Lymphatic vessels are important in removing excess fluid from the inte
stine and transporting the fluid to veins in the neck. However, in som
e diseases, neck vein pressure is increased and the high pressures may
slow lymph flow. This study was to test the hypothesis that lymphatic
clearance of fluid from the intestine may be increased by draining th
e lymphatics. Inflatable cuffs were used to increase neck vein pressur
e and portal venous pressure in anesthetized sheep. The lymphatic vess
el from one segment of small intestine was cannulated and drained. The
lymphatic vessel to a control segment of intestine was left intact. A
fter 90 min. we found significantly less fluid in the lumen of the dra
ined vs. control segments (7.4 +/- 3.1 (SD) ml vs 11.5 +/- 4.7 ml per
gram dry tissue, respectively). Also we found significantly less tissu
e fluid in the drained vs control segments (5.3 +/- 0.3 ml/g vs 6.0 +/
- 0.4 ml/g). The findings support the hypothesis that external diversi
on of lymph in the presence of an elevated central venous pressure red
uces edema formation.