The effects of hyperbaric oxygen on normal and ischemic colon anastomoses

BACKGROUND: Leakage from colonic anastomoses is a major complication causin g increased mortality and morbidity, and ischemia is a well-known cause of this event. Inadequate tissue oxygenation could be reversed by using hyperb aric oxygen. This study was designed to investigate the effects of hyperbar ic oxygen on the healing of ischemic and normal colon anastomoses in the ra t model. METHODS: Standardized left colon resection 3 cm above the peritoneal reflec tion and colonic anastomosis were performed in 40 Wistar rats divided into four groups. The control group (I) received no further treatment To mimic i schemia, 2 cm mesocolon was ligated on either site of the anastomosis in gr oup II and IV rats. Hyperbaric oxygen therapy was started immediately after surgery in group III and IV rats (therapeutic groups). All animals were sa crificed on the fourth postoperative day. After careful relaparotomy, in si tu bursting pressure was measured. The hydroxyproline contents of the anast omotic segments in equal length were determined. RESULTS: The hydroxyproline assay revealed that rats in group II with ische mic colonic anastomosis have significantly lower levels (P <0.05), The high est levels are in the group III rats with normal colonic anastomosis treate d by hyperbaric oxygen (P <0.05). There was no significant difference in hy droxyproline levels between group II and group IV animals (P >0.05). Group III animals had significantly higher bursting pressures than any other grou p (P <0.05). Group II rats had lowest bursting pressures (P <0.05). Group I V animals had significantly higher levels than group II (P <0.05). Mean bur sting pressure values both in groups III and IV and hydroxyproline levels i n group III were significantly increased by hyperbaric oxygen therapy (P <0 .05). CONCLUSIONS: Ischemia impairs anastomotic healing. Hyperbaric oxygen increa ses anastomotic healing of both normal and ischemic colonic anastomosis and reverses ischemic damage. This study demonstrated that hyperbaric oxygen i mproves anastomotic healing. Am J Surg, 1998; 176:458-461, (C) 1998 by Exce rpta Medica, Inc.