A morphological study of the thoracic duct at the jugulo-subclavian junction.

Chylous fistulae are uncommon but serious complications of neck surgery, occurring with an incidence of 1-3% after radical neck dissection. The majority occur on the left side (75-92%) and are due to damage to the terminal segment of the thoracic duct as it drains into the great veins of the neck in the region of the venous angle. The risk of trauma to the terminal thoracic duct may be influenced by anatomical variations. The macroscopic arrangement of the termination of the thoracic duct in the left neck was examined in 24 UK cadavers. Twenty-one ducts terminated as a single vessel, two ducts showed a bifid termination and one duct had three terminal branches. The precise site of termination was variable. Five thoracic ducts showed branching and reanastamosing patterns prior to their termination, irrespective of the number of terminal branches. Subsidiary cervical lymph trunks were identified in four dissections. These variations are described and their relevance to surgery involving the left side of the neck is discussed.