ABSTRACT
The objectives of this study sere to investigate how the local irradiation affect the survival of random pattern skin flap, and whether or not hyperbaric oxygen and allopurional can improve the survival of the irradiated rat skin flap. There have been many reports about the effects of hyperbaric oxygen and allpurinol on skin flaps. However, very few reports have been presented on the effects of hyperbaric oxygen and allpurinol in treating irradiated skin flaps. The author examined the local irradiation effect on rat skin flap survival after irradiation of 20 Gy, 3 days postoperatively, on cranially based random pattern dorsal skin flap, which was 3 x 9cm in size. The flap survival length was measured in experimental groups treated with hyperbaric oxygen (2.5 atm absolute, 100% oxygen, once a day for 7days) after irradiation and with hyperbaric oxygen combined with allopurinol (100mg/kg, once a day for 7 days), in comparison with a radiation-only group. On reviewing the flap survival length 10 days postoperati-vely, the average flap survival length in the radiation-only group was 2.2+/-0.5cm, while in the non-radiation group it was 5.5+/-0.3cm. The reduction ratio of flap survival by irradiation was 60%. There was a significant increase in the mean flap survival length in the groups treated with hyperbaric oxygen (4.0+/-1.6cm) and hyperbaric oxygen combined with allopurinol (5.5+/-1.8cm). The increased ratio of flap survival in each group was 85% and 150% when compared to the radiation-only group. The author found that rat skin flap survival decreased, even at an early stage, as a result of high dose local irradiation and that decreased flap survival by irradiation could be restored by hyperbaric oxygen and allopurinol. The group treated with hyperbaric oxygen combined with allopurinol showed increased flap survival over the group treated with hyperbaric oxygen only. The results showed a method which could possibly increase flap survival in cancer patients who require early radiation after flap surgery.