Conditioning of the abdominal cavity reduces tumor implantation in a laparoscopic mouse model.
OBJECTIVE
The addition of 4 % O2 and 10 % N2O to the CO2 pneumoperitoneum (PP), together with slight cooling and humidification (conditioning), contributes to reducing adhesions by preventing mesothelial damage. We investigated the effect of peritoneal damage during laparoscopy on tumor implantation.


METHODS
In Experiment 1, different tumor cell concentrations were injected into control mice without PP and into mice with 60-min dry CO2PP (mesothelial damage). In Experiment 2, tumor cells were injected into control mice (group I) and in mice with mesothelial damage (group II). In groups III to VI, mesothelial damage was decreased by adding humidification, humidification + 10 % N2O, humidification + 10 % N2O + 4 % O2, and conditioning, respectively.


RESULTS
In Experiment 1, the tumors increased with the number of cells injected and with mesothelial damage in the abdominal cavity (p = 0.018) and abdominal wall (p < 0.0001). Experiment 2 confirmed that 60 min of dry CO2PP increased the number of tumors in the abdominal cavity and wall (p = 0.026 and p = 0.003, respectively). The number of tumors was decreased in the abdominal cavity by conditioning (p = 0.030) and in the abdominal wall using humidified CO2 (p = 0.032) or conditioning (p = 0.026).


CONCLUSIONS
Tumor implantation was enhanced by peritoneal damage (60 min of dry CO2PP and desiccation), but this was prevented by conditioning. If confirmed in humans, conditioning would become important for oncologic surgery.
Laboratory of Abdominal Surgical Oncology, Department of Oncology, Catholic University of Leuven, Herestraat 49, Bus 7003, 3000, Leuven, Belgium, mercedes.binda@med.kuleuven.be.
Maria Mercedes
MM
Binda
Roberta
R
Corona
Frederic
F
Amant
Philippe Robert
PR
Koninckx
D000818:Animals; D002245:Carbon Dioxide; D045744:Cell Line, Tumor; D004848:Epithelium / Q000473:pathology; D005260:Female; D006813:Humidity; D007036:Hypothermia, Induced; D010535:Laparoscopy / Q000009:adverse effects*; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D009368:Neoplasm Transplantation / Q000473:pathology; D009609:Nitrous Oxide; D010100:Oxygen; D010529:Peritoneal Cavity / Q000473:pathology* / Q000601:surgery*; D011028:Pneumoperitoneum, Artificial; D000267:Tissue Adhesions / Q000517:prevention & control
D002245:Carbon Dioxide; D009609:Nitrous Oxide; D010100:Oxygen