Nonablative Fractional Laser Resurfacing for the Treatment of Hypertrophic Scars: A Randomized Controlled Trial

Low-level laser activates Wnt/β-catenin signaling pathway-promoting hair follicle stem cell regeneration and wound healing: Upregulate the expression of key downstream gene Lef 1

BACKGROUND

The objective of this study is to investigate the mechanism by which low-level laser stimulation promotes the proliferation of intraepithelial hair follicle stem cells (HFSCs) in wounds. This research aims to expand the applications of laser treatment, enhance wound repair methods, and establish a theoretical and experimental foundation for achieving accelerated wound healing.

METHODS

The experimental approach involved irradiating a cell model with low-level laser to assess the proliferation of HFSCs and examine alterations in the expression of proteins related to the Wnt/β-catenin signaling pathway. A mouse back wound model was established to investigate the effects of low-level laser irradiation on wound healing rate, wound microenvironment, and the proliferation of HFSCs in relation to the Wnt/β-catenin signaling pathway.

RESULTS

The research findings indicate that low-level laser light effectively activates the Wnt signaling pathway, leading to the increased accumulation of core protein β-catenin and the upregulation of key downstream gene Lef 1. Consequently, this regulatory mechanism facilitates various downstream biological effects, including the notable promotion of HFSC proliferation and differentiation into skin appendages and epithelial tissues. As a result, the process of wound healing is significantly accelerated.

CONCLUSION

Low levels of laser activates the Wnt signalling pathway, promotes the regeneration of hair follicle stem cells and accelerates wound healing.

Reporting of scar outcomes in the hand and wrist; a state-of-the-art literature review

OBJECTIVES

The aim of this literature review was to synthesise and report current practice in evaluation and reporting of scar outcomes in hand and wrist clinical research.

METHODS

A systematic search from inception to 2022 was conducted using three electronic databases. English language randomized controlled trials and observational cohort studies reporting standardised scar outcome measures and/or scar symptoms, appearance, impairment, function, or mental health outcomes in patients with hand and wrist scars were included. Two independent reviewers determined study eligibility and performed data extraction of a priori identified scar outcome domains. Data analysis included descriptive statistics and identification of discordance in taxonomy.

RESULTS

Fifty-nine studies were included. Elective surgery cohorts were the most frequently included clinical population (n = 28; 47%) followed by burns (n = 16; 27%). Six different standardised scar outcome measures were reported by 25% of studies however only 7% of studies utilised a patient-reported measure. Scar symptoms were the most frequently reported outcome domain (81%); but taxonomy was incongruous, constructs lacked working definitions required for generalisability and outcome measurement was variable and unreported. Nineteen different measures of scar appearance and structure were reported by 30 (51%) of studies however only nine (23%) were patient-reported. Seven different hand function PROMs were reported by 25 (43%) studies. Person-centred domains including scar acceptability (12%), mental health impact (5%), and social participation (4%) were rarely reported.

CONCLUSIONS

This review highlights that evaluation and reporting of hand and wrist scar outcomes is not standardised, assessment methods and measures are under-reported and there is discordance in taxonomy. Evaluation is not person-centred, rather it is dependent on clinician assessment. Domains including scar acceptability, mental health, and social participation are rarely addressed. A stakeholder consensus derived hand and wrist scar core outcome measurement set will promote standardisation and underpin improvements in clinical research quality, transparency, and rigour.

Hypertrophic Scars and Keloids: Advances in Treatment and Review of Established Therapies

Hypertrophic scars and keloids can have significant detrimental effects on patients both psychosocially and functionally. A careful identification of patient risk factors and a comprehensive management plan are necessary to optimize outcomes. Patients with a history of dystrophic scarring should avoid unnecessary procedures and enhance the wound-healing process using various preventive strategies. As there is no single, fully efficacious treatment modality, prevention remains the best approach in reducing aberrant scar formation. When prevention therapies fail, keloids have been shown to be respond to a variety of therapies including topical and injectable corticosteroids, 5-fluorouracil, radiotherapy, lasers, and surgical excision, all with varying efficacies. As such, management should be tailored to the individual patient's risk factors with the use of combination therapies to reduce recurrence rates. Still, keloid and hypertrophic scar therapies are widely diverse with novel treatment modalities providing alternatives for recurring lesions. Laser-assisted drug delivery, skin priming, and novel topical therapies may provide alternative options for the management of hypertrophic scars and keloids.

Laser therapy for treating hypertrophic and keloid scars

BACKGROUND

Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. They can cause itching, pain and have a negative physical and psychological impact on patients' lives. Different approaches are used aiming to improve these scars, including intralesional corticosteroids, surgery and more recently, laser therapy. Since laser therapy is expensive and may have adverse effects, it is critical to evaluate the potential benefits and harms of this therapy for treating hypertrophic and keloid scars.

OBJECTIVES

To assess the effects of laser therapy for treating hypertrophic and keloid scars.

SEARCH METHODS

In March 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO Plus and LILACS. To identify additional studies, we also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports. There were no restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) for treating hypertrophic or keloid scars (or both), comparing laser therapy with placebo, no intervention or another intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted the data, assessed the risk of bias of included studies and carried out GRADE assessments to assess the certainty of evidence. A third review author arbitrated if there were disagreements.

MAIN RESULTS

We included 15 RCTs, involving 604 participants (children and adults) with study sample sizes ranging from 10 to 120 participants (mean 40.27). Where studies randomised different parts of the same scar, each scar segment was the unit of analysis (906 scar segments). The length of participant follow-up varied from 12 weeks to 12 months. All included trials had a high risk of bias for at least one domain: all studies were deemed at high risk of bias due to lack of blinding of participants and personnel. The variability of intervention types, controls, follow-up periods and limitations with report data meant we pooled data for one comparison (and only two outcomes within this). Several review secondary outcomes - cosmesis, tolerance, preference for different modes of treatment, adherence, and change in quality of life - were not reported in any of the included studies. Laser versus no treatment: We found low-certainty evidence suggesting there may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585-nm pulsed-dye laser (PDL) -treated scars compared with no treatment (risk ratio (RR) 1.96; 95% confidence interval (CI): 1.11 to 3.45; two studies, 60 scar segments). It is unclear whether non-ablative fractional laser (NAFL) impacts on hypertrophic scar severity when compared with no treatment (very low-certainty evidence). It is unclear whether fractional carbon dioxide (CO2) laser impacts on hypertrophic and keloid scar severity compared with no treatment (very low-certainty evidence). Eight studies reported treatment-related adverse effects but did not provide enough data for further analyses. Laser versus other treatments: We are uncertain whether treatment with 585-nm PDL impacts on hypertrophic and keloid scar severity compared with intralesional corticosteroid triamcinolone acetonide (TAC), intralesional Fluorouracil (5-FU) or combined use of TAC plus 5-FU (very low-certainty evidence). It is also uncertain whether erbium laser impacts on hypertrophic scar severity when compared with TAC (very low-certainty evidence). Other comparisons included 585-nm PDL versus silicone gel sheeting, fractional CO2 laser versus TAC and fractional CO2 laser versus verapamil. However, the authors did not report enough data regarding the severity of scars to compare the interventions. As only very low-certainty evidence is available on treatment-related adverse effects, including pain, charring (skin burning so that the surface becomes blackened), telangiectasia (a condition in which tiny blood vessels cause thread-like red lines on the skin), skin atrophy (skin thinning), purpuric discolorations, hypopigmentation (skin colour becomes lighter), and erosion (loss of part of the top layer of skin, leaving a denuded surface) secondary to blistering, we are not able to draw conclusions as to how these treatments compare. Laser plus other treatment versus other treatment: It is unclear whether 585-nm PDL plus TAC plus 5-FU leads to a higher percentage of good to excellent improvement in hypertrophic and keloid scar severity compared with TAC plus 5-FU, as the certainty of evidence has been assessed as very low. Due to very low-certainty evidence, it is also uncertain whether CO2 laser plus TAC impacts on keloid scar severity compared with cryosurgery plus TAC. The evidence is also very uncertain about the effect of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser plus intralesional corticosteroid diprospan plus 5-FU on scar severity compared with diprospan plus 5-FU and about the effect of helium-neon (He-Ne) laser plus decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream on scar severity compared with decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream. Only very low-certainty evidence is available on treatment-related adverse effects, including pain, atrophy, erythema, telangiectasia, hypopigmentation, regrowth, hyperpigmentation (skin colour becomes darker), and depigmentation (loss of colour from the skin). Therefore, we are not able to draw conclusions as to how these treatments compare.  AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the effectiveness of laser therapy for treating hypertrophic and keloid scars. The available information is also insufficient to perform a more accurate analysis on treatment-related adverse effects related to laser therapy. Due to the heterogeneity of the studies, conflicting results, study design issues and small sample sizes, further high-quality trials, with validated scales and core outcome sets should be developed. These trials should take into consideration the consumers' opinion and values, the need for long-term follow-up and the necessity of reporting the rate of recurrence of scars to determine whether lasers may achieve superior results when compared with other therapies for treating hypertrophic and keloid scars.

Observation on the efficacy of 1565-nm non-ablative fractional laser combined with compound betamethasone topical application on the treatment of early scar in Chinese patients

The objective of the study was to evaluate the efficacy of combining 1565-nm non-ablative fractional laser with low-dose compound betamethasone topical application in the treatment of immature early red hypertrophic scar. We enrolled 38 cases of patients who had immature red hypertrophic scar due to surgery or trauma which are all less than 6 months old. About 28 patients were assigned to the treatment group, and 10 patients were assigned to the control group. The patients in the treatment group were all treated with 1565-nm non-ablative fractional laser with the following parameters: spot size 10-16 mm, round or square-shaped according to lesional morphology, fluence 20-35 mJ/cm², and density 150-200 microspot/cm². The treated area was then applied immediately with low-dose compound betamethasone through topical application. Treatment cycles were repeated every month for a total 5 months. Photos were taken before the start of the treatment, and then monthly after. Vancouver Scar Scale score was used to evaluate the scar changes; all the patients were followed up for 3 more months after the last treatment. All side effects were documented. The patients in the control group received no treatment at all. All the parameters were recorded as the same as the treatment group. The total VSS score after the combination therapy is 0.96 ± 1.53, which in comparison with prior treatment VSS score 8.86 ± 1.43, showed a significant reduction following the treatments (P < 0.001). The control group without any treatment shows VSS score 7.10 ± 0.99 at the end of the study vs VSS score 7.70 ± 0.82 at the start of the study (P > 0.05). The patient satisfaction rate reaches 89.2% after treatment, The major side effects reported include 3 patients with post-inflammatory hyperpigmentation (10.7% of patients in the treatment group), and other minor discomfort such as transient warmth, erythema, and swelling of treatment sites. The combination approach using 1565-nm non-ablative laser and low dose of local application of compound betamethasone can effectively improve the immature red hypertrophic scar with no significant side effects; this should provide our practitioners with a new weapon in fighting those hard-to-manage early scar formations.

Management of hypertrophic scars in adults: A systematic review and meta-analysis

Hypertrophic scars (HTS) are elevated scars which occur due to abnormalities in wound healing after injury and may be associated with pain, pruritus and functional impairment. Despite multiple available treatment options, there is no universal approach to treating HTS. We searched the Web of Science (Core Collection), MEDLINE and EMBASE databases. Title, abstract and full-text screening, along with data extraction, were performed in duplicate. Risk of bias was assessed using the Cochrane risk-of-bias tool. The Vancouver Scar Scale (VSS) scores and mean differences were used for meta-analysis. We screened 3800 abstracts and included 34 randomised controlled trials evaluating treatments for HTS in adults. Silicone and laser modalities improved VSS scores by 5.06 (95% CI: 6.78, 3.34) and 3.56 (95% CI: 5.58, 1.54), respectively. Intralesional triamcinolone combined with silicone or 5-fluorouracil was superior to intralesional triamcinolone monotherapy. Limitations of this study include exclusion of studies which did not utilise VSS, and pooling of studies based on common modalities. Further studies are needed to examine the efficacy of existing and emerging treatment modalities for HTS. Our study supports the treatment of HTS in adults with silicone gel or sheets, injected triamcinolone (preferably combined with 5-fluorouracil or silicone products), pulsed dye laser and fractionated CO₂ laser.

The Most Current Algorithms for the Treatment and Prevention of Hypertrophic Scars and Keloids: A 2020 Update of the Algorithms Published 10 Years Ago

BACKGROUND

In 2010, this Journal published my comprehensive review of the literature on hypertrophic scars and keloids. In that article, I presented evidence-based algorithms for the prevention and treatment of these refractory pathologic scars. In the ensuing decade, substantial progress has been made in the field, including many new randomized controlled trials. To reflect this, I have updated my review.

METHODS

All studies were evaluated for methodologic quality. Baseline characteristics of patients were extracted along with the interventions and their outcomes. Systematic reviews, meta-analyses, and comprehensive reviews were included if available.

RESULTS

Risk factors that promote hypertrophic scar and keloid growth include local factors (tension on the wound/scar), systemic factors (e.g., hypertension), genetic factors (e.g., single-nucleotide polymorphisms), and lifestyle factors. Treatment of hypertrophic scars depends on scar contracture severity: if severe, surgery is the first choice. If not, conservative therapies are indicated. Keloid treatment depends on whether they are small and single or large and multiple. Small and single keloids can be treated radically by surgery with adjuvant therapy (e.g., radiotherapy) or multimodal conservative therapy. For large and multiple keloids, volume- and number-reducing surgery is a choice. Regardless of the treatment(s), patients should be followed up over the long term. Conservative therapies, including gel sheets, tape fixation, topical and injected external agents, oral agents, and makeup therapy, should be administered on a case-by-case basis.

CONCLUSIONS

Randomized controlled trials on pathologic scar management have increased markedly over the past decade. Although these studies suffer from various limitations, they have greatly improved hypertrophic scar and keloid management. Future high-quality trials are likely to improve the current hypertrophic scar and keloid treatment algorithms further.

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.

Combination therapy using non-ablative fractional laser and intralesional triamcinolone injection for hypertrophic scars and keloids treatment

Combinations of various treatment modalities were shown to be more effective than monotherapy when treating hypertrophic scars and keloids. This study was conducted to assess the effectiveness of combination therapy with non-ablative fractional laser and intralesional steroid injection. From May 2015 to June 2017, a total of 38 patients with hypertrophic scars or keloids were evaluated. The control group of 21 patients received steroid injection alone, and 17 patients (the combined group) received 1550-nm erbium-glass fractional laser treatment and steroid injection simultaneously. The mean number of treatment sessions was statistically fewer in the combined group than in the control group (6.95 vs 5.47, P = .042). There was a significant difference in the patient's scale in the combined group (14.62 vs 22.82, P = .005); however, the observer's scale was not significantly different (17.92 vs 20.55, P = .549). The recurrence rate was 38.1% (8/21) in the control group and 35.3% (6/17) in the combined groups and showed no significant difference (P = .859). However, the mean remission period was statistically longer in the combined group (3.00 months vs 4.17 months, P = .042). Combination therapy with non-ablative fractional laser and intralesional steroid injection showed better results for the treatment of hypertrophic scars and keloids with fewer treatment sessions, better patient satisfaction, and longer remission periods.

The Important Factors Associated with Treatment Response in Laser Treatment of Facial Scars: A Single-Institution Based Retrospective Study

Background

There is increased interest in laser treatment of facial scars.

Objective

To determine the factors associated with treatment response.

Methods

We conducted an institution-based retrospective study by including the patients treated with laser for facial scars from 2012 to 2015. Treatment methods were determined with an algorithm according to individual scar characteristics. In each treatment session, either a 595-nm pulsed-dye laser or a non-ablative fractional laser was used, often in combination with a corticosteroid injection. We evaluated treatment responses based on the number of treatment sessions required to reach the treatment endpoint. Data were analyzed using multinomial logistic regression analysis to examine the association between treatment response and various factors of the scar.

Results

A total of eighty-four scars were analyzed. The onset of treatment (defined as the period between the injury and treatment initiation), used laser modality, and the location of the scar were all found to be significantly associated with treatment responses. Early implementation was more likely to provide better treatment response. Scars on the perioral area were more likely to be associated with worse treatment response.

Conclusion

The important factors for the treatment response in facial scars were the location of the scar and the timing of the initiation of treatment. Such information can be used to predict treatment response and tailor the treatment plan to the patient, depending on scar characteristics.

Treatment of keloid scars using light-, laser- and energy-based devices: a contemporary review of the literature

Keloid scars are common and have a predilection for young, ethnic skin often with a family history. Keloids can be painful and pruritic and cause significant emotional distress when particularly visible or prominent. In this article, we review the evidence underlying the use of laser- and energy-based devices for treatment of keloid scars, either as monotherapy or in conjunction with other therapies such as corticosteroids, surgery and silicone gel in the treatment of keloid scars.

Split face evaluation of long-pulsed non-ablative 1,064 nm Nd:YAG laser for treatment of direct browplasty scars

PURPOSE

To investigate 1,064 nm long-pulse Nd:YAG laser for postoperative treatment of direct browplasty scars.

METHODS

Nine patients who underwent direct browplasty were enrolled in this prospective study. Subjects were randomized to unilateral laser treatment at 2-week intervals for six total treatments, with the contralateral scar used as a control. Prior to each treatment, subjects rated treated and control scars on overall cosmesis. Post-treatment, subjects rated each for erythema, swelling, discomfort, and perceived hair loss. Finally, examiners masked to treatment side were asked to judge side-by-side photographs of first and final visits for improvement and side effects.

RESULTS

Subjects rated the overall appearance of the treated scar significantly higher at the time of treatment number 5 (mean score 5.13 ± 2.03, P = 0.008) and treatment number 6 (6.25 ± 1.98, P = 0.005) compared to treatment 1 (3.75 ± 2.12); by contrast, they failed to rate the control scar more highly. On masked examination of photographs, the treated scar was selected as most improved 50.0 ± 12.5% of the time. Both subjects and graders reported side effects as transient and mild to moderate (mean score 1-4), with no reports of hair loss from either subjects or observers.

CONCLUSIONS

The 1,064 nm Nd:YAG laser provided significant improvement in scar cosmesis after direct browplasty, as rated by subject self-report, but not by masked observers, and appears to be a useful tool for increasing satisfaction among those dissatisfied with direct browplasty scars. Side effects-including erythema, edema, and discomfort-were transient and universally rated as mild to moderate. Lasers Surg. Med. 48:742-747, 2016. © 2016 Wiley Periodicals, Inc.

Non-ablative fractional resurfacing in the treatment of scar contracture

BACKGROUND AND OBJECTIVES

A 28-year-old female presented with extensive scarring after a traumatic injury to her right lower extremity. She had been hit by a vehicle one year prior to presentation and had several open fractures with extensive overlying cutaneous damage, which required multiple surgeries and skin grafts. She had limited range of motion of the affected limb secondary to scar contracture.

STUDY DESIGN/MATERIALS AND METHODS

The patient received 6 treatments with a non-ablative fractional resurfacing (NAFR) device with two wavelengths (Fraxel DUAL, Solta Medical, Hayward, CA) spaced 4-8 weeks apart. The patient received two treatments with the 1927 nm NAFR thulium laser (10 mJ, 30% density, 8 passes) and two treatments with the 1550 nm NAFR laser (40 mJ, 17-26% density, 8 passes). Before and after treatment photographs were taken, as well as range of motion measurements with respect to her right ankle.

RESULTS

The patient had 50-75% improvement in the texture and discoloration. There was both subjective and objective improvement in the range of motion of her right lower extremity. The patient experienced mild erythema and edema, both of which resolved after 7-10 days.

CONCLUSION

Recent studies have shown great functional improvement in scar contractures with ablative fractional laser treatments; however, these treatments are accompanied by significant downtime along with risk of further scarring and infection. NAFR is an accessible treatment with a low side effect profile and to our knowledge has not been reported as efficacious in the treatment of scar contracture. This case report is novel in its demonstration of the utility of a dual wavelength NAFR in the treatment of scar contracture and functional impairment.