Evaluation of Centrifugation Technique and Effect of Epinephrine on Fat Cell Viability in Autologous Fat Injection

Background: Centrifugation helps refine autologous fat for use as an injectable filler, but the process can be injurious to fat cells. Epinephrine may be harmful to fat cells. Objective: We studied the effects of different centrifugation levels and epinephrine dosages on fat cell viability. Methods: Autologous fat was obtained from 8 patients who underwent lipoplasty, and the fat samples were centrifuged for 1, 3, and 5 minutes at 1500, 3000, and 5000 revolutions per minute (RPM), respectively, with uncentrifuged fat used as a control. Fat was also obtained from 8 patients undergoing autologous fat injection who had received anesthesia in a mixture of Hartman solution and a 2% lidocaine solution. The samples were mixed with epinephrine at ratios of 1:100,000, 1:200,000, and 1:400,000; a sample without epinephrine served as a control. The samples were centrifuged at 3000 RPM for 3 minutes. Fat cell viability for both experiments was evaluated by the number of surviving cells. Results: Cell survival rates were significantly lower for the groups centrifuged at 1500 and 3000 RPM for more than 5 minutes and for the group centrifuged at 5000 RPM for more than 1 minute. There was no significant difference in survival rates among the samples mixed with different ratios of epinephrine. Conclusions: Centrifugation with 3000 RPM for 3 minutes is recommended. The effect of epinephrine on fat cell viability is negligible.