Post-skin incision scar tissue assessment using patient and observer scar assessment scales: A randomised controlled trial

BACKGROUND: The scalpel was once the gold standard for surgical incisions. Electrosurgery has started to supplant scalpels but is not yet acceptable for skin incisions due to the risk of burns and deeper injury relative to the scalpels' neat incision with less tissue damage. The unnecessary burden of excessive scar formation makes comparing these two methods challenging. Therefore, this study aims to compare post-incision skin scarring created after monopolar electrosurgery and scalpel surgery, and evaluate the Patient and Observer Scar Assessment Scale (POSAS) suitability for assessing skin incision scars by comparing patients' and observers’ scores. METHODS: This self-controlled study involved patients undergoing elective and emergency skin surgery procedures. A singular wound site was created using two incision methods (monopolar electrosurgery and scalpel) simultaneously. Post-incision scar tissue formation was evaluated using the POSAS, a subjective scar assessment tool that involved patients self-reporting on pain, itching, color, thickness flexibility, and surface relief. Observer-rated vascularity, pigmentation, thickness, flexibility, and surface relief both using a 5-point Likert-type scale. We performed this assessment three months post-surgery, and the results were analyzed by a battery of statistical tests and linear mixed models. RESULTS: Twenty patients were included in this study. Data analyzed using the paired t-test or Wilcoxon rank-sum test indicated no statistically significant differences between the scar tissue created by monopolar electrosurgery and scalpels according to both the patients and the observers. Correlation analyses between the patients' and observers’ total POSAS scores indicated these followed a moderate linear relationship (r = 0.51; p < 0.001). Linear mixed models further supported the agreement of POSAS total scores between patients and observers. They also confirmed that electrosurgery was not inferior to the scalpel technique. CONCLUSION: Scar tissue from skin incisions made by monopolar electrosurgery were indistinguishable from those created with a scalpel. The POSAS instrument is an acceptable means of assessing scar formation on the skin.