Flow in lymphatic networks: Interaction between hepatic and intestinal lymph vessels

Objective: Lymph from both the liver and intestine flows into the cisterna chyli. We hypothesized that increasing liver lymph flow would increase cist erna chyli pressure and, thereby, decrease intestinal lymph flow, potentiat ing intestinal edema formation. Methods: Anesthetized dogs were instrumented to measure and manipulate port al vein pressure and cisterna chyli pressure. The effects of directly incre asing portal pressure with and without directly increasing cisterna chyli p ressure on intestinal wet-to-dry ratio and intestinal ascites formation rat e were determined. Target values for portal and cisterna chyli pressures we re determined following elevation of inferior vena caval pressure to levels seen in patients with obstructive caval disease. Results: Direct elevation of portal pressure (P-port) alone to 17.5 mm Hg c aused a significant increase in intestinal wet-to-dry ratio (3.98 +/- 0.24 vs. 3.40 +/- 0.43) and the rate of ascites formation (0.36 +/- 0.12 vs. 0.0 5 +/- 0.03 mL/g dry wt/h). Simultaneous direct elevation of cisterna chyli pressure to 6.0 mm Hg and P-port to 17.5 mm Hg caused further increases in intestinal wet-to-dry ratio (5.52 +/- 1.20 and ascites formation (0.57 +/- 0.11 mL/g dry wt./h). Conclusions: Inferior vena caval hypertension increases liver lymph flow th at elevates cisterna chyli pressure. which inhibits intestinal lymph flow a nd augments intestinal edema formation.