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.

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.

Síndrome de isocromosoma 18q / Isochromosome 18q syndrome

Introducción: Los isocromosomas constituyen una aberración cromosómica producto de un rearreglo poco frecuente en el cual, debido a una división errónea, surge un cromosoma con dos copias de un mismo brazo y ausencia del otro. Esto se tradujo para los sujetos en estudio en una trisomía parcial para un brazo y una monosomía parcial para el otro brazo. Objetivo: Analizar lo inusual que resulta un hallazgo de esta naturaleza en un bebé de dos años y la posible existencia de un mosaicismo no detectado. Presentación del caso: Se realizó un estudio cromosómico a un paciente por presentar un anillo aórtico y un crecimiento retardado, y se determina la presencia de un isocromosoma de brazo largo del cromosoma 18. El cariotipo de ambos padres resultó ser normal. Conclusiones: La presencia de un isocromosoma de brazo largo del cromosoma 18 se manifiesta con signos intermedios entre una trisomía 18 un síndrome por deleción de brazo corto del cromosoma 18. El estudio citogenético permitió brindar una respuesta precisa del origen de la anomalía cromosómica…(AU)

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.