Peritoneal mesothelial hypoxia during pneumoperitoneum is a cofactor in adhesion formation in a laparoscopic mouse model

Objective: To develop a laparoscopic mouse model to evaluate the hypothesis that mesothelial hypoxia during pneumoperitoneum is a cofactor in adhesion formation. Design: Prospective randomized trials. Setting: Academic research center. Animal(s): One hundred thirty female Naval Medical Research Institute (NMRI ) mice. Intervention(s): Adhesions were induced by opposing monopolar lesions in ut erine horns and pelvic side walls during laparoscopy and evaluated after 7 or 28 days under microscopic vision during laparotomy. The following pneumo peritoneum variables were assessed: duration (10 or 60 minutes), insufflati on. pressure (5 or 15 cm of water), insufflation gas (CO2 or helium), and a ddition of oxygen (0-12%). Main Outcome Measure(s): Adhesions were scored quantitatively and qualitati vely for extent, type, and tenacity. Result(s): Scoring of adhesions 7 or 28 days after laparoscopic, surgery wa s comparable. Adhesions increased with duration of pneumoperitoneum and wit h insufflation pressure and decreased with the addition of oxygen. Half-max imal reduction of adhesions was obtained at 1.5% oxygen, whereas a maximal reduction required only 2%-3%. The, effect of CO2 and helium was similar. Conclusion(s): These data demonstrate the feasibility of the intubated lapa roscopic, mouse model and confirm previous observations in rabbits, indicat ing that mesothelial hypoxia plays a key role in adhesion formation. (Ferti l Steril(R) 2001;76:560-7. (C) 2001 by American Society for Reproductive Me dicine).