The effect of intra-abdominal pressure on the generation of 8-iso prostaglandin F2α during laparoscopy in rabbits.

BACKGROUND: Carbon dioxide pneumoperitoneum induces peritoneal oxidative stress. The aim of this study was to verify the effect of intra-abdominal pressure on oxidative stress in the peritoneum and on post-operative adhesion formation. METHODS: Forty-one rabbits underwent laparoscopic surgery: either gasless, or with CO₂-pneumoperitoneum at pressures of 5, 10 or 15 mmHg. Serial parietal peritoneal biopsies were taken at various time-points: immediately after reaching the abdominal cavity, 30, 60, 90 and 120 min afterwards, and 15 min after abdominal desufflation. 8-iso prostaglandin F_2α (8-iso PGF_2α), a marker of oxidative stresss, was assayed by enzyme immunoassay and adhesion formation was scored by second-look laparoscopy on day 14. RESULTS: The gasless group showed no significant changes in 8-iso PGF_2α. Conversely, significant changes occurred in CO₂-pneumoperitoneum in a time- and pressure-dependent manner. Adhesions developed only in the CO₂-pneumoperitoneum groups, and total adhesion score was correlated with the amount of CO₂ insufflated and intra-abdominal pressure, but not with 8-iso PGF_2α, which was correlated with intra-abdominal pressure. CONCLUSION: Intra-abdominal pressure increased 8-iso PGF_2α in the parietal peritoneum in a graded fashion, whilst gasless laparoscopy had no impact. It also influenced the frequency and severity of adhesion formation, but no causal link was found between 8-iso PGF_2α and post-operative adhesion formation. [ABSTRACT FROM AUTHOR]