Acne-induced pathological scars: pathophysiology and current treatments

Acne is a common chronic inflammatory dermatosis that can lead to pathological scars (PSs, divided into hypertrophic scars and keloids). These kinds of abnormal scars seriously reduce the quality of life of patients. However, their mechanism is still unclear, resulting in difficult clinical prevention, unstable treatment effects and a high risk of recurrence. Available evidence supports inflammatory changes caused by infection as one of the keys to abnormal proliferation of skin fibroblasts. In acne-induced PSs, increasing knowledge of the immunopathology indicates that inflammatory cells directly secrete growth factors to activate fibroblasts and release pro-inflammatory factors to promote the formation of PSs. T helper cells contribute to PSs via the secretion of interleukin (IL)-4 and IL-13, the pro-inflammatory factors; while regulatory T cells have anti-inflammatory effects, secrete IL-10 and prostaglandin E2, and suppress fibrosis production. Several treatments are available, but there is a lack of combination regimens to target different aspects of acne-induced PSs. Overall, this review indicates that the joint involvement of inflammatory response and fibrosis plays a crucial role in acne-induced PSs, and also analyzes the interaction of current treatments for acne and PS.

Picosecond Nd:YAG versus Fractional CO2 Lasers in Management of Postburn Scars

Background

The picosecond laser was primarily designed to enhance tattoo removal. Because it has a new innovative mechanism for energy delivery, it has been modified to be used in other conditions such as skin resurfacing, which was usually treated with fractional CO2 laser. Comparing both technologies in managing postburn scars has not been widely addressed.

Methods

The current prospective comparative randomized intrapatient study was done on 15 patients who presented with unsightly postburn scarring. As a split study, one-half of the affected areas were treated using the picosecond Nd: YAG laser. The other areas were treated with a fractional CO2 laser. After three treatment sessions, the results were analyzed both objectively and subjectively.

Results

The assessment by the image analysis system (Antera camera) showed improvement in all the parameters in both groups. The melanin relative variation decreased from 11.65 ± 2.86, 15.85 ± 5.63 to 10.60 ± 1.96, 12.56 ± 3.98, respectively in picosecond laser sites and fractional CO2 sites. The percentage change in overall opinion decreased in in favor of the fractional CO2 laser sites, which is a statistically significant improvement. Instead, color scores revealed a greater reduction in the picosecond sites in comparison with the fractional CO2 sites, as it decreased from 7.67 ± 1.76, 7.73 ± 1.83 to 2.87 ± 1.06, 6 ± 1.2, respectively.

Conclusions

When compared with fractional CO2 lasers, picosecond Nd:YAG shows comparable improvements in scars' erythema, texture, and height, with some superiority in the management of hyperpigmented scars.

Molecular analysis of the extracellular microenvironment: from form to function

The extracellular matrix (ECM) proteome represents an important component of the tissue microenvironment that controls chemical flux and induces cell signaling through encoded structure. The analysis of the ECM represents an analytical challenge through high levels of post-translational modifications, protease-resistant structures, and crosslinked, insoluble proteins. This review provides a comprehensive overview of the analytical challenges involved in addressing the complexities of spatially profiling the extracellular matrix proteome. A synopsis of the process of synthesizing the ECM structure, detailing inherent chemical complexity, is included to present the scope of the analytical challenge. Current chromatographic and spatial techniques addressing these challenges are detailed. Capabilities for multimodal multiplexing with cellular populations are discussed with a perspective on developing a holistic view of disease processes that includes both the cellular and extracellular microenvironment.

Fractional ablative CO2 laser and oral isotretinoin-A prospective randomized controlled split-face trial comparing concurrent versus delayed laser treatment for acne scars

BACKGROUND

Therapeutic dogma has been to treat acne scars with ablative fractional laser no less than 6 months after isotretinoin (ITN) cessation.

OBJECTIVE

To evaluate the safety and efficacy of fractional ablative CO2 laser (FACL) in patients treated concurrently with ITN.

METHODS

We conducted a prospective split-face randomized control trial in patients treated with FACL concurrently with ITN versus patients treated with FACL 6 months post-ITN treatment. Patients received 3 monthly sessions of FACL with concurrent ITN treatment on half of the face; the other side of the face received the same FACL treatment regimen 6 months post-ITN cessation. Patients were followed for adverse effects up to 6 months post-FACL treatment. Final cosmesis was scored using the Quantitative Global Acne Scarring Grading System (GASGS) by three independent dermatologists.

RESULTS

The GASGS of the concurrent ITN-FACL treated side of the face was significantly lower than the side treated with delayed laser therapy (4.7 ± 2.5 vs. 7.7 ± 2.9, respectively, p < 0.001).

LIMITATIONS

The laser's settings were standardized, and not adjusted per patient skin type.

CONCLUSION

Per our prospective trial, concurrent treatment of FACL -ITN is superior to delayed FACL treatment 6 months post-ITN cessation. Fractional ablative laser treatment is effective in improving acne scars, which persist despite isotretinoin therapy.

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.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Treatment of burn hypertrophic scar with fractional ablative laser-assisted drug delivery can decrease levels of hyperpigmentation

BACKGROUND

Laser treatments have been used to treat a variety of scar symptoms, including the appearance of scars following burn injury. One such symptom is hyperpigmentation. There are several qualitative and quantitative measures of assessing improvement in hyperpigmentation over time. The Patient and Observer Scar Assessment Scale (POSAS) and Vancouver Scar Scale (VSS) are two scales that describe characteristics of scar such as pigmentation level. These scales are limited by their qualitative nature. On the other hand, spectrophotometers provide quantitative measures of pigmentation. Prior studies have reported that laser can change scar pigmentation, but no quantitative values have been reported. The current study examines changes in scar melanin index after CO₂ fractional ablative laser scar revision (FLSR) via noninvasive probe measurement in patients of various Fitzpatrick skin types (FST).

MATERIALS AND METHODS

Patients with scars of various sizes and etiologies were treated with FLSR. A database was constructed including 189 patients undergoing laser treatment. From this pool, individuals were selected based on the criteria that they completed at least two laser sessions and had Melanin index measurements for both of these sessions and the pre-operative visit. This criteria resulted in 63 patients of various FST in the cohort. Melanin index, POSAS-Observer (O) and -Patient (P) pigmentation and color scores and VSS-pigmentation scores were examined over time. Demographic information (age of patient at time of first treatment, age of scar at time of first treatment, use of laser-assisted drug delivery (LADD), gender, FST, and Ethnicity) were collected from the medical record. Patients were grouped as "responder" if their Melanin index indicated decreased levels of hyperpigmentation after FLSR treatment in more than half of their total number of visits and "nonresponder" if it did not.

RESULTS

The majority of patients were responders (41/63). In responder patients, measurements of Melanin index showed significantly improved levels of hyperpigmentation in hypertrophic scars after two FLSR sessions (p < 0.05). Age of patient, gender, FST, age of scar, ethnicity, or type of drug delivered by LADD did not predict responder grouping. POSAS-O and -P pigmentation/color scores showed improved scores after two FLSR sessions within the responder group. POSAS-P color scores showed improved scores after two and three FLSR sessions in the nonresponder group. VSS pigmentation scores showed improved scores after three FLSR sessions in the responder group only.

CONCLUSION

Based on Melanin index values, FLSR leads to improvements in hyperpigmentation in certain patients.

Early Fractional Ablative Laser for Skin Cancer Excision Scars: A Randomized Split-Scar Study

BACKGROUND

Fractional ablative laser resurfacing has been shown to improve the final cosmetic appearance of surgical scars, but optimal timing is unknown.

OBJECTIVE

To compare surgical scars treated with fractional carbon dioxide (CO 2 ) laser performed on Day 0 and Day 14.

METHODS

Prospective, randomized, split-scar, physician-blinded study of 30 surgical scars on the limbs. Scars halves received fractional CO 2 laser on either Day 0 or Day 14. Scar assessment at 6 months evaluated patient preference, physician modified Manchester Scar Scale (MMSS) score, and quantitative scar analysis on histology (fractal dimension [F D ] and lacunarity [L] analysis).

RESULTS

There was no significant difference in patient assessment (54% preferred Day 0 side, 46% preferred Day 14 side, p = .58) or physician assessment (mean MMSS 8.4 for Day 0 vs 8.7 for Day 14, p = .28). Fractal dimensions were similar for both interventions (mean 1.778 for Day 0 vs 1.781 for Day 14, p = .80). Lacunarity was similar for both interventions (mean 0.368 for Day 0 vs 0.345 for Day 14, p = .44).

LIMITATIONS

Single-center study with wounds limited to limbs of skin Phototype I-II subjects; 4 of whom were lost to follow-up.

CONCLUSION

Intraoperative CO 2 laser is noninferior to Day 14 laser resurfacing for surgical scar treatment.

Extended Application of Fractional Carbon Dioxide Laser in the Treatment of Port Wine Stain Birthmarks with Hypertrophy: A Case Report

Background: Conventional treatments of port wine stain birthmarks often do not achieve the desired outcome in patients with hypertrophy. Potential reasons include deeper and larger blood vessels, abnormal arrangement of blood vessels, and darker or thicker epidermis. However, these factors may not significantly limit the efficacy of fractional carbon dioxide (CO2) laser. The aim of this case report was to examine the extended application of fractional CO2 laser in treating patients with hypertrophic port wine stain birthmarks. Methods: Two cases with hypertrophic port wine stain birthmarks treated with fractional CO2 laser for 5 years are described in this case report. Results: When compared with conventional treatment, both cases reported better outcomes, including a reduced risk of infection, pigmentation, and scarring, a decrease of clinical erythema, and much less pain. Conclusions: The findings demonstrate that fractional CO2 laser has the potential to be an effective modality for the treatment of patients with hypertrophic port wine stains.

Advances in Photoelectric Therapy for the Early Intervention and Treatment of Traumatic Scars

Traumatic scar is a disease that affected approximately tens of millions of patients worldwide. According to the histological and morphological properties of scars, the traumatic scar typically includes superficial scar, atrophic scar, hypertrophic scar, and keloid. Its formation is a natural consequence of wound healing, regardless of whether the wound was caused by trauma or surgery. However, the production of scars has considerable impacts on the physical and mental health of patients, even causing substantial aesthetic and functional impairments. Prevention or early treatment of scars is the most suitable therapeutic method, including surgical and non-surgical procedures; nevertheless, the benefits of non-operative therapies for scars are quite limited, and surgical treatments are always hard to achieve satisfying outcomes. Through the application of innovative technologies such as lasers, intense pulsed light, and radiofrequency, significant progress has been made in the treatment of traumatic scars. This review highlights the current advancements of photoelectric therapy for the prevention and treatment of various traumatic scars, which may throw light on innovative therapeutic options for scar therapies.

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 systematic review of the comparison between needling (RF-needling, meso-needling, and micro-needling) and ablative fractional lasers (CO2, erbium YAG) in the treatment of atrophic and hypertrophic scars

The aim of this study is to compare needling (RF-needling, meso-needling, micro-needling) and ablative fractional lasers (CO2, erbium-YAG) in the treatment of atrophic and hypertrophic scars in a systematic review. The database was searched, and 10 articles were selected that were relevant in terms of content, topic, and purpose and met the inclusion criteria. Of all the articles reviewed in this study, there were 2 randomized split-face trials (20%), 1 controlled nonrandomized trial (10%), 1 controlled randomized phase III clinical trial (10%), 1 prospective trial (10%), 1 prospective nonrandomized open-label trial (10%), and 1 randomized comparative trial (10%), with the type of study not reported in 3 articles. We used Endnote X8 to review the articles and extract data. After review, the studies were analyzed and categorized. No statistically significant difference was found between the two methods, laser and micro-needling, in the treatment of atrophic and hypertrophic scars in 60% of the articles studied, and both showed significant improvement (70% or more improvement to complete response). Significant improvement was noted in 20% of the studies reviewed for the laser and micro-needling treatment methods. The results of this study show that needling and ablative fractional lasers are tolerable and safe procedures with no significant difference in the treatment of skin scars in sixty percent of the studies.

Comparison of stationary and dynamic fractional CO2 laser modalities of large burns treatment: Experimental laboratory model

OBJECTIVES

To experimentally compare two fractional ablative CO₂ laser handpieces intended for the treatment of large area burn scars. Each handpiece coverage rate, depth of penetration and application time were measured and compared in a simulation model of large area burns scars using a dynamic/roller handpiece (small footprint) and a stationary/stamping handpiece (large footprint).

METHODS

A 30 W fractional ablative CO₂ laser was applied using 2 different handpieces and footprints on a A4 size paper stack. The handpieces were a stationary (stamping) handpiece with 7 × 7 (49 pixels/square shape) and dynamic (roller) handpiece with 7 × 1 (7 pixels/single row shape). For both handpieces the laser settings were fixed at "High" power (30 W), providing an energy level of 100 mJ/pixel. Both handpieces were applied perpendicular to the surface, with the process repeated for the dynamic handpiece with an angled operation. The depth of laser penetration was assessed by the number of pages of paper having visible holes and burn area coverage time measured under each handpiece/condition.

RESULTS

The application time was faster and the penetration deeper for the dynamic handpiece compared to the stationary handpiece in both the perpendicular and angled conditions. This study has practical implications for lasers operators to improve time efficacy in large area scars with improved clinical endpoints.

CONCLUSION

The fractional ablative dynamic handpiece demonstrated superior application efficiency compared to the stationary handpiece in the simulated treatment of large surface area burn scars, reducing treatment time with improved depth of penetration.

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.

Fractional microneedle radiofrequency versus fractional carbon dioxide laser in the treatment of postburn hypertrophic scars

BACKGROUND AND OBJECTIVE

New and improved treatment modalities, including lasers and energy-based devices, are promising treatment options for hypertrophic scars. This study aimed to assess the efficacy and safety of fractional microneedle radiofrequency (FMR) compared with fractional carbon dioxide (CO₂ ) laser in the treatment of postburn hypertrophic scars.

PATIENTS AND METHODS

Twenty patients with hypertrophic scars were enrolled in the study. Two areas in each patient were randomly assigned to fractional CO₂ laser or FMR. Four sessions, 6-8 weeks apart were performed. The Patient and Observer Scar Assessment Scale (POSAS) was used for clinical evaluation, H & E and orcein-stained samples were examined for histopathological assessment, and tissue transforming growth factor beta 1 (TGFβ₁ ) levels were measured for biochemical evaluation.

RESULTS

Both fractional CO₂ and FMR-treated areas showed significant improvement in all parameters 1 month after treatment. Fractional CO2-treated areas showed a higher degree of improvement compared with FMR in OSAS (p = 0.025), elastin grading (p = 0.004), and TGFβ₁ levels (p = 0.000). Patients reported less downtime and showed less postinflammatory hyperpigmentation with FMR compared with fractional CO_2, but this did not reach statistical significance (p = 0.327, p = 0.231; respectively).

CONCLUSION

Our results demonstrate the value of FMR as an effective alternative to fractional CO₂ in the treatment of hypertrophic scars, with a potentially favorable safety profile.

Ablative fractional carbon dioxide laser improves quality of life in patients with extensive burn scars: A nested case-control study

BACKGROUND AND OBJECTIVES

Ablative fractional carbon dioxide laser (CO₂ -AFL) for small-area burn scar management shows encouraging outcomes. Few studies, however, focused on comprehensive outcomes following CO₂ -AFL treatment for extensive burn scars. This study evaluated whether CO₂ -AFL surgery improved the quality of life (QoL) for burn survivors with extensive hypertrophic scars.

METHODS

A retrospective nested case-control study was initiated to analyze the efficacy of CO₂ -AFL treatment for patients with large-area burn scars. Patients with extensive burn scars (≥30% total body surface area [TBSA]) were registered in our hospital from March 2016 to October 2018. Patients undergoing CO₂ -AFL surgery were divided into CO₂ -AFL group, and patients undergoing conventional surgery were matched in a 1:1 ratio as the conventional surgery group according to the burned area. The questionnaires were collected and followed up. The 36-Item Short Form Health Survey (SF-36) and Burns Specific Health Scale-Brief (BSHS-B) were the primary parameters. Secondary parameters included the Pittsburgh Sleep Quality Index (PSQI), University of North Carolina "4P" Scars Scale (UNC4P), Patient Scars Assessment Scale for Patient (POSAS-P), and Douleur Neuropathique 4 questions (DN4).

RESULTS

23 patients (55.96 ± 21.59% TBSA) were included in CO₂ -AFL group and 23 patients (57.87 ± 18.21% TBSA) in conventional surgery group. Both the BSHS-B total score (CO₂ -AFL vs. conventional surgery: 115.35 ± 29.24 vs. 85.43 ± 33.19, p = 0.002) and the SF-36 total score (CO₂ -AFL vs. conventional surgery: 427.79 ± 118.27 vs. 265.65 ± 81.66, p < 0.001) for the CO₂ -AFL group were higher than those for the conventional surgery group. Parameters for the CO₂ -AFL group were lower than those for the conventional surgery group in all of the following comparisons: PSQI total score (CO₂ -AFL vs. conventional surgery: 7.70 ± 3.74 vs. 12.26 ± 4.61, p = 0.001), POSAS-P total score (CO₂ -AFL vs. conventional surgery: 26.48 ± 6.60 vs. 33.04 ± 4.56, p < 0.001), UNC4P total score (CO₂ -AFL vs. conventional surgery: 5.57 ± 1.97 vs. 7.26 ± 1.81, p = 0.004), and DN4 score (CO₂ -AFL vs. conventional surgery: 3 [2-5] vs. 5 [4-8], p = 0.004).

CONCLUSIONS

Compared to conventional surgery, whole scar CO₂ -AFL surgery dramatically improved physical and mental health as well as QoL for people with extensive burn scars. Additionally, CO₂ -AFL enhanced the evaluation of scars including their appearance, pain, itching, and a host of other symptoms.

THE IMPORTANCE OF BIOMECHANICS AND THE KINETIC CHAINS OF HUMAN MOVEMENT IN THE DEVELOPMENT AND TREATMENT OF BURN SCARS – A NARRATIVE REVIEW WITH ILLUSTRATIVE CASES

BACKGROUND

Burn scars are a major clinical sequelae of severe burn wound healing. To effectively establish a successful treatment plan and achieve durable results, understanding the pathophysiology of scar development is of utmost importance.

METHODS

A narrative review of the principles of the kinematic chain of movement and the hypothesised effect on burn scar development based on properties of burn scars was performed. An examination of the literature supporting these concepts is presented in conjunction with illustrative cases, with a particular focus on the effect of combination treatments that include ablative fractional resurfacing with surgical contracture releases.

DISCUSSION

Ablative fractional resurfacing combined with the surgical release of contractures are an effective treatment modality for burn scar reconstruction. This treatment approach seems particularly effective because it is one of the only approaches where the principles of functional kinematics can be addressed when tailoring a reconstructive approach to an individual burn patient. The presented cases illustrate the importance of recognising and including the principles of functional kinematic chains in any reconstructive treatment approach for burn scars. Further, epifascial contracture bands are cord like structures which can be found underneath the subcutaneous fat of scar contractures which follow the principles of functional kinematics. Contractures can be more efficiently released if these structures are divided as well.

CONCLUSION

Ablative fractional resurfacing combined with local tissue re-arrangements is a promising approach to address the underlying forces leading to hypertrophic burn scarring. To achieve an optimal outcome, it is essential to recognise and address the origin of the pathology when treating burn scars. Ablative fractional laser resurfacing allows a different scar approach as it is not limited to one surgical site and thus enables for effective treatment at the cause of the pathology.

Molecular Features of Hypertrophic Scars After Thermal Injury: Is There a Biologic Basis for Laser Therapy?

Significance: Hypertrophic scars (HTS) and keloids are common after thermal injuries and other trauma to deep regions of dermis of the skin. These abnormal scars can cause contractures and the thick masses of scar tissue that result in functional and cosmetic impairment. Management of these dermal fibrotic conditions includes a wide range of medical and surgical treatments, which can be time consuming, only partially effective, and often uncomfortable for patients. Recent Advances: The molecular pathophysiology of HTS has become more understood over the past two decades, where thermal injury to the reticular dermis results in an inflammatory response, fibrogenic growth factor release, and the formation of a dermal scar with increased collagen and proteoglycan composition in an abnormal morphology. Lasers are becoming a widely used form of treatment for these types of scars; however, the evidence for the beneficial effects of laser treatments and the understanding of their mechanism of action are still evolving. Critical Issues: Paradoxically, laser delivery of thermal energy to the skin is suggested to improve scar remodeling and wound healing, yet HTS is a well-recognized complication of excessive thermal energy delivered by laser treatments. This review aims to examine the current evidence for the use of lasers for HTS, and to investigate the molecular mechanisms where re-injury of a burn scar from laser treatment could result in overall improvements in scar quality. Future Directions: Improved design of clinical trials for the treatment of scarring in the future will evolve from new methodology and models of HTS in animals and humans.

Efficacy and safety of a dual-scan protocol for carbon dioxide laser in the treatment of split-thickness skin graft contraction in a red Duroc pig model

BACKGROUND

Fractional CO₂ laser plays an important role in scar management post split-thickness skin graft by loosening the graft contracture and restoring the smoothness of the surface. However, the optimal treatment protocol remains unknown. This study applied a dual-scan protocol to achieve both releasing and ablation of contracted skin graft. We comprehensively describe this treatment method and compare the efficacy and safety between this dual-scan method and the conventional mono-scan mode.

METHODS

A hypercontracted scar model after split-thickness skin grafting in red Duroc pigs was established. All scars meeting the inclusion criteria were randomly divided into four groups: high fluence-low density (HF-LD), low fluence-high density (LF-HD), combined group and control group. The energy per unit area was similar in the HF-LD and LF-HD groups. Two laser interventions were performed at a 6-week interval. The efficacy of the treatment was evaluated by objective measures of scar area, release rate, elasticity, thickness and flatness, while the safety was evaluated based on adverse reactions and melanin index. Collagen structure was observed histologically. The animals were followed up for a maximum of 126 days after modeling.

RESULTS

A total of 28 contracted scars were included, 7 in each group. At 18 weeks postoperatively, the HF-LD and the combined groups showed significantly increased scar release rate (p = 0.000) and elasticity (p = 0.036) and decreased type I/III collagen ratio (p = 0.002) compared with the control and LF-HD groups. In terms of flatness, the combined group was significantly better than the HF-LD group for elevations <1 mm (p = 0.019). No significant skin side effects, pigmentation or scar thickness changes were observed at 18 weeks.

CONCLUSIONS

Dual-scan protocol could achieve superficial ablation and deep release of contracted split-thickness skin graft in a single treatment, with similar contraction release and texture improvement compared to a single deep scan. Its main advantage is to restore a smoother scar appearance. Adequate laser penetration was necessary for the release of contracted scars.

Efficacy and safety of thermomechanical fractional injury-assisted corticosteroid delivery versus intralesional corticosteroid injection for the treatment of hypertrophic scars: A randomized split-scar trial

BACKGROUND

Disruption of the natural skin barrier in a controlled manner may be used to deliver drugs that enhance scar resolution.

OBJECTIVE

To compare the efficacy and safety of thermomechanical fractional injury (TMFI)-assisted topical corticosteroid delivery with corticosteroid injection in the treatment of hypertrophic scar (HTS).

MATERIALS AND METHODS

This was a randomized, split-scar, double-blinded study. Twenty-one subjects with HTS on the abdomen received five split-scar treatments of TMFI + Steroid and steroid injection alone. Changes in scar thickness, scar volume, and Vancouver Scar Scale (VSS) were analyzed. Patient self-assessment, VAS scores, and adverse effects were also evaluated.

RESULTS

Scar thickness, volume, and VSS scores of both segments improved significantly compared to baseline. On every follow-up visit, there were no significant differences in mean scar thickness reduction between the two treatment groups except at the 6-month follow-up where the mean scar thickness reduction of the steroid injection segment was significantly lower than that of the TMFI + Steroid segment (95% confidence interval [CI], 0.09-0.35; p = 0.002). Scar volume, VSS scores, and patient self-assessment also showed no significant differences between both segments on all visits. The steroid injection segment was significantly more painful than the TMFI + Steroid segment (95% CI, -2.16 to -1.29; p < 0.001). Adverse effects of skin atrophy, telangiectasia, and post-inflammatory hyperpigmentation were noted in the steroid injection segment, while no adverse effects were observed at the TMFI + Steroid segment.

CONCLUSIONS

TMFI-assisted topical corticosteroid delivery is an effective treatment for HTS with a lower risk of adverse effects compared with corticosteroid injection.

Efficacy of Fractional Carbon Dioxide Laser (FCO2) with Intralesional 5-Fluorouracil (5-FU) in the Treatment of Keloids

Context:

Managing keloids remains a challenge in clinical practice. Many therapeutic options are available, but none is universally accepted or without recurrence. Therefore, an effort is required to choose the treatment with maximal outcomes.

Aims:

To evaluate the effectiveness of combining fractional carbon dioxide (FCO₂) laser and intralesional 5-fluorouracil (5-FU) for the treatment of keloids.

Materials and Methods:

In this prospective open-label study, 24 patients received FCO₂ laser treatment, started at baseline, for a total of six sittings. The patients also received 1 mL/cm²/keloid of 5-FU (50 mg/mL) intralesionally, following irradiation, at identical time points. The primary outcome evaluated was the clinical response concerning height, pliability, vascularity, and pigmentation, using the Vancouver Score Scale (VSS). Adverse reactions and recurrences were recorded as secondary outcomes.

Results:

A significant reduction was observed in the VSS in terms of pliability and height after three treatment sessions. The mean VSS reduction was 65%, from 8.45 ± SD 0.93 at baseline to 3 ± SD 1.8 one month after the last treatment (P < 0.05). Most patients (79.1%; n = 19) showed a satisfactory response to treatment, with 57.8% (n = 11) achieving an excellent result. Adverse reactions included post-inflammatory hyperpigmentation in four patients and ulceration in two. Recurrences were reported in 21% of the patients who responded well.

Conclusions:

Combination therapy with FCO₂ laser and intralesional 5-FU showed a promising effect in the treatment of resistant keloids, with an acceptable safety profile and low recurrence rate.

Combined CO2 and dye laser technique in the treatment of outcomes due to flap necrosis after surgery for basal cell carcinoma on the nose

BACKGROUND AND OBJECTIVE

Basal cell carcinoma (BCC) is the most frequent cutaneous cancer worldwide, and the nasal area is the most commonly affected region. Skin flaps are usually performed to achieve radical results, but various adverse events often occur. The necrosis of the skin flap is one of the most frequently observed, resulting in scars and anti-aesthetic outcomes. Ablative and non-ablative lasers have been proposed to improve scars resulting from surgical failure and skin flap necrosis.

STUDY DESIGN/MATERIALS AND METHODS

This study aims to evaluate a new laser protocol combining ablative CO₂ -laser with flashlamp pulsed dye laser for the treatment of nasal scars resulting from the necrosis of flap that occurred after surgery. Twelve patients were enrolled in the study, and a total of five laser sessions were planned, spaced from 14 days to 1 month apart.

RESULTS

Seven out of 12 patients underwent all the five laser sessions planned, while 5/12 patients achieved optimal cosmetic results within the fourth session. Eighty percent of the patients reported good/optimal cosmetic results, and no significant side effects were observed during the study.

CONCLUSION

Combining fractionated CO₂ laser with flashlamp pulsed dye laser represents a new effective modality for treating skin flap necrosis after BBC removal, representing a valid alternative to other surgical procedures.

Efficacy and safety of CO2 laser in the treatment of chronic wounds: A Retrospective Matched Cohort Trial

OBJECTIVES

Treating chronic cutaneous wounds is challenging, and debridement is a central concept in treating them. Studies have shown that CO₂ laser debridement can control local infection and promote the wound healing process. The present study aimed to investigate the efficacy and safety of fully ablative CO₂ laser debridement compared to routine surgical debridement in the treatment of chronic wounds.

METHODS

The retrospective cohort study was conducted on patients with chronic (>1 month) cutaneous wounds (≥1 cm² ) between December 1, 2017, and December 1, 2020, in the Wound Healing Center at Shanghai Ruijin Hospital, China. Patients treated with CO₂ laser debridement with a DEKA SmartXide2 C80 (DEKA) (the CO₂ laser group) were compared with matched control patients with similar baseline characteristics who had undergone routine surgical debridement (the routine group). The primary outcome was time-to-heal (days) for chronic wounds in two groups, and secondary outcomes included the wound area and BWAT (Bates-Jensen wound assessment tool) score before treatment, and at 1, 2, 3, and 4 weeks after treatment.

RESULTS

The study included 164 patients (82 in the CO₂ laser group and 82 matched in the routine group). The time-to-heal for patients in the CO₂ laser group (41.30 ± 17.11) was significantly shorter than that of the patients in the routine group (48.51 ± 24.32) (p = 0.015). At 3 and 4 weeks after treatment, the absolute wound area of the CO₂ laser group was significantly smaller than that of the routine group. Also, the CO₂ laser group exhibited a significantly lower relative area at 2, 3, and 4 weeks after treatment. The CO₂ laser group yielded significantly lower BWAT scores at 2, 3, and 4 weeks after treatment. Additionally, the relative BWAT score was significantly lower in the CO₂ laser group than the relative scores in the routine group at 2, 3, and 4 weeks after treatment. No adverse events related to the treatments were observed in either group during the study period.

CONCLUSIONS

The present study has shown that fully ablative CO₂ laser debridement has several advantages over routine sharp surgical debridement. It is superior at ameliorating wound status and reducing wound area, and it also significantly reduces the time-to-heal for chronic wounds, without causing any adverse events.

Automated Microneedling Versus Fractional CO2 Laser in Treatment of Traumatic Scars: A Clinical and Histochemical Study

BACKGROUND/OBJECTIVES

Microneedling has shown satisfactory effects in scar rejuvenation. Comparisons of its results with fractional laser are limited. This study aims to compare the efficacy and safety of automated microneedling versus fractional carbon dioxide (CO2) laser in treatment of traumatic scars on clinical and histochemical bases.

MATERIALS AND METHODS

Thirty patients with traumatic facial scars were randomized to treatment with 4 monthly sessions of either automated microneedling or fractional CO2 laser. Assessment of scars was performed at baseline and 3 months after the last treatment session, clinically by the modified Vancouver Scar Scale (mVSS) and histochemically by quantitative assessment of collagen and elastic fibers.

RESULTS

Both groups showed improvement in mVSS, collagen, and elastin contents after treatment. Percentage improvement of collagen and elastin content was higher after treatment by a laser compared with microneedling, in case of the collagen content. Percentage increase in the collagen content after treatment was higher in atrophic scars of the laser group than those of the microneedling group.

CONCLUSION

In this small study, microneedling was as safe as fractional CO2 laser for rejuvenation of traumatic scars with comparable clinical effects. Fractional CO2 laser is more powerful in stimulating neocollagenesis. Automated microneedling is effective for treatment of hypertrophic scars.

Evolution of compressive mechanical properties of early hypertrophic scar during laser treatment

Laser therapy has been widely used in the treatment of hypertrophic scars (HPS), but whether the mechanical properties of HPS tissue after laser treatment can be restored to those of normal skin remains unclear. In this paper, the relationship between the evolution of compressive mechanical properties and histological changes of HPS tissues following three successive combined pulsed dye laser (PDL) and fractional CO₂ laser (CO₂) treatments was investigated by compression tests and histological analysis. The early HPS model of rabbit ear was established by CO₂ laser ablation. The loading-unloading tests and strain creep tests under the compression forces of 1 N, 2 N, and 3 N were carried out for normal skin, untreated HPS and HPS after different treatment times, respectively. The results showed that the compression ratio λ of all tissues revealed force dependence and rose with the increasing compression force, which was similar to the trend of most biological soft tissues. The histological changes of HPSs following laser treatment have a significant influence on the compressive mechanical response. Compared with the normal skin, the toughness and anti-deformation ability of HPS reduced due to the proliferation of collagen fibers and the destruction of elastic fibers, resulting in higher energy dissipation, compression ratio λ, and stable creep rate D, and lower elastic modulus. After three successive combined PDL/ CO₂ laser treatments, the compressive mechanical properties and creep properties of HPS gradually approached that of the normal skin owing to the gradual restoration of the amount and distribution of collagen and elastic fibers in HPS. The results provide a new method for evaluating the clinical efficacy of laser therapy for treatment of HPS tissue.

The efficacy and safety of fractional CO2 laser therapy in the treatment of burn scars: A meta-analysis

Although we have numerous publications about the effect of fractional CO₂ laser therapy for burn scars, quantitative data about its efficacy and safety are sparse. The purpose of this meta-analysis was to assess the efficacy and safety of fractional CO₂ laser therapy for the treatment of burn scars. Pertinent studies were identified by a search of PubMed, Embase and Web of Science up to 20 September 2020. Weighted mean difference (WMD) was conducted to combine the results, and a random-effect model was used to pool the results. Publication bias was estimated using Begg and Egger's regression asymmetry test. Twenty articles were included. Our pooled results suggested that fractional CO₂ laser therapy significantly improved the Vancouver Scar Scale (VSS) score (WMD = -3.24, 95%CI: -4.30, -2.18; P < 0.001). Moreover, the Patient and Observer Scar Assessment Scale (POSAS)-patient (WMD = -14.05, 95%CI: -22.44, -5.65; P = 0.001) and Observer (WMD = -6.31, 95%CI: -8.48, -4.15; P < 0.001) also showed significant improvements with the treatment of fractional CO₂ laser therapy. Fractional CO₂ laser significantly reduced scar thickness measured with ultrasonography (WMD = -0.54, 95%CI: -0.97, -0.10; P < 0.001). For other outcomes, including pigmentation, vascularity, pliability, and height of scar, vascularity and relief, laser therapy was associated with significant improvements. However, only the cutometer measure R2 (scar elasticity) (WMD = -0.06, 95%CI: -0.10, -0.01; P = 0.023) was significantly improved with the laser therapy, but cutometer measures R0 (scar firmness) (WMD = 0.03, 95%CI: -0.04, 0.09; P = 0.482) was not. Side effects and complications induced by fractional CO₂ laser were mild and tolerable. Fractional CO₂ laser therapy significantly improved both the signs and symptoms of burn scars. Considering potential limitations, more large-scale, well-designed RCTs are needed to verify our findings.

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

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

Ablative fractional CO2 laser surgery improving sleep quality, pain and pruritus in adult hypertrophic scar patients: a prospective cohort study

Background

Poor sleep quality is associated with a decrease in quality of life in patients with major burn scars, combined with pruritus and pain. Few interventions have been reported to improve the sleep quality of patients with scars. In the current prospective cohort study, we investigated the efficacy of CO₂-ablative fractional laser (AFL) surgery vs conventional surgery in post-burn patients with hypertrophic scars with sleep quality as the primary study outcome.

Methods

In total 68 consecutive patients undergoing scar surgical treatment were recruited, including a CO₂-AFL surgery cohort (n = 35) and a conventional surgery cohort (n = 33). A subgroup from the AFL cohort was selected. Sleep quality, pain and pruritus were evaluated. Multiple linear regression analyses were performed to reveal the effect of CO₂-AFL surgery.

Results

The CO₂-AFL surgery cohort had significantly lower Pittsburgh sleep quality index (PSQI) global scores than the conventional surgery cohort after the last surgical treatment. In the subgroup of patients receiving hardware sleep monitoring, CO₂-AFL markedly increased deep sleep time, deep sleep efficiency and reduced initial sleep latency. Compared to the conventional surgery cohort, the CO₂-AFL cohort presented significantly lower pain and pruritus scores. Correlation analysis showed pain and pruritus were significantly associated with PSQI scores, and there were also significant correlations between pain and pruritus scores. Multiple linear regression analysis showed that surgery method was negatively linearly correlated with visual analog scale (VAS) pain score, brief pain inventory (BPI) total, VAS pruritus score, 5-D itch scale total, four-item itch questionnaire (FIIQ) total and PSQI total.

Conclusions

CO₂-AFL surgery significantly improved sleep quality and reduced pain and pruritus of hypertrophic scar patients. The alleviation of sleep disorder was associated with improvement of deep sleep quality including deep sleep time and deep sleep deficiency.

Trial registration

The Chinese Clinical Trial Registry (ChiCTR200035268) approved retrospectively registration on 5 Aug 2020.

Effectiveness and safety of ablative fractional CO2 laser for the treatment of burn scars: A case-control study

BACKGROUND

Burn scars are a major clinical challenge. The aim of this study was to determine the effectiveness and safety of one treatment with the ablative fractional CO2 laser (AFL-CO2) compared to standard burn scar treatment.

METHOD

From December 2014 to October 2018 patients were prospectively recruited and treatment effects analyzed by assessing various outcome parameters from the date of first consultation and after treatment. A case control study was conducted looking at the impact of one AFL-CO2 treatment compared to a cohort subjected to conventional conservative treatment. Adverse effects were noted at follow up.

RESULTS

187 patients were included, with 167 in the AFL-CO2, and 20 in the control cohort. Baseline demographics and scar characteristics showed no significant differences. Ultrasound measured scar thickness as well as the Vancouver Scar Scale (VSS) revealed a significant reduction in the treatment cohort, but no significant improvement in the control group. The POSAS-O was significantly improved in both cohorts. Subjective parameters (POSAS-P, DN4-Pain, and modified D4Pruritus scores) decreased significantly in the AFL-CO2 cohort but remained unchanged in the control group. The BSHS-B quality of life score increased significantly in the AFL-CO2 group, but worsened at the follow up of the untreated patients. Sub-domain analyses found the biggest differences in Affect, Body Image, Heat Sensitivity, Treatment and Work. Complications occurred in 5 patients (2.9%).

CONCLUSIONS

This study demonstrates that AFL-CO2 is an effective and safe treatment modality for burn scars improving thickness, symptoms and quality of life of burn survivors when compared to conventional scar treatment.

Comparison of Nd: YAG Laser and Combined Intense Pulsed Light and Radiofrequency in the Treatment of Hypertrophic Scars: A Prospective Clinico-Histopathological Study

INTRODUCTION

Hypertrophic scars are fibroproliferative disorders, seen after burn, trauma, and/or surgery. We aimed to compare the clinical and histopathological results of 1064-nm Nd:YAG laser and combined intense pulsed light and radiofrequency in the treatment of hypertrophic scars.

METHODS

Fifty patients with hypertrophic scars were included in this prospective, randomized study. Twenty-five patients were treated with Nd:YAG laser and 25 patients with combined intense pulsed light and radiofrequency (E-light). The scars were evaluated at baseline, during and at 3 months after the final treatment session using the Vancouver scar scale. Biopsy specimens from scars were obtained before, during, and 3 months after the final treatment session and were stained with hematoxylin and eosin stain, Masson's trichrome stain, and immunostaining procedures for collagen I, collagen III, and TGF-β1.

RESULTS

Significant improvements in the total Vancouver scar scale scores before and after the treatment in both groups (P < 0.001); however, a significant difference between both groups (P < 0.001), regarding the E-light, which showed better response than Nd:YAG laser. Hematoxylin and eosin and Masson's trichrome staining showed arrangement and thinning of collagen bundles and reduction in collagen density by in both groups, but the collagen bundles thinning and parallelism were more obvious in the E-light group. Significant decrease in the concentration of collagen I, collagen III, and TGF-β1 in the E-light group as compared with the laser group (P = 0.005, P = 0.003 and P < 0.001, respectively).

CONCLUSIONS

Both modalities were successful in the treatment of hypertrophic scars; however, a significant improvement in the clinical and histopathological findings was detected with the E-light method.

Effects of the lower energy and pulse stacking in carbon dioxide laser skin treatment: an objective analysis using second harmonic generation

PURPOSE

To evaluate the effect of fractional carbon dioxide (CO2) laser treatment using lower power associated with pulse stacking within collagen fibers, using second harmonic generation microscopy and computerized image analysis.

METHODS

Twenty male Wistar rats aging eight weeks were used. Each treatment area received a single-pass CO2 fractional laser with different parameters. The 20 animals were divided into two groups and euthanized after 30 and 60 days. Second harmonic generation images were obtained and program ImageJ was utilized to evaluate the collagen organization within all areas. Collagen anisotropy, entropy and optical density were quantified.

RESULTS

Increased anisotropy over time was observed in all four areas, but only reached statistical significance (p = 0.0305) when the mildest parameters were used (area four). Entropy decreased over time in all areas, but without significance(p = 0.1779) in area four. Density showed an overtime increase only in area four, but no statistical significance was reached (p = 0.6534).

CONCLUSIONS

When combined, the results obtained in this study regarding anisotropy, entropy and density tend to demonstrate that it is possible to achieve collagen remodeling with the use of lower power levels associated with stacked pulses.

Split-thickness skin graft donor-site morbidity: A systematic literature review

The purpose of this systematic literature review is to critically evaluate split-thickness skin graft (STSG) donor-site morbidities. The search of peer-reviewed articles in three databases from January 2009 to July 2019 identified 4271 English-language publications reporting STSG donor-site clinical outcomes, complications, or quality of life. Of these studies, 77 met inclusion criteria for analysis. Mean time to donor-site epithelialization ranged from 4.7 to 35.0 days. Mean pain scores (0-10 scale) ranged from 1.24 to 6.38 on postoperative Day 3. Mean scar scores (0-13 scale) ranged from 0 to 10.9 at Year 1. One study reported 28% of patients had donor-site scar hypertrophy at 8 years. Infection rates were generally low but ranged from 0 to 56%. Less frequently reported outcomes included pruritus, wound exudation, and esthetic dissatisfaction. Donor-site wounds underwent days of wound care and were frequently associated with pain and scarring. Widespread variations were noted in STSG donor-site outcomes likely due to inconsistencies in the definition of outcomes and utilization of various assessment tools. Understanding the true burden of donor sites may drive innovative treatments that would reduce the use of STSGs and address the associated morbidities.

A 6-Year Experience of Laser Treatments for Burn Scars in a Regional Burn Center-Safety, Efficacy, and Quality Improvement

Laser treatments have long been used as a treatment method for burn scars. Since 2012, more than 1800 laser treatments were performed at Lehigh Valley Health Network Burn Center, far exceeding any previous cohort in studies exploring laser treatments for burn scars. Although previous research has looked at improving scar appearance and physiology with laser treatments, very few have focused on safety. The purpose of the study was to determine whether laser treatments are a safe treatment option for burn scars. Four hundred and fourteen patients who had undergone at least one laser treatment in the outpatient burn center since 2012 were analyzed. Electronic medical records (EPIC) were reviewed. The data were entered in REDCap and later exported to Microsoft Excel and R Studio for statistical analysis. Most of the complications found were related to the moderate sedation during the procedures and were mild, ie, nausea. The most common adverse effect was prolonged recovery time, which can affect practice flow. The overall postoperative complication rate for laser treatments with and without moderate sedation was minimal at 2.2% and 1.4%, respectively. Pain during and after the procedure averaged 3.9 and 1.7, respectively, on a 1 to 10 scale. The Vancouver Scar Scale showed modest improvement in scar appearance over time with an average improvement of 1.4. The high variability of the Vancouver Scar Scale observed in this series underlines its lack of sensitivity. The study results show that laser treatments for burn scars in the outpatient setting generally are safe for patients in need of burn scar intervention. Some practice flow adjustments need to be taken into consideration when offering these procedures in an outpatient setting.

A retrospective study to identify the optimal parameters for pulsed dye laser in the treatment of hypertrophic burn scars in Chinese children with Fitzpatrick skin types III and IV

For over several decades, 595-nm pulsed dye laser (PDL) has been used effectively, reducing erythema and improving the pliability and texture of burn scars. Children usually tolerate PDL treatment as it is non-invasive and causes only mild pain compared to other laser treatments. However, currently, there are limited data on scar management in children who underwent PDL treatment, especially for Fitzpatrick skin types III and IV. The objective of the study was to identify the optimal parameters for the PDL treatment that induce inhibitory effects on scar tissue in children with Fitzpatrick skin types III and IV. Besides, the study assessed the usefulness of high-frequency ultrasound (20 MHz) and laser Doppler flowmetry in assessing these lesions. A total of 165 (79 males and 86 females) children with hypertrophic scars treated by PDL were assessed by the Vancouver scar scale (VSS), high-frequency ultrasound (20 MHz), and laser Doppler flowmetry. The parameters used for the 595-nm PDL treatment were pulse duration of 0.45 ms, fluence between 5 and 9 J/cm², a spot size of 7 mm, and treatment intervals from 3 to 8 weeks. There were no significant differences between pretreatment and post-treatment in terms of the distribution of sex, type of skin color, and low and high fluences. While the mean scores of all scar parameters based on VSS, except thickness and pliability between pre and post-treatment, showed significant differences in ≤3-year-old children vs. to >3-year-old children, except for the subscore, a significant improvement was observed when PDL was initiated within 4 to 6 months of the scar age. In Chinese children with Fitzpatrick skin types III and IV, early intervention, appropriate treatment intervals, and low fluence of PDL were optimal parameters in treating hypertrophic burn scars. The combined high-frequency ultrasound and laser Doppler flowmetry assessment of scars helped assess these lesions and compare the efficacy of different treatment modalities.

Fractionally Ablative Er: YAG Laser Resurfacing for Thermal Burn Scars: a Split-Scar, Controlled, Prospective Cohort Study

BACKGROUND

Thermal burn scars can have catastrophic impact on the quality of life and personal image, and over time can lead to profound physical and psychological debilitation. There are no established treatments to significantly improve burn scars.

OBJECTIVE

To demonstrate the safety, efficacy, and tolerability of fractionally ablative Er:YAG resurfacing of mature burn scars.

METHODS

Sixteen subjects were enrolled and received 3 treatments of fractionally ablative Er:YAG resurfacing at monthly intervals. Twelve completed the study. Scars were scored with the Vancouver Scar Scale (VSS) by the patient and physician before and after treatment. Blinded photographic analysis (Visual Analog Scale [VAS]) and blinded histologic analysis of tissue before and after treatment was also performed.

RESULTS

Significant Improvement in VSS scores were seen in all 12 patients, reported by patients and the evaluating physician alike. Photographic analysis demonstrated subjective improvement in all 12 patients. Histologically, there was significant improvement in collagen architecture and the number of vessels per high-power field. The treatments were tolerated well by patients, and 1 superficial skin infection occurred.

CONCLUSION

Fractionally ablative Er:YAG laser resurfacing is a safe and effective modality in the treatment of thermal burn scars with subjective and objective improvement as seen from the patient and physician.

High- Versus Low-Density Fractional Laser in the Treatment of Hypertrophic Postburn Scars: A Randomized Clinical Trial

BACKGROUND

Fractional CO2 laser has been shown effective in improving pigmentation, pruritus, and tightness of hypertrophic burn scars. However, there is no consensus on the optimal treatment parameters.

OBJECTIVE

To compare effectiveness of different densities of fractional CO2 laser in the treatment of mature hypertrophic burn scars.

MATERIALS AND METHODS

The study included 25 patients, each with 3 or more mature hypertrophic burn scars. Scars were randomly assigned to treatment with low-, medium-, and high-density fractional CO2 laser. Each scar received 3 sessions of laser at 1-month interval. The degree of improvement was assessed clinically using Vancouver Scar Scale (VSS) and Patient and Observer Scar Assessment Scale (POSAS) scores, and histologically through evaluation of collagen (Masson's Trichrome stain) before and 1 month after end of therapy.

RESULTS

High-density parameters showed significant higher improvement in VSS and POSAS assessment scores (p-value < .001). Pliability and relief are the most improved parameters. Histopathological evaluation revealed a significant drop in the mean area percent of collagen in the 3 used parameters, with highest improvement with high-density laser treatment (p-value < .001).

CONCLUSION

High-density fractional CO2 laser treatment provides more improvement in burn scars both clinically and histopathologically.

Effects of combined Pulsed Dye Laser and Fractional CO2 Laser treatment of burn scars and correlation with plasma levels of collagen type I, MMP-2 and TIMP-1

Hypertrophic burn scars remain a significant burden for patients and a challenge for clinicians.

THE AIM

Assessement of the efficacy of combined Pulsed Dye Laser and Ablative Fractional CO₂ Laser therapy on hyperthophic scars and correlation with plasma levels of MMP-2, TIMP-1 and alpha-1 type I collagen.

PATIENTS AND METHODS

Twenty five pediatric subjects were enrolled into the study. Control group consisted of age-matched subjects admitted for surgical repair of inguinal hernia. For the assessment of the results of laser treatment we used the Vancouver scar scale (VSS), and Patient-Observer Scar Assessment Scale (POSAS). We also correlated clinical results with plasma levels of MMP-2, TIMP-1 and alpha-1 type I collagen.

RESULTS

All subjects reported the laser treatment resulted in improvement and were somewhat satisfied or very satisfied with their experience. No adverse events were reported. The levels of MMP-2, TIMP-1 and alpha-1 type I collagen in our patients with scars before laser threatment were higher in comparison to controls. We also found statistically significant decrease in the levels of MMP-2, TIMP-1 and alpha-1 type I collagen after laser treatment of burn scars CONCLUSIONS: Our study clearly shows that combined CO2-AFL treatment for burn scars improve texture, colour, function and alleviate pruritus. We believe that decrease in the levels of MMP-2, TIMP-1 and alpha-1 type I collagen after laser treatment of burn scars, reflects reduced dynamic of scar.

Effects of Fractional CO2 Laser Treatment on Subglottic Scar in a Rabbit Model

OBJECTIVE

The objective of this study was to investigate the effects of fractional CO₂ laser on subglottic scar.

STUDY DESIGN

Randomized controlled animal study.

SETTING

Academic medical center.

METHODS

Subglottic scar was induced in 12 New Zealand white rabbits via an endoscopic brush technique. This was followed by an open airway surgery that included vertical division of the cricoid and proximal trachea. Eight rabbits underwent fractional CO₂ laser treatment of the scar via a Lumenis Ultrapulse Deep FX handpiece. Four rabbits underwent the open surgical approach without laser treatment. Bronchoscopy was performed at weeks 1, 2, 4, and 8. The animals were euthanized and laryngotracheal complexes harvested 12 weeks postsurgery. Immunohistochemistry was performed to determine the collagen composition of treated and untreated scars.

RESULTS

All 12 subjects survived to the study endpoint with no significant respiratory complications, despite 10 of 12 developing some degree of lateral tracheal narrowing. The median ratio of type I collagen to type III collagen in the laser group (1.57) was significantly more favorable than that of the untreated group (2.84; P = .03).

CONCLUSION

Treatment with fractional CO₂ laser appears to have similar effects on subglottic scars as with cutaneous scars, improving the ratio of type I to type III collagen. Additionally, we developed an open airway approach in the rabbit model to deliver fractional CO₂ laser treatment to the subglottis without introducing respiratory complications or compromising survival.

Fractional CO2 laser treatment for burn scar improvement: A systematic review and meta-analysis

Burn injury can cause abnormal healing and pathologic scar formation that significantly impairs patients' ability to return to baseline levels of functioning. Quality of life can be significantly diminished due to pain, stiffness, contracture, and the psychological burden of disfigurement. Traditional scar therapies such as silicone sheeting and compression garments are highly reliant on patient compliance, and have not demonstrated satisfactory efficacy. Even more invasive therapies such as intralesional medication delivery or surgical contracture release have high recurrence rates. Recently, fractional CO₂ laser therapy has emerged as a promising treatment modality for burn scars, but there is a lack of recent studies that aggregates extant data to demonstrate outcomes after laser therapy. To address this, we conducted a systematic review and meta-analysis to determine the efficacy of fractional CO₂ lasers in treating burn scars, and found that laser therapy alone yielded statistically significant improvements in scar profiles. There were very few reports of adverse effects, most treatments were provided as outpatient, and both patient and burn practitioners reported high satisfaction. By sharing our findings, we hope that more burn practitioners will consider adopting laser therapy as a safe and cost-effective first-line therapy for burn scar management.

Combination treatment utilizing fractional ablative and continuous wave CO2 lasers for hypertrophic burn scars

BACKGROUND

Hypertrophic scars are devastating outcomes of severe burn injuries, producing physical and mental burdens. Adequate treatment is of benefit to relieve these burdens. Laser therapy has shown scar reducing effects. In this study, we compared outcomes after combination of two different lasers or single laser treatment to treat severe hypertrophic burn scars.

METHODS

Forty patients with hypertrophic burn scars were included in one of two therapeutic groups: continuous wave CO₂ laser and fractional ablative CO₂ laser group (group 1, n = 20) or fractional ablative CO₂ laser alone group (group 2, n = 20). Hypertrophic scars were evaluated by the observer-rated Vancouver Scar Scale (VSS) before and after treatment and by patient-completed questionnaires after treatment. Comparative analyses were performed before and after treatment, and time-dependent improvement was also analyzed.

RESULTS

Forty patients (54 hypertrophic scars) completed the laser treatment protocols. Group 1 exhibited significantly more improvement in VSS vascularity, pliability, and height indices than group 2 (p < 0.05). Time-dependent analysis of total VSS scores suggested that group 1 experienced more improvement during a shorter treatment period (p < 0.05). For patient-reported outcomes, group 1 noted better grades than group 2 in four indices, namely scar appearance, scar thickness, pain, and pruritus (p < 0.05).

CONCLUSION

Effective scar reduction was achieved using combination laser treatment, with significant improvement in multiple observer- and patient-reported outcomes. The shorter treatment period of the combination method can be a merit, as prolonged hypertrophic scars may increase morbidity. Nonetheless, cautious treatment protocols are necessary to avoid undesirable sequelae related to laser application.

Ablative fractional laser treatment of hypertrophic burn and traumatic scars: a systematic review of the literature

Hypertrophic scars (HTS) following burns and other trauma and are associated with significant functional and psychosocial impairment. Ablative fractional lasers (AFLs) are increasingly being applied in the treatment of HTS supported by a rapidly expanding multidisciplinary base of literature. The multidisciplinary authors sought to evaluate existing literature, provide context and identify gaps, and make recommendations for a path forward. A systematic review was conducted to identify literature pertinent literature through September 2019. Retrospective cohort, randomized controlled trials, quasi-randomized controlled trials, observational prospective cohort, or case series with five or more subjects with hypertrophic scars incurred from burns and related trauma were considered. Twenty-two of the 23 evaluated studies documented statistically significant and/or meaningful qualitative improvements in nearly all outcome measures. Adverse events were generally infrequent and minor. Significant heterogeneity was observed among the studies included in this systematic review, precluding metaanalysis of pooled data. There is abundant existing literature on the use of AFLs in the management of HTS but study heterogeneity limits generalizability. Future studies should prioritize standardized protocols including assessments of function and quality of life.

Using rational strategies for children's scars based on more than 5 years assessment after burn

BACKGROUND

Paediatric patients with scars after burn are regularly encountered. Discussion of rational strategies for management are of value. The objective of the study was to describe development and utilisation of strategies for paediatric burn scars up to five years after injury.

METHODS

We included 164 cases aged from 5 to 8 years old in our study; all had burn scar deformities.

RESULTS

Assessments were made up to December 31, 2019. The following strategies were used: sequential treatment, reconstruction based on facial aesthetic units, predicting the effect of surgery on development, releasing skin tension and application of photoelectric technology or other non-surgical measures.

CONCLUSIONS

Using rational strategies for paediatric burn scars is very important.

3D Mesh Releasing Method: A Retrospective Analysis of Fractional CO2 Treatment on Contracture Scars

BACKGROUND AND OBJECTIVES

There has been reports on fractional CO₂ laser successfully improving contracture scars that impair the function of a joint. It seems that certain contracture problems could be solved by laser instead of surgery. However, the clinical application could be difficult when the efficacy of the method remains unknown. The purpose of this study is to report the releasing capacity of the fractional CO₂ laser on contracture scars based on a defined treatment method.

STUDY DESIGN/MATERIALS AND METHODS

We conducted a retrospective study in patients with limited function in joints caused by contracture scars. Fractional CO₂ laser and our "3D mesh releasing" protocol were applied. The primary outcome was the improvement measured in range of motion (ROM) of the relevant joint before all intervention and 6 months after the last treatment.

RESULT

From November 2016 to January 2018, 11 joints of 10 cases were treated by the fractional CO₂ laser. Patients went through 2.27 (standard deviation [SD] 1.42, 1-5) sessions. The average progress of ROM before and 6 months after all treatments was 19.13° (SD 10.25, P < 0.02). In six cases, we recorded that there was an 8.53° (SD 5.81, P < 0.02) of increase in ROM immediately after the laser session, and the average improvement reached up to 13.58° (SD 8.15, P < 0.02) after 2-3 months during the next follow-up.

CONCLUSION

The fractional CO₂ laser could achieve functional improvement in contracture scars and it maintained its effect for at least 6 months. The "3D Mesh Releasing" protocol would help to standardize the treatment procedure. This modality has minimal-invasiveness and potentially could become a supplement to the current treatment choices for mild contracture scars. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.