Efficacy of fractional carbon dioxide laser therapy for burn scars: a meta-analysis

Management of the Sequelae of Skin Grafting: Pruritis, Folliculitis, Pigmentation Changes, and More

Scars commonly give rise to unpredictable, potentially irritating, cutaneous complications including pruritis, folliculitis, and pigment changes. These problems can be self-limiting and are prevalent in many burn cases, although their expression varies among individuals. A better understanding of the presentation, risk factors, and pathophysiology of these long-term sequelae allows for more comprehensive care of burn survivors.

Influence of scar age, laser type and laser treatment intervals on paediatric burn scars: a systematic review and meta-analysis

Background

Laser therapy has emerged to play a valuable role in the treatment of paediatric burn scars; however, there is heterogeneity in the literature, particularly concerning optimal timing for initiation of laser therapy. This study aims to investigate the effect of factors such as scar age, type of laser and laser treatment interval on burn scar outcomes in children by meta-analysis of previous studies.

Methods

A literature search was conducted across seven databases in May 2022 to understand the effects of laser therapy on burn scar outcomes in paediatric patients by metanalysis of standardized mean difference (SMD) between pre- and post-laser intervention. Meta-analyses were performed using the Comprehensive Meta-Analysis software version 4.0. Fixed models were selected when there was no significant heterogeneity, and the random effects model was selected for analysis when significant heterogeneity was identified. For all analyses, a p-value < 0.05 was considered significant.

Results

Seven studies were included in the meta-analysis with a total of 467 patients. Laser therapy significantly improved Vancouver Scar Scale (VSS)/Total Patient and Observer Scar Assessment Scale (Total POSAS), vascularity, pliability, pigmentation and scar height of burn scars. Significant heterogeneity was found between the studies and thus subgroup analyses were performed. Early laser therapy (<12 months post-injury) significantly improved VSS/POSAS scores compared to latent therapy (>12 months post-injury) {SMD -1.97 [95% confidence interval (CI) = -3.08; -0.87], p < 0.001 vs -0.59 [95%CI = -1.10; -0.07], p = 0.03} as well as vascularity {SMD -3.95 [95%CI = -4.38; -3.53], p < 0.001 vs -0.48 [95%CI = -0.66; -0.30], p < 0.001}. Non-ablative laser was most effective, significantly reducing VSS/POSAS, vascularity, pliability and scar height outcomes compared to ablative, pulse dye laser and a combination of ablative and pulse dye laser. Shorter treatment intervals of <4 weeks significantly reduced VSS/POSAS and scar height outcomes compared to intervals of 4 to 6 weeks.

Conclusions

Efficacy of laser therapy in the paediatric population is influenced by scar age, type of laser and interval between laser therapy application. The result of this study particularly challenges the currently accepted initiation time for laser treatment. Significant heterogeneity was observed within the studies, which suggests the need to explore other confounding factors influencing burn scar outcomes after laser therapy.

Influence of scar age, laser type and laser treatment intervals on adult burn scars: A systematic review and meta-analysis

AIM

The study aims to identify whether factors such as time to initiation of laser therapy following scar formation, type of laser used, laser treatment interval and presence of complications influence burn scar outcomes in adults, by meta-analysis of previous studies.

METHODS

A literature search was conducted in May 2022 in seven databases to select studies on the effects of laser therapy in adult hypertrophic burn scars. The study protocol was registered with PROSPERO (CRD42022347836).

RESULTS

Eleven studies were included in the meta-analysis, with a total of 491 patients. Laser therapy significantly improved overall VSS/POSAS, vascularity, pliability, pigmentation and scar height of burn scars. Vascularity improvement was greater when laser therapy was performed >12 months (-1.50 [95%CI = -2.58;-0.42], p = 0.01) compared to <12 months after injury (-0.39 [95%CI = -0.68; -0.10], p = 0.01), the same was true for scar height ((-1.36 [95%CI = -2.07; -0.66], p<0.001) vs (-0.56 [95%CI = -0.70; -0.42], p<0.001)). Pulse dye laser (-4.35 [95%CI = -6.83; -1.86], p<0.001) gave a greater reduction in VSS/POSAS scores compared to non-ablative (-1.52 [95%CI = -2.24; -0.83], p<0.001) and ablative lasers (-0.95 [95%CI = -1.31; -0.59], p<0.001).

CONCLUSION

Efficacy of laser therapy is influenced by the time lapse after injury, the type of laser used and the interval between laser treatments. Significant heterogeneity was observed among studies, suggesting the need to explore other factors that may affect scar outcomes.

Efficacy of fractional CO2 laser in combination with stromal vascular fraction (SVF) compared with fractional CO2 laser alone in the treatment of burn scars: a randomized controlled clinical trial

BACKGROUND

The appearance of skin scars is known as one of the main side effects of skin burns. Stromal vascular fraction (SVF), as a rich source of cell populations with tissue regeneration properties, plays an important role in the healing of skin lesions. Fractional CO2 lasers have occupied a special place in treating skin lesions, particularly skin scars, since their introduction. Our study aimed to compare the combination of SVF and fractional CO2 laser with fractional CO2 laser alone in the treatment of burn scars.

METHOD

This double-blind clinical trial study was conducted on ten patients with burn scars that were treated three times with a fractional CO2 laser at site of burn lesions, and one of the two areas studied was randomly injected with SVF. Two months after completion of the procedure, patients' scars were assessed using the Vancouver scar scale (VSS), biometric criteria, and physician and patient satisfaction ratings.

RESULTS

The results confirmed a significant improvement in VSS, cutometry, R7 criteria, complete density sonography, and skin density sonography in the fractional CO2 laser-treated group. The VSS criteria, epidermal thickness sonography, complete density sonography, and skin density sonography in the group treated with the combination of fractional CO2 laser and SVF also showed significant improvement. The VSS criteria and melanin index of Mexameter in the group treated with SVF in combination with fractional CO2 laser were significantly better than the group treated with fractional CO2 laser alone. Also, physician and patient satisfaction in the group treated with SVF injection in combination with fractional CO2 laser was significantly higher than the other group.

CONCLUSION

The results confirm the efficacy of SVF injection in combination with fractional CO2 laser in the treatment of burn scars and can be considered as a treatment option for better management of these lesions.

TRIAL REGISTRATION

The study protocol was retrospectively registered at Iranian Registry of Clinical Trials with code: IRCT20210515051307N1, Registration date: 2021-11-14, URL: https://www.irct.ir/trial/56337 .

Carbon dioxide laser treatment of burn-related scarring: Results of the ELIPSE (Early Laser Intervention Promotes Scar Evolution) prospective randomized controlled trial

AIM

To investigate the impact of ablative fractional carbon dioxide laser (AFCO2L) on patient-reported outcomes measures, subjective scar appearance, dermal architecture, and gene transcription in early burn scars.

METHODS

Fifteen adult patients with a burn-related scar were recruited. Inclusion criteria were two non-contiguous scar areas of 1% total body surface area, similar baseline Vancouver scar scale (VSS) score and 3months since the time of injury. All participants acted as their own control. Scars were randomized to treatment or control. Treatment scars received three AFCO2L treatments at 6-week intervals. Outcome measures were recorded at baseline, 3, 6, and 12-months post-treatment. Measures included blinded VSS, Patient Observer Scar Assessment Scale (POSAS), Brisbane Burn Scar Impact Profile (BBSIP), blinded scar photo assessment, histological tissue analysis, and RNA sequencing analysis.

RESULTS

No significant difference was found in VSS, scar erythema, or pigmentation. Patient POSAS improved in scar thickness and texture following AFCO2L. All elements of BBSIP improved in control and laser groups. AFCO2L-treated scars were scored better than control scars by blinded raters. RNA sequencing illustrated that AFCO2L induced sustained changes in fibroblast gene expression.

CONCLUSIONS

AFCO2L treated scars had significantly altered scar thickness and texture 6 months post-laser and were rated better than controls on blinded photo analysis after 3 treatments. RNASeq results suggest laser treatment alters the transcriptome of treated fibroblasts for at least 3 months after treatment. Expansion of this research to study in more depth fibroblast changes in response to laser, as well as assessing the impact on daily activity and quality of life, will be beneficial.

The Efficacy of Fractional Carbon Dioxide Laser in Surgical Scars Treatment: A system Review and Meta-analysis

BACKGROUND

Surgical scars seriously affect a patient's quality of life, and they have a strong impact on individuals. Many studies have reported the results of using fractional carbon dioxide (CO₂) laser to treat surgical scars and have generally found it to be effective.

OBJECTIVES

We conducted a meta-analysis with the objective of evaluating and proving the efficacy of fractional CO₂ laser therapy for surgical scars.

METHODS

We performed a search of databases including PubMed, Web of Science, Embase and the Cochrane Library. The outcomes of the meta-analysis were overall scores on the Vancouver Scar Scale (VSS) and its four dimensions (pigmentation, vascularity, pliability and height). Statistical analysis was performed using RevMan 5.4 software.

RESULTS

A total of ten studies were included in this meta-analysis, including six randomized controlled trials (RCTs) and four nonrandomized controlled trials (N-RCTs). In the meta-analysis of RCTs and N-RCTs, similar results were obtained, and fractional CO₂ laser irradiation significantly decreased VSS scores (P < 0.00001). In addition, fractional CO₂ laser irradiation also had a significant effect on scores on the pigmentation (P = 0.08), vascularity (P = 0.001), flexibility (P = 0.005) and height (P = 0.008) dimensions. Except for mild pain during treatment and temporary erythema after treatment, most patients had no obvious adverse reactions.

CONCLUSION

Our study found that fractional CO₂ laser exhibits excellent efficacy and safety in terms of surgical scar treatment. Thus, we hope it becomes more widely available to patients with surgical scars.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Traditional Chinese medicine for hypertrophic scars—A review of the therapeutic methods and potential effects

Hypertrophic scar (HS) is a typical pathological response during skin injury, which can lead to pain, itching, and contracture in patients and even affect their physical and mental health. The complexity of the wound healing process leads to the formation of HS affected by many factors. Several treatments are available for HS, whereas some have more adverse reactions and can even cause new injuries with exacerbated scarring. Traditional Chinese Medicine (TCM) has a rich source, and most botanical drugs have few side effects, providing new ideas and methods for treating HS. This paper reviews the formation process of HS, the therapeutic strategy for HS, the research progress of TCM with its relevant mechanisms in the treatment of HS, and the related new drug delivery system of TCM, aiming to provide ideas for further research of botanical compounds in the treatment of HS, to promote the discovery of more efficient botanical candidates for the clinical treatment of HS, to accelerate the development of the new drug delivery system and the final clinical application, and at the same time, to promote the research on the anti-HS mechanism of multiherbal preparations (Fufang), to continuously improve the quality control and safety and effectiveness of anti-HS botanical drugs in clinical application.

Automated Structural Analysis and Quantitative Characterization of Scar Tissue Using Machine Learning

An analysis of scar tissue is necessary to understand the pathological tissue conditions during or after the wound healing process. Hematoxylin and eosin (HE) staining has conventionally been applied to understand the morphology of scar tissue. However, the scar lesions cannot be analyzed from a whole slide image. The current study aimed to develop a method for the rapid and automatic characterization of scar lesions in HE-stained scar tissues using a supervised and unsupervised learning algorithm. The supervised learning used a Mask region-based convolutional neural network (RCNN) to train a pattern from a data representation using MMDetection tools. The K-means algorithm characterized the HE-stained tissue and extracted the main features, such as the collagen density and directional variance of the collagen. The Mask RCNN model effectively predicted scar images using various backbone networks (e.g., ResNet50, ResNet101, ResNeSt50, and ResNeSt101) with high accuracy. The K-means clustering method successfully characterized the HE-stained tissue by separating the main features in terms of the collagen fiber and dermal mature components, namely, the glands, hair follicles, and nuclei. A quantitative analysis of the scar tissue in terms of the collagen density and directional variance of the collagen confirmed 50% differences between the normal and scar tissues. The proposed methods were utilized to characterize the pathological features of scar tissue for an objective histological analysis. The trained model is time-efficient when used for detection in place of a manual analysis. Machine learning-assisted analysis is expected to aid in understanding scar conditions, and to help establish an optimal treatment plan.

Effects of multiple modes of UltraPulse fractional CO2 laser treatment on extensive scarring: a retrospective study

The main therapeutic options for extensive scarring (e.g., > 20% of the total body surface area, or TBSA) after burns and trauma have focused on conservative treatments, such as compression, moisturization, and topical agent application. However, these treatments may not achieve optimal effects due to the large size and complexity of the scars. UltraPulse fractional CO₂ laser treatment is a novel approach that is currently a subject of intense interest; this treatment is most widely used to improve texture, pliability, and pigmentation in all types of scars. However, no studies on the independent use of UltraPulse fractional CO₂ laser treatment for extensive scars have been reported. This retrospective study evaluated a total of 21 patients, whose scars covered 20 to 65% TBSA. Scar thickness was measured by ultrasonography before treatment. Personalized treatment modalities and parameters were set according to the scar type and thickness. Scar formation and treatment effects were evaluated by photography, the Patient and Observer Scar Assessment Scale (POSAS), and patients’ judgment of effectiveness. Where the scars covered joints, joint function was assessed by measuring the maximum range of motion (ROM). With laser therapy, scars became flatter and lighter; furthermore, pruritus, pain, and discomfort decreased significantly. POSAS scores significantly decreased after laser therapy, including the item scores for pain and pruritus. There were no instances of joint contracture, ROM reduction, apparent functional impairment, serious adverse events, or comorbidities. This study demonstrates the safety and efficiency of UltraPulse fractional CO₂ laser treatment for extensive scarring.

Early Treatment Effects of Nonablative Fractional Lasers (NAFL) on Hypertrophic Scars in an Animal Model

BACKGROUND AND OBJECTIVES

Recently, there have been several attempts to apply the laser therapy to hypertrophic scars (HTS). In particular, the fractional laser is in the spotlight for its usefulness in rapid wound healing and dermal remodeling. However, most previous studies have focused on the ablative fractional laser (AFL), and there are no studies on the mechanism of the nonablative fractional laser (NAFL) effect in HTS treatment. In this study, we aimed to evaluate the changes in histology and molecular chemistry to provide scientific evidence for the early treatment of HTS with NAFL.

STUDY DESIGN/MATERIALS AND METHODS

A total of 40 hypertrophic burn scars were made on the abdomens of two female pigs. After epithelialization, the HTS were randomly subdivided into four groups-control, AFL, NAFL (low energy), and NAFL (high energy). Laser treatment was initiated 1 week after the crust fell and the epithelium became covered, and it was repeated for six sessions over an interval of 2 weeks. Five excisional biopsies were obtained for histologic analysis and biomarker assessment.

RESULTS

Histologically, dermal remodeling with thin coil-shaped collagen fibers was observed in the NAFL groups. It also showed a significant increase of matrix metalloproteinase-2 (MMP-2) and Decorin at 16 weeks in an enzyme-linked immunosorbent assay. The reverse-transcription polymerase chain reaction analysis showed a tendency that high-pulse energy of NAFL led to higher messenger RNA expression than did the low-energy group.

CONCLUSION

The NAFL-treated groups showed characteristic collagen re-arrangement and a significant increase in MMP-2 and Decorin. These molecular changes suggest that MMP-2 and Decorin play a significant role in dermal remodeling. Early NAFL treatment for HTS could be supported with both histological and molecular evidence. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.