Synergistic effects of pentoxifylline and hyperbaric oxygen on skin flaps

This study investigated the effects of pentoxifylline and hyperbaric oxygen (HBO) on experimental skin flaps in rats under four conditions. Sixty animals were randomly divided into one of four groups: (1) a control group, (2) a pentoxifylline- or (3) an HBO-treated group, and (4) a pentoxifylline- plus HBO-treated group. Cranially based skin flaps were elevated on the dorsum. The surviving length was evaluated with fluorescein dye seven days after the operation. Rats that were treated with pentoxifylline received 20 mg/kg intraperitoneally at 24, 12, and 1 hour(s) before flap elevation and every 12 hours after the operation for seven days. Rats that were treated with HBO received a total of 14 two-hour treatments at 2.5 absolute atmospheres in divided doses. Results indicated that the surviving length of flaps in the pentoxifylline- or HBO-treated groups was significantly greater than those in the control group, but were not significantly different from each other. Animals treated with both pentoxifylline and HBO had significantly greater flap survival than animals in any of the other three groups. This reflected a 30% to 39% improvement over pentoxifylline alone- or HBO alone-treated animals, and an 86% improvement over control animals. Mechanisms of action for this apparent synergistic effect on flap survival are discussed.