Use of botulinum toxin type A to improve treatment of facial wounds: A prospective randomised study

Abstract

The tension vectors acting on the wound edges are transmitted to immature collagen fibres synthesised during the normal healing phase. This accounts for scar widening as well as hypertrophic and hyperpigmented scars. The aim of our study was to evaluate whether early injections of botulinum toxin type A (BTA), which induces temporary muscular paralysis, decreases tension vectors on wound edges and enhances scarring of facial wounds. Thirty patients with facial wounds were enrolled in this study and randomised into two groups with or without injection of BTA within 72h postoperatively. BTA was injected into the facial muscles directly or indirectly involved in scar widening. Scars were assessed at a 1-year follow-up visit by patients using the Patient Scar Assessment Scale (PSAS) scale, by an independent evaluator using the Observer Scar Assessment Scale (OSAS) and the Vancouver Scar Scale (VSS), and by a board of six experienced medical specialists using the Visual Analogue Scale (VAS) with standardised photographs. At the 1-year visit, 24 patients were reviewed and six patients were lost to follow-up. No statistically significant differences were found between the two groups for the PSAS, OSAS and VSS scores. However, the median VAS rated by the six evaluators was 8.25 for the botulinum toxin-treated group compared with 6.35 for the control group. This result was statistically different, demonstrating improved scarring with BTA. Thanks to chemoimmobilisation, injections of BTA appear to improve cosmesis of facial wounds. Accordingly, they would be beneficial for use in young patients for wounds without tissue loss, lying perpendicular to the reduced tension lines of the skin of the face.