Wound metastasis after laparoscopy with different insufflation gases

Background: There is growing evidence that laparoscopy for malignancy is associated with an increased incidence of metastasis to port sites. This study investigated the effect of different insufflation gases on port-site metastasis after laparoscopy in an established animal model. Methods: Forty-eight Dark Agouti rats with an established adenocarcinoma in the left flank underwent laparoscopic intraperitoneal tumor laceration. The gas used for insufflation was one of the following (12 rats in each group): (1) CO2, (2) N2O, (3) helium, or (4) air. Rats were killed 7 days after the procedure, and the port sites were examined for the presence of tumor metastasis. Results: Tumor involvement of port sites was significantly less likely after helium insufflation than in the other groups (p < 0.0001). There was no significant difference between the air, CO2, and N2O groups. Conclusions: This study suggests that the development of metastases in port sites after laparoscopy may be influenced in part by the choice of insufflation gas used to create the pneumoperitoneum. In particular, helium was associated with a reduced rate of metastases.