Background: The aim of this study was to investigate the effect of low-pressure pneumoperitoneum and pentoxifylline, a methylxanthine derivative, in the prevention of injury caused by free oxygen radicals generated during CO₂ pneumoperitoneum. Methods: Twenty-eight rabbits were allocated randomly to 4 groups. Control group rabbits (group 1) were subjected to anesthesia for 60 min; group 2 and 3 animals were subjected to a CO₂ pneumoperitoneum (15 or 7 mm Hg); and group 4 rabbits received 50 mg/kg pentoxifylline, followed by a 15-mm-Hg pneumoperitoneum. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), lipid hydroperoxide, glutathione reductase and total antioxidant status were measured. Results: Compared with group 1, a significant increase in lipid hydroperoxide levels at the end of the pneumoperitoneum and 30 min after deflation and a significant decrease in total antioxidant status 24 h after deflation were recorded in group 2. In addition, a significant increase was observed in ALT, AST and LDH levels. These changes were attenuated by low-pressure pneumoperitoneum, whereas pentoxifylline pretreatment appeared to attenuate only transaminase levels. Conclusion: Low-pressure pneumoperitoneum could attenuate ischemia/reperfusion injury induced by CO₂ pneumoperitoneum in a rabbit model whereas pentoxifylline pretreatment appeared to attenuate only transaminase levels. Pentoxifylline did not prevent the development of oxidative stress.

Transient elevation of hepatic transaminases occurred after laparoscopic surgery, but they returned to normal values within 48 h. These increases were more prominent with higher and longer intra abdominal pressures irrespective of the type of insufflated gas. Alteration in aminotransferases was not associated with any clinical signs of hepatic dysfunction in experimental animals.