Gas- und druckabhängige Auswirkung des Pneumoperitoneums auf die abdominelle Wundheilung am Kleintiermodell

The aim of this randomised study in the animal model was to explore possible gas- and pressure-dependend effects of pneumoperitoneum on abdominal wound healing. Carbon dioxid (CO2) and helium were analyzed using two different animal adapted pressure levels in comparison to controls (no pneumoperitoneum). Altogether, 78 Sprague-Dawley rats were randomized to 10 examination groups. Postoperative wound healing was assessed clinically. The animals were killed after 5 and 10 days, and the abdominal wall was explanted for subsequent histopathologic examinations of the laparotomy wound. The granuloma formation in hematoxylin and eosin-stained sections was analyzed. Infiltration of macrophages (CD68) and expression of matrix metalloproteinase 13 (MMP-13) were examined by immunohistochemistry. The collagen type 1 to type 3 ratio was investigated by cross-polarization microscopy after Sirius Red staining. Clinically, no differences were found with regard to postoperative wound healing between groups. After 5 and 10 days, the percentages of CD68-positive cells and granuloma formation did not differ between the groups. In contrast, after both 5 and 10 days, the expression of MMP-13 and the collagen 1 to 3 ratio were higher after helium pneumoperitoneum than in the control animals. These differences were statistically significant after 5 days. Different pressure levels had no impact on wound healing parameters. In conclusion, our comparative investigation of the insufflation gases CO2 and helium showed no marked influence of pneumoperitoneum on abdominal wound healing