<unk> , or<unk>  syndrome refers to a rare anatomical variant of the origin of the right or left<unk><unk> .  This abnormality is the most common congenital vascular anomaly of the aortic arch.  The<unk><unk>  usually arises just distal to the left<unk><unk>  and passes posterior to the mediastinum on its way to the right upper extremity.  Such course of this<unk>  vessel may cause a vascular ring around a mediastinal structure.
Dysphagia due to an<unk>  right<unk><unk>  is termed dysphagia lusoria.  Palsy of the recurrent laryngeal nerve is termed Ortner's syndrome.
The<unk>  right<unk><unk>  frequently arises from a dilated segment of the proximal descending aorta, the so-called Diverticulum of Kummerel.
Aberrant subclavian artery
Persistent left superior vena cava
Persistent left inferior vena cava
Persistent thyroglossal duct
Interrupted aortic arch
Double inferior vena cava
Persistent truncus arteriosus
Overriding aorta