Inflammation-attenuating effect of carbon dioxide versus room-air environment in a rat laparotomy model.

Background: The mechanism by which laparoscopic operations induce lower post-operative inflammatory response compared to open surgery was investigated with regard to the effect of the type of gas environment.

Methods: Rats were subjected to midline laparotomy at either CO (group CO) or room-air environment (group Air) or to anesthesia only (group Control) under atmospheric pressure conditions. At various timepoints after surgery (1, 3, 6, 24, or 48 h), the expression of inflammation biomarkers interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), and nuclear factor-κΒ (NFκΒ) were assessed immunohistochemically in tissue samples excised from the liver, intestine, and kidneys, accompanied by histopathologic analysis, and their levels were measured by ELISA in blood samples.

Results: Tissue expression of IL-6, TNFα, and NFκΒ was downregulated in the liver and intestine in group CO compared to group Air and in the kidneys in group Air compared to group CO. However, no differences were noted among groups regarding the histopathologic score of organ tissues and the blood serum levels of inflammation biomarkers.

Conclusion: Post-operative local inflammatory response was lower in intra-peritoneal organs of rats subjected to laparotomy at CO rather than room-air environment under atmospheric pressure conditions.