Resistance at the Thoracic Duct Subclavian Vein Junction

CANNULATION of the cervical thoracic duct and external lymphatic drainage has been observed, by Dumont,¹ to lead to a reduction in portal pressure and ascites in the cirrhotic patient. The physiological basis for this response has not been clarified.

A functional resistance at the venolymphatic area is an attractive concept which has received some support from previous investigation. Zemel and Gutelius² have observed a valve structure at the junction that might limit a potential increase in lymphatic flow. The reduction in ascites following thoracic duct-esophageal shunting of lymph also supports the presence of a significant resistance at the junction.³ If a mechanical factor limiting flow at the lymphatic venous junction can be confirmed, a permanent reduction of portal pressure might result from thoracic duct venous anastomosis.⁴ Therefore, the present study was undertaken to evaluate resistance at the lymphatic venous junction at normal and elevated flow rates.