Clinical Considerations on Contamination Rates of Cryopreserved Autologous Fat

Purpose: Autologous fat graft is a widely accepted technique used for soft tissue augmentation. Nonetheless, the use of fat graft is limited by unpredictable survival rates and repeated grafting. To avoid repeated grafting, cryopreserved fat graft technique has recently been widely used. On the other hand, the number of patients with chronic infection(who received cryopreserved fat injection) has currently been increasing. Therefore, this study was focused on the safety of cryopreserved fat injection from the infection. Methods: We collected 150 samples from local aesthetic clinics to examine the safety of cryopreserved autologous fat. To test for microbacterial contaminations of the cryopreserved fat specimens, microbacterial cultures & antibiotics sensitivity tests were performed. Then, we examined possible correlation between the preservation period and donor sites, focused on the results of microbacterial culture. Results: Cultures were positive for Staphylococcus epidermidis in 5 samples(methicillin - resistant Staphylococcus epidermidis in 4 samples), Micrococcus species in 3 samples. An average duration of preservation was 191 days and there was no significant correlation between the duration of preservation and microbacterial growth. Conclusion: Staphylococcus epidermidis was the leading cause of cryopreserved fat contamination, and the resistance to methicillin is common. Based on the above results, aseptic handling of fat during harvesting and preservation appeared to be most important.

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