Choice of insufflating gas influences on wound metastasis

Background: Laparoscopic cancer surgery is limited by concerns about port-s ite metastasis. No study has definitively addressed the behavior and growth of tumor cells after the use of specific laparoscopic gases. Methods: In athymic rats, 10,000 colon cancer cells were injected intraperi toneally, The rats received either no pneumoperitoneum (pneumo) or pneumo ( 8 mmHg, 10 min) with carbon dioxide (CO2), nitrous oxide (N2O), or air. Two full-thickness incisions were made and closed in the upper abdomen of each animal. After 4 weeks, implants were identified grossly at necropsy, and i nvasiveness was scored according to penetration through the layers of the a bdominal wall. Results: Rats receiving pneumo had more frequent implants (p < 0.01) with d eeper penetration (p < 0.001) than rats not receiving pneumo. Implants were more common after air pneumo than after CO2 (p < 0.05) or N2O (p = 0.07) p neumo, and were less penetrating after CO2 pneumo than after air (p < 0.001 ) or N2O (p < 0.05) pneumo. Conclusions: Carbon dioxide gas may limit the viability and invasiveness of free intraperitoneal tumor cells, as compared with air or N2O.