Prevalence and Morphological Variations of Aberrant Right Subclavian Artery among Adults at Maina Soko Medical Centre in Lusaka, Zambia

Abstract

Globally, aberrant right subclavian artery (ARSA) occurs in 0.16% to 2% of the population, however, ARSA is not well documented in this country. Therefore, this study determined the prevalence of ARSA and its morphological variations. A retrospective, descriptive, cross-sectional study was conducted at Maina Soko Medical Centre, encompassing 151 archived radiological data files from patients receiving care between January 2020 and December 2022. Computed tomography (CT) angiograms of the thoracic aorta and contrasted CT chest studies conducted for any reason were reviewed to assess the morphological variations and prevalence of ARSA. The data was analysed descriptively using Stata/SE version 17. Of the total 151 participants included, aberrant right subclavian artery was detected in two female participants (1.32%), aged 39 and 65 years old. The metrics for case one were: a diameter of 15.4 mm; wall thickness was 1.5 mm, and length of truncus bicaroticus was 19.8 mm. The metrics for case two were: diameter of 30.2 mm; wall thickness was 4.4 mm, and length of truncus bicaroticus was 5.4 mm. ARSA originated from the distal part of the aortic arch and followed a retroesophageal course in case one and retrotracheal course in case two. Both cases presented with truncus bicaroticus, a neurovascular anomaly. The study revealed that ARSA is a very rare anomaly. The findings contribute to our understanding of this rare anatomical variation and its clinical implications, while also highlighting areas for future research in vascular anatomy and embryology.