Evaluation of Clinical Results, Histological Architecture, and Collagen Expression Following Treatment of Mature Burn Scars With a Fractional Carbon Dioxide Laser

Abstract

OBJECTIVE: To assess mature burn scars treated with a fractional carbon dioxide laser for changes in histological architecture, type I to III collagen ratios, density of elastic tissue, and subjective measures of clinical improvements. DESIGN: Uncontrolled, prospective study of patients with mature burn scars, from a clinical and histological perspective. Biopsy specimens were obtained before and 2 months after 3 treatment sessions. The tissue was prepared with Verhoff von Giesen (VVG) stain to discern elastic tissue and Herovici stain to differentiate types I and III collagen. SETTING: Subjects were recruited from the Grossman Burn Centers. PARTICIPANTS: Of 18 patients with mature burn scars, 10 completed the entire treatment protocol. INTERVENTION: Participants received 3 treatments with a fractional carbon dioxide laser. MAIN OUTCOME MEASURES: Vancouver Scar Scale and Patient and Observer Scar Assessment Scale survey scores. In histological analysis, imaging software was used to measure changes in collagen subtype and elastic tissue. A rating scale was developed to assess normal vs scar architecture. RESULTS: The first hypothesis that significant histological improvement would occur and the second hypothesis of a statistically significant increase in type III collagen expression or a decrease in type I collagen expression were confirmed. There were no significant changes in elastic tissue. Statistically significant improvements were seen in all survey data. CONCLUSIONS: Treatment with a fractional carbon dioxide laser improved the appearance of mature burn scars and resulted in a significant improvement in collagen architecture following treatment. Furthermore, in treated skin specimens, a collagen subtype (types I and III collagen) profile resembling that of nonwounded skin was found.