A Randomized Controlled Pilot Study on Ablative Fractional CO2 Laser for Consecutive Patients Presenting With Various Scar Types

Fractional picosecond laser treatment of non-acne atrophic scars and scar erythema in Chinese patients

BACKGROUND

Fractional picosecond lasers (FPL) are reported to be effective and safe for atrophic acne scars and post-acne erythema. However, there is no evidence regarding the effectiveness and safety of FPL treatment for non-acne atrophic scars and scar erythema among Chinese patients.

METHODS

In this retrospective study, 12 Chinese patients with non-acne atrophic scars, including nine with scar erythema, were treated with one to three sessions of 1064 nm FPL treatment. Clinical improvement was objectively assessed through blinded evaluations by external physicians. A modified Manchester Scar Scale (mMSS) and the Clinician Erythema Assessment Scale (CEAS) were individually used to evaluate atrophic scars and scar erythema based on photographs. Physician-assessed and subject-assessed Global Aesthetic Improvement Scale (GAIS) were used to assess changes before and after FPL treatment. Patient satisfaction and adverse events were also documented.

RESULTS

Total mMSS scores, as well as three parameters (color, distortion, and texture), were significantly decreased after FPL treatment, with a mean reduction of 3.18 ± 1.60 in total scores (p < 0.05). The CEAS scores were significantly reduced from 2.41 ± 0.98 before treatment to 0.41 ± 0.40 at the final visit (p < 0.05). Based on physician-assessed and subject-assessed GAIS scores, 11 (91.7%) patients were improved after FPL treatment. 33.3% of patients were very satisfied, and 41.7% were satisfied. No serious, prolonged (> 3 weeks) adverse events were observed.

CONCLUSION

Our study suggests that 1064 nm FPL treatment may be a promising option for non-acne atrophic scars, especially with scar erythema. Further studies are needed to confirm our results.

Efficacy and safety of fractional 1064-nm picosecond laser for atrophic traumatic and surgical scars: A randomized, single-blinded, split-scar-controlled study

OBJECTIVE

A fractional 1064-nm picosecond laser is an efficient and safe treatment for atrophic acne scars. However, evidence of using a picosecond laser for atrophic posttraumatic and surgical scar therapy is lacking. This study aimed to evaluate the efficacy and safety of using a 1064-nm picosecond laser with a microlens array (MLA) for the treatment of atrophic posttraumatic and surgical scars.

METHODS

This was a prospective, intraindividual, single-blinded, randomized split-lesion-controlled trial. Twenty-five subjects with atrophic traumatic or surgical scars that existed for more than 1 year were enrolled. All atrophic scars were divided at the midline into two halves and randomly assigned to a treatment or control side. The treatment group was treated with a 1064-nm picosecond laser with an MLA handpiece (spot size: 6-8 mm, fluence: 1.0-1.2 J/cm² , repetition rate: 5 Hz, three passes) for 3 monthly sessions. The scar volumes were objectively measured using a three-dimensional (3D) photograph at baseline, 1 month after the first and second treatments, and 3 and 6 months after the final treatment. Subjective assessments were conducted by a blinded dermatologist and patients' self-assessment to evaluate improvements at 3 months after the final treatment.

RESULTS

The treated sides exhibited a significant volume reduction, with statistically significant improvements over the control group at 1 month after the first and second treatments and at 3 months after the final treatment (p = 0.024, 0.005, and 0.019, respectively). At 3 months after the final treatment, a blinded dermatologist correctly identified the treated side in 24 of 25 patients (96%). The patients rated the improvements as excellent (>75%) and marked (50%-75%) in 36% and 48% of patients, respectively.

CONCLUSION

At 3 months, the 1064-nm picosecond laser with a fractionated MLA can significantly reduce the posttraumatic and postsurgical atrophic scar volume in patients with Fitzpatrick skin types III-V. Insufficient data preclude inferences regarding efficacy at 6 months.

Fractional ablative laser therapy for the treatment of severe burn scars: A pilot study of the underlying mechanisms

Ablative fractional resurfacing is clinically an efficient treatment for burn scar management. The aim of this pilot study was to investigate the poorly understood mechanisms underlying ablative fractional CO2 laser (AFL-CO2) therapy in relation to biomarkers S100 and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). S100 stains for Langerhans cells and neuronal cells, potentially representing the pruritus experienced. 11β-HSD1 catalyses the interconversion of cortisol and cortisone in cells, promoting tissue remodelling. Immunohistochemical analysis of S100 and 11β-HSD1 protein expression in the dermis and epidermis of the skin was performed on normal skin, before and after AFL-CO2 therapy. Data assessing outcome parameters was collected concurrently with the skin biopsies. 13 patients were treated with AFL-CO2 therapy. Langerhans cells decreased by 39% after 2nd treatment. Neuronal cells were overexpressed before treatment in the scar tissue by 91% but levels returned to that resembling normal skin. 11β-HSD1 expression in keratinocytes was significantly higher after laser treatment compared to before in scar tissue (p <0.01). No clear correlation was found in dermal fibroblast numbers throughout the treatment course. Whilst the role of the explored mechanisms and their association with clinical outcomes cannot conclusively be stated, this pilot study demonstrates promising trends that encourages investigation into this relationship.

Salvianolic Acid B Attenuates Hypertrophic Scar Formation In Vivo and In Vitro

BACKGROUND

Hypertrophic scars (HTSs) are a fibroproliferative disorder that occur following skin injuries. Salvianolic acid B (Sal-B) is an extractant from Salvia miltiorrhiza that has been reported to ameliorate fibrosis in multiple organs. However, the antifibrotic effect on HTSs remains unclear. This study aimed to determine the antifibrotic effect of Sal-B in vitro and in vivo.

METHODS

In vitro, hypertrophic scar-derived fibroblasts (HSFs) were isolated from human HTSs and cultured. HSFs were treated with (0, 10, 50, 100 μmol/L) Sal-B. Cell proliferation and migration were evaluated by EdU, wound healing, and transwell assays. The protein and mRNA levels of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 were detected by Western blots and real-time PCR. In vivo, tension stretching devices were fixed on incisions for HTS formation. The induced scars were treated with 100 μL of Sal-B/PBS per day according to the concentration of the group and followed up for 7 or 14 days. The scar condition, collagen deposition, and α-SMA expression were analyzed by gross visual examination, H&E, Masson, picrosirius red staining, and immunofluorescence.

RESULTS

In vitro, Sal-B inhibited HSF proliferation, migration, and downregulated the expression of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 in HSFs. In vivo, 50 and 100 μmol/L Sal-B significantly reduced scar size in gross and cross-sectional observations, with decreased α-SMA expression and collagen deposition in the tension-induced HTS model.

CONCLUSIONS

Our study demonstrated that Sal-B inhibits HSFs proliferation, migration, fibrotic marker expression and attenuates HTS formation in a tension-induced HTS model in vivo.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

Laser therapy for treating hypertrophic and keloid scars

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

Effect of the combination of photobiomodulation therapy and the intralesional administration of corticoid in the preoperative and postoperative periods of keloid surgery: A randomized, controlled, double-blind trial protocol study

Keloid scars are characterized by the excessive proliferation of fibroblasts and an imbalance between the production and degradation of collagen, leading to its buildup in the dermis. There is no “gold standard” treatment for this condition, and the recurrence is frequent after surgical procedures removal. In vitro studies have demonstrated that photobiomodulation (PBM) using the blue wavelength reduces the proliferation speed and the number of fibroblasts as well as the expression of TGF-β. There are no protocols studied and established for the treatment of keloids with blue LED. Therefore, the purpose of this study is to determine the effects of the combination of PBM with blue light and the intralesional administration of the corticoid triamcinolone hexacetonide on the quality of the remaining scar by Vancouver Scar Scale in the postoperative period of keloid surgery. A randomized, controlled, double-blind, clinical trial will be conducted involving two groups: 1) Sham (n = 29): intralesional administration of corticoid (IAC) and sham PBM in the preoperative and postoperative periods of keloid removal surgery; and 2) active PBM combined with IAC (n = 29) in the preoperative and postoperative periods of keloid removal surgery. Transcutaneous PBM will be performed on the keloid region in the preoperative period and on the remaining scar in the postoperative period using blue LED (470 nm, 400 mW, 4J per point on 10 linear points). The patients will answer two questionnaires: one for the assessment of quality of life (Qualifibro-UNIFESP) and one for the assessment of satisfaction with the scar (PSAQ). The team of five plastic surgeons will answer the Vancouver Scar Scale (VSS). All questionnaires will be administered one, three, six, and twelve months postoperatively. The keloids will be molded in silicone prior to the onset of treatment and prior to excision to assess pre-treatment and post-treatment size. The same will be performed for the remaining scar at one, three, six, and twelve months postoperatively. The removed keloid will be submitted to histopathological analysis for the determination of the quantity of fibroblasts, the organization and distribution of collagen (picrosirius staining), and the genic expression of TGF-β (qPCR). All data will be submitted to statistical analysis.

Trial registration: This study is registered in ClinicalTrials.gov (ID: NCT04824612).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Scoping Review of Therapeutic Strategies for Keloids and Hypertrophic Scars

Background:

Keloids are an abnormal proliferation of scars that can involve large areas of tissue beyond the original injury site. Hypertrophic scars are similar clinically, but do not exceed the original scar limits. These scarring abnormalities can cause noxious symptoms such as pain, tenderness, itching, and ulcerations. The aim of this review is to discuss current therapies for both types of abnormal scarring, and to determine if guidelines can be provided for excisional treatment with adjuvant therapies versus non-excisional methods.

Methods:

A systematic literature search was performed through the Web of Science database. The search revolved around keywords such as “keloid,” “hypertrophic scars,” and “treatment.” Articles were reviewed and screened for inclusion and exclusion criteria. The review focuses on an analysis and summarization of randomized control trials regarding keloid or hypertrophic scar treatments.

Results:

The original searches produced 1161 and 1275 articles for keloid and hypertrophic scars, respectively. In total, 316 duplicates were found. After accounting for 2014–2019 publication time, 655 keloid and 893 hypertrophic scar articles were reviewed. This resulted in 15 articles that pertained to treatment and randomized control trials.

Conclusions:

Keloids and hypertrophic scars present a clinical challenge. Based on qualitative review of recurrence, neither excision plus adjuvant therapy or nonsurgical treatments can be recommended preferentially at this time. More research is needed to determine if recurrence rate bias exists between the treatment regimens, as excisional treatment plus adjuvant therapy is reserved for refractory scars.

Fractional CO2 laser ablation of porcine burn scars after grafting: Is deeper better?

INTRODUCTION

Fractional CO₂ lasers have been used in clinical settings to improve scarring following burn injury. Though used with increasing frequency, the appropriate laser settings are not well defined and overall efficacy of this therapy has not been definitively established. As it has been proposed that for thick hypertrophic scars proportionally greater fluence and thus deeper ablation into the scar tissue would be most effective, the goal of this study was to examine the role of ablation depth on scar outcomes in a highly-controlled porcine model for burn scars-after grafting.

METHODS

Properties of laser ablated wells were quantified on ex vivo pig skin as a function of laser energy (20, 70 or 150mJ). Full-thickness burn wounds were created on the dorsum of red Duroc pigs with the eschar excised and grafted with a split-thickness autograft meshed and expanded 1.5:1. After four weeks of healing, sites were treated with either 20, 70, or 150mJ pulse energy from a fractional CO₂ laser at 5% density or left untreated as a control. Sites were treated every four weeks with three total sessions. Scar area, pigmentation, erythema, roughness, histology, and biomechanics were evaluated prior to each laser treatment at day 28, 56, and 83, as well as four weeks after the final laser treatment, day 112. Additional biopsies were collected at day 112 for gene expression analysis.

RESULTS

The depth of the laser ablated wells increased with increasing pulse energy while the width of the wells was smaller in the 20mJ group and not significantly different in the 70 and 150mJ groups. Scar properties (area, color, biomechanics) were not significantly altered by laser therapy at any of the laser energies tested versus controls. Average scar roughness was improved by laser therapy in a dose dependent manner with scars treated with 150mJ of energy having the smoothest surface; however, these changes were not statistically significant. Assessment of matrix metalloproteinase 9 gene expression showed a slight upregulation in scars treated with 70 or 150mJ versus control scars and scars treated with 20mJ pulse energy.

CONCLUSION

The current study demonstrated that the properties of the ablative well (depth and width) are not linearly correlated with laser pulse energy, with only a small increase in well depth at energies between 70 and 150mJ. Overall, the study suggests that there is little difference in outcomes as a function of laser energy. Fractional CO₂ laser therapy did not result in any statistically significant benefit to scar properties assessed by quantitative, objective measures, thus highlighting the need for additional clinical investigation of laser therapy efficacy with non-treated controls and objective measures of outcome.

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

Background

There is increased interest in laser treatment of facial scars.

Objective

To determine the factors associated with treatment response.

Methods

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

Results

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

Conclusion

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

Experimental Study of 5-fluorouracil Encapsulated Ethosomes Combined with CO2 Fractional Laser to Treat Hypertrophic Scar

OBJECTIVE

This study is designed to explore permeability of ethosomes encapsulated with 5-florouracil (5-FU) mediated by CO₂ fractional laser on hypertrophic scar tissues. Moreover, therapeutic and duration effect of CO₂ fractional laser combined with 5-FU encapsulated ethosomes in rabbit ear hypertrophic scar model will be evaluated.

METHODS

The permeated amount of 5-FU and retention contents of 5-FU were both determined by high-performance liquid chromatography (HPLC). Fluorescence intensities of ethosomes encapsulated with 5-FU (5E) labeled with Rodanmin 6GO (Rho) were measured by confocal laser scanning microscopy (CLSM). The permeability promotion of 5E labeled with Rho in rabbit ear hypertrophic scar mediated by CO₂ fractional laser was evaluated at 0 h, 6 h, 12 h, 24 h, 3 days and 7 days after the irradiation. The opening rates of the micro-channels were calculated according to CLSM. The therapeutic effect of 5EL was evaluated on rabbit ear hypertrophic scar in vivo. Relative thickness of rabbit ear hypertrophic scar before and after the treatment was measured by caliper method. Scar elevation index (SEI) of rabbit ear hypertrophic scar was measured using H&E staining.

RESULTS

The data showed that the penetration amount of 5EL group was higher than 5E group (4.15 ± 2.22 vs. 0.73 ± 0.33; p < 0.05) after 1-h treatment. Additionally, the penetration amount of 5EL was higher than that of the 5E group (107.61 ± 13.27 vs. 20.73 ± 3.77; p < 0.05) after 24-h treatment. The retention contents of the 5EL group also showed higher level than 5E group (24.42 ± 4.37 vs.12.25 ± 1.64; p < 0.05). The fluorescence intensity of Rho in hypertrophic scar tissues of the 5EL group was higher than that of the 5E group at different time points (1, 6, and 24 h). The opening rates of the micro-channels were decreased gradually within 24 h, and micro-channels were closed completely 3 days after the irradiation by CO₂ fractional laser. The relative thickness and SEI of rabbit ear hypertrophic scar after 7 days of treatment in the 5EL group were significantly lower than the 5E group.

CONCLUSION

CO₂ fractional laser combined with topical 5E can be effective in the treatment of hypertrophic scar in vivo and supply a novel therapy method for human hypertrophic scar.

Fractional CO2 laser treatment of caesarean section scars-A randomized controlled split-scar trial with long term follow-up assessment

BACKGROUND AND OBJECTIVES

Caesarean section (c-section) scars can be pose functional and cosmetic challenges and ablative fractional laser (AFXL) treatment may offer benefit to patients. We evaluated textural and color changes over time in AFXL-treated versus untreated control scars.

MATERIALS AND METHODS

A randomized, controlled, intra-individual split-scar trial with three sessions of AFXL-treatments for mature c-section scars. Settings of AFXL were adjusted to each individual scar. End-points were blinded on-site clinical evaluations at 1, 3, and 6 months follow-up (Patient and Observer Scar Assessment Scale [POSAS] and Vancouver Scar Scale [VSS]), blinded photo-evaluations, reflectance measurements, tissue histology, and patients satisfaction.

RESULTS

Eleven of 12 patients completed the study. At 1 month follow-up, AFXL-treated scars were significantly improved in pliability (POSAS P = 0.01 VSS P = 0.02) and smoother in surface relief (POSAS P = 0.03) compared to control scars. At 1-3 months, overall scar appearance was dominated by transient erythema and hyperpigmentation, confirmed by reflectance measurements (erythema% and pigmentation% peaked at 1 and 3 month follow-up, respectively). At 6 months follow-up, AFXL-treated scars improved on POSAS-total score though not significantly (P = 0.06). Correspondingly, blinded photo-evaluation found AFXL-treated scars significantly improved compared to controls (VAS P = 0.02). Histology indicated new dermal collagen and elastic fibers on AFXL-treated scars. At 6 months follow-up, a majority of patients (64%) favored subsequent AFXL-treatment of their untreated control scar tissue.

CONCLUSIONS

Scar remodeling is initiated 1 month after AFXL treatment, but overall scar improvement is concealed until laser-induced color changes resolve. At 6 months follow-up, the benefit of AFXL treatment on c-section scars emerges. Lasers Surg. Med. 49:189-197, 2017. © 2016 Wiley Periodicals, Inc.