Comparison of autologous fat transfer in fresh, refrigerated, and frozen specimens: an animal model

The rising popularity of autologous fat transfer (AFT) has raised the questions whether cryopreserved adipocytes are a suitable substrate for soft-tissue augmentation, and which storage techniques may be most suitable for a maximally successful surgical result. An animal model of AFT was conceived using isogeneic Sprague-Dawley rats. Suction harvesting of fat and subcutaneous implantation was performed with specimens stored at -16 degrees C or 1 degrees C for a period of 1 or 2 weeks, as well as a group that underwent immediate implantation. A histological comparison of the experimental and control groups clearly demonstrated a decrease in viable adipocytes and an increase in signs of inflammation and fat cell necrosis in those animals that received stored fat instead of immediate fat implantation. These changes became more severe with increased length of storage and the use of refrigeration over freezing. The authors conclude that the practice of storing harvested adipocytes for later injection is not supported by the experimental evidence and should be avoided.