Local and systemic impact of pneumoperitoneum on prepuberal rats

Pneumoperitoneum (PN) and the gas used to insufflate the abdominal cavity during laparoscopy seem to be responsible for local and systemic modifications. The aim of this study was to verify the effects of intra-abdominal carbon dioxide (CO(2)) and air insufflation on the peritoneum, as well as the cortico-surrenal response in prepuberal rats. Sixty prepuberal rats were divided into three groups: in the first (S, n = 36), PN was induced with CO(2), whereas in the second (A, n = 14), it was induced with filtered room air; in both conditions, insufflation lasted 30 min at a pressure of 10-12 mmHg. The third group (C, n = 10), underwent general anesthesia only. Two hours after inducing anaesthesia, 12 rats in group S, 6 in group A and 6 in group C were killed and the remaining, after 24 h; specimens of the visceral and the parietal peritoneum were obtained for histological examination, blood sample was taken for cortisol and DHEA-S assays at the different study periods. At the histological examination performed 2 h later, the groups S and A presented inflammatory cell infiltrate in the parietal and visceral peritoneum; this finding was even more marked in group A, which presented also congestion, hemorrhage and disruption of the cell line. Twenty-four hours after the experiment, the peritoneum of the two insufflated groups presented chronic infiltrate and reactive mesothelial cells with congestion, which was more evident in group A, but totally absent in group C. Cortisol levels were significantly higher in groups S and A (2.15:1 ratio) killed 2 h later compared to those killed 24 h later and to the control group. DHEA-S levels were not significantly different between the groups. Our results demonstrate that the chemical, physical and molecular impact of CO(2) on the peritoneum causes inflammation and tissue damage, this was even more evident 24 h after our experiment and in the air insufflated group. PN induced a significant variation in blood cortisol levels at 2 h. The CO(2) insufflation should be limited in patients with pre-existing peritoneal damage.