Computed Tomographic Lymphography of the Thoracic Duct by Mesenteric Lymph Node Injection

Abstract

OBJECTIVE: To document a novel technique to image the thoracic duct and its tributaries by contrast enhanced computed tomography (CT) lymphography. STUDY DESIGN: Clinical report. ANIMALS: Dogs (n=6) idiopathic chylothorax. METHODS: Ultrasonography was used to guide percutaneous injection of intestinal lymph nodes with nonionic iodinated contrast medium for preoperative CT lymphography of the thoracic duct in 6 dogs with chylothorax. Thoracic CT images were acquired immediately after contrast medium injection. All dogs had subtotal pericardectomy and thoracic duct ligation. Postoperative thoracic duct lymphography was performed in 3 dogs. Superficial cervical lymph node lymphography was performed in 2 dogs to determine cervical lymphatic contribution to thoracic effusions. RESULTS: Preoperative thoracic duct lymphography using this technique was successful in delineating the cisterna chyli, thoracic duct, and associated lymphatic vessels in all dogs. Immediate postoperative lymphography performed in 2 dogs revealed successful duct ligation in 1 dog and persistent lymphatic leakage in the other. A 1-month postoperative thoracic duct lymphogram performed in 1 dog revealed unsuccessful ligation or recannulation of 1 of 3 redundant vessels seen preoperatively. CONCLUSION: Percutaneous CT lymphography results in excellent detection of the thoracic duct and abnormal thoracic duct drainage patterns both pre- and postoperatively. The contribution of superficial cervical lymph node drainage to reoccurrence of effusions can be evaluated. CLINICAL RELEVANCE: Percutaneous CT lymphography using ultrasound-guided contrast medium injection should be considered as an alternative to conventional open abdominal approaches to radiographic or CT lymphography.