Long-term fate of transplanted autologous fat in a novel rabbit facial model

Background: The concept of fat transplantation is not a new one in plastic surgery. Studies assessing fat graft viability following transplantation, however, have yielded conflicting observations. The present study evaluated the long-term fate of transplanted autologous fat using a novel facial augmentation model the authors have developed in the rabbit. Methods: Thirteen adult New Zealand White rabbits underwent fat harvest using a modified Coleman technique. The left upper lip was used as the recipient site; the right upper lip remained unaltered in each case. After harvest from the groin, 1 ml of adipose tissue was transplanted to the left upper lip of each rabbit. Rabbits were euthanized 1, 3, 6, and 12 months after unilateral lip augmentation. Coronal sections of both upper lips were evaluated histologically; the right tipper lip served as an internal control in each case. Results: Histologic evaluation of specimens harvested at all postoperative time points demonstrated viable, transplanted fat graft in each case. Use of the nonoperated right lip allowed for paired evaluation of the experimental and control sides. A significant inflammatory response was present in the early phases, with evidence of neovascularization. Transplanted fat tissue was clearly visible in rabbits harvested 1 year postoperatively. Conclusions: The authors have established a novel, reproducible model with an internal control for long-term evaluation of transplanted fat. Histologic examination suggests ail early inflammatory response to the injected fat followed by sequestration of nonviable tissue. The transplanted fat remained viable at 1 year, with good overall survivability and minimal fibrosis.