Evidence-based therapy in hypertrophic scars: An update of a systematic review

Pathological-microenvironment responsive injectable GelMA hydrogel with visualized biodegradation for pressure-assisted treatment of hypertrophic scars

Intralesional injection of 5-fluorouracil for the clinical treatment of hypertrophic scars (HS) remains challenging due to its short half-life, as well as the absence of evidence-based dosage and frequency injection guidelines. Herein, we developed a matrix metalloproteinases (MMPs)/reactive oxygen species (ROS)-responsive injectable prodrug hydrogel (GFP) that exhibits sustained drug release and fluorescence imaging capability, aiming to facilitate the optimization of injection dosage and frequency in HS treatment. The GFP hydrogel comprises gelatin methacryloyl and pendant methacryloyl-decorated tetrapeptide (PPPK) with 5-fluorouracil acetic acid/rhodamine B at the N-terminus. After intralesional injection and blue light irradiation, the crosslinked hydrogel in HS lesions exhibited long-term sustained drug release by consuming overexpressed MMPs and ROS, which could be visualized by fluorescence imaging to guide injection frequency for HS treatment. In addition, due to its exceptional swelling and mechanical properties, the GFP hydrogel exerts a certain pressure inside the HS tissues, functioning as an adjunctive therapy to inhibit HS. Our results demonstrate that the GFP hydrogel can promote fibroblast apoptosis, inhibit collagen synthesis, and remodel the microenvironment of HS. This study presents a promising visualized drug delivery platform that potentially guides the optimization of injection frequency and dosage in the treatment of HS.

A Randomized Controlled Trial of Home-based Virtual Rehabilitation to Improve Adherence to Prescribed Home Therapy After Burn Injury: A Northwest Regional Burn Model System Trial

Daily rehabilitation after burn injury is vital for the prevention of function-limiting contractures. However, adherence to prescribed therapy following acute burn hospitalization has historically been low and not well-studied. Studies involving virtual reality technology have demonstrated an association with improved functional outcomes in burn therapy. We conducted a 5-year randomized controlled trial comparing 12 weeks of a home-based virtual rehabilitation (HBVR) system with standard burn therapy. Our primary outcome was adherence to prescribed home therapy, measured by e-diary self-report. Secondary outcomes included steps walked daily and patient-reported outcomes regarding stiffness, upper extremity function, and mobility. We enrolled 50 subjects, of which 48 provided data for analysis (23 HBVR, 25 control). Overall adherence to prescribed home therapy was low, 37.2% in the HBVR group and 60.0% in the control group. Reasons for nonadherence in the HBVR group included lack of time, engagement, and replacement of therapy with other physical activity. However, some subjects enjoyed HBVR and believed it aided their recovery. There was no difference in daily steps walked between the 2 groups. Daily walking gradually improved from 3500 steps per day in the first week after baseline and plateaued at 6000 steps per day at week 5. There were no differences in stiffness, upper extremity function, and mobility between the 2 groups at baseline and 3-, 6-, and 12-month follow-up. Subjects demonstrated improved upper extremity function and mobility in the first year after discharge, which coincided with increasing stiffness.

Efficacy and safety of sequential treatment with botulinum toxin type A, fractional CO2 laser, and topical growth factor for hypertrophic scar management: a retrospective analysis

Hypertrophic scars arise from aberrant wound healing and can lead to functional and aesthetic impairments. One of the common interventions for treating hypertrophic scars is fractional carbon dioxide (CO2) laser, which employs narrow laser beams to stimulate dermal collagen deposition. Recent studies and reports have suggested that combining laser therapy with other interventions such as botulinum toxin type A (BTX-A) and topical growth factors may enhance treatment outcomes. Here, we examine the efficacy and safety of a sequential combination of BTX-A, fractional CO2 laser, and topical growth factors, referred to as combined therapy, for treating hypertrophic scars compared with only using fractional CO2 laser and topical growth factors, referred to as monotherapy. Our retrospective study includes 128 patients with hypertrophic scars (56 underwent monotherapy and 72 underwent combined therapy), which were followed-up for up to 15 months after the initiation of treatment to collect demographic and clinical data. Our analysis showed that the combined therapy significantly outperformed monotherapy in improving Vancouver scar scale scores (P < 0.05) and in the reduction of scar thickness (P < 0.05), without increasing adverse complications. Repeated treatments further augmented the efficacy of the combined therapy. Subgroup analysis revealed that combined therapy was notably more effective in reducing Vancouver scar scale scores and scar thickness in early-stage scars compared to late-stage (P = 0.023 and P = 0.045, respectively). Our study suggests that including BTX-A treatment before fractional CO2 laser and topical growth factors offers superior efficacy in reducing hypertrophic scars. We encourage early intervention and repeated treatments for optimal treatment outcomes.

A Practice Approach to Acne Fulminans in Adolescents

Acne fulminans (AF) is a severe form of inflammatory acne commonly associated with adolescents. It is characterized by an abrupt onset of painful nodules and plaques and can progress to suppurative, ulcerative, and hemorrhagic lesions. AF can be associated with systemic symptoms such as fever, arthralgia, and bone pain. The etiology of AF is unknown but it has been linked to the use of certain medications and has been rarely found in autoinflammatory syndromes. In previous years, there have been reports of <200 cases in the literature; however, AF may be more common in clinical practice than reported. The most common presentation of AF is seen in adolescents starting isotretinoin therapy. Diagnosis of AF is determined based on its clinical findings. The main purpose of this article is to provide clinicians with a practical approach to treating AF. Current evidence for its treatment is limited to case reports and case series. The mainstay treatment of AF is a combination of prednisone and isotretinoin. It is important to taper or discontinue any exacerbating or precipitating medications such as isotretinoin, antibiotics, or androgens when AF is identified. Along with treatment of AF, it is important to treat associated scarring. Early identification and treatment of AF in adolescents is crucial to minimize both acute symptoms and long-term scarring, and further research is needed to determine optimal management.

Using Neuromodulators to Improve Scar Formation, Keloids, Rosacea, and Antiaging

BACKGROUND

Botulinum toxin A (BoNT-A) treatment has many uses in dermatology. Its mechanism of action and long-term effects for scar formation, rosacea, and antiaging are still being investigated.

OBJECTIVE

To conduct a literature review on BoNT-A to further investigate its use in scar formation, rosacea, and antiaging.

METHODS

A literature review was conducted using PubMed on botulinum toxin treatment for scar formation, rosacea, and antiaging. Studies discussing the toxin mechanism of action and treatment algorithm were included. The authors also provided their personal experience in BoNT-A use for these 3 conditions.

RESULTS

The mechanism of action of Botulinum toxin A in improving scar formation, rosacea, and antiaging is now better understood. While it is effective in the short term, little is still known about how frequently treatment needs to be repeated and if there are any long-term effects.

CONCLUSION

While in vitro studies have supporting evidence on the mechanism of action of BoNT-A on scar formation, rosacea, and antiaging, further studies are needed to identify long-term treatment effects.

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.

The Molecular Mechanisms Involved in the Hypertrophic Scars Post-Burn Injury

Scar formation is a normal response to skin injuries. During the scar-remodeling phase, scar tissue is usually replaced with normal, functional tissue. However, after deep burn injuries, the scar tissue may persist and lead to contractures around joints, a condition known as hypertrophic scar tissue. Unfortunately, current treatment options for hypertrophic scars, such as surgery and pressure garments, often fail to prevent their reappearance. One of the primary challenges in treating hypertrophic scars is a lack of knowledge about the molecular mechanisms underlying their formation. In this review, we critically analyze studies that have attempted to uncover the molecular mechanisms behind hypertrophic scar formation after severe burn injuries, as well as clinical trials conducted to treat post-burn hypertrophic scars. We found that most clinical trials used pressure garments, laser treatments, steroids, and proliferative inhibitors for hypertrophic scars, with outcomes measured using subjective scar scales. However, fundamental research using human burn injury biopsies has shown that pathways such as Transforming Growth factor β (TGFβ), Phosphatase and tensin homolog (PTEN), and Toll-like receptors (TLRs) could be potentially regulated to reduce scarring. Therefore, we conclude that more testing is necessary to determine the efficacy of these molecular targets in reducing hypertrophic scarring. Specifically, double-blinded clinical trials are needed, where the outcomes can be measured with more robust quantitative molecular parameters.

Human Umbilical Mesenchymal Stem Cells-Derived Microvesicles Attenuate Formation of Hypertrophic Scar through Multiple Mechanisms

Mesenchymal stem cells and the derived extracellular microvesicles are potential promising therapy for many disease conditions, including wound healing. Since current therapeutic approaches do not satisfactorily attenuate or ameliorate formation of hypertrophic scars, it is necessary to develop novel drugs to achieve better outcomes. In this study, we investigated the effects and the underlying mechanisms of human umbilical mesenchymal stem cells (HUMSCs)-derived microvesicles (HUMSCs-MVs) on hypertrophic scar formation using a rabbit ear model and a human foreskin fibroblasts (HFF) culture model. The results showed that HUMSCs-MVs reduced formation of hypertrophic scar tissues in the rabbit model based on appearance observation, and hematoxylin and eosin (H&E), Masson, and immunohistochemical stainings. HUMSCs-MVs inhibited invasion of HFF cells and decreased the levels of the α-SMA, N-WASP, and cortacin proteins. HUMSCs-MVs also inhibited cell proliferation of HFF cells. The MMP-1, MMP-3, and TIMP-3 mRNA levels were significantly increased, and the TIMP-4 mRNA level and the NF-kB p65/β-catenin protein levels were significantly decreased in HFF cells after HUMSCs-MVs treatment. The p-SMAD2/3 levels and the ratios of p-SMAD2/3/SMAD2/3 were significantly decreased in both the wound healing tissues and HFF cells after HUMSCs-MVs treatment. CD34 levels were significantly decreased in both wound healing scar tissues and HFF cells after HUMSCs-MVs treatment. The VEGF-A level was also significantly decreased in HFF cells after HUMSCs-MVs treatment. The magnitudes of changes in these markers by HUMSCs-MVs were mostly higher than those by dexamethasone. These results suggested that HUMSCs-MVs attenuated formation of hypertrophic scar during wound healing through inhibiting proliferation and invasion of fibrotic cells, inflammation and oxidative stress, Smad2/3 activation, and angiogenesis. HUMSCs-MVs is a potential promising drug to attenuate formation of hypertrophic scar during wound healing.

Pressure therapy for scars: Myth or reality? A systematic review

BACKGROUND

Hypertrophic scarring is a deviate occurrence after wound closure and is a common burn sequela. The mainstay of scar treatment consists of a trifold approach: hydration, UV-protection and the use of pressure garments with or without extra paddings or inlays to provide additional pressure. Pressure therapy has been reported to induce a state of hypoxia and to reduce the expression pattern of transforming growth factor-β1 (TGF-β1), therefore limiting the activity of fibroblasts. However, pressure therapy is said to be largely based on empirical evidence and a lot of controversy concerning the effectiveness still prevails. Many variables influencing its effectivity, such as adherence to treatment, wear time, wash frequency, number of available pressure garment sets and amount of pressure remain only partially understood. This systematic review aims to give a complete and comprehensive overview of the currently available clinical evidence of pressure therapy.

METHODS

A systematic search for articles concerning the use of pressure therapy in the treatment and prevention of scars was performed in 3 different databases (Pubmed, Embase, and Cochrane library) according to the PRISMA statement. Only case series, case-control studies, cohort studies, and RCTs were included. The qualitative assessment was done by 2 separate reviewers with the appropriate quality assessment tools.

RESULTS

The search yielded 1458 articles. After deduplication and removal of ineligible records, 1280 records were screened on title and abstract. Full text screening was done for 23 articles and ultimately 17 articles were included. Comparisons between pressure or no pressure, low vs high pressure, short vs long duration and early vs late start of treatment were investigated.

CONCLUSION

There is sufficient evidence that indicates the value of prophylactic and curative use of pressure therapy for scar management. The evidence suggests that pressure therapy is capable of improving scar color, thickness, pain, and scar quality in general. Evidence also recommends commencing pressure therapy prior to 2 months after injury, and using a minimal pressure of 20-25 mmHg. To be effective, treatment duration should be at least 12 months and even preferably up to 18-24 months. These findings were in line with the best evidence statement by Sharp et al. (2016).

Evaluation of botulinum toxin type A for treating post burn hypertrophic scars and keloid in children: An intra-patient randomized controlled study

BACKGROUND

Consequently, the management of post burn hypertrophic scars and keloid in children are a great challenge for the physicians, parents, and children themselves.

PURPOSE OF THE STUDY

To assess the efficacy and safety of treating hypertrophic and keloid scars with botulinum toxins injections.

PATIENTS AND METHODS

This is a randomized intra-patient comparative study was conducted on 15 children with post burn hypertrophic and keloid scars. Children were randomized to receive Intralesional injection of botulinum toxins on one part of the hypertrophic scar/keloid where the other part was left as a control. The assessment of clinical improvement was measured by the Vancouver scar scale (VSS) and by skin analysis camera system. Sessions were performed every month for 6 months.

RESULTS

Clinical and statistical dramatic improvement in the vascularity, pliability, and height of the lesions which have been injected with neuronox. Evaluation of the lesions by the Antera camera has proven marked changes in the vascularity and height. There was no correlations between Vancouver score improvement and variables such as the age, sex, skin type, and duration and lesion type.

CONCLUSIONS

The botulinum toxins proved its efficacy and safety in treatment of hypertrophic scars and keloid in children. It improved the associated itching and pain. Moreover it improves the pliability, erythema, and thickness of the scars.

The Role of Local Inflammation and Hypoxia in the Formation of Hypertrophic Scars-A New Model in the Duroc Pig

Hypertrophic scars continue to be a major burden, especially after burns. Persistent inflammation during wound healing appears to be the precipitating aspect in pathologic scarring. The lack of a standardized model hinders research from fully elucidating pathophysiology and therapy, as most therapeutic approaches have sparse evidence. The goal of this project was to investigate the mechanisms of scar formation after prolonged wound inflammation and to introduce a method for generating standardized hypertrophic scars by inducing prolonged inflammation. Four wound types were created in Duroc pigs: full-thickness wounds, burn wounds, and both of them with induced hyperinflammation by resiquimod. Clinical assessment (Vancouver Scar Scale), tissue oxygenation by hyperspectral imaging, histologic assessment, and gene expression analysis were performed at various time points during the following five months. Native burn wounds as well as resiquimod-induced full-thickness and burn wounds resulted in more hypertrophic scars than full-thickness wounds. The scar scale showed significantly higher scores in burn- and resiquimod-induced wounds compared with full-thickness wounds as of day 77. These three wound types also showed relative hypoxia compared with uninduced full-thickness wounds in hyperspectral imaging and increased expression of HIF1a levels. The highest number of inflammatory cells was detected in resiquimod-induced full-thickness wounds with histologic features of hypertrophic scars in burn and resiquimod-induced wounds. Gene expression analysis revealed increased inflammation with only moderately altered fibrosis markers. We successfully created hypertrophic scars in the Duroc pig by using different wound etiologies. Inflammation caused by burns or resiquimod induction led to scars similar to human hypertrophic scars. This model may allow for the further investigation of the exact mechanisms of pathological scars, the role of hypoxia and inflammation, and the testing of therapeutic approaches.

BioFiber: An advanced fibrous textured dressing to manage exudate in severe wounds

Biofiber is a new generation of highly absorbent, and textured bandage with patented fiber technology. Biofiber has a sophisticated texture that provides an optimum balance of moisture, flexibility, and conformability, and it has been developed with specific properties to treat complex injuries like burns. The dressing has been designed to be completely adaptable to human anatomy, and it can be fitted to any part of the body, adapting to all curves and jointures, as well as fitting the facial features. Prototypes of PLA-PCL-based textured bandages were developed by electrospinning, characterized, and evaluated for complex wound care. The texture is both esthetic and functional; fibers were uniformly sized (2.2 ± 0.8 and 4.5 ± 0.3 µm) and well interconnected. The texture facilitates vertical absorption of exudate up to 2.5 g/g of bandage, and the high contact angle values (120 - 100°) create an optimum balance of moisture for the healing process. The textured prototypes turned out to be extremely stable; no sign of bandage debris was found by the standard test, BS EN 13726-1.7. In addition, the round texture (3R) showed improvements in tensile strength (0.27 ± 0.019 MPa), ultimate tensile strength (0.83 ± 0.05 MPa) with higher breaking point (0.91 ± 0.05 MPa) compared to control (Mepilex Lite®). The amount of albumin (BSA) and Fibrinogen (Fb) adhered on textured fiber prototypes was calculated by BCA Assay, all prototypes demonstrated strong BSA (ranging from 81.66 ± 8.93 to 182.73 ± 2.07 μg protein/mg dressing) and enhanced Fb shielding (ranging from 108.25 ± 7.3 to 238.12 ± 17.76 μg protein/mg dressing). Their MVTR values ranged from 2313.27 ± 58.86 to 2603.33 ± 50.41 g/m²· day and vertical wicking heights were between 24.6 ± 2.5 and 29.3 ± 4.1 mm; biological tests demonstrated good compatibility of prototypes (cell vitality > 70 %), percentage of cells attachment was in-between 114 and 225 %. The extent of attachment depends on texture, differing topographical patterns presented higher attachment compared with both CTR + and 1P prototype (no texture). Cells were growth on textured fiber prototypes, and the extent of proliferation depend on incubation time.

V-EMF treatment of facial scar: First results

AIM OF STUDY

This is a retrospective study aimed at evaluating the effectiveness of the use of electromagnetic fields and negative pressure treatment (V-EMF) for facial scars, from an aesthetic and functional point of view, and considering the variations in the levels of hydration.

MATERIAL AND METHODS

25 subjects with facial scarring were re-evaluated after being treated with the V-EMF method. The hydration levels of the scars before and after treatment were compared. The results were evaluated considering the satisfaction levels of the patients with the VAS, and of the medical specialists who performed the treatment, and of 3 independent dermatologists with the Likert scale.

RESULTS

Mean hydration levels of scars went from 41.8 to 53.3, with mean hydration levels of healthy reference points equal to 54.6. The minimum patient satisfaction level was 2 in the VAS. The minimum level of satisfaction of specialists and dermatologists was equal to IV on the Likert scale for all patients, except for 1 subject in which it was III for the specialist who had treated him. Anti-aging and re-pigmentation effects were also noted as secondary results.

CONCLUSIONS

From an aesthetic and functional point of view, and for the overall anti-aging effect of the treated area, V-EMF applied to facial scars has shown extremely promising results.

Safety and efficacy of treating post-burn pathological scars with extracorporeal shock wave therapy: A meta-analysis of randomised controlled trials

The clinical application of shockwave therapy has expanded to the treatment of pathological scars. The objective of this systematic review and meta-analysis is to quantitatively evaluate the efficacy and safety of extracorporeal shockwave therapy combined with comprehensive rehabilitation therapy on post-burn pathological scars compared to comprehensive rehabilitation therapy alone. The randomised controlled trials of extracorporeal shockwave therapy for post-burn pathological scars published in English and Chinese languages before October 2021 were included. The methodological quality and risk of bias of the selected articles were assessed with the Cochrane Collaboration's 'risk of bias' tool. RevMan software was applied for data analysis. This is the first systematic review and meta-analysis considering the effectiveness and safety of extracorporeal shockwave therapy on post-burn pathological scars. And nine randomised controlled trials involving 422 patients were included in this meta-analysis. The meta-analysis results showed that, compared with comprehensive rehabilitation therapy alone, extracorporeal shockwave therapy combined with comprehensive rehabilitation therapy was more effective in relieving pain (standardized mean difference [SMD] = -0.59, 95% confidence interval [CI]: [-0.87 to -0.31], p < 0.0001) and pruritus related to pathological scars (SMD = -0.94; 95% CI: [-1.25 to -0.63], p = 0.004), improving scars' appearance (SMD = -1.78, 95% CI: [-3.37 to -0.19], p = 0.03) and elasticity (SMD = 0.25, 95% CI: [0.29-0.21], p < 0.00001), decreasing scars thickness (SMD = -0.13, 95% CI: [-0.25 to -0.01], p = 0.04) and promoting the maturation status of scars (SMD = -2.86, 95% CI: [-3.96 to -1.76], p < 0.00001). There were no reported serious adverse events during and after extracorporeal shockwave therapy in the included studies. Available data preliminarily suggested that the combination of extracorporeal shockwave therapy and comprehensive rehabilitation therapy had better therapeutic effect on post-burn pathological scars than comprehensive rehabilitation therapy alone, without obvious side effects. However, further clinical well-controlled randomised controlled trials are needed. Systematic review registration ID: PROSPERO CRD42022297573.

In Vivo Models for Hypertrophic Scars—A Systematic Review

Backgroundand Objectives: Hypertrophic scars following surgeries or burns present a serious concern for many patients because these scars not only lead to an aesthetical but also to a functional and psychological burden. Treatment of hypertrophic scars is challenging because despite various treatment options, a low level of evidence hinders preference of any specific treatment plan. To properly identify new therapeutic approaches, the use of in vivo models remains indispensable. A gold standard for hypertrophic scars has not been established to date. This review aims at giving a comprehensive overview of the available in vivo models. Materials and Methods: PubMed and CINAHL were queried for currently existing models. Results: Models with mice, rats, rabbits, pigs, guinea pigs and dogs are used in hypertrophic scar research. Rodent models provide the advantage of ready availability and low costs, but the number of scars per animal is limited due to their relatively small body surface, leading to a high number of test animals which should be avoided according to the 3Rs. Multiple scars per animal can be created in the guinea pig and rabbit ear model; but like other rodent models, these models exhibit low transferability to human conditions. Pig models show a good transferability, but are cost-intensive and require adequate housing facilities. Further, it is not clear if a currently available pig model can deliver clinical and histological features of human hypertrophic scars concurrently. Conclusions: None of the analyzed animal models can be clearly recommended as a standard model in hypertrophic scar research because the particular research question must be considered to elect a suitable model.

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.

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.

Effects of Apremilast on Induced Hypertrophic Scar of Rabbits

The present study aimed to assess the effect of Apremilast on experimentally induced hypertrophic scars in rabbits. A total of 40 healthy male New Zealand White rabbits between 6 and 12 months of age were assigned to four groups (n=10). Group I consists of apparently healthy control rabbits, in group II, the rabbits with an induced hypertrophic scar received no treatment, except for base gel. In group III, the rabbits with induced hypertrophic scar were treated with triamcinolone acetonide (TAC) 0.1% as standard medication. In group IV, rabbits with induced hypertrophic scars were treated with Apremilast 5%. On the first day, four surgical incisions were made using an 8-mm biopsy punch on the ventral surface of the rabbit ear down to cartilage. The TAC and Apremilast were topically administered to the developed scars on day 31. The results included an examination of skin histopathology, the level of transforming growth factor beta-1 (TGF-β1), and collagen III in skin tissue. In the treatments, the inflammatory score, scar index, as well as immunological scores of TGFβ1 and collagen III, significantly decreased, compared to the hypertrophic induced scar group (P≤ 0.001). Moreover, there was a significant reduction in fibroblast count, compared to the group of induced hypertrophic scars (P<0.05). Apremilast was efficacious in the treatment of hypertrophic scars due to its ability to reduce inflammations and fibroblast counts and scar index. Nonetheless, the reduction of immunological scores was almost comparable to that of topical TAC.

Fractional carbon dioxide laser for treating hypertrophic scars: A systematic review of randomised trials

Hypertrophic scars present collagen deposition and an abnormal extracellular matrix that cause abnormal shape changes and limit normal movement. Although fractional carbon dioxide (CO₂ ) laser therapy has provided promising evidence, the improvement of scarring has not been thoroughly reviewed. A systematic review of prospective randomised trial articles collected from PubMed, MEDLINE, EMBASE, Cochrane and Scopus databases was conducted on 15 March 2020 in accordance with the PRISMA-P statement. Types and duration of fractional carbon dioxide laser used in this study along with the comparative modalities were recorded in this review. Treatment efficacy was assessed as the primary outcome. Adverse events and patient satisfaction were assessed as the secondary outcome. Five prospective randomised studies were included in this study. All studies included showed a consistent result with a conclusion that CO₂ fractional laser treatment demonstrated statistically significant improvement for various scar scoring methods. Combination with other modalities may yield better results in some studies with the risk of more severe adverse events. Temporary side effects such as itching or burning sensation, erythema and oedema were present but appeared to be minimal and well tolerated. Overall patients reported significant improvement in quality of life. Some of the studies are uncontrolled with relatively short-term follow-up. Controlled comparative studies within the same scar with larger sample size and longer follow-up period are required. This evidence suggests that fractional CO₂ laser treatment is effective for improving the clinical appearance of hypertrophic scars with a good safety profile.

Safety and efficacy of botulinum toxin type A in preventing and treating scars in animal models: A systematic review and meta-analysis

Previous studies have used botulinum toxin type A (BTXA) to improve postoperative and hypertrophic scars; however, there is lack of detailed verification on the safety and effectiveness of this approach. This study aimed to evaluate the therapeutic effect of BTXA on postoperative hypertrophic scars and its influence on cytokine expression in animal models. A computerised search of different databases was performed, including PubMed, Web of Science, Scopus, Cochrane, Embase, CNKI, and Wanfang, up to 10 March 2021. A meta-analysis was performed using R 4.0.0 based on hypertrophic index, epithelialisation time, wound area, and vascular endothelial growth factor (VEGF) expression. Eleven studies were included. The meta-analysis showed a significant difference in hypertrophic index (standardised mean difference [SMD] = -2.63, 95% confidence interval [CI]: -3.50 to -1.76, P < .01), wound area (SMD = -0.54, 95% CI: -1.24 to 0.16, P < .01), and VEGF expression (SMD = -2.56, 95% CI: -3.50 to -1.62, P < .01). This study shows that BTXA is safe and effective in preventing and treating scar hypertrophy in animal models, but excessive doses of BTXA and BTXA to treat large areas should be avoided.

[Complications after laser treatment of facial vascular lesions]

Laser technology represents a major advance in the treatment of vascular changes. Excellent knowledge combined with technological advances in new laser sources form the basis of this safe and effective option in many acquired or congenital vascular changes on the face. With regard to the different laser sources, the pulsed dye laser (PDL) has the best efficacy-to-safety ratio. This type of laser remains the gold standard for vascular lesions. Neodymium-doped yttrium aluminium garnet (Nd: YAG) lasers and diode lasers, among others, as well as intensed pulsed light (IPL), play an important role in addressing vascular changes in the face. Good knowledge of the laser approach to vascular lesions and technological progress have led to safety features that seek to minimize side effects. These advances mainly include the introduction of cooled tips, cooling devices and cooling systems, changes in pulse duration, and the introduction of different wavelengths, among others. However, undesirable side effects can still occur. Although these are mostly discrete and resolve spontaneously, some complications can be serious and difficult to manage. Therefore, the prevention and early management of complications are all the more important in the treatment of vascular changes on the face.

Statin treatment and hypertrophic scarring after cardiac surgery

Wound healing process after surgical procedure plays a crucial role to prevent blood loss and infections. Hypertrophic scars might occur after surgery and are generally associated with an inflammatory burden. Cardiac surgery is intrinsically related to a strong systemic inflammatory state that might favor hypertrophic scarring. Besides lipid-lowering effects, statins are known for their pleiotropic and anti-inflammatory activity. The aim of this study was to investigate the impact of statins in the healing process after median sternotomy in patients undergoing cardiac surgery. All patients undergoing major cardiac surgery with median sternotomy and cardiopulmonary bypass, and subsequently evaluated in the outpatient clinic after discharge, were included in this study. A total of 930 Caucasian patients were retrospectively reviewed. At outpatient visit, 276 patients (29.7%) showed the formation of hypertrophic scars. Patients with hypertrophic scars tended to be younger (P = .001) and nonstatin users (P = .001). Logistic regression analysis confirmed the protective role of statins (odds ratio 0.39, 95% confidence interval 0.29-0.53, P = .001), after adjustment for age. A dose-dependent effect was confirmed, showing a more intensive protective effect for higher doses of statins. Statin use might be correlated with reduced hypertrophic scars after cardiac surgery through median sternotomy. A dose-dependent effect has been shown, and statin effect seems to be independent of age in a selected population undergoing surgery with an elevated inflammatory burden. Although further studies are warranted to elucidate the biologic mechanisms, the concept of using statins as anti-scarring agents is novel and should be investigated with tailored studies.

Evidence-based therapy in hypertrophic scars: An update of a systematic review

Hypertrophic scars are still a major burden for numerous patients, especially after burns. Many treatment options are available; however, no evidence-based treatment protocol is available with recommendations mostly emerging from experience or lower quality studies. This review serves to discuss the currently available literature. A systematic review was performed and the databases PubMed and Web of Science were searched for suitable publications. Only original articles in English that dealt with the treatment of hypertrophic scars in living humans were analyzed. Further, studies with a level of evidence lower than 1 as defined by the American Society of Plastic Surgeons were excluded. After duplicate exclusion, 1638 studies were screened. A qualitative assessment yielded 163 articles eligible for evidence grading. Finally nine studies were included. Four of them used intralesional injections, four topical therapeutics and one assessed the efficacy of CO₂ -laser. Intralesional triamcinolone + fluorouracil injections, and topical pressure and/or silicone therapy revealed significant improvements in terms of scar height, pliability, and pigmentation. This systematic review showed that still few high-quality studies exist to evaluate therapeutic means and their mechanisms for hypertrophic scars. Among these, most of them assessed the efficacy of intralesional triamcinolone injections with the same treatment protocol. Intralesional injection appears to be the best option for hypertrophic scar treatment. Future studies should focus on a possible optimization of infiltrative therapies, consistent end-point evaluations, adequate follow-up periods, and possibly intraindividual treatments.