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

Abstract

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 cardiac findings and 22q11.2 deletion syndrome: Fetal detection and evaluation

“…The prevalence of 22q11.2DS in the context of ARSA with normal intracardiac anatomy is not well defined and challenging to discern from the current literature given the variability in the documentation of associated cardiac or extracardiac features, and the inconsistency of genetic testing. Overall, a 22q11.2 deletion is seemingly rare in a fetus with ARSA with normal intracardiac anatomy particularly if no other extracardiac or nonspecific obstetrical features are identified 44,48–50 . However, given the frequency with which patients with 22q11.2DS have an ARSA with normal intracardiac anatomy (personal observation), the identification of ARSA with normal intracardiac anatomy in the fetus should prompt careful evaluation for other extracardiac or obstetrical features that support the diagnosis of 22q11.2DS.…”

Technical considerations in robotic aberrant right subclavian artery resection for dysphagia lusoria

“…An aberrant right subclavian artery (ARSA) represents the most prevalent congenital anomaly associated with the aortic arch, 1 in which the aberrant artery originates from the proximal descending aorta and crosses the mediastinum to course into the right upper extremity. 2 An ARSA occurs in approximately 1% of the population and is usually asymptomatic. 3 , 4 The indications for surgical intervention include dysphagia, chest pain, dyspnea, and aneurysmal degeneration of the arterial origin, known as Kommerell diverticulum.…”