Digital Image Analysis for the comparative study of skin erythema after skin closure of surgical wounds

Digital images of clean surgical wounds following suturing were obtained and computer-assisted image analysis was performed. Surgical wounds were sutured by two different kinds of sutures each. A comparative study of the quality of five different suture materials according to the quantity of skin erythema that they caused was carried out. The aim of study was to establish an objective method for quantitative measurement of skin erythema. Our Digital Image Analysis (DIA) software was focused on the necessary transformations of the images obtained, in order to evaluate the superiority of red color value in every pixel using normalized red-green-blue (RGB) values. Each surgical wound was sutured by two different kinds of material in a randomized way using five different materials. Comparison of skin erythema was performed between the pair of suturing materials used in the same surgical wound. Digital images were obtained before, after suturing, right after removal of sutures and a month later. The mean value of normalized red was measured in both halves of the wound in every image obtained. DIA was performed by the software “ΦΩΣ” (PHOS) of digital morphometric analysis which was developed for the purposes of the study. Statistical analysis of the results was performed by the paired Wilcoxon Signed Rank test. The present study shows a non-invasive quantitative method of skin erythema evaluation. The software “ΦΩΣ” calculated the mean values of normalized red in surgical wounds closed by the pairs of sutures AB, AC, AD and AE (p<0.05 in 3 out of 4 groups). Skin erythema produced by suture material A is lower than that of the rest four kinds of sutures and was reliably evaluated as the mean value of normalized red by the software “ΦΩΣ”. The developed software can, non-invasively, evaluate quantitatively the skin erythema caused in surgical wounds after skin closure. Key-Words: Skin erythema; Digital Image Analysis; Normalized red; Morphometric; Software “ΦΩΣ”;