Persistent right aortic arch with an aberrant left subclavian artery, Kommerell’s diverticulum and bicarotid trunk in a 3-year-old cat

Abstract

Case summaryA 3-year-old male, neutered, domestic shorthair cat with a history of chronic regurgitation since being obtained as a kitten was presented for weight loss and regurgitation of all ingested food. The cat was in poor body condition and had a firm swelling in the ventral neck at the time of presentation. Thoracic radiographs showed severe dilation of the entire cervical and cranial intrathoracic esophagus to the level of the heart base. Computed tomographic angiography (CTA) showed a persistent right aortic arch with an aberrant left subclavian artery and severe dilation of the cervical and intrathoracic esophagus cranial to the heart base. CTA also showed a bicarotid trunk and Kommerell’s diverticulum to be present, which are rare vascular structures in the cat. Esophagoscopy showed esophageal dilation and multiple compact trichobezoars obstructing the esophagus. Removal of the obstructing trichobezoars resulted in resolution of clinical signs, and the cat was able to drink water and eat a canned food slurry without regurgitation. Surgical correction was not pursued.Relevance and novel informationVascular ring anomaly (VRA) should be considered in all cats with a history of regurgitation, regardless of their age at the time of presentation. CTA is a valuable diagnostic imaging procedure that allows differentiation of a VRA from other causes of esophageal obstruction and provides information about the VRA that can be used to determine amenability to surgical correction.

Severe oesophageal constriction due to an aberrant right subclavian artery with Kommerell’s diverticulum in a cat

“…13 In humans, Kommerell’s diverticulum has been shown to compress the oesophagus in the absence of any other vascular anomaly. 14 Although that anomaly was rarely reported in cats, 7,8 a markedly dilated origin of the aberrant right subclavian artery (Kommerell’s diverticulum) would have pressed the oesophagus more strongly, 13–15 inducing the severe oesophageal constriction in this case.…”

“…3 However, accurate anatomic diagnosis and treatment planning for animals with rare and complex vascular anomalies are sometimes difficult. 3,6–8 In this case, the site of the oesophageal constriction, as visible on the positive contrast oesophagram, was considered too far cranial to have been associated with the persistent right aortic arch and left ligamentum arteriosum. 1–3,5 In contrast, CTA proved to be valuable in that it confirmed the presence of a congenital malformation as the cause of the oesophageal constriction in this cat.…”

“…1–3 They are common in dogs but rarely observed in cats. 1–8 The most common type of VRA is a persistent right aortic arch with a left ductus arteriosus or ligamentum arteriosum. 1–3,8 A presumptive diagnosis of a VRA is commonly made from the history of the patient and results of the clinical and radiographic examinations.…”

“…1–5,8 However, clinical diagnosis is sometimes difficult in the case of rare and complex vascular anomalies. 3,6–8 Furthermore, the treatment of choice for complex VRAs depends on an accurate anatomic diagnosis. 8,9…”

Surgical correction of a persistent right aortic arch in a kitten with concurrent mitral and tricuspid valve insufficiency and long‐term post‐operative management of residual megaoesophagus

“…Oesophageal enlargement with a narrowed strictured area at the heart base along with tracheal deviation is highly suggestive of a compressive VRA 30 . While survey radiography or contrast radiography is sensitive for diagnosing a VRA, computed tomography with angiographic studies is recommended to identify the type of VRA and aberrant vessels and to assist with surgical planning 7,8,32,33 . Oesophagoscopy is often not used as a diagnostic modality in suspected VRA cases.…”