Reappraisal of ischemia-reperfusion injury in laparoscopic surgery

Background: Serum biochemical changes during laparoscopic surgery and positive pressure pneumoperitoneum (PP) may reflect mild oxidative stress due to the ischemia-reperfusion (I/R) mechanism. However, there is still a controversy regarding the exact mechanism of PP in creating oxidative stress and whether the induction of PP causes I/R effects at all. To elucidate this debated issue, we studied, for the first time, the changes of I/R parameters in the serum, using a reliable, independent exogenous oxidative biomarker, together with common intrinsic biomarkers of oxidative stress. Patients and Methods: Our study included 20 patients scheduled for elective laparoscopic cholecystectomy. We evaluated the levels of the extrinsic and endogenous markers for oxidative stress during awareness, under anesthesia, the end of surgery (abdominal CO2 evacuation), and 2 hours afterward. Results: After an initial increase in oxidative stress following anesthesia, we did not notice any further significant rise in the levels of the synthetic exogenous and the endogenous biomarkers at the end of the surgery and 2 hours later on. However, a positive correlation was noted between the levels of both the intrinsic and extrinsic markers. Conclusions: In our study, the capability of the extrinsic biomarker to detect mild oxidative stress was not shown. Our study stresses the heterogeneous nature of the oxidative reactions and the diversity of the endogenous and exogenous biomarkers while detecting various biochemical patterns under mild oxidative stress, especially during the short period of laparoscopic surgery.