Laparoscopic surgery in the rat. Beneficial effect on body weight and tumor take.

Background: The ability of laparoscopic techniques to treat malignant disease is controversial. We developed a rat model to assess metabolic and oncological effects of laparoscopic surgery.

Methods: Experiment I. The postoperative body weight in 10 rats having laparoscopic bowel resection (group I), 10 rats having open bowel resection (group II) and 5 rats having anesthesia only (group III) was determined. Experiment II. Tumor take was scored in 11 rats having laparoscopic bowel resection (group IV), 11 rats having open bowel resection (group V), 6 rats having CO2 pneumoperitoneum without bowel resection (group VI) and 6 rats having anesthesia only (group VII). All rats had CC531 cancer cells injected intraperitoneally postoperatively.

Results: Experiment I. Body weight loss in group I compared to group II (p<0.036). Rats of group III lost no weight postoperatively. Experiment II. Tumor take was less in the subcutis (p=0.005), parietal peritoneum (p<0.001) and bowel anastomosis (p=0.021) in group IV compared to group V. Tumor take was significantly greater at all sites except for subcutis in group VI compared to VII (all p<0.022).

Conclusions: Laparoscopic surgery is associated with less postoperative weight loss and less tumor take compared to open surgery. CO2 insufflation appears to increase tumor take.