Statistical Analysis
Statistical analyses were performed using SPSS version 25 (IBM Corp). No a priori sample size calculation was possible for the phase I study. For the phase II study, the estimated minimum required sample size was 20 patients, including the phase I group. Continuous variables are presented as mean and SD in case of a normal distribution and as median and interquartile range (25th, 75th percentile) for variables with a nonnormal distribution. Categorical variables are presented as frequencies and percentages. Differences between the dermal matrix and control sites were analyzed by a paired-sample 