Peritoneal response to a septic challenge - Comparison between open laparotomy, pneumoperitoneum laparoscopy, and wall lift laparoscopy

Background: Laparoscopic surgery has a lower incidence of surgical infectio n than open surgery. Differential factors that may modify the bacterial bio logy and explain this finding to some extent include CO2 atmosphere, less d esiccation of intraabdominal structures, fewer temperature changes, and a b etter preserved peritoneal and systemic immune response. Previous data sugg est that the immune response and acute phase response are better preserved after laparoscopy. Therefore, we designed a study to evaluate the early per itoneal response to sepsis in an experimental peritonitis model comparing o pen surgery with CO2 and abdominal wall lift laparoscopy. Methods: The study subjects comprised 360 mice distributed into the followi ng four groups: group 1, n = 72 (controls); group 2, n = 96 (open surgery), 2-3 cm laparotomy, with abdominal cavity exposed to the air for 30 min; gr oup 3, n = 96, CO2 laparoscopy (5 mmHg pneumoperitoneum) for 30 min; group 4, n = 96, wall lift laparoscopy for 30 min. Intraabdominal contamination i n the four groups was induced with 1 mi of E. coli suspension (1 x 10(4) CF U/ml) 10 min before abdomen closure. Peritoneal fluid and blood samples wer e obtained 1.5, 3, 24, and 72 h after surgery, and TNF, IL-1, and IL-6 were measured (via ELISA), as well as quantitative culture. Results: The number of CFU (colony-forming units) obtained in peritoneal fl uid and positive blood culture rates were significantly lower in the laparo scopic groups than in the open group. IL-1 peritoneal levels were significa ntly lower after 24 h and 72 h in the laparoscopy groups. IL-6 levels decre ased sharply in the laparoscopy groups at 24 h and 72 h. There were no diff erences between the two types of laparoscopy models (CO2 and wall lift). Conclusions: Peritoneal response to sepsis is better preserved after laparo scopy: than after open surgery. CO2 does not seem to influence bacterial gr owth. According to these findings, laparoscopy entails less local trauma an d better preserved intraabdominal conditions.