The effect of laparoscopic pre- and postconditioning on pneumoperitoneum induced injury of the peritoneum

Pneumoperitoneum, widely used in laparoscopic surgery increases the intraabdominal pressure, leading to hypoperfusion of the abdominal organs, and promoting the buildup of reactive oxygen species(ROS) and inflammatory cytokines which in turn impairs the body postoperatively. Aim of our investigation was to evaluate the potential protective effects of short ischemic episodes on ischemic damages.

70 Wistar rats were used, divided into 7 groups: 1st group sham, 2nd group pneumoperitoneum with 5 mmHg, 3rd group preconditioning with 5 mmHg, 4th group: postconditioning with 5 mmHg, 5th group pneumoperitoneum with 10 mmHg, 6th group: preconditioning with 10 mmHg, 7th group postconditioning with 10 mmHg. Pneumoperitoneum was created by Veres needle. Oxidative stress parameters: malondialdehyde (MDA) concentration, reduced glutathione (GSH), sulfhydril (SH-), myeloperoxidase (MPO) levels and superoxide-dismutase (SOD) activity were measured. We measured TNF-α and IL-6 concentrations. We monitored the activation of anti- and proapoptotic common signaling pathways (bax, bcl-2, p53) during the early phase of reperfusion. Histology was made from kidney samples.

GSH concentrations were significantly reduced, MDA concentrations were significantly higher in each group compared to the Sham. SOD enzyme: a pressure of 10 mmHg elicited significantly greater damage than 5 mmHg. There was a significantly higher SOD activity in group 10 mmHg IPC compared to 10 mmHg. We found that the expression of bax was considerably higher in the none conditioned groups. Noticeably higher expression of anti-apoptotic bcl-2 level was measured in 10 mmHg IPC and 10 mmHg IPoC groups. In case of p53 expression: significant decrease could be seen in groups 10 mmHg IPC and 10 mmHg IPoC compared to the 10 mmHg group.

Based on our results, the elevated intraabdominal pressure due to pneumoperitoneum induces oxidative stress, which is dependent on the applied pressure. Mostly precondiotioning - but also postconditioning - reduces surgical stress following laparoscopic procedures. In order to explore its mechanism it requires further investigations.