[Retro-tracheal left pulmonary artery. Report of 2 cases]

The authors report the cases of two neonates with retro-tracheal left pulmonary arteries (pulmonary artery sling). In the first case, there was rapid onset of cardiac failure with signs of airway compression. Echocardiography showed the vascular anomaly associated with a large ventricular septal defect (VSD). After standard radiological investigation and bronchoscopy to exclude an associated tracheo-bronchial malformation, the VSD was repaired surgically with reimplantation of the left pulmonary artery. Unfortunately, the patient died of major airways obstruction in the postoperative period. Autopsy showed tracheo-bronchial anomalies which had not been diagnosed preoperatively. The second patient presented with hypoventilation of the right lung. After echocardiographic diagnosis of the anomaly, a thorough investigation (thoracic CT, helicoidal scan, bronchoscopy) was carried out and no associated bronchial malformations were observed. Reimplantation of the left pulmonary artery was successful and the postoperative course was uneventful. Retro-tracheal left pulmonary artery is a rare malformation Which is difficult to diagnose. It requires extensive pulmonary investigations and a multi-disciplinary approach. The prognosis is poor when there are associated tracheo-bronchial malformations.