title: Normobaric hyperoxygenation enhances initial survival, regeneration, and final retention in fat grafting.
abstract: BACKGROUND
  Fat grafting is a promising modality for soft-tissue augmentation/reconstruction. However, grafted fat tissue is not initially perfused and relies on plasmatic diffusion from the recipient bed until revascularization occurs. The authors evaluated the therapeutic effects of normobaric hyperoxygenation for enhancing fat graft retention.
  
  
  METHODS
  Aspirated human fat tissue was cultured under tissue hypoxia (1% oxygen), normoxia (6%), and hyperoxia (20%) levels, and evaluated for adipocyte viability. Inguinal fat pads were autografted under mouse scalps (n=36), and mice were housed in either 20% (control) or 60% (normobaric hyperoxygenation) atmospheric oxygen for the first 3 days, and then returned to normoxia. Samples harvested at 0, 1, 2, 4, 8, and 12 weeks were analyzed immunohistochemically for adipocyte viability and regeneration.
  
  
  RESULTS
  Organ culture adipocytes died more quickly under lower oxygen tensions; thus, hyperoxygenation of recipient tissues may delay adipocyte death after fat grafting. Autografted mouse adipose tissue underwent dynamic remodeling, from ischemic degeneration to partial regeneration, over 12 weeks. Normobaric hyperoxygenation grafted samples showed significantly larger survival zones and engraftment scores (calculated using sample weight and adipocyte viability) at 1 and 12 weeks, respectively, than control samples. In addition, adipocyte regeneration (number of perilipin-positive preadipocytes), which peaked at 4 weeks, was significantly increased in normobaric hyperoxygenation samples.
  
  
  CONCLUSIONS
  The normobaric hyperoxygenation protocol using 60% oxygen can be safely applied to enhance adipocyte survival, regeneration, and final engraftment after fat grafting.
authors: Tokyo, Japan From the Department of Plastic Surgery, University of Tokyo School of Medicine.
authors: Harunosuke
authors: H
authors: Kato
authors: Jun
authors: J
authors: Araki
authors: Kentaro
authors: K
authors: Doi
authors: Shinichiro
authors: S
authors: Kuno
authors: Kahori
authors: K
authors: Kinoshita
authors: Kazuhide
authors: K
authors: Mineda
authors: Koji
authors: K
authors: Kanayama
authors: Kotaro
authors: K
authors: Yoshimura
mesh_terms: D017667:Adipocytes / Q000637:transplantation*; D000328:Adult; D000818:Animals; D064592:Autografts; D002470:Cell Survival / Q000502:physiology*; D004195:Disease Models, Animal; D005260:Female; D006085:Graft Survival; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D011897:Random Allocation; D012038:Regeneration / Q000502:physiology; D012680:Sensitivity and Specificity; D020858:Tissue and Organ Harvesting