CT of the bronchopulmonary veins in patients with superior vena cava or left brachiocephalic vein obstruction.

Abstract

The purpose of this study was to show the arrangement and connections of the bronchopulmonary veins (i.e., vessels draining the bronchi, bronchioles, and pleura in patients with chronic superior vena cava (SVC) or left brachiocephalic vein (LBCV) obstruction using CT. Contrast-enhanced CT scans of the chest of 16 patients with chronic SVC or LBCV obstruction were analyzed retrospectively. Scans were acquired using various standard protocols. The mean age of the patients (10 men and six women) was 63 years (range, 41-86 years). The causes of obstruction were malignancy (7/16, 44%), catheter-related thrombosis (7/16, 44%), chronic fibrosing mediastinitis (1/16, 6%), and unknown (1/16, 6%). The following sites were obstructed: SVC (9/16, 56%), SVC below the azygos vein (4/16, 25%), and lower LBCV (3/16, 19%). The bronchopulmonary veins were opacified via the brachiocephalic, azygos, or accessory hemiazygos veins or their branches. We observed long vessels that could be traced along the lateral mediastinum or alongside the trachea and central bronchi to their termination in the central pulmonary veins from the level of the ostia to segmental divisions. These vessels intercommunicated and gave rise to smaller veins contiguous with the walls of the bronchi and pulmonary arteries. The pulmonary venous connections of the bronchopulmonary veins were more frequent with the lower lobe pulmonary veins. Pericardial and esophageal veins were also opacified through the brachiocephalic or azygos veins and anastomosed commonly with the bronchopulmonary veins. The arrangement and connections of the bronchopulmonary veins in patients with chronic SVC or LBCV obstruction can be depicted by CT; these vessels form an intricate network connecting the systemic and pulmonary venous circulations and can act as systemic-pulmonary shunts.