Fractional CO2 Laser Therapy for Effective Treatment of Facial Traumatic Hypertrophic Scar: A Case Report.

BACKGROUND Hypertrophic scars occur when there is an excessive wound-healing response in the skin. Fractional, or fractionated, carbon dioxide (CO2) laser therapy uses narrow shafts of light to smooth the skin surface and stimulate dermal collagen, which tightens the skin. This case report describes a 57-year-old woman with a traumatic hypertrophic scar of the face treated with fractional carbon dioxide laser therapy. The purpose of this case report was to highlight the role of fractional CO2 laser therapy in treatment of a facial traumatic hypertrophic scar in a patient after a motor vehicle crash. CASE REPORT A 57-year-old female patient presented with a hypertrophic, rigid, post-traumatic scar on the left side of her face following a motor vehicle crash. For the hypertrophic scar removal, the patient underwent 1 treatment session with fractional CO2 laser using the µ-Scan DOT scanning system. After 1 laser treatment session, the photographic documentation, which permits monitoring the treatment's effectiveness in esthetic improvement, showed a significant improvement in scar texture and color. In addition, a significant reduction in scar height was observed following laser therapy. Fractional laser treatment with the device was very well tolerated by the patient, who reported no pain or discomfort, complications, or adverse effects either during treatment or in the follow-up period (3 months). CONCLUSIONS This report demonstrates the cosmetic application of fractional carbon dioxide laser therapy in a case of hypertrophic scar with the use of an effective therapeutic protocol that did not require the use of suturing.

Risk factors for local recurrence of keloids and hypertrophic scars after postoperative electron beam radiotherapy.

OBJECTIVE: Keloids and hypertrophic scars are benign fibroproliferative lesions that occur as a result of skin injury. Postoperative radiation therapy is used to reduce the recurrence rate because of the high recurrence rate with surgical treatment alone. This study aimed to identify the risk factors for recurrence after postoperative electron beam radiotherapy. MATERIALS AND METHODS: Patients with keloid or hypertrophic scars with at least one lesion and who underwent postoperative electron beam radiotherapy at our institution from June 2013 to March 2022 were included in the study, while patients with a follow-up period of fewer than three months were excluded. RESULTS: A retrospective analysis was performed on 94 lesions in 81 patients. Exactly two years after the treatment, the actuarial local control rate was 86.4%. The chest wall, shoulder, and suprapubic area were identified as high-risk recurrence sites. Compared to other body sites, these sites had significantly lower local control rates (two-year local control rates: 75.5% vs. 95.2%, P = 0.005). After multivariate analysis, treatment site (P = 0.014), male gender (P = 0.019), and younger age (P = 0.029) were revealed to be statistically significant risk factors for local recurrence. Risk factors for keloid recurrence after postoperative electron beam radiotherapy were therefore identified. CONCLUSION: This result could be used for follow-up and as a determinant for the optimal dose/fractionation of postoperative radiotherapy.

The efficacy, satisfaction, and safety of carbon dioxide (CO2) fractional laser in combination with pulsed dye laser (PDL) versus each one alone in the treatment of hypertrophic burn scars: a single-blinded randomized controlled trial.

The tendency to use less-invasive laser-based methods with far more obvious effectiveness has been taken into consideration today for improvement of burning scars. The present study thus aimed to assess the efficacy of two laser-based techniques including pulsed dye laser (PDL) and ablative fractional CO2 laser (AFCL) and its combination on improving different aspects of burning scars regardless of the types of scar as hypertrophic or keloid scars. This randomized single-blinded clinical trial was performed on patients suffering hypertrophic or keloid burning scars. The patients were randomly assigned into three groups scheduling for treatment with PDL alone, AFCL alone, or its combination. All patients were visited before and 40 days after the last treatment session, and their scars were assessed. In all groups, significant improvement was revealed in the Vancouver scar scale (VSS) score, the color of scar, vascular bed in the scar, the and height of scar and its pliability; however, the improvement in each item was more highlighted in the group receiving a combination therapy with PDL and AFCL techniques. In this regard, the highest improvement was found in vascular bed and pliability in the combination therapy group as compared to other groups. Although the superiority of the combined group was not statistically significant, due to the high percentage of improvement in total VSS and most of its indicators, it can be clinically significant. The efficacy of the treatment protocols was different considering subgroups of mature and immature scars (less than 1 year), so that more improvement in pliability of scar, vascularity, and color of scar was found in the group scheduling for PDL + AFCL as compared to those who were treated with PDL alone in immature scar group but not in mature scar group. Combined treatment can be much more effective in improving the appearance and pathological characteristics of scars than each individual treatment. This effectiveness can be seen mainly in immature scars.

Treatment of Hypertrophic Burn Scars With Laser Therapy: A Review of Adverse Events.

ABSTRACT: Hypertrophic scarring, characterized by excessive scar tissue formation, is a debilitating outcome that significantly impairs physical and psychosocial recovery after burn injury. Hypertrophic scarring affects a substantial proportion of burn survivors, with reported prevalence as high as 70%. Fractional CO 2 laser (FCL) therapy, a therapy commonly used in acne scar treatment or skin rejuvenation, has become popular in treating hypertrophic scars. Little is known regarding FCL's adverse events for burn scar treatment. We hypothesize that FCL is a safe treatment modality with minimal adverse events in the management of hypertrophic burn scars. This is a retrospective chart review of adverse events after FCL at 2 centers within a single institution. Burn patients undergoing FCL between May 1, 2019, and June 1, 2021 were included. Demographics, injury etiology, laser treatment details, and adverse events were collected. A total of 170 patients, 77 (45.3%) males and 93 (54.7%) females, underwent 544 FCL therapies for burn scars. The average number of treatments per patient was 3 ± 2.23, with a range of 1 to 17 sessions. From the total 544 laser therapy sessions, 13 adverse events (2.4%) were reported. There were 5 reports (0.9%) of increased postprocedural pain and 1 report (0.2%) of increased paresthesia/numbness to laser site. Three instances (0.6%) of increased erythema and 4 reports (0.7%) of epidermal sloughing or blistering were reported. All but 5 patients (2.9%) reported improvements to scar symptoms. This study demonstrates minimal adverse events associated with FCL for hypertrophic burn scar treatment.

SMOOTH protocol: A pilot randomised prospective intra-patient single-blinded observational study for examining the mechanistic basis of ablative fractional carbon dioxide laser therapy in treating hypertrophic scarring.

BACKGROUND: Burn injuries are the fourth most common type of trauma and are associated with substantial morbidity and mortality. The impact of burn injury is clinically significant as burn injuries often give rise to exuberant scarring. Hypertrophic scarring (HTS) is a particular concern as up to 70% of burns patients develop HTS. Laser therapy is used for treating HTS and has shown positive clinical outcomes, although the mechanisms remain unclear limiting approaches to improve its effectiveness. Emerging evidence has shown that fibroblasts and senescent cells are important modifiers of scarring. This study aims to investigate the cellular kinetics in HTS after laser therapy, with a focus on the association of scar reduction with the presence of senescent cells. METHODS: We will conduct a multicentre, intra-patient, single-blinded, randomised controlled longitudinal pilot study with parallel assignments to achieve this objective. 60 participants will be recruited to receive 3 interventional ablative fractional CO2 laser treatments over a 12-month period. Each participant will have two scars randomly allocated to receive either laser treatment or standard care. Biopsies will be obtained from laser-treated, scarred-no treatment and non-scarred tissues for immune-histological staining to investigate the longitudinal kinetics of p16INK4A+-senescent cells and fibroblast subpopulations (CD90+/Thy1+ and αSMA+). Combined subjective scar assessments including Modified Vancouver Scar Scale, Patient and Observer Scar Assessment Scale and Brisbane Burn Scar Impact Profile; and objective assessment tools including 3D-Vectra-H1 photography, DermaScan® Cortex, Cutometer® and ColoriMeter®DSMIII will be used to evaluate clinical outcomes. These will then be used to investigate the association between senescent cells and scar reduction after laser therapy. This study will also collect blood samples to explore the systemic biomarkers associated with the response to laser therapy. DISCUSSION: This study will provide an improved understanding of mechanisms potentially mediating scar reduction with laser treatment, which will enable better designs of laser treatment regimens for those living with HTS. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04736251.

Efficacy and safety of ablative CO2 fractional laser and narrowband intense pulsed light for the treatment of hypertrophic scars: a prospective, randomized controlled trial.

BACKGROUND AND OBJECTIVES: Hypertrophic scarring is a complex process, and numerous methods have been introduced to treat scars. This study aims to evaluate the effect of combined CO2 fractional laser and narrowband intense pulsed light (IPL) compared to IPL alone in the treatment of hypertrophic scars. MATERIALS AND METHODS: This was a prospective, randomized controlled study enrolled 138 patients with hypertrophic scars. The participants were randomly divided into two groups: CO2-IPL and IPL group, and received three sessions at 10-14-week intervals for 3-month follow-up. Two independent plastic surgeons evaluated the treatments using the Patient and Observer Scar Assessment Scales (POSAS). Overall satisfaction was evaluated using the Patient Satisfaction Scale (PSS). RESULTS: 101 subjects completed the study. Compared to single IPL, the combination CO2-IPL group showed a significant improvement in itching, color, stiffness, thickness, and irregularity, except for pain, and an enhancement in vascularization, pigmentation, thickness, relief, and pliability of the scar, assessed by POSAS (p < .01). 100% patients in the combination group were satisfied compared to 84% in IPL alone. CONCLUSION: The combination of CO2 fractional laser and narrowband IPL efficiently improved the appearance and profile of hypertrophic scars, offering a comprehensive and reliable approach for scar therapy.

Quantitative simulation of photothermal effect in laser therapy of hypertrophic scar.

BACKGROUND: Laser technology has been widely used in the treatment of hypertrophic scar (HPS). Due to the lack of effective quantitative relationship between laser doses and thermal effect of lesion tissue, the selection of laser doses in clinical laser treatment of HPS is blind, which cannot guarantee the best treatment effect. MATERIALS AND METHODS: The photothermal model of HPS was established by using finite element method. The effects of laser dose parameters such as laser energy density, pulse width, and spot diameter on the thermal effects of laser treatment were analyzed. According to tissue temperature threshold and thermal damage degree of the simulation results, the optimal laser doses of HPS were selected for the laser treatment experiments of rabbit ear HPSs to verify the rationality of the quantitative photothermal model. RESULTS: The temperature rise and thermal damage degree of HPS following laser treatment were directly correlated to the laser doses, which grew with the increase of energy density and laser pulse width. For the different spot diameters, the temperature rise decreased with the increase of spot diameter, whereas the thermal damage degree worsened with the increase of spot diameter. Both simulation and experimental results show that the optimal treatment parameters of HPS were as follows: The laser energy density was 7.5 J/cm3 , the pulse width was 4 ms, and the spot diameter was 7 mm. CONCLUSION: The laser dose parameters optimized by the photothermal model have achieved good therapeutic effects in the rabbit ear HPS, indicating that the model can be used for quantitative evaluation of laser doses before clinical treatment.

A Review of Laser Therapies for the Treatment of Scarring and Vascular Anomalies.

Significance: Laser use has become part of the gold standard of treatment as an effective adjuvant in multimodal therapy for pathologic scarring caused by burns, trauma, acne, and surgery, as well as vascular anomalies. Understanding indications and applications for laser therapy is essential for physicians to improve patient outcomes. Recent Advances: Since the 1980s, the medical use of lasers has continuously evolved with improvements in technology. Novel lasers and fractionated technologies are currently being studied in the hopes to improve treatment efficacy, while reducing complications. Recent advancements include acne treatment with novel picosecond lasers, new hypertrophic scar therapies with simultaneous laser and intense pulsed light use, and novel systems such as lasers with intralesional optical fiber delivery devices. In addition, optimizing the timing of laser therapy and its use in multimodal treatments continue to advance the field of photothermolysis. Critical Issues: Selecting the correct laser for a given indication is the fundamental decision when choosing a laser balancing effective treatment with minimal complications. This article covers the principles of laser therapy, the preferred lasers used for the treatment of scarring and vascular anomalies, and discusses the current evidence behind these laser choices. Future Directions: To optimize laser therapy, larger randomized control trials and split scar studies are needed. Continued advancement through better randomized controlled studies will help to improve patient outcomes on a broader scale.

CO2 fractional laser combined with triamcinolone acetonide injection for the hypertrophic scars: which is first?

The aim of this study is to investigate and analyze the effect of different application sequences of CO2 fractional laser and triamcinolone acetonide injection on the application effect of hypertrophic scar in one operation. Patients with hypertrophic scars who received CO2 lattice laser combined with triamcinolone acetonide injection from January 2021 to December 2022 were retrospectively analyzed. According to the different initial operations, they were divided into CO2 FL-TA group and TA-CO2 FL group. The Vancouver Scar Scale score and scar thickness of the two groups before and after treatment were analyzed. The complications occurred in the two groups during the treatment period. The clinical efficacy of the two groups before and after the treatment was calculated. Before treatment, there was no difference in scar thickness and VSS score between the two groups (P > 0.05). After treatment, the above indexes in CO2 FL-TA group were significantly better than those in TA-CO2 FL group (P < 0.05); the incidence of adverse reactions in CO2 FL-TA group was 9.38%, which was significantly lower than that in TA-CO2 FL group (18.75%) (P < 0.05); the total effective rate of CO2 FL-TA group was 90.63%, which was significantly higher than that in TA-CO2 FL group (65.63%) (P < 0.05). In the process of combined CO2 fractional laser and triamcinolone acetonide injection in the treatment of hypertrophic scars, CO2 fractional laser treatment first, and then triamcinolone acetonide injection can reduce the number of treatments, reduce the incidence of adverse reactions, and achieve more satisfactory treatment effect.

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.

Laser Treatment of Burn Scars. / Tratamiento láser de cicatrices por quemaduras.

Burn scars cause high morbidity in the form of contractures, body disfigurement, and itching, and they also have a high emotional impact that adversely affects patient quality of life. Laser therapy has proven effective in this setting. It is superior to topical treatments and can be used in conjunction with surgery, helping to reduce morbidity. The use of lasers in hospital dermatology departments, however, is still limited. Carbon dioxide laser resurfacing is the most widely used modality for reducing scar thickness, improving textural abnormalities, and treating contractures. Treatments improve mobility for patients with constrictions. Pulsed dye laser treatments are particularly useful for reducing erythema in recent burn scars and preventing subsequent hypertrophy. Pigment laser treatments with short pulse durations (nanoseconds or picoseconds) can improve hyperpigmentation. In this article, we review the evidence for the use of laser therapy for burn scars and propose a treatment algorithm.

Efficacy of the Neodymium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Keloid and Hypertrophic Scars: A Systematic Review and Meta-analysis.

BACKGROUND: Keloid and hypertrophic scars are the most common types of pathological scars. They can cause itching, pain, erythema, and psychological stress due to cosmetic problems, decreasing the quality of life for affected individuals. The neodymium-doped yttrium aluminum garnet (Nd:YAG) multipurpose laser is used to treat pathological scars, and studies have shown that the Nd:YAG laser can markedly improve scarring. AIMS: We performed a meta-analysis to evaluate the efficacy of the Nd:YAG laser in the treatment of keloid and hypertrophic scars. METHODS: A literature search of PubMed, Web of Science, Scopus, Cochrane, Embase, CNKI, and Wanfang was performed between January 1st, 2010, and July 14th, 2021. The Vancouver Scar Scale (VSS) was used to evaluate treatment outcomes. We used the R version 4.0.0 software for statistical analysis. RESULTS: The Nd:YAG laser improved the condition of keloid and hypertrophic scars and reduced VSS score (mean difference [MD]: 2.96, 95% confidence interval [CI]: 2.08-3.84, p < 0.01). There was no obvious difference in the results between regions. A subgroup analysis by scar type revealed that the curative effect of the Nd:YAG laser on keloid scars (MD: 2.02, 95% CI: 0.58-4.63, p = 0.10) was less marked compared with that on hypertrophic scars (MD: 3.05, 95% CI: 1.58-4.52, p < 0.01). With the combined use of the Nd:YAG laser and other treatment methods, a more significant change in VSS score was noted (MD: 4.28, 95% CI: 2.07-6.49). CONCLUSIONS: This meta-analysis showed that the Nd:YAG laser can improve the condition of keloid and hypertrophic scars and effectively reduce VSS score. Moreover, the curative effect of this approach on keloid scars is less marked compared with that on hypertrophic 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.

The efficacy and safety of low-energy carbon dioxide fractional laser use in the treatment of early-stage pediatric hypertrophic scars: A prospective, randomized, split-scar study.

BACKGROUND: Various laser therapies have been introduced in scar management. However, pain during treatment has limited the application of laser therapy in pediatrics. OBJECTIVES: To evaluate whether the use of the low-energy mode of a carbon dioxide (CO2 ) laser improves hypertrophic scars in a pediatric population. METHODS: This prospective, randomized, split-scar trial was designed to assess the safety and efficacy of low-energy CO2 laser use. Patients aged <12 years with hypertrophic scars were enrolled. Each hypertrophic scar was equally divided into three parts: the two ends of each scar were randomly assigned to control and experimental groups, and the center portion was considered a transition zone and was not included in the analysis. A total of three laser treatments were performed at 1-month intervals. Scar scale scores 6 months after the final treatment was the primary outcome. Additionally, the Visual Analog Scale (VAS) was used to evaluate pain after each treatment. RESULTS: Of the 23 patients enrolled, 20 completed the study. The total Patient and Observer Scar Assessment Scale (POSAS) score at the 6-month follow-up was significantly lower for the treated site (44.95 for the treated group vs. 64.85 for the control group, p < 0.0001). Both the patient and observer POSAS scores showed an obvious difference between the treated and control groups (19.95 vs. 29.95 for patient scores, respectively, p < 0.0001, and 26.00 vs. 34.90 for observer scores, respectively, p < 0.0001). All observer and patient scores describing pain, pruritus, color, stiffness, and thickness were statistically different and favored the treated site. No significant difference was found in patient score of irregularity. The average VAS therapeutic pain score was 3.5 ± 1.43 out of 10. CONCLUSIONS: Low-energy CO2 fractional laser therapy improved hypertrophic scars in a pediatric population. Therefore, for children with hypertrophic scar, low-energy CO2 laser with less procedure pain may be more appropriate.

595-nm pulsed dye laser combined with fractional CO2 laser reduces hypertrophic scar through down-regulating TGFß1 and PCNA.

595-nm pulsed dye laser and fractional CO2 laser have been demonstrated effective to treat hypertrophic scar. The underlying mechanism may involve transforming growth factor-beta1 (TGFß1) and proliferating cell nuclear antigen (PCNA), but remains to be clarified. Our study was performed to investigate how 595-nm pulsed dye laser combined with fractional CO2 laser treats hypertrophic scars in a rabbit model through regulating the expression of TGFß1 and PCNA. Twenty-four New Zealand white rabbits were randomly divided into control group, pulsed dye laser group, fractional CO2 laser group, and pulsed dye laser + fractional CO2 laser (combination) group. Surgical wounds were made and allowed to grow into hypertrophic scars at day 28. Next, 595-nm pulsed dye laser (fluence: 15 J/cm2; square: 7 mm; pulse duration: 10 ms) was used in pulsed dye laser and combination group, while fractional CO2 laser (combo mode, deep energy: 12.5 mJ; super energy: 90 mJ) in fractional CO2 laser and combination groups, once every 4 weeks for 3 times. The appearance and thickness of hypertrophic scar samples were measured with hematoxylin-eosin and Van Gieson's straining. The expressions of TGFß1 and PCNA were evaluated by immunohistochemical and western blot analysis. A significant improvement was noted in the thickness, size, hardness, and histopathology of hypertrophic scar samples after laser treatment, especially in combination group. Scar Elevation Index (SEI), fiber density (NA), and collagen fiber content (AA) decreased most significantly in combination group (2.10 ± 0.14; 2506 ± 383.00; 22.98 ± 2.80%) compared to 595-nm pulsed dye laser group (3.35 ± 0.28; 4857 ± 209.40; 42.83 ± 1.71%) and fractional CO2 laser group (2.60 ± 0.25; 3995 ± 224.20; 38.33 ± 3.01%) (P < 0.001). Furthermore, TGFß1 and PCNA expressions were more suppressed in combination group (8.78 ± 1.03; 7.81 ± 1.51) than in 595-nm pulsed dye laser (14.91 ± 1.68; 15.73 ± 2.53) and fractional CO2 laser alone group (15.96 ± 1.56; 16.13 ± 1.72) (P < 0.001). The combination of 595-nm pulsed dye laser with fractional CO2 laser can improve the morphology and histology of hypertrophic scars in a rabbit model through inhibiting the expression of TGFß1 and PCNA protein. Our findings can pave the way for new clinical treatment strategies for hypertrophic scars.

Fractional Ablative Laser Therapy is an Effective Treatment for Hypertrophic Burn Scars: A Prospective Study of Objective and Subjective Outcomes.

OBJECTIVE: The aim of this study is to determine objective and subjective changes in mature hypertrophic burn scars treated with a fractional ablative carbon dioxide (CO2) laser. BACKGROUND: Fractional CO2 laser treatment has been reported to improve burn scars, with increasing clinical use despite a paucity of controlled, prospective clinical studies using objective measures of improvement. METHODS: A multicenter, site-controlled, prospective open-label study was conducted from 2013 to 2016. Objective and patient-reported outcome measures were documented at baseline, at each monthly laser treatment, and 6 months after treatment. Objective measurements employed were: mechanical skin torque to measure viscoelastic properties; ultrasonic imaging to measure scar thickness; and reflectometry to measure erythema and pigmentation. Subjective measures included health-related quality of life, patient and investigator scar assessment scales, and blinded scoring of before and after photographs. Subjects aged 11 years or older with hypertrophic burn scars were recruited. Each subject received 3 monthly treatment sessions with an ablative fractionated CO2 laser. RESULTS: Twenty-nine subjects were enrolled, of whom 26 received at least 1 fractional CO2 laser treatment and 22 received 3 treatments. Mean age of those completing all 3 treatments was 28 years. Statistically significant objective improvements in elastic stretch (P < 0.01), elastic recovery (P < 0.01), extensibility (P < 0.01), and thickness (P < 0.01) were noted. Patient- and physician-reported scar appearance and pain/pruritus were significantly improved (P < 0.01). There was no regression of improvement for at least 6 months after treatment. CONCLUSIONS: Fractional ablative laser treatment provides significant, sustained improvement of elasticity, thickness, appearance, and symptoms of mature hypertrophic burn scars.

Efficacy and safety of Nd:YAG laser alone compared with combined Nd:YAG laser with intralesional steroid or botulinum toxin A in the treatment of hypertrophic scars.

The aim of this study is to evaluate the efficacy and safety of Nd:YAG laser alone or in combination with intralesional injection of botulinum toxin type A or intralesional injection of steroid in treatment of hypertrophic scars. This study included 45 patients with hypertrophic scars who were randomly divided into three equal groups. All participants received 4 sessions of Nd:YAG laser at 4-week intervals. Immediately after the laser treatment, patients in group II were assigned to intralesional triamcinolone acetonide, and those in group III were assigned to intralesional botulinum toxin type A. All patients were followed up monthly for 3 months after the last session for any recurrence, or side effects. Clinical evaluation of the cases was done by Vancouver Scar Scale. Hypertrophic scars in the three groups showed a significant improvement (p < 0.001) compared with before treatment in all variables (except for pigmentation) and also a significant improvement in pruritus, pain, and patient relief. The highest percentage of improvements was seen in patients treated with Nd:YAG laser combined with intralesional steroid in all variables according to Vancouver Scar Scale. The degree of improvement was negatively correlated with the patients' age. The three treatment modalities were effective, safe with minimal side effects. Nd:YAG laser followed by intralesional injection of Triamcinolone acetonide had the highest percentage of Vancouver Scar Scale reduction. Combination therapy of Nd:YAG laser with intralesional injection of either Triamcinolone acetonide or Botox revealed better results than using Nd:YAG as a single therapeutic modality for HTS.

Effect of UVA1 on hypertrophic scarring in the rabbit ear model.

Hypertrophic scars (HTSs) are common and cause functional and psychological morbidity. UVA1 (340-400 nm) phototherapy has been previously shown to be effective in the treatment of localized scleroderma, systemic sclerosis, and POEMS syndrome with minimal side effects, all of which are presented as collagen fibrils hyperplasia that is common with scarring in skin histology. In the present study, we aimed to investigate the impact of UVA1 on the protein expression of TGF-ß signal pathway and myofibroblasts in a rabbit model of cutaneous scarring. Full-thickness skin wounds (2 cm × 5 cm in diameter) were made in New Zealand white rabbits to establish the hypertrophic scarring model. New Zealand white rabbits were divided into two treatment groups (n=30 wounds per group with an equal number of controls): medium-dose of UVA1 phototherapy group: 60 J/cm2; high-dose of UVA1 phototherapy group: 110 J/cm2. Left ears were used for treatment and the right ones were used for control. Treatment was administered five times weekly for 6 weeks. Treated and untreated control wounds were harvested at various time points and examined by histologic examination, immunohistochemical assessment, and ultrastructural evaluation. The results showed that UVA1 phototherapy caused a significant reduction in dermal thickness by histological features, whereas the scar index was descended significantly in both medium- and high-dose UVA1 groups compared with the control group. Examination of immunohistochemistry also revealed a marked suppression of tissue growth factor-ß (TGF-ß) (both medium- and high-dose), α smooth muscle actin (α-SMA) (only high-dose), and tissue inhibitor of metalloproteinase 1 (TIMP-1) (only high-dose), and apparent increase in matrix metalloproteinases (MMP-1) (both medium- and high-dose) compared with the control. The ultrastructural evaluation showed the collagen fibers' diameter had shrunk, and that fibroblastic cytoplasm was not affluent and in a quiescent stage. These findings of the present study suggested that administration of UVA1 irradiation is effective to improve the experimental HTS model and raises a possibility of the therapeutic approach of UVA1 in the scar. Although not directly examined in the present study, MMP inhibition is hypothesized to be responsible for this effect. However, early UVA1 treatment could not prevent the formation of scar model.

Efficacy of Combined Intense Pulsed Light (IPL) With Fractional CO2 -Laser Ablation in the Treatment of Large Hypertrophic Scars: A Prospective, Randomized Control Trial.

BACKGROUND AND OBJECTIVES: Scar rehabilitation is a complex process that incorporates medical, surgical, and physical therapeutic measures to best restore function and visual normalcy. Lasers have emerged as essential tools in the management of scars, with devices available to address scar size, dyschromia, and contour irregularities. As different lasers treat these different features, multi-laser, same session therapeutic approaches may offer a more comprehensive approach to scar revision. In this study, we aim to demonstrate the effect of a combinatorial, same session treatment with intense pulsed light (IPL) and fractional ablative CO2 as compared to single laser treatment with fractional ablative CO2 laser alone or control in the treatment of mature hypertrophic scars. MATERIALS AND METHODS: This institutional review board-approved, randomized controlled trial, enrolled 23 healthy adults with large (>100 cm2 ) hypertrophic scars who were randomized to one of three treatment arms: (i) IPL and CO2 ablative fractional laser (AFL), (ii) CO2 AFL alone, and (iii) control (no laser treatment). Subjects underwent a total of four treatment sessions at 6-8-week intervals with follow-up visits at 1, 3, and 6 months following the last treatment session. Primary endpoints included blinded scoring of before and after photographs via the Manchester Scar Scale (MSS). Secondary endpoints included the Patient-Observer Scar Assessment Scale (POSAS). RESULTS: As compared to control and CO2 AFL laser alone, the combination of CO2 AFL and IPL demonstrated statistically significant improvement across a greater number of scar domains, as assessed by the MSS. 100% of subjects in both treatment groups showed a statistically significant decrease in the POSAS scale after the series of four treatment sessions. No adverse events were reported. CONCLUSION: Treatment with combined IPL and CO2 AFL demonstrated higher average improvements across the majority of assessed scar domains, as compared to both control and CO2 laser alone. The difference was not statistically significant in overall MSS score as expected due to the role of CO2 as the main source of improvement. However, only the combination group had statistically significant improvement in both color and texture. These findings support the assertion that a multi-photo-thermolytic approach with combined IPL and CO2 AFL can have a positive impact on the treatment of hypertrophic scars by using multiple wavelengths to maximize laser-skin interactions in targeting the different chromophores expressed in scar tissue. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Effective treatment for hypertrophic scar with dual-wave-length PDL and Nd:YAG in Chinese patients.

There are several ways to prevent and treat hypertrophic scars. In recent years, lasers have been quite extensively used in treating scars. For example, Pulsed Dye Laser (PDL) and Intense Pulsed Light (IPL) can accelerate mutation of scar, whereas non-ablative and ablative fractional laser can improvescar texture. Dual-wave-length laser treatment is extensively used for blood vessel diseases but is rarely used and less reported for treatment of hypertrophic scars. Our study focuses on the efficacy and safety of dual-wave-length PDL and Nd:YAG in treatment of hypertrophic scars. Twenty-five patients in our study complaining of hypertrophic scars were treated with combined PDL/Nd:YAG laser at 4-6 weeks intervals. Following this, the patients and observers assessed these scars by using Patient Scar Assessment Scale (PSAS) and Observer Scar Assessment Scale (OSAS). The resultsshowed that hypertrophic scar was significantly improved after several laser treatments, and no severe adverse effects were observed. Considering the safety and satisfactory effects of dual-wave-length laser treatment, it can be regarded as a good method for treating hypertrophic scars. This study clearly demonstrates that combined PDL/Nd:YAG laser treatment is an effective, safe and well-tolerated treatment option for hypertrophic scars.