PULMONARY SLING - MORPHOLOGICAL FINDINGS - PREOPERATIVE AND POSTOPERATIVE COURSE

Pulmonary sling (PS) is a congenital condition in which the left pulmo nary artery (LPA) arises from the right pulmonary artery (RPA), formin g a sling around the trachea causing tracheal compression. The inciden ce is not so rare as initially thought. Symptoms of severe airway obst ruction often begin in the newborn or young infant. Echo-colour-Dopple r may reveal the PS but emphysema can mask the typical findings. Devia tion of fluid-filled lungs may be detected prenatally. Chest radiograp hs show unusual air distribution, deviation of heart and mediastinum a nd altered tracheobronchial angles. Bronchography and bronchoscopy dem onstrate the high incidence of associated tracheal anomalies such as c artilagenous rings and long tracheal stenosis. Anterior oesophageal in dentation is not always seen in the oesophogram. Magnetic resonance im aging (MRI) and computed tomography (CT) reveal the PS, but cautious i nterpretation is necessary because of different levels of the anomalou s LPA. PS and associated cardiovascular malformations can be clearly d etected by angiography. Associated extrathoracic anomalies are common. Early diagnosis and therapy of PS is mandatory and consists of reimpl antation of the LPA into the pulmonary trunk and division of the ligam entum arteriosum. The postoperative course may be cumbersome necessita ting bronchological interventions. Tracheal resection may be necessary but restenosis is frequent. A one-stage repair has been proposed in s uch cases and was successfully done in a few reported cases. Relief of respiratory obstruction is often complete when there are no associate d tracheobronchial anomalies. Late postoperative course is favourable but respiratory obstructive attacks may occur with decreasing incidenc e over lime and tracheal growth.