The effect of intra-abdominal pressure on the generation of 8-iso prostaglandin F2alpha 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 CO(2)-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(2alpha) (8-iso PGF(2alpha)), 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(2alpha). Conversely, significant changes occurred in CO(2)-pneumoperitoneum in a time- and pressure-dependent manner. Adhesions developed only in the CO(2)-pneumoperitoneum groups, and total adhesion score was correlated with the amount of CO(2) insufflated and intra-abdominal pressure, but not with 8-iso PGF(2alpha), which was correlated with intra-abdominal pressure.


CONCLUSIONS
Intra-abdominal pressure increased 8-iso PGF(2alpha) 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(2alpha) and post-operative adhesion formation.
D034841:Abdominal Cavity / Q000502:physiology*; D000818:Animals; D002245:Carbon Dioxide / Q000009:adverse effects; D015237:Dinoprost / Q000031:analogs & derivatives / Q000096:biosynthesis*; D005260:Female; D010535:Laparoscopy; D010532:Peritoneal Diseases / Q000209:etiology; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects; D011184:Postoperative Period; D011312:Pressure; D011817:Rabbits; D013997:Time Factors; D000267:Tissue Adhesions / Q000209:etiology
D002245:Carbon Dioxide; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost