title: Morphological changes in hepatic vascular endothelium after carbon dioxide pneumoperitoneum in a murine model.
abstract: BACKGROUND
  Liver metastasis is an important prognostic factor in advanced colorectal cancer. Several studies have demonstrated that carbon dioxide (CO2) pneumoperitonem enhances liver metastasis in an animal model. In the present study, we used scanning electron microscopy (SEM) to investigate morphological changes in hepatic vascular endothelium after CO2 pneumoperitoneum in a murine model.
  
  
  METHODS
  Thirty-three male BALB/c mice were randomized to undergo pneumoperitoneum (CO2, air, or helium), open laparotomy, and anesthesia alone. After each procedure, the animals' livers were excised at days 0, 1, and 3 and examined by SEM.
  
  
  RESULTS
  In the CO2 pneumoperitoneum group, we observed rough surface and derangement of the hepatic vascular endothelial cells and intercellular clefts on day 1. In the other groups, no major morphologic changes were observed at any time.
  
  
  CONCLUSIONS
  Hepatic vascular endothelium changes after CO2 pneumoperitoneum. Such characteristic changes may play an important role in establishing liver metastasis after CO2 pneumoperitoneum.
authors.affiliation: Department of Surgery I, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Oita 879-5593, Japan. kizumi@med.oita-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Izumi
authors.forename: K
authors.initials: K
authors.lastname: Ishikawa
authors.forename: H
authors.initials: H
authors.lastname: Shiroshita
authors.forename: Y
authors.initials: Y
authors.lastname: Matsui
authors.forename: N
authors.initials: N
authors.lastname: Shiraishi
authors.forename: S
authors.initials: S
authors.lastname: Kitano
mesh_terms: D000138:Acidosis / Q000139:chemically induced / Q000473:pathology; D000388:Air; D000768:Anesthesia, General; D000818:Animals; D002245:Carbon Dioxide / Q000008:administration & dosage*; D004198:Disease Susceptibility; D042783:Endothelial Cells / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000293:injuries* / Q000648:ultrastructure; D006371:Helium / Q000008:administration & dosage; D006935:Hypercapnia / Q000139:chemically induced / Q000473:pathology; D007327:Insufflation; D007511:Ischemia / Q000209:etiology / Q000473:pathology; D007813:Laparotomy; D008099:Liver / Q000098:blood supply*; D008114:Liver Neoplasms, Experimental / Q000556:secondary; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects*; D011897:Random Allocation
chemical_list: D002245:Carbon Dioxide; D006371:Helium