Surgical Correction of a Persistent Right Aortic Arch in a Foal

Abstract

A persistent right fourth aortic arch causing esophageal stenosis was diagnosed in a foal. Presenting signs included cervical swelling that developed following introduction to solid feed at weaning, and symptoms of chronic aspiration pneumonia. The esophagus was distended at the thoracic inlet; neither an endoscope nor a small nasogastric tube could be passed through the strictured esophagus at the heart base. The esophagus was seen to be dilated to the level of the heart base on plain and contrast radiographs. A left lateral thoracotomy through the fifth intercostal space was used to gain access for surgical correction of the defect. Radiographic and clinical evaluation of the foal 2 and 6 months following surgery showed a gradual decrease in size of the esophageal dilatation and an enlargement in the functional diameter of the esophagus at the previously strictured area at the heart base. Ten months following surgery the colt was eating normally and was of normal height and weight.