Computed tomographic lymphography of the thoracic duct by mesenteric lymph node injection

Area of Science:

• Veterinary Radiology
• Thoracic Surgery
• Diagnostic Imaging

Background:

• Chylothorax is a serious condition in dogs characterized by lymphatic fluid accumulation in the chest.
• Accurate imaging of the thoracic duct is crucial for effective surgical intervention.

Purpose of the Study:

• To describe and evaluate a novel technique for imaging the thoracic duct and its tributaries using contrast-enhanced computed tomography (CT) lymphography.
• To assess the utility of this technique for preoperative planning and postoperative evaluation of thoracic duct ligation.

Main Methods:

• A percutaneous technique involving ultrasound-guided injection of iodinated contrast medium into intestinal lymph nodes was used in 6 dogs with idiopathic chylothorax.
• CT lymphography was performed preoperatively and postoperatively to visualize the thoracic duct and lymphatic vessels.
• Surgical procedures included subtotal pericardectomy and thoracic duct ligation.

Main Results:

• Preoperative CT lymphography successfully delineated the cisterna chyli, thoracic duct, and associated lymphatic vessels in all dogs.
• Postoperative lymphography identified successful duct ligation in one dog and persistent lymphatic leakage in another.
• One-month follow-up revealed unsuccessful ligation or recannulation in one dog.

Conclusions:

• Percutaneous CT lymphography provides excellent visualization of the thoracic duct and abnormal drainage patterns.
• This technique is valuable for both pre- and postoperative assessment of thoracic duct abnormalities.
• It offers an alternative to conventional open abdominal approaches for CT lymphography.