title: The fate of nonvascularized fat grafts: histological and bioluminescent study.
abstract: BACKGROUND
  Nonvascularized fat grafting has become one of the most popular options for breast contouring. However, the survival process of the grafts remains to be elucidated. In this study, we tracked the fate of nonvascularized fat grafts with in vivo bioluminescence and immunohistochemistry.
  
  
  METHODS
  Nonvascularized fat grafts or vascularized adiposal flaps from luciferase transgenic rats were transplanted to Lewis rats. The bioluminescent signals from the grafts were monitored longitudinally. In addition, nonvascularized fat grafts from Lewis rats were engrafted to Lewis rats and the viability of the adipocytes in the grafts was evaluated with immunohistochemical staining for perilipin at postoperative week 1, 2, 3, 4, and 6.
  
  
  RESULTS
  The bioluminescent signals from the nonvascularized fat grafts increased drastically from postoperative day 3 to 7, stayed flat from day 7 to 12, and declined from day 12 to 17, whereas those from the vascularized fat flaps remained throughout the entire postoperative period. Immunohistochemistry revealed that the survival zones with large adipocytes were decreased within 2 weeks and the regenerating zones with small adipocytes appeared after 3 weeks.
  
  
  CONCLUSIONS
  Our study showed the process of survival and regeneration of nonvascularized fat grafts and suggested that graft-derived stromal cells proliferated within 7 days after transplantation and differentiated into adipocytes after postoperative week 3.
authors.affiliation: Department of Plastic Surgery, Jichi Medical University, Shimotsuke, Tochigi, Japan; and Division of Advanced Treatment, Center for Development of Advanced Medical Technology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Ataru
authors.initials: A
authors.lastname: Sunaga
authors.affiliation: Department of Plastic Surgery, Jichi Medical University, Shimotsuke, Tochigi, Japan; and Division of Advanced Treatment, Center for Development of Advanced Medical Technology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sugawara
authors.affiliation: Department of Plastic Surgery, Jichi Medical University, Shimotsuke, Tochigi, Japan; and Division of Advanced Treatment, Center for Development of Advanced Medical Technology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Katsuragi-Tomioka
authors.affiliation: Department of Plastic Surgery, Jichi Medical University, Shimotsuke, Tochigi, Japan; and Division of Advanced Treatment, Center for Development of Advanced Medical Technology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kobayashi