Fractionated Ablative Carbon Dioxide Laser Therapy Decreases Ultrasound Thickness of Hypertrophic Burn Scar

Abstract

Introduction Carbon dioxide (CO2) laser treatment is routinely used to treat hypertrophic burn scars (HBS). Although prior research has documented subjective improvement in HBS after treatment, there is little data evaluating objective changes in scar characteristics after therapy. The aim of our process improvement project was to evaluate changes to scar thickness (ST) using high-frequency ultrasound in patients with HBS undergoing CO2 laser therapy. Methods Ultrasound measurements of ST were obtained from patients with HBS before initial and at each subsequent treatment. ST, reduction in ST per treatment, and percentage reduction in ST from baseline were tabulated. Post hoc analyses examining the effect of initial ST and scar maturity on outcome were performed. First, patients were grouped by baseline ST into thicker (group 1, initial ST ≥ median value) and thinner (group 2, initial ST < median value) scar groups. Second, patients were divided into quartiles based on time from injury to treatment. Outcomes at each time point were compared with either Mann-Whitney U or Kruskal-Wallis tests, with Bonferonni corrections performed for post hoc subgroup analyses. Significance was set at P < 0.05. Results Twenty-one consecutive patients with HBS treated with CO2 laser were included. All patients completed 1 or more treatment, 48% completed 2 or more treatments, and 28% completed 3 treatments. Median initial ST was 0.71 cm (0.44–0.98 cm), and median scar maturity was 7.5 months (4.9–9.8 months). Overall, ST decreased over the treatment course (P < 0.001), with post hoc analysis demonstrating that 2 treatments were required to achieve a significant ST reduction (P < 0.01). On subgroup analysis comparing initial ST, ST decreased significantly in group 1 (thicker scars) overall (P < 0.001) but not in group 2 (P = 0.109). ST reduction was greatest after 1 treatment in group 1 (P = 0.022) and group 2 (P = 0.061). Percent reduction was greater in group 1 relative to group 2 after 1 treatment (P = 0.016). On subgroup analysis of scar maturity, there were no significant differences in either baseline ST or ST at any subsequent visit. Conclusions Fractionated ablative CO2 laser treatment improved ST after 1 to 2 treatments. Patients with thicker scars demonstrated greater ST reduction than those with thinner scars. Ultrasound adequately assessed treatment response.

Analysis of the Utility of CO2 and Pulse-Dye Lasers Together and Separately in the Treatment of Hypertrophic Burn Scars

“…Some studies have found a benefit to laser therapy after just one treatment. 20,22,23 In a process improvement initiative led by our group, 21 patients with HTBS treated with CO 2 laser experienced improvement in ST with the greatest im-provement seen after the first treatment for both thin and thick scars ( P = 0.061 and 0.022, respectively). 23 Hultman et al 22 conducted a prospective, before-after cohort study of 147 patients receiving PDL, CO 2 , intense pulsed light, or Alexandrite laser treatments, and found that Vancouver Scar Scale (VSS) and University of North Carolina "4P" Scar Scale both decreased significantly ( P < 0.0001, P < 0.0001, respectively) with the largest decrease occurring following the first laser session.…”

Effectiveness of fractional carbon dioxide laser combined with botulinum toxin type A in a rabbit ear model with the underlying mechanism

“…Studies have found that fractional CO 2 laser treatments improve HS using selective photothermolysis, producing microthermal damage of almost the same density and depth 4 . Furthermore, some researchers have reported that fractional CO 2 laser treatment can soften and flatten the scar and reshape the collagen arrangement 24 . In addition, numerous clinical and preclinical studies have shown that fractional CO 2 laser therapy for HS is safe and effective with rare side effects 7 .…”

“…4 Furthermore, some researchers have reported that fractional CO 2 laser treatment can soften and flatten the scar and reshape the collagen arrangement. 24 In addition, numerous clinical and preclinical studies have shown that fractional CO 2 laser therapy for HS is safe and effective with rare side effects. 7 Regarding the molecular mechanism, fractional CO 2 laser treatments can regulate TGFβ, BMP-7, Fas, and other signaling pathways, inhibit TGF-β1 production, create microholes to replace collagen fibrils, and decrease the number of abnormal collagen fibers, thus improving HS.…”

Effectiveness and safety of fractional micro-plasma radio-frequency treatment combined with ablative fractional carbon dioxide laser treatment for hypertrophic scar: a retrospective study

“…A further subgroup analysis was also performed which revealed that patients at the early stage could experience more significant improvement after the treatment of combined therapy. Ablative fractional CO 2 laser technology has been employed for many years; however, it is only in recent years that this technique has been applied to the treatment of hypertrophic scars (3,4,(13)(14)(15)(16)(17)(18)(19). Several case reports firstly reported the effectiveness of ablative fractional CO 2 laser treatment for hypertrophic scars (20,21), then Makboul et al enrolled 40 patients with hypertrophic scars and confirmed ablative fractional CO 2 laser treatment as a feasible management for hypertrophic scarring (22).…”

“…Hypertrophic scars caused by burns are also very common, and the injury to patients is greater due to the randomness and unpredictability of scar site. It has been reported that hypertrophic scar affects 32-72% of burn survivors based on patient age, wound infection, gender, and burn depth (4,5). The formation of hypertrophic scar can lead to unsightly appearance, restricted movement, psychological burden, and abnormal bodily sensations.…”