Joris van Dongen

193 tSVF as a treatment for scar remodeling Table 2. Intra- and interobserver agreements based on Fleiss weighted kappa coefficient. Observers Fleiss weighted kappa intra-observer 1 0.277 2 0.212 3 0.146 4 0.150 5 0.143 6 0.120 7 0.212 8 0.153 9 0.249 Observer groups Fleiss weighted kappa inter-observer 1 0.028 2 0.101 3 0041 DISCUSSION This prospective randomized multicenter clinical trial testing the effect of tSVF on wound healing demonstrated a significant effect of tSVF on wound healing; immediate postoperative injection of tSVFsignificantly suppresses scar formation after a reduction mammoplasty as evaluated after six months. The scars were significantly improved in color and a decrease of thickness as well as irregularity was seen. This clearly indicates an accelerated early wound healing resulting in a faster transition from wound to final scar. After twelve months, the saline treated scars show a comparable aesthetic appearance with the tSVF treated scars indicating a slower wound healing. Apparently, during the final phase of wound healing i.e. remodeling phase, the initial advantage of tSVF is overtaken. One can speculate, that the disappearing effect of tSVF indicate a faster transition from the inflammation to remodeling phase during wound healing without creating structural differences in finalized scars. A faster transition might be caused by a larger influx of immune cells such as macrophages and subsequently increased shift fromM1 to M2 phenotype under the influence of ASCs (under revision ASJ). M2 macrophages are largely responsible for initiating tissue repair following immune suppression at the end of the inflammation phase of wound healing. 22 Once the remodeling phase has started after several weeks, the injected tSVF cells might not be therapeutic anymore to improve scar appearance.