Development of a lethal model of peritonitis for assessment of laparoscopic and laparotomic treatments in rats

Purpose: Development of a lethal model of peritonitis to assess the results of treating that peritonitis using video laparoscopy and laparotomy. Methods: We developed a model of peritonitis in rats using cecal ligation (CLP) against a 2-mm diameter rigid mold and puncture. Two experiments were performed: determination of seven-day lethality; and analysis of white cell counts, blood cultures and cytokines (Interleukin-1 beta, Tumor Necrosis Factor-alpha and IL-6). The animals were divided into four groups: I - Sham surgery; H - CLP; III - CLP + Videolaparoscopy; and IV- CLP + Laparotomy. Results: Seven-day lethality was 0% in group I, 80% in the group II (p<0.05),60% in group III, and 20 %in group IV. There was a significant reduction in leukocyte counts and higher levels of serum IL-1 beta, TNF-alpha and IL-6 in the group II compared to controls. The percentages of positive blood cultures were higher after videolaparoscopic compared to laparotomic treatment. Conclusion: The experimental model provoked a lethal form of peritonitis and that videolaparoscopic treatment had more bacteraemia than laparotomy.