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 metasta sis following laparoscopic tumor surgery remain controversial. Therefore, w e decided to investigate the influence of trocar placement and CO2 pneumope ritoneum on abdominal wound implantation in relation to intraperitoneal tum or growth in a rabbit model. Methods: Rabbits received either CO2 pneumoperitoneum with insertion of nin e 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 pneum operitoneum group (24.4%) and nonpneumoperitoneum group (27.4%) tended to b e higher than that in the control group (15.3%) (p = 0.06). There was no si gnificant 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.