Effects of Heated Pneumoperitoneum on Inflammation, Oxidative Stress, and Peritoneal Histology in Female Dogs That Underwent Video-Assisted Ovariohysterectomy.

Laparoscopic procedures require the creation of pneumoperitoneum. CO, which must be cold and dry, is the standard gas used in such surgeries. The type of gas used, its temperature, and moisture may change the peritoneal surface and cause systemic and local oxidative stress. Our objective is to evaluate the influence of pneumoperitoneum heating on the occurrence of histological lesions in the peritoneum, inflammation, plasma oxidative stress, and on the mesothelial surface in patients undergoing video-assisted ovariohysterectomy. Twenty canine females were included and distributed evenly into two groups: heated CO (HG) and unheated CO (UHG). The biomarkers of inflammation and oxidative stress were evaluated before insufflation (0), at 30 min (1), and at 60 min (2) of exposure to CO. Biopsies of the peritoneal tissue for histological evaluation were performed at 0 and 2. Regarding plasma parameters, acetylcholinesterase (AChE) showed a greater activity in the HG at 1 (=0.0268) and 2 (=0.0423); in turn, butyrylcholinesterase (BChE) showed a greater activity at 2 in the HG (=0.0175) compared with 0. Catalase activity (CAT) was different between HG times; it was higher at 1 (=0.0253). There was a decrease in the levels of substances reactive to thiobarbituric acid (TBARS) (=0.0117) and in glutathione (GSH) (=0.0114) between 0 and 2 in the UHG. Regarding tissue oxidative stress, the CAT in the HG showed a greater activity at 2 than 1 (=0.0150). By comparing the groups at each time, there was a difference only at 2 (=0.0288), being greater in the HG. Regarding the activity of superoxide dismutase (SOD) in the HG, there was a difference between 2 in relation to 0 and 1 (=0.0181); finally, there was an increase only at 1 (=0.0287) in the UHG when comparing groups at the same time. There were no differences in the histological parameters evaluated. Our study demonstrates that the heating of CO generates a greater inflammatory response and forms reactive oxygen species (ROS) at the plasma and peritoneal levels.