Peritoneal response to a septic challenge

Abstract

Background: Laparoscopic surgery has a lower incidence of surgical infection than open surgery. Differential factors that may modify the bacterial biology and explain this finding to some extent include CO₂ atmosphere, less desiccation of intraabdominal structures, fewer temperature changes, and a better preserved peritoneal and systemic immune response. Previous data suggest that the immune response and acute phase response are better preserved after laparoscopy. Therefore, we designed a study to evaluate the early peritoneal response to sepsis in an experimental peritonitis model comparing open surgery with CO₂ and abdominal wall lift laparoscopy.

Methods: The study subjects comprised 360 mice distributed into the following 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; group 3, n= 96, CO₂ laparoscopy (5 mmHg pneumoperitoneum) for 30 min; group 4, n= 96, wall lift laparoscopy for 30 min. Intraabdominal contamination in the four groups was induced with 1 ml of E. coli suspension (1 × 10⁴ CFU/ml) 10 min before abdomen closure. Peritoneal fluid and blood samples were 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 fluid and positive blood culture rates were significantly lower in the laparoscopic groups than in the open group. IL-1 peritoneal levels were significantly lower after 24 h and 72 h in the laparoscopy groups. IL-6 levels decreased sharply in the laparoscopy groups at 24 h and 72 h. There were no differences between the two types of laparoscopy models (CO₂ and wall lift).

Conclusions: Peritoneal response to sepsis is better preserved after laparoscopy than after open surgery. CO₂ does not seem to influence bacterial growth. According to these findings, laparoscopy entails less local trauma and better preserved intraabdominal conditions.