Joris van Dongen

194 Chapter 8 While we report on tSVF i.e . a fraction of fat, others reported the immediate effect of fat grafting after reductionmammoplasty or cleft-lip repair. 23-25 Kemaloğlu et al. treated thirty patients with either fat grafting or nanofat-enriched fat grafting immediate after a reduction mammoplasty while fifteen patients did not receive additional treatment. 25 This study also found a significant scar appearance improvement as evaluated by a VAS andVancouver Scar Scale (VSS) after treatmentwith fat grafting or nanofat-enriched fat grafting as compared to the control group at six months. Their VAS and VSS subscores were comparable for both the fat grafting and the nanofat-enriched fat grafting groups, except for the amount of pigmentation. The level of pigmentation was reduced in the nanofat-enriched fat grafting group. These results are thus fully in line with the six months results in this study. This shows that adipocytes are not necessary to initiate a faster wound healing because tSVF deprived of adipocytes shows comparable results with nanofat-enriched fat grafting. The study of Kemaloğlu et al. did not evaluate their results after 1 year. 25 It is well-known that scar maturation takes at least one year and therefore, no definite conclusions regarding final scar appearance after immediate fat grafting can be drawn within one year period. In contrast to scar prevention therapy, scar remodeling therapy focuses on reducing the amount of already deposit collagen instead of preventing collagen deposition. In scar remodeling, ASCs injections in mature fibrotic areas might stimulate matrix metalloproteinase release causing matrix remodeling as seen in in vitro studies. 26,27 Matrix remodeling contains replacement of thick and aligned collagen bundles by smaller, randomly aligned collagen bundles. These changes might occur under influence of ASCs in highly vascularized tissue with influx of immune cells e.g. T-lymphocytes, mast cells and M2 macrophages (under revision ASJ). Several studies investigating fat grafting or any therapeutic component of adipose tissue e.g. ASCs or SVFformodulation of matured scars show promising results: improvement of the general appearance of scars occurs by normalizing the color, reducing irregularities and fibrotic area. 28-30 Multiple clinical studies regarding fat grafting and dermal wound healing have shown encouraging results with increasedwound healing rates. 31 Though, controversy remains because some clinical trials report a high rate of only partially closedwounds. 32-34 Two of these studies used enzymatically isolated SVF comprising of a heterogeneous mixture of a single cell suspension devoted from cell-cell connections including extracellular matrix (cSVF). 32,33 After application of cSVF, the vast majority of cells will probably diffuse away from the site of injections within hours. Hence, the regenerative effect of cSVF at the wound bed might be limited. In this study, tSVF containing intact cell-cell interactions as well as extracellular matrix is injected in a freshly created wound bed. These cell-cell interactions prevent cells e.g. ASCs to emigrate directly after injection.