Malposition of a total parenteral nutrition catheter in the accessory hemiazygos vein.

A total parenteral nutrition catheter was surgically introduced into the left cephalic vein of a 31-yr-old man with regional enteritis. After placement, a frontal radiograph indicated malplacement of the catheter. Its left vertical paramedian position indicated a left internal thoracic vein, a persistent left superior cava, or a left superior intercostal-accessory hemiazygos vein position. The left internal thoracic vein is very anterior within the thorax, a persistent left superior vena cava is centrally located, and the left superior intercostal-accessory hemiazygos vein is quite posterior. A lateral radiograph revealed a markedly posterior catheter course, with its tip at the level of the vertebral bodies. A venogram confirmed its location within the left superior intercostal-hemiazygos vein. The catheter was removed and replaced. After placement of all total parenteral nutrition catheters, a chest radiograph should be obtained. A single frontal film is usually adequate; if not, a supplemental lateral view may be taken. If uncertainty still exists, a venogram through the catheter may be obtained for precise localization.