Aberrant right subclavian artery causing megaoesophagus in three cats

Abstract

Three entire, domestic, shorthair male cats (age range: 3 months to 5 years) were referred because of regurgitation. Megaoesophagus attributable to aberrant right subclavian artery, originating from the aorta at the level of the fourth intercostal space, was diagnosed in all cats using thoracic radiography and CT angiography. One cat had concurrent patent ductus arteriosus with a normal aortic arch. Three-dimensional volume-rendered CT images were used to assess the malformations and to plan surgery for the treatment of the vascular anomalies. Different surgical approaches were used in the two kittens. The third cat was not operated. CT angiography is well suited for preoperative planning in cats with aberrant right subclavian artery alone or in combination with other vascular anomalies.

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

“…The most common post‐operative complications reported are aspiration pneumonia and persistence of regurgitation 7,15 . Less common post‐operative complications include unilateral Horner's syndrome, chylothorax and front limb neuropraxia 7,8,10 . In two reported cases of front limb neuropraxia, the exact cause was not identified, but was most likely as a result of excessive extension of the limbs during positioning, or excessive displacement of the ribs cranial to the surgical site 8,10 .…”

“…In dogs a PRAA with an aberrant artery has been reported in between 33% to 85% of cases 7,33,38 . Advanced diagnostic modalities, specifically computed tomography with angiography, are important to specifically identify the nature of the VRA, identify aberrant arteries and give an accurate location of the constriction and plan surgery accordingly 7,8,32,33 …”

“…Gastrotomy tubes offer a long‐term feeding solution but require the patient to undergo general anaesthesia and disadvantages include blockage and infection 15,16,22 . Cats with constricting VRAs are also at high risk for suffering from concurrent aspiration pneumonia, and patients should be carefully evaluated for any signs of respiratory compromise 8–11,13,17,23,28 . Arterial blood gas analysis is very sensitive in detecting pulmonary pathology and it may be wise to perform arterial blood gas on all patients prior to general anaesthesia when there are any clinical signs of respiratory compromise even in the light of normal diagnostic imaging findings 40 …”

“…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.…”

“…VRAs such a PRAA was previously considered a rare condition in cats 6,19,20 . It is however, becoming a more well‐recognised condition as reports on cases are increasing 1,6,8,15 . The culmination of case studies provides much needed information regarding the successful treatment, prognosis and long‐term prospects of surgically treated patients.…”