Influence of different pneumoperitoneal pressures on tumor cell distribution in rats

Background The effect of different pneumoperitoneal pressures on tumor cell distribution was investigated.Methods Donryu rats were allocated to receive carbon dioxide pneumoperitoneum at 5, 10, or 15 mmHg for 60 min or to serve as a control. During the procedure, each rat was inoculated with radiolabeled ascites hepatoma cells via the portal vein (experiment 1) or femoral vein (experiment 2). In both experiments, the rats were killed 30, 60, 90, or 120 min after tumor cell inoculation, and the liver and lungs were extirpated for radioactivity count (n = 5 or 6 for each time point in each group).Results In experiment 1, the percentage of injected dose (% ID) for the liver was greater than for the other three groups 120 min after tumor cell inoculation. There were no significant differences in the %IDs of the lungs at any time point among the groups. In experiment 2, there were no significant differences in the %IDs of the liver and lungs at any time point among the groups.Conclusions These results suggest that an elevated insufflation pressure facilitates the location of intraportally injected tumor cells in the liver, and that pulmonary location of the tumor cells may not depend on insufflation pressures in this animal model.