Carbon dioxide pneumoperitoneum is associated with increased liver metastases in a rat model

Background. In patients with primacy colorectal cancer, liver metastases are the most important indicators of prognosis and survival; the effect of laparoscopic surgery on the development of hepatic tumor spread is still largely unknown. Methods. Thirty WAG/Rij rats were randomly divided into 3 operative groups for intraportal tumor cell inoculation: carbon dioxide pneumoperitoneum (group I, n = 10), gasless laparoscopy (group II, n = 10) and open laparotomy (group III, n = 10). The total operating time was 90 minutes with tumor cell injection (50,000 CC531 colon carcinoma cells/mL) performed 45 minutes after the start of the procedure. Hepatic tumor growth and the total tumor load were evaluated 28 days after surgery. Results. Hepatic tumor growth and total tumor load were significantly reduced in the gasless laparoscopy group (group II) as compared with the carbon dioxide pneumoperitoneum group (group I) and the open laparotomy group (group ITT) (P < .05). No significant difference was found between the carbon dioxide and the open laparotomy groups. Conclusions. Insufflation of carbon dioxide may actually stimulate metastatic disease of the liver Gasless laparoscopy seems to preserve hepatic resistance against tumor growth.