title: Effects of hyperbaric oxygen preconditioning on ischemia-reperfusion inflammation and skin flap survival.
abstract: BACKGROUND
  Hyperbaric oxygen preconditioning (HBO) is a new method of ischemia preconditioning. In this study, we examined its effects on skin flap survival and the mechanisms involved.
  
  
  METHODS
  Thirty-six rats were divided into three groups: HBO preconditioning, control, and sham groups. An extended epigastric adipocutaneous flap based on the right superficial epigastric artery and vein was raised. A 3-hour period of flap ischemia was induced by clamping the pedicle vessels with a microvascular clamp. At the end of ischemia induction, the clamp was removed and the flap was resutured. Rats in the HBO preconditioning group were treated with HBO four times before surgery. Microcirculation in the skin flap was measured on postoperative days 1, 3 and 5. The size of the flap was measured on postoperative day 5, before the animals were sacrificed. Samples of the skin flap were prepared and stained with hematoxylin and eosin. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in the flap samples were measured.
  
  
  RESULTS
  Surviving flap size was significantly higher in the HBO preconditioning group compared with controls, with a reduced inflammatory response and increased perfusion. IL-1, TNF-α, and IL-6 levels in the HBO preconditioning group were lower than in controls.
  
  
  CONCLUSIONS
  HBO preconditioning improved flap survival in this ischemia-reperfusion rat model. The mechanisms responsible for this effect may relate to attenuation of the inflammatory response and increased flap perfusion following HBO preconditioning.
authors.affiliation: Department of Plastic Surgery, Peking Union Medical College Hospital, Beijing 100032, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Qi
authors.forename: Chun-jin
authors.initials: CJ
authors.lastname: Gao
authors.forename: You-bin
authors.initials: YB
authors.lastname: Wang
authors.forename: Xue-mei
authors.initials: XM
authors.lastname: Ma
authors.forename: Ling
authors.initials: L
authors.lastname: Zhao
authors.forename: Fu-jia
authors.initials: FJ
authors.lastname: Liu
authors.forename: Xue-hua
authors.initials: XH
authors.lastname: Liu
authors.forename: Xue-jun
authors.initials: XJ
authors.lastname: Sun
authors.forename: Xiao-jun
authors.initials: XJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D006085:Graft Survival; D006931:Hyperbaric Oxygenation / Q000379:methods*; D007511:Ischemia / Q000601:surgery*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin; D013524:Surgical Flaps