Ischemic preconditioning decreases laparoscopy-induced oxidative stress in small intestine

BACKGROUND/AIMS: Laparoscopy is advantageous but its adverse effects have not yet been completely elucidated. Pneumoperitoneum performed to facilitate laparoscopy causes the organ perfusion decrease such as in the intestine. Oxidative stress reflects the tissue injury related to ischemia and reperfusion. We previously showed that laparoscopy causes oxidative stress in intestinal tissues. To assess whether the preconditioning phenomenon could be taken advantage of during laparoscopy we designed this randomized, controlled, experimental study with blind outcome assessment. We evaluated the effect of preconditioning, including sequential periods of pneumoperitoneum and desufflation on laparoscopy-induced tissue injury of small bowel with the help of two important markers of oxidative stress, thiobarbituric acid reactive substances and reduced glutathione. METHODOLOGY: Forty Sprague-Dawley male rats were used. After anesthesia, an intraperitoneal catheter was inserted. Pneumoperitoneum was created in all except controls, by CO2 insufflation under a pressure of 15 mmHg. The rats were randomized into the groups below: Group P was subjected to 60 minutes of pneumoperitoneum; Group P/D was subjected to 60 minutes of pneumoperitoneum followed by 45 minutes of desufflation; Group IP + P was subjected to 10 minutes of pneumoperitoneum, 10 minutes of desufflation and 60 minutes of pneumoperitoneum; Group IP + P/D was subjected to 10 minutes of pneumoperitoneum, 10 minutes of desufflation, 60 minutes of pneumoperitoneum and 45 minutes of desufflation; Group C (Control) was subjected to a sham operation, without pneumoperitoneum. Small bowel tissue malondialdehyde and reduced glutathione activities were measured, as applicable, by investigators blinded to the study design. The results were decoded and statistically analyzed with Kruskal-Wallis test. Mann-Whitney U test was used to compare the paired groups. p < 0.05 was considered significant. RESULTS: Small bowel tissue malondialdehyde levels were increased, whereas glutathione values were decreased in Groups P and P/D, as compared to Groups PRE/P and PRE/P/D; the latter two groups had results similar to the Control Group. CONCLUSIONS: Laparoscopic preconditioning may reduce the oxidative injury in intestine following laparoscopic procedures.