Use of imaging for assessing anatomical relationships of tracheobronchial anomalies associated with left pulmonary artery sling

Background. Proper recognition, classification and assessment of the tracheobronchial anatomy are essential for surgical management planning in left pulmonary artery sling (LPAS). Objective. To demonstrate the various imaging modalities in diagnosing and assessing anatomical relationships with tracheobronchial tree in LPAS. Materials and methods. Seven patients (three infants, three children, one adult) with LPAS were evaluated. The confirmative imaging modalities included electron-beam tomography (EBT, n = 2), MRI (n = 1) and helical CT (n = 4). Other imaging modalities included plain chest radiographs (n = 7), barium oesophagogram (n = 2), echocardiography (n = 3), cardiac and pulmonary angiography (n = 2) and bronchoscopy (n = 5). Results. There were two cases of type IA, one case of type IIA and four cases of type IIB. All five cases of type II had a long segment of tracheobronchial stenosis. A long segment of thoracic tracheal stenosis was unusually associated in one case of type IA, All confirmative modalities were sufficient for diagnosing LPAS and assessing the tracheobronchial tree anomaly, However, helical CT could not obviate angiography due to associated congenital cardiac defects. Conclusions. Sectional imaging modalities of EBT, MRI and helical CT were all sufficient for diagnosing and assessing the anatomical relationships of the tracheobronchial tree in LPAS.