title: Application of normobaric hyperoxygenation to an ischemic flap and a composite skin graft.
abstract: BACKGROUND
  Hyperbaric oxygenation has been used for various purposes, but its clinical application is limited due to its pulmonary toxicity. We evaluated the therapeutic value of normobaric hyperoxygenation (NBO) for vascularized and nonvascularized tissue transplantation.
  
  
  METHODS
  Tissue oxygen partial pressure (PtO2) was measured for various organs in mice under inspiratory oxygen of 20%, 60%, or 100%. A rectangular skin flap (1 × 4 cm) or a composite skin graft (2 × 2 cm) was made on the back of mice, which were housed under 20% or 60% oxygen for the first 3 days after surgery. Cell survival was also examined in organ culture skin samples.
  
  
  RESULTS
  PtO2 varied among tissues/organs, but increased depending on inspiratory oxygen concentration in all tissues/organs. Although NBO with 100% O2 was toxic, NBO with 60% O2 was safe even when used continuously for a long period. NBO did not significantly improve survival of the rectangular skin flap. On the other hand, in the composite skin graft model, the engraftment area increased significantly (52 ± 10 at 20% vs 68 ± 5.1 at 60%) and contraction decreased significantly (42 ± 8.0 at 20% vs 27 ± 5.7 at 60%). Organ culture of a composite skin sample showed significant cell death under lower oxygen concentrations, supporting the data in vivo.
  
  
  CONCLUSIONS
  The composite graft was maintained until revascularization by plasmatic diffusion from surrounding tissues, in which PtO2 was improved by NBO. NBO may be an effective adjunct therapy that can be performed readily after nonvascularized tissue grafting.
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Araki
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Harunosuke
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Doi
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kuno
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Kahori
authors.initials: K
authors.lastname: Kinoshita
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Mineda
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kanayama
authors.affiliation: Department of Plastic Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Yoshimura