Peritoneal response to pneumoperitoneum and laparoscopic surgery

Background: It is generally believed that laparoscopic surgery inflicts less trauma to the peritoneum than open surgery. Local peritoneal fibrinolysis is a critical factor in adhesion development. The objective was to investigate fibrinolytic changes in the peritoneum during laparoscopic and open surgery. Methods: At laparotomy (n = 10) peritoneal biopsies were taken at opening of the abdomen and just before closure. At laparoscopy (n = 12) opening peritoneal biopsies were taken after carbon dioxide insufflation, and closure biopsies just before exsufflation. Tissue concentrations of tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1) and the resulting tPA activity were assayed. Results: Concentrations of tPA in peritoneal tissue declined during operation in both groups, but significantly so only in the laparotomy group (-53 per cent; P = 0.01). PAI-1 levels were higher in opening biopsies from the laparoscopy group (P = 0.004). There was an increase in PAI-1 concentration during laparotomy, but not during laparoscopy. At the end of the operation, there was no difference between the groups. The resulting tPA activity did not differ between groups at opening or closure. In both groups there was a significant decline during operation (laparotomy: -59 per cent, P = 0.02; laparoscopy: -63 per cent, P = 0.01). Conclusion: These findings indicate that the peritoneal response to open and laparoscopic surgery is similar. The initial rise in peritoneal PAI-1 concentration during laparoscopy suggests an adverse effect of carbon dioxide insufflation, which might affect peritoneal repair.