RESUMEN
Arteria lusoria or retroesophageal right subclavian artery is the most common aortic arch malformation, accounting for 0.5-2.5% of cases. It can be detected in patients with symptoms including airway and/or esophageal compression such as dyspnea or dysphagia or even recurrent respiratory infections; but it is mostly asymptomatic, as reported by several authors. We here report the case of a 44-year-old female patient treated in our emergency room due to respiratory distress syndrome associated with arteria lusoria. This is a rare cause of dyspnea which should be suspected in patients with dyspnea not responding to medical treatment. Asymptomatic patients undergo medical treatment associated with simple surveillance. Surgery is necessary when it becomes symptomatic or when it is associated with Kommerell diverticulum (KD).