Joris van Dongen

202 Chapter 9 METHODS Study overview The study conducted was a single-centre, patient and investigator blinded, placebo- controlled trial undertaken at Bergman Clinics The Hague, the Netherlands. A flow- chart overview of the study is shown in Figure 1. Patients’ follow-up was 12 months in order to obtain long-term lasting results. The study protocol complied with the Declaration of Helsinki and was approved by local medical ethics committee Zuid-west Holland (National legislator trial code: NL35142.098.11, local METC code: 12-014). All patients provided written informed consent. Patient population and randomization Prior to inclusion, a power calculation was performed based on the limited available published data at that time. Following this calculation, aim was to include 32 subjects that would receive facial lipofilling in this study, with one half of the population receiving PRP, the other half a placebo (sterile saline), serving as control group. A detailed description of the randomization process in available online. Inclusion- exclusion criteria were strict, and are listed in Figure 1. The primary outcome of the study was skin elasticity improvement (R7 parameter measured by the MPA580 device) on predetermined fixed measurement locations (Figure 2) overlaying the area of intervention. Secondary outcome parameters of the study were: other changes in skin characteristics (R5-R6 parameters, MPA850, same locations), graft take (nasolabial fold decrease) and patient questionnaires regarding recovery time and satisfaction. Patient enrollment in the study started in 2012 and ended mid 2015. During enrollment in this study, patients were prohibited to undergo further subsequent facial rejuvenating procedures. If a patient still did, the patient was excluded from the study.