Immediate and Intermediate Adjuvant Wound Therapy Following Partial-Thickness Thermal Burn Injury in a Porcine Model

Purpose: A porcine model was utilized to determine the clinical and histological impact of several currently available therapies for wound healing modification following partial-thickness thermal burn injury. Methods: A prospective study in a porcine model of partial-thickness thermal burn injury was performed, assessing immediate adjuvant wound therapy with amniotic membrane grafting, onabotulinum toxin A injection, and verteporfin injection compared with intermediate wound adjuvant therapy by intralesional 5-fluorouracil with microneedling, verteporfin injection, and triamcinolone injection with and without 5-fluorouracil. Clinical assessments were conducted by blinded plastic surgeons utilizing a validated porcine burn scar scale. Histologic analysis was accomplished with hematoxylin and eosin stains and Masson’s trichrome stains. A repeated measures mixed model analysis of variance was performed to identify clinical or histological statistical significance. Results: Comparing immediate versus intermediate treatments, a statistically significant difference in regards to mean clinical grade at the postinjury day 14 and postinjury day 28 time points was identified, yielding a 0.57 scale difference ( p = 0.0096) and 0.7 scale difference ( p = 0.0006), respectively. A statistically significant difference in regards to decreased mean histologic grade at the postinjury day 28 time points was identified for epithelial hyperplasia (−30.532 mean difference, p -value <0.0001), inflammatory response (−11.472 mean difference, p = 0.0133), and dermal remodeling (−13.78 mean difference, p = 0.0058). Conclusions: The results of this study suggest immediate treatment of partial-thickness thermal injury with adjuvant wound therapy decreases subsequent burn scar formation when compared with adjuvant wound therapy applied in the intermediate phase of healing.