Short period of preconditioning protects by decreasing the TNF-alpha and IL-6 values before laparoscopic surgery (a rat experiment)

Background: Laparoscopy produces ischemia reperfusion injury mediated by inflammatory cytokines. Preconditioning is a protective maneuver in laparoscopic surgery; however, there is an argument in the literature about the length and number of the preconditioning sequence(s), thus the present study evaluates the effects of short (5 min) and long (10 min) periods of preconditioning on laparoscopy-induced inflammatory response.
Material and Method: Thirty-two rats were enrolled into 4 groups: control, laparoscopy, 5 min preconditioning and 10 min preconditioning groups, each containing 8 rats. Laparoscopy was performed by application of 60 min of pneumoperitoneum with 15 mmHg. The preconditioning maneuvers were performed before laparoscopy in respective groups. Following the cessation of experiment blood samples were obtained to determine the TNF-alpha and IL-6 levels.
Results: Laparoscopy produced significantly increased levels of plasma TNF-alpha and IL-6 values as compared to the sham group. Five min preconditioning caused significant decrease in plasma TNF-alpha and IL-6 values compared to laparoscopy group. Although 10 min preconditioning caused partially decreased levels of TNF-alpha and IL-6 values, they were still higher than that of the 5 min preconditioning group.
Conclusions: Preconditioning maneuvers longer than 5 min lose protective activity and begin to produce ischemia reperfusion injury. We found that 5 min of inflation followed by 5 min of deflation seems to protect against subsequent post-laparoscopic inflammatory response. Thus it is advisable not to use any preconditioning maneuvers longer than 5 min in order to avoid increasing the operation and anesthesia times.

Keywords: Time Factors, Rats, Rats, Sprague-Dawley, Laparoscopy, Ischemic Preconditioning, Interleukin-6 - metabolism, Animals, Tumor Necrosis Factor-alpha - metabolism