Diagnosis and localization of laceration of the thoracic duct: usefulness of lymphangiography and CT.

The usefulness of lymphangiography and CT in the diagnosis and localization of laceration of the thoracic duct was evaluated in 12 patients with chylothorax or chylous ascites after surgery. Bipedal lymphangiography was performed in all 12 patients. The last four patients studied also had CT after lymphangiography. Seven patients had abnormal findings on lymphangiograms; five with leaks from the thoracic duct, one with a lymphocele in a nephrectomy bed, and one with obstructed intestinal lymphatic vessels after thoracotomy. Five patients had no evidence of lymphatic leakage. CT in one patient with evidence of a leak on lymphangiography showed extravasation of contrast medium into the mediastinum and pleural space. CT in three patients with no abnormalities on lymphangiography also showed no abnormalities. Four of the five thoracic duct lacerations and the lymphocele were confirmed surgically. The diagnosis of obstructed intestinal lymphatic vessels was supported clinically. Four of the five patients with normal findings on lymphangiograms had resolution of their pleural effusions and no evidence of recurrence during a follow-up period of 1-27 months. One patient with normal findings on lymphangiography had an alternative diagnosis established at surgery. Laceration of the thoracic duct was accurately diagnosed and localized with lymphangiography, which allowed definitive surgical repair. CT was of little additional value in diagnosing these injuries.