The Effects of Hyperbaric Oxygen Treatment on the Healing of Tracheal Anastomosis Following Irradiation in Rats

Abstract

Background: After tracheal resection and end-to-end anastomosis, granulation tissue formation and stenosis along the anastomotic line are major problems. This experimental study in rats evaluated the effects of hyperbaric oxygen therapy on the healing of tracheal anastomosis after irradiation. Methods: Forty-four rats were divided into four groups: Group I (n = 12) underwent tracheal anastomosis after irradiation (30 Gy) and received hyperbaric oxygen treatment; Group II (n = 12) underwent tracheal anastomosis and received hyperbaric oxygen treatment; Group III (n = 11) underwent tracheal anastomosis after irradiation (30 Gy); and Group IV (n = 9) underwent only tracheal anastomosis. Hyperbaric oxygen treatment was administered at 2.5 atmospheres of absolute pressure once a day for 1 week. The rats were sacrificed 28 days after tracheal anastomosis. The cross-sectional area (CSA) of the tracheal lumen was compared between groups. Inflammation, fibrosis, epithelization, alveolar congestion and alveolar hemorrhage were evaluated by histological analysis. Results: The rats in all groups survived the study period, except for two in Group III which died from anastomotic dehiscence. Macroscopically, rats in the hyperbaric oxygen therapy groups showed excellent healing at the anastomosis. In these groups, CSA scores and epithelization were higher than in the other groups. There was local necrosis at the anastomosis in 3 rats in Group III. Fibrosis and alveolar congestion observed in Groups III and IV were significantly higher than in Groups I and II. Conclusion: This study suggests that hyperbaric oxygen treatment contributes to the healing of tracheal anastomosis following irradiation and may be a useful supportive treatment after tracheal resection and end-to-end anastomosis.