Effects of platelet-RİCH plasma infiltration to donor area on harvested fat grafts

Introduction: Fat grafting is a frequently performed procedure in plastic surgery. There are numerous studies conducted with the goal of increasing the survival rate of an existing fat graft at the recipient area. In our research, we have discovered that stimulating the fat tissue at the donor area with biological auxiliary factors and putting it through the priming process prior to harvesting for the purpose of boosting the survival rate of the graft weren't in the literature. In our study, the purpose was to reveal the changes caused by the infiltration of platelet-rich plasma (PRP) to the donor area as well as its effect on the survival rate of fat grafts in rats, using various parameters. Method: In the study, a total of 30 Sprague-Dawley rats weighing between 300 and 350 grams were used, dividing them into random groups of 6, for a total of 4 groups. 6 rats were used for PRP preparation. The control group was administered saline solution and the study group was administered PRP. After the administration, half of the control and PRP groups were sacrificed in the 1st week by harvesting fat grafts from their left inguinal fat pads, The same procedure was repeated for then 2nd half in the 2nd week. The harvested fat graft samples were evaluated via histological (evaluation of the histological appearance of the fat tissues, inflammation status, fibrotic changes, health and number of vessels via light microscope examination and immunohistochemistry) and biochemical analysis (Measurement of IL-1β, IL-6, TNF-α, EGF, VEGF, CK18-M30, TAS and TOS levels using ELISA kits). For statistical analysis, Shapiro-Wilk, Student t and Mann Whitney U tests were used in SPSS Windows Version 24.0 package program. A value of p<0.05 was considered statistically significant. Results: In our study, the levels of proinflammatory markers such as IL-1β, IL-6, TNF-α, were determined to be significantly lower in both the 1st and 2nd weeks in the PRP group compared to the control group (p<0.05). VEGF and EGF levels were determined to be higher both in the 1st and 2nd weeks in the PRP group compared to the control group (p<0.05). CK18-M30 levels were determined to be significantly lower in the PRP group compared to the control group both in the 1st and 2nd weeks (p<0.05). TOS values of the control group were determined to statistically be significantly higher than the PRP group in the 1st week (p=0.002). However, TOS values observed in the 2nd week were determined to be similar in the two groups (p=0.180). TAS values of the PRP group were determined to statistically be significantly higher than those of the control group for both weeks (p<0,05). TOS values of the control group were determined to statistically be significantly higher than the PRP group for both weeks (p=0.05). In histological examination, sections performed on the fat tissues of the PRP group were observed to contain more vessels compared to the control group in the 1st week Upon sectioning the fat tissues of the 1st week's PRP group, fat tissue areas with less degeneration and surrounding necrosed areas were observed compared to the control group. No inflammatory cell infiltration with signs of inflammation was observed. Compared to the control group, fibrotic connective tissues were observed at more limited and fewer areas. In the 2nd week, upon sectioning the fat tissues of the PRP group, the healthy fat tissue was noted to have decreased and the areas of necrosed tissue to have increased. Presence of fibrotic connective tissues was observed; however, there wasn't as significant an increase as that of the 2nd week's control group. No inflammatory cell infiltration with signs of inflammation was observed. Conclusion: In our study, as the results obtained with the utilized parameters revealed that the PRP group had fat cells that were more resistant to oxidative stress, impacted less by inflammation, had less apoptosis and a higher neovascularization potential compared to the control group and as the values for the 1st week were even more dramatic for the 1st week has led us to believe that a delay period of 1 week would suffice. We're of the opinion that the data revealed by our current study will grant a new perspective to fat grafting and pave the way for new studies on fat graft survival.