Does CO₂ pneumoperitoneum in laparoscopy interfere with collagen deposition in abdominal surgical wounds?

Purpose: To determine by histomorphometric analysis whether CO₂ pneumoperitoneum interferes with collagen deposition in surgical wounds in the aponeurosis of rats. Methods: This experiment involved 80 male Wistar rats, randomly allocated into four groups according to pneumoperitoneum period (PRE: 30 min preoperatively; POST: 30 min postoperatively; PP: 30 min pre-and postoperatively; C: control group). CO₂ pneumoperitoneumwas insufflated to 5 mmHg of pressure. A laparotomy was performed; 1 cm of the left colon was then resected, and an end-to-end anastomosis was performed to simulate surgical trauma, after which the abdominal wall was closed. On postoperative days 7 or 14, a sample of the abdominal wall was collected, stained with picrosirius red and observed under polarized light in an optical microscope. The amount of collagen was estimated by computerized histomorphometric analysis. Results: There were no significant differences in collagen deposition between the control and experimental groups on postoperative days 7 (p=0.720) or 14 (p=0.933). The amount of collagen increased as expected in all groups between postoperative days 7 and 14 (p=0.0003). Conclusion: At 5 mmHg, CO₂ pneumoperitoneum does not interfere with collagen deposition in abdominal wall surgical wounds in rats.