Effects of supplemental perioperative oxygen on post-operative abdominal wound adhesions in a mouse laparotomy model with controlled respiratory support

BACKGROUND: Post-operative adhesion formation is a major clinical problem. Tissue oxygenation is one of the most important determinants in adhesion formation. The objective of this study was to investigate whether supplemental perioperative oxygen could reduce post-operative adhesion formation through increasing the peritoneal tissue oxygen tension (PitO(2)) in a mouse model. METHODS: Adult C57BJ6 mice were randomly assigned to two groups: Group 1 (n = 20), Fraction of Inspired Oxygen (FiO(2)): 0.21; Group 2 (n = 20), FiO(2): 0.80. On day 0, over the course of the 90 min procedure including the 60 min of laparotomy, PitO(2) was continuously monitored. On day 7, a second laparotomy was performed to assess abdominal wound adhesions. Real-time RT-PCR was performed to measure expression levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) mRNA in peritoneal tissues. RESULTS: The PitO(2) levels in Group 2 were significantly higher compared to Group 1 (P < 0.001) and controls (P < 0.003). There was no significant difference in the incidence of abdominal wound adhesions; however, the severity of adhesions was significantly reduced in Group 2 compared to Group 1 (P < 0.03). A significantly higher tPA/PAI-1 mRNA ratio was detected in Group 2 and the controls compared to Group 1 (P < 0.02 and P < 0.002, respectively). CONCLUSIONS: Supplemental perioperative oxygen may help to reduce post-operative adhesion formation.