Aberrant right subclavian artery in a dog ˗ case report

Abstract

The brachiocephalic trunk and the left subclavian artery originate from the aortic arch, and both supply blood to the head, neck, and thoracic limbs. Anatomical variations, such as an aberrant right subclavian artery, are congenital conditions rarely observed in dogs, Thus, the objective of the present report was to describe a case of aberrant right subclavian artery in a 9-year-old Dalmatian. However, this anomaly was a finding in which the patient was asymptomatic during its 9 years of life and only at this age did he exhibit signs including sialorrhea, vomiting, hyporexia, and noisy deglutition. Blood count, biochemical profile, and thoracic radiography led to a diagnosis of megaesophagus and aspiration pneumonia. Despite the recommended treatment, the patient did not respond well; as such, the owner elected to euthanize the animal. On necropsy, the right subclavian artery originated directly from the aortic arch, followed a route from left to right dorsally to the esophagus, and then formed an impression of the vascular path over the muscular wall of the esophagus. The esophagus, in turn, exhibited a flaccid wall and dilation in the caudal portion to the vascular path made by the ectopic position of the right subclavian artery.

Anomalous origin of the right subclavian artery in a Neotropical otter (Lontra longicaudis, Olfers—1818)

“…This anomalous origin of the right subclavian artery rarely causes clinical signs (Schorn et al., 2021; Sebastian‐Marcos et al., 2019; Sinowatz, 2009; Vitums, 1962), which agrees with that found in the L. longicaudis specimen, which did not have signs before death. There are some reports where it generated clinical signs in C. lupus familiaris , such as regurgitation due to oesophageal compression (Miller et al., 2015; Tavares et al., 2020) and hypotension of the right thoracic limb (Kim et al., 2017). In the dissection of a C. lupus familiaris specimen, the anomalous origin of the right subclavian artery caused oesophageal dilation and provided a compression mark in the esophagus (de Kleer, 1971).…”

Persistent right aortic arch and aberrant left subclavian artery in a dog

“…The absence of such an examination makes it impossible to correctly diagnose this vascular anomaly, as occurred in one report. Even in this report, the patient was euthanized due to clinical worsening even with treatment, and the diagnosis was only made at necropsy (Tavares et al, 2020).…”

“…Therefore, the choice not to intervene on the aberrant left subclavian artery was based on the lack of clinical indication due to the absence of compression of adjacent structures. It is essential to highlight that, in many cases, an aberrant left subclavian artery is asymptomatic (Tavares et al, 2020;Nasser et al, 2023). Regurgitation presented by the patient at the time of care was associated with the esophageal external compression by the ligamentum arteriosum since such regurgitation completely regressed after surgery.…”

“…Although there are few publications in the scientific literature, ALSA occurs in about 33% of dogs with PRAA (Maryann & Fossum, 2018) and is already reported in Dalmatian (Tavares et al, 2020), Bull Terriers (Antunes et al, 2022), Belgian Shepherds (Saunders et al, 2013), Beagles (Vedrine & Durieux, 2017), Border Collies, Golden Retrievers, and Labradors (Scansen et al, 2014).…”