[A scanning microscopy study of the peritoneum in mice after application of a CO2-pneumoperitoneum]

The application of a CO2-pneumoperitoneum in operative laparoscopy presumably leads to basic alterations of the intraperitoneal homeostasis. In order to better understand the pathophysiology of this phenomenon, the morphologic alterations of the mesothelium after CO2-application will be examined.In 36 mice (C 57, black mice) a CO2-pneumoperitoneum with an intraperitoneal pressure of 6 mm Hg was applied for 30 minutes. After 1, 2, 6, 12, 24, 48, 72 and 96 hours each of 4 animals were killed and the entire peritoneum was examined by scanning electron microscopy.Already after 1 hour mesothelial cells became cuboidal, were detached and showed condensation. After 2 hours this initial reaction reached its peak; immature cells then attached to the free basal membrane. After 96 hours the entire mesothelium was regenerated.The morphologic integrity of the mesothelium is temporarily disturbed by a CO2-pneumoperitoneum. Reasons for this phenomenon may be either the abdominal pressure or a CO2-induced surface acidosis. In further studies, the influence of the described phenomena on intraperitoneal formation of metastases will be examined.