The Use of Higher Proportions of Platelet-Rich Plasma to Enrich Microfat Has Negative Effects: A Preclinical Study

Background: Platelet-rich plasma improves engraftment after fat transfer. However, the effects of platelet dose have never been investigated. The authors used magnetic resonance imaging to compare surviving graft volumes in mice after administration of four different formulations (microfat alone, and three platelet-rich plasma–enriched microfat mixes). Methods: The authors used a random, double-blinded, fat transfer protocol using three different platelet levels: 1 million (low-dose), 500 million (medium-dose), and 1000 million (high-dose) platelets/ml, and fat alone (control). The authors grafted 0.4 ml of the 70/30 platelet-rich plasma–enriched microfat mixtures (0.4 million, 200 million, and 400 million platelets per 0.12 ml for the low-dose, medium-dose, and high-dose mixtures, respectively) or 0.4 ml of microfat alone into 22 nude mice and monitored surviving graft volumes every month for 3 months. Then, the authors histologically analyzed all grafts to assess neoangiogenesis status and fat integrity. Results: Three-dimensional magnetic resonance imaging showed that the median surviving graft volumes at 3 months were 9.5 percent (interquartile range, 0 to 25 percent; p = 0.003) (high-dose), 4.1 percent (interquartile range, 0 to 18 percent; p = 0.001) (medium-dose), and 18 percent (interquartile range, 8 to 38 percent; p = 0.41) (low-dose) compared to 36 percent (interquartile range, 28 to 53 percent) for the control value. The histologic integrity of microfat-alone grafts was significantly better than those of the other grafts, although the high-dose and low-dose grafts exhibited higher levels of neoangiogenesis. Conclusion: Higher platelet levels in microfat grafts were associated with poor graft survival in nude mice; a clinical review would be appropriate.