Adverse impact of pneumoperitoneum on intraperitoneal implantation and growth of tumour cell suspension in an experimental model

Background: An investigation of the effect of laparoscopy and CO2 pneumoperitoneum on the pattern of tumour implantation and growth in the peritoneal cavity was carried out. Methods: A suspension of Viable adenocarcinoma cells was introduced into the left upper quadrant of the peritoneal cavity of 36 syngeneic immune-competent rats at laparotomy, laparoscopy with CO2 insufflation, and gasless laparoscopy (12 rats in each group). Six days later the peritoneal cavity and surgical wounds were examined for macroscopic evidence of implanted tumour. The abdominal cavity was divided into sectors and macroscopic tumour implantation was determined for each sector and wound. This was confirmed by histological examination. Results: While tumour implantation occurred in the vicinity of the tumour suspension introduction site in the laparotomy and gasless laparoscopy groups, implantation occurred throughout the peritoneal cavity, including areas remote to the introduction site, in the laparoscopy with CO2 insufflation group. Tumour growth was more likely in the port wounds of rats undergoing laparoscopy with insufflation than without. Conclusions: In this model, CO2 insufflation during laparoscopy resulted in widespread tumour dissemination and implantation, when compared to laparotomy and gasless laparoscopy, supporting the postulate that wound metastasis and tumour spread may be more likely following laparoscopic cancer surgery in humans when CO2 insufflation is used.