Aberrant right subclavian artery, also known as arteria lusoria, is the most common malformation of the aortic arch, with an estimated incidence between 0.5 and 2% in the general population [1]. This vascular anomaly was described for the first time, to our knowledge, in 1735 by Hunauld [2].

Embryologically, the right subclavian artery develops through the remodeling of the fourth right aortic arch, the section of the dorsal aorta distal to this arch, and the sixth cervical intersegmental artery. The right dorsal aorta regresses beyond the sixth cervical intersegmental artery, and as the aorta grows caudally, anchored by its thoracic parietal branches, it separates. This detachment allows the right subclavian artery to be released from its connection to the thoracic aorta. The emergence of an arteria lusoria is a consequence of an interruption in this remodeling process There is abnormal degeneration of the fourth right aortic arch, and a lack of involution of the distal part of the right dorsal aorta. The aberrant right subclavian artery will therefore no longer be connected to the proximal part of the arch (ascending aorta) but will be attached to the descending aorta by the remainder of the right dorsal aorta. It then becomes the 4th and last branch of the aortic arch [4]. The pathophysiology of this malformation remains poorly understood and could involve a hemodynamic factor, in addition to a genetic and evolutionary basis [3].

The anatomical variation most frequently associated with the arteria lusoria is the origin of the left common carotid artery from the brachiocephalic arterial trunk, referred to as truncus bicaroticus. This occurs in about 30% of cases, as observed in our study [7]. Clinically, the arteria lusoria is often asymptomatic, as it does not form a complete ring around the esophagus or trachea. It is typically discovered incidentally during thoracic examinations for other conditions. However, it can become symptomatic primarily in three scenarios: firstly, when the esophagus and trachea are compressed between the arteria lusoria behind and the bicarotid trunk in front [5]; secondly, in the case of an aneurysm of this artery, which poses a significant complication. Lastly, with age, there may be atherosclerotic degeneration of the artery or the occurrence of fibro-muscular dysplasia [6]. The main clinical sign is dysphagia, referred to as lusorian dysphagia.

The diagnosis of arteria lusoria is established through imaging techniques. The first description of this anatomical variant was made by Kommerell, who utilized an esophageal transit X-ray with a radiopaque substance. As technology has advanced, so too have the methods of diagnosis. In this series, the diagnosis of arteria lusoria was confirmed through a CT scan following intravenous administration of a contrast agent. This method allowed for detailed visualization of the artery's origin, course, caliber, and other characteristics. Computed tomography is the preferred technique for incidental diagnoses, as it is a standard procedure commonly employed to investigate other thoracic lesions [8,9]. No treatment is required for an asymptomatic arteria lusoria. Treatment is only warranted if it leads to bothersome dysphagia or in cases of complications related to this artery, such as aneurysms, whether symptomatic or not.