of the major arteries in the chest have been classified into 5 groups: 1) double aortic arch; 2) right aortic arch with left ligament or persistent ductus arteriosus; 3) aberrant subclavian artery; 4) aberrant left pulmonary artery, and 5) anomalous innominate artery. We reviewed the patients with aberrant right subclavian artery and their treatment.

METHODS

We studied retrospectively the records of 29 patients with aberrant right subclavian artery in childhood, from January 1992 to December 2012, analyzing the following variables: age at onset, clinical manifestations, associated cardiovascular defects, diagnosis and surgical approach method.

RESULTS

We found that most patients have an asymptomatic course, only 31% of them course with symptoms during the first year of life, with an incidental diagnosis of 35% during catheterization or other imaging studies. Patent ductus arteriosus was the most frequently associated congenital malformation, with 13%. Down's syndrome was found in 21%. The most common treatment was surgical section of the aberrant subclavian artery to release the esophagus.

CONCLUSIONS

This vascular abnormality must be suspected in those patients with dysphagia, dyspnea, chest pain during feeding or breathing difficulties. A significant number of patients are not diagnosed in time, some reach adulthood without a diagnosis. This malformation is often found in imaging studies when evaluating the aorta or in a gastroesophageal reflux study, in which the barium bolus reveals the extrinsic compression of the esophagus.

Aberrant subclavian artery origin in tetralogy of Fallot with pulmonary stenosis is associated with chromosomal or genetic abnormality

We determined the relationship between aortic arch anatomy in tetralogy of Fallot with pulmonary stenosis and chromosomal or genetic abnormality, by performing analysis of 257 consecutive patients undergoing surgical repair from January, 2003 to March, 2011. Chromosomal or genetic abnormality was identified in 49 of the 257 (19%) patients. These included trisomy 21 (n = 14); chromosome 22q11.2 deletion (n = 16); other chromosomal abnormalities (n = 9); CHARGE (n = 2); Pierre Robin (n = 2); and Kabuki, Alagille, Holt-Oram, Kaufman McKusick, Goldenhar, and PHACE (n = 1 each). Aortic anatomy was classified as left arch with normal branching, right arch with mirror image branching, left arch with aberrant right subclavian artery, or right arch with aberrant left subclavian artery. Associated syndromes occurred in 33 of 203 (16%) patients with left arch and normal branching (odds ratio 1); three of 36 (8%) patients with right arch and mirror image branching (odds ratio 0.4, 95% confidence interval 0.1-1.6); seven of eight (88%) patients with left arch and aberrant right subclavian artery (odds ratio 36, 95% confidence interval 4-302); and six of 10 (60%) patients with right arch and aberrant left subclavian artery (odds ratio 8, 95% confidence interval 2-26). Syndromes were present in 13 of 18 (72%) patients with either right or left aberrant subclavian artery (odds ratio 15, 95% confidence interval 4-45). Syndromes in patients with an aberrant subclavian artery included trisomy 21 (n = 4); chromosome 22q11.2 deletion (n = 5); and Holt-Oram, PHACE, CHARGE, and chromosome 18p deletion (n = 1 each). Aberrant right or left subclavian artery in tetralogy of Fallot with pulmonary stenosis is associated with an increased incidence of chromosomal or genetic abnormality, whereas right aortic arch with mirror image branching is not. The assessment of aortic arch anatomy at prenatal diagnosis can assist counselling.

[Aberrant right subclavian artery (arteria lusoria) and the risk for trisomy 21. Retrospective study of 11,479 fetopathological examinations]

OBJECTIVE

The aberrant right subclavian artery is a malformation of the aortic arch present at less than 2 % of the individuals in the general population. This incidence is higher in trisomy 21, making it possible use the aberrant right subclavian artery as a prenatal marker of trisomy 21.

MATERIAL AND METHODS

This work, which relates to a series of 11,479 consecutive fetal autopsies aims to measure the force of association between the aberrant right subclavian artery and trisomy 21, to confront our results with the sonographic series previously published and to contribute to assess the place that can have this sign in the echographic screening and the fetopathologic diagnosis of trisomy 21.

RESULTS

The isolated presence of an aberrant right subclavian artery does not represent an argument sufficient for the indication of a karyotype. But the detection of this anomaly must make pay a special attention in search of other associated signs.

CONCLUSION

On the results of this study, the aberrant right subclavian artery has to be considered as a part of the spectrum not only of trisomy 21, but also of many other congenital syndromes.

The cavum septi pellucidi in euploid and aneuploid fetuses

OBJECTIVE

To examine whether the cavum septi pellucidi (CSP) is larger in second- and third-trimester fetuses with chromosomal abnormalities than in euploid fetuses.

METHODS

This was a retrospective study utilizing stored two-dimensional images of second- and third-trimester fetuses between 18 and 40 weeks' gestation from three centers in Germany. The width of the CSP was measured by placing the calipers on the inner portion of its lateral borders. Two operators, both of whom were blinded to the fetal karyotype and to the measurements obtained by the other, measured the CSP width. The normal range in euploid fetuses was computed based on the biparietal diameter (BPD) by applying univariate regression analysis. The CSP width in euploid and aneuploid fetuses was transformed into Z-scores and compared using Student's t-test. Univariate regression analysis was used to determine the dependency of Z-score on head biometry.

RESULTS

The study population consisted of 406 singleton pregnancies, 267 with euploid fetuses, 81 with trisomy 21, 50 with trisomy 18 and eight with trisomy 13. In the euploid group, the mean CSP width was 4.5 (range, 1.8-7.4) mm. Regression analysis showed a significant dependency of CSP width on BPD (CSP width = 0.658 + (0.064 × BPD), r = 0.781, P < 0.0001; both parameters in mm). The mean CSP width increased from 3.2 to 7.1 mm for BPD values of 40 to 100 mm, respectively. In the groups of fetuses with trisomy 21, 18 and 13, mean CSP width was 5.7 (range, 2.8-10.5), 7.9 (range, 3.5-12.8) and 5.8 (range, 4.0-9.0) mm, respectively. In 42.0% of the fetuses with trisomy 21, CSP width was above the 95(th) centile. In trisomy 18 and 13, CSP width was above the 95(th) centile in 92.0% and 37.5% of cases, respectively.

CONCLUSION

A large CSP width should prompt a detailed ultrasound examination to further assess the risk for chromosomal abnormalities.

A pictorial guide for the second trimester ultrasound

Introduction: The second trimester ultrasound remains an important screening tool for detecting fetal abnormalities. This pictorial guide for the second trimester ultrasound is designed to assist practitioners to produce a high quality diagnostic survey of the fetus by demonstrating and describing recommended images. Methods: Each image is discussed in detail and has an associated drawn line diagram to aid in the identification of the important features of that image. There is a description of the salient landmarks and relevant measurements. Result: The authors hope this article may act as a useful guide to all practitioners performing second trimester ultrasounds.