Right aortic arch with aberrant left subclavian artery—prenatal diagnosis and evaluation of postnatal outcomes: Report of three cases

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Prenatal Detection, Comorbidities, and Management of Vascular Rings

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

Natural History of Asymptomatic and Unrepaired Vascular Rings: Is Watchful Waiting a Viable Option? A New Case and Review of Previously Reported Cases

Vascular rings are a rare form of congenital heart disease in which abnormal aortic arch anatomy leads to encircling of the esophagus and/or trachea by the aortic vasculature. Symptoms can develop from this and prompt the need for surgery. A natural history study has been done on mildly symptomatic patients but no such study has been done on asymptomatic patients. We present a case report of three children with asymptomatic vascular rings who continue to receive follow-up without intervention and review all published cases of asymptomatic or unrepaired vascular rings. Clinical observation of asymptomatic and mildly symptomatic vascular rings, regardless of aortic arch anatomy, seems to be a safe approach. Children with mild symptoms almost invariably seem to have resolution of their symptoms by four years of age.

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

OBJECTIVES

Use of recent antenatal screening guidelines for cardiac abnormalities has increased fetal diagnoses of right aortic arch (RAA). We aimed to establish the outcome of fetal RAA without intracardiac abnormalities (ICA) to guide postnatal management.

METHODS

In the retrospective cohort part of our study, outcome measures were rates of chromosomal abnormalities, 22q11.2 deletion, fetal extracardiac abnormalities (ECA), postnatal ICA and ECA, and symptoms of and surgery for vascular ring. A systematic review and meta-analysis was also performed; results are reported as proportions. Kaplan-Meier analysis of vascular ring cases with surgery as endpoint was performed.

RESULTS

Our cohort included 86 cases; 41 had a vascular ring. Rates of chromosomal abnormalities, 22q11.2 deletion and fetal ECA were 14.1%, 6.4% and 17.4%, respectively. Sixteen studies including our cohort (312 fetuses) were included in the systematic review. Overall rates of chromosomal abnormalities and 22q11.2 deletion were 9.0% (95% CI, 6.0-12.5%) and 6.1% (95% CI, 3.6-9.3%), whilst the respective rates for cases with no ECA were 4.6% (95% CI, 2.3-7.8%) and 5.1% (95% CI, 2.4-8.6%). ECA were seen in 14.6% (95% CI, 10.6-19.0%) prenatally and in 4.0% (95% CI, 1.5-7.6%) after birth. Postnatal ICA were identified in 5.0% (95% CI, 2.7-7.9%). Rate of symptoms of vascular rings (follow-up ≥ 24 months postpartum) was 25.2% (95% CI, 16.6-35.0%), and 17.1% (95% CI, 9.9-25.7%) had surgery. Two-year freedom from surgery was 83.0% (95% CI, 74.3-90.1%).

CONCLUSIONS

Fetal RAA without ICA is more frequently associated with ECA than with chromosomal abnormalities. Most cases, however, are isolated. Vascular-ring symptoms occur in about 25% of cases. Postnatal surveillance is required mainly in the first 2 years after delivery.

HDliveFlow in the Assessment of Fetal Circulation

With the appearance of the latest three/four-dimensional (3D/4D) ultrasound machine (HDliveFlow, Voluson E10, GE Healthcare, Zipf, Austria), HDliveFlow with glass-body rendering mode or silhouette mode will facilitate more precise assessments of the fetal heart and peripheral circulation. The resolution of 3D/4D color/power Doppler using the HDlive technique shows a significant improvement compared to conventional 3D/4D color/power Doppler and the fetal heart with great vessels, small peripheral vessels, and placental blood flow can now be clearly recognized. HDliveFlow with glass-body rendering mode or silhouette mode combines the advantages of a spatial view of the great arteries in addition to the visualization of anatomical landmarks, such as the spine or diaphragm. Its use may provide potential advantages in cases of congenital heart anomalies and placental vascularity over the use of conventional 3D/4D color/power Doppler. This novel technique may assist in the evaluation of the fetal cardiovascular system and fetoplacental vascularity, and offer potential advantages relative to conventional 2D color/power Doppler assessments. In this article, we present the latest state-of-the-art HDliveFlow with glass-body rendering mode or silhouette mode of normal and abnormal fetal hearts, placentas, and umbilical cords. We also discuss the present and future applicability of 3D/4D color/ power Doppler to assess the fetal circulation. HDliveFlow with glass-body rendering mode or silhouette mode may become an important modality in future research on fetal cardiac and placental blood flow, and assist in the prenatal diagnosis of fetal congenital heart disease and placental vascular abnormalities.

How to cite this article

Hata T, AboEllail MAM, Sajapala S, Ito M. HDliveFlow in the Assessment of Fetal Circulation. Donald School J Ultrasound Obstet Gynecol 2015;9(4):462-470.