Influence of trocar placement and CO2 pneumoperitoneum on port site metastasis following laparoscopic tumor surgery

Background: The mechanisms involved in the development of port site metastasis following laparoscopic tumor surgery remain controversial. Therefore, we decided to investigate the influence of trocar placement and CO2 pneumoperitoneum on abdominal wound implantation in relation to intraperitoneal tumor growth in a rabbit model. Methods: Rabbits received either CO2 pneumoperitoneum with insertion of nine trocars (pneumoperitoneum group, n = 15), insertion of nine trocars alone (nonpneumoperitoneum group, n = 15), or nine abdominal incisions (control group, n = 13) 3 days after intraperitoneal inoculation of VX2 cancer cells. Results: The frequency of overall wound implantation on day 17 in the pneumoperitoneum group (24.4%) and nonpneumoperitoneum group (27.4%) tended to be higher than that in the control group (15.3%) (p = 0.06). There was no significant difference among the three groups in the growth of cancer nodules on the omentum. Conclusions: The presence of a trocar may be a factor contributing to port site metastasis but CO2 pneumoperitoneum appears not to be a factor.