Introduction: Several studies have shown that laparoscopic surgery (LS) minimizes surgical trauma and preserves immune response. Another advantage is the lower incidence of infectious complications. However, several in vitro studies have shown that an atmosphere with CO2 affects macrophage physiology, which would affect the response to peritoneal contamination. This observation is controversial, given the experimental evidence of a better conserved response to peritoneal contamination. The aim of the present study was to investigate the immediate response of the peritoneum to contamination in an atmosphere with CO2.
Material and method: A total of 192 CD-1 rats were distributed into three groups: group I, LP, n= 64, (laparotomy); group II, LC-CO2, n= 64, (laparoscopy-CO2), group III, LC-T, n= 64, (laparoscopy-traction). The rats were randomized to receive 1 ml of a suspension of Escherichia coli (1x10(4) CFU/ml) (contamination [C]) or saline serum (no contamination [NC]). Peritoneal fluid was obtained at 1.5, 3, 6, and 12 h after surgery. Monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-6 and prostaglandin.E2 (PGE2) were determined.
Results: MCP-1 levels were significantly higher and increased earlier in group II (LC-CO2-NC) than in group I (LP-NC) (p< .007). Simultaneously, the increase in the traction group was significantly higher (p< .002) than after laparotomy, without differences with respect to group II (LC-CO2-NC). When contamination was added, there was a significant increase in the three groups (p< .5). The modifications in MCP-1 in the LP-C group were statistically significantly greater and appeared earlier than those in the traction groups, LC-T-C (p< .002) and LC-CO2-C (p< .02). Interleukin 6: the three models showed a significant increase, which appeared later in the LP-NC group. Simultaneously, the increase in IL-6 appeared earlier and was significantly greater in the LC-T-NC group than in the LP group (p< .003), with no differences between the LC-CO2-NC and LC-T-NC groups. There was a significant difference between contaminated and uncontaminated groups in the LC-CO2 model. The traction model (LC-T-C group) showed a greater increase than the LP-C and LC-CO2-C groups (p< .001). PGE2: a significant increase was observed in the three models without contamination. However, when contamination was added, no differences were observed.
Conclusion: Pneumoperitoneum with CO2 provokes a peritoneal response that is qualitatively different from open surgery and modifies the response to contamination with a greater increase in MCP-1 and IL-6.