title: Studies in fat grafting: Part III. Fat grafting irradiated tissue--improved skin quality and decreased fat graft retention.
abstract: BACKGROUND
  Following radiation therapy, skin becomes fibrotic and can present a difficult problem for reconstructive surgeons. There is an increasing belief that fat grafting under irradiated skin can reverse the damage caused by radiation. The present study evaluated the effect of fat grafting on irradiated skin, along with fat graft quality and retention rates in irradiated tissue.
  
  
  METHODS
  Nine adult Crl:NU-Foxn1 CD-1 mice underwent 30-Gy external beam irradiation of the scalp. Four weeks after irradiation, scalp skin from irradiated and nonirradiated mice was harvested and compared histologically for dermal thickness, collagen content, and vascular density. Human fat grafts were then injected in the subcutaneous plane of the scalp. Skin assessment was performed in the irradiated group at 2 and 8 weeks after grafting, and fat graft retention was measured at baseline and every 2 weeks up to 8 weeks after grafting using micro-computed tomography. Finally, fat graft samples were explanted at 8 weeks, and quality scoring was performed.
  
  
  RESULTS
  Fat grafting resulted in decreased dermal thickness, decreased collagen content, and increased vascular density in irradiated skin. Computed tomographic analysis revealed significantly decreased fat graft survival in the irradiated group compared with the nonirradiated group. Histologic scoring of explanted fat grafts demonstrated no difference in quality between the irradiated and nonirradiated groups.
  
  
  CONCLUSIONS
  Fat grafting attenuates dermal collagen deposition and vessel depletion characteristic of radiation fibrosis. Although fat graft retention rates are significantly lower in irradiated than in nonirradiated tissue, the quality of retained fat between the groups is similar.
authors: Stanford, Calif. From the Hagey Laboratory for Pediatric Regenerative Medicine, Plastic and Reconstructive Surgery Division, Department of Surgery, Stanford University School of Medicine; and the Institute for Stem Cell Biology and Regenerative Medicine, Stanford University.
authors: Rebecca M
authors: RM
authors: Garza
authors: Kevin J
authors: KJ
authors: Paik
authors: Michael T
authors: MT
authors: Chung
authors: Dominik
authors: D
authors: Duscher
authors: Geoffrey C
authors: GC
authors: Gurtner
authors: Michael T
authors: MT
authors: Longaker
authors: Derrick C
authors: DC
authors: Wan
mesh_terms: D000328:Adult; D000818:Animals; D005260:Female; D006085:Graft Survival; D006801:Humans; D051379:Mice; D017063:Outcome Assessment, Health Care; D012535:Scalp / Q000000981:diagnostic imaging / Q000473:pathology / Q000528:radiation effects / Q000601:surgery*; D012867:Skin / Q000000981:diagnostic imaging / Q000473:pathology / Q000528:radiation effects*; D050151:Subcutaneous Fat / Q000637:transplantation*; D014057:Tomography, X-Ray Computed