Treatment of facial wounds with botulinum toxin A improves cosmetic outcome in primates

Intralesional Insulin is Superior to Intralesional Botulinum Toxin-A in the Treatment of Keloids

BACKGROUND

Keloids represent a troublesome condition that lacks a proper standard management protocol. Insulin and botulinum toxin A (BTX-A) both have evidence-based anti-scarring effects. Hence, their role in treating keloids needs to be investigated.

OBJECTIVE

To compare insulin's efficacy versus BTX-A in treating keloids.

PATIENTS AND METHODS

Sixty-three patients with keloids were randomly allocated into 3 equal groups. Group A was treated with intralesional insulin, Group B with intralesional BTX-A, and Group C with intralesional corticosteroids, each for 4 monthly sessions. The results were assessed objectively and subjectively using the patient and observer scar assessment scale.

RESULTS

All 3 groups showed a statistically significant reduction in volume before and after therapy, with percent changes of 66.6%, 25.3%, and 75% for Groups A, B, and C, respectively. Insulin and corticosteroids were statistically superior to BTX-A in improving pigmentation, reducing thickness, and inducing relief in treated keloids.

CONCLUSION

Both insulin and BTX-A show a promising role in managing keloids, with insulin demonstrating better efficacy. Botulinum toxin A is better recommended as an adjuvant therapy alongside other mainstay treatment modalities. Larger-scale studies are needed to confirm their roles and establish guidelines for their use.

The Efficacy and Safety of Botulinum Toxin Type A in Prevention of Hypertrophic Scars After Epicanthoplasty: A Split-Face Double-Blinded Randomized Controlled Trial

BACKGROUND

Timely intervention can improve the aesthetic outcome of surgical scars, and botulinum toxin type A (BTXA) has demonstrated its potential as an effective treatment. However, conclusive scientific evidence is needed to definitively confirm the specific efficacy of BTXA following epicanthoplasty.

METHODS

A total of 21 patients who underwent epicanthoplasty were enrolled. Either BTXA or normal saline was randomly injected into the left or right epicanthus immediately after epicanthoplasty. The efficacy of scar prevention was assessed at a 1-month and 6-month follow-up visit using various assessment scales, and scar widths were also measured. The safety assessment included evaluating the complications and adverse effects after injections.

RESULTS

Totally, 20 patients completed the entire follow-up period. At 6-month follow-up, significant improvements were noted (P<0.05) in the treatment group compared to the control group across all evaluated metrics: the Modified Stony Brook Scar Evaluation Scale (total scores: 6.73±1.26 vs 5.75±1.60), Observer Scar Assessment Scale (total scores: 6.35±5.93 vs 8.55±5.65), Patient Scar Assessment Scale (color scores: 1.10±1.17 vs 1.85±1.69), Visual Analog Scale (total scores: 8.48±1.24 vs 7.94±1.37), and the average scar widths (0.37±0.18mm vs 0.68±0.42mm). No adverse effects were observed.

CONCLUSIONS

BTXA can effectively prevent scar hyperplasia after epicanthoplasty, especially in improving scar pigmentation, width, and softness.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Dose-Dependent Effects of Botulinum Toxin Type A on Prevention of Postoperative Scars in Various Regions in the Body: A Prospective, Double-Blind Randomized Controlled Trial

BACKGROUND

Botulinum toxin type A (BTXA) can improve wound healing and reduce scar formation; however, the exact dose required to prevent postoperative scarring across various anatomical sites remains unclear. This study aimed to investigate the effectiveness and optimal concentrations of BTXA for preventing postoperative scarring across various common surgical sites throughout the body.

METHODS

In this prospective randomized controlled trial, 46 patients with benign skin tumors received injections of 1, 2.5, or 5 U/0.1 mL of BTXA or 0.9% saline immediately following surgical tumor excision on both sides of the incisions. Follow-ups were conducted at 7 days, 15 days, and 1, 3, and 6 months postoperatively. Patient-reported adverse events and standardized digital photographs were collected. Scar formation was assessed using the modified Stony Brook Scar Evaluation Scale (mSBSES).

RESULTS

All 46 patients completed the trial without severe complications. The mSBSES scores were higher in the experimental groups at all follow-ups. The 5 U/0.1 mL BTXA dose group demonstrated optimal scar prevention at all high-risk sites for scar hyperplasia. No significant difference was observed between the 2.5 U/0.1 mL and 5 U/0.1 mL doses for intermediate-risk sites, while 1 U/0.1 mL dose was sufficient for low-risk sites. Overall, 86.5% of patients were satisfied with their treatments, with 16.3% being very satisfied.

CONCLUSIONS

Early postoperative BTXA injection can reduce or prevent hypertrophic scarring, with optimal doses ranging from 1 to 5 U/0.1 mL depending on the surgical site, supporting broader clinical application of BTXA. The effectiveness of different concentrations of botulinum toxin type A (BTXA) in preventing postoperative scarring was compared, expanding the scope of previous research, which focused only on the head, face, and neck regions, to include the trunk and extremity areas. Different optimal injection strategies were determined based on different surgical sites and their risks of developing hypertrophic scars. The study demonstrates that BTXA not only reduces scar formation but also enhances patient satisfaction and reduces postoperative itching and pain, contributing to overall better postoperative outcomes. By establishing the efficacy and optimal dosing of BTXA for various surgical sites, this research supports the potential for broader clinical application of BTXA in aesthetic and reconstructive surgeries.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Botulinum Toxin to Improve Scar Quality in Cleft Lip Repair: A Systematic Review

OBJECTIVE

Cleft lip repair (CLR) can be complicated by hypertrophic scar or keloid. Botulinum toxin type A (BTA) may improve postoperative scarring by reducing muscle tension and cytokine activity at the scar site. This systematic review analyzes the available evidence regarding the effect of BTA on scar quality after CLR.

DESIGN

The search was conducted in 6 different databases in accordance with PRISMA guidelines (PubMed, Scielo, Embase, Scopus, Web of Science, and Cochrane) using "botulinum toxin" and "cleft lip" as keywords.

SETTING

Academic hospital.

PATIENTS

Exclusive to patients who underwent CLR and BTA injection.

OUTCOME MEASURES

Mean visual analog scores (VAS), mean Vancouver scar scale (VSS), scar width, and BTA or CLR-related complications.

RESULTS

Five studies for a total of 216 patients met inclusion criteria. Four studies reported on primary CLR during infancy while 1 study recruited older patients seeking revision. All patients had BTA (range: 1-2 units/kg) injected in the orbicularis oris muscle. One study documented BTA injections in additional perioral muscles. All 4 studies that measured scar width and had a saline control arm found a significant decrease in width with BTA injection. Improvement of VAS and VSS with BTA was reported in 3 of 5 studies and 2 of 5 studies, respectively. There were no reports of complications associated with BTA or CLR.

CONCLUSION

The existing studies support the use of BTA injection to improve scar quality following CLR with low concern for complication. Further investigations with a greater number of patients are necessary.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Effectiveness of Botulinum Toxin-A on Face, Head, and Neck Scars: A Systematic Review and Meta-Analysis

Background: Botulinum toxin A (BTA) temporarily paralyzes nearby muscles to reduce tension in wound sites, inhibiting scar hyperplasia. Objective: To evaluate the effectiveness of BTA injection on scar formation and quality in various face, head, and neck sites. Methods: A comprehensive search was conducted across four electronic databases and registries to identify relevant studies. We assessed the following outcomes: visual analog scale (VAS), Vancouver scar scale (VSS), scar width, patient self-assessment scale, Stony Brook scar evaluation scales, Observer scar assessment scale, Manchester scar scale, and patient scar-assessment scale. Results: This systematic review included 20 studies encompassing 894 patients, of which, 18 studies were eligible for meta-analysis. The VAS and VSS significantly improved with BTA compared to controls which significantly reduced scar width at the first and second measurement points compared to controls. Subgroup analyses revealed that BTA had better upper lip and forehead outcomes. Conclusion: This systematic review and meta-analysis found that scars of the face, head, and neck were improved with BTA treatment compared to controls. This highlights the need for further study, especially concentrating on the upper lip and forehead regions, where improved outcomes were identified on subgroup analysis.

In-vivo assessment of application of folinic acid and botulinum toxin A in cleft lip surgical defects

INTRODUCTION

Folinic acid and botulinum toxin A have shown promising results in wound healing in different studies. This study aimed to compare the effects of these approaches on wound healing after simulating cleft lip surgery in rats.

METHODS

In this experimental animal study, after creating lip defects, 30 rats were randomly divided into three groups and received normal saline (CTL), botulinum toxin A (BOT), and folinic acid (FOL). Biopsy from the skin wounds was performed after 14- and 28-days. These samples were stained with haematoxylin and eosin and Masson trichrome staining. Finally, each pathological parameter of wound healing was rated in this study.

RESULTS

While the inflammatory response was not different among the study groups, fibroblast proliferation and collagen deposition were significantly higher in FOL group compared to BOT group. Moreover, both BOT and FOL facilitated epithelial healing and 14-day angiogenesis as compared with normal saline.

CONCLUSIONS

Improved wound healing was observed using both botulinum toxin A and folinic acid in rat animal models. However, the application of botulinum toxin A caused less fibroblast proliferation and collagen deposition which can potentially lead to less scar formation, which can be particularly important in the aesthetic zone.

Botulinum toxin type A inhibits M1 macrophage polarization by deactivation of JAK2/STAT1 and IκB/NFκB pathway and contributes to scar alleviation in aseptic skin wound healing

The non-neuronal and non-muscular effects of botulinum toxin type A (BTXA) on scar reduction has been discovered. This study was designed to investigate the effects of BTXA on macrophages polarization during the early stage of skin repair. A skin defect model was established on the dorsal skin of SD rats. BTXA was intracutaneous injected into the edge of wound immediately as the model was established. Histological examinations were performed on scar samples. Raw 264.7 was selected as the cell model of recruited circulating macrophages, and was induced for M1 polarization by LPS. Identify the signaling pathways that primarily regulated M1 polarization and respond to BTXA treatment. Application of BTXA at early stage of injury significantly reduced the scar diameter without delaying wound closure. BTXA treatment improved fiber proliferation and arrangement, and inhibited angiogenesis in scar granular tissue. The number of M1 macrophages and the levels of pro-inflammation were decreased after treated with BTXA in scar tissues. LPS activated JAK2/STAT1 and IκB/NFκB pathways were downregulated by BTXA, as well as LPS induced M1 polarization. At early stage of skin wound healing, injection of BTXA effectively reduced the number of M1 macrophages and the levels of pro-inflammatory mediators which contributes to scar alleviation. BTXA resisted the M1 polarization of macrophages induced by LPS via deactivating the JAK2/STAT1 and IκB/NFκB pathways.

Comparison research on the therapeutic effects of botulinum toxin type A and stromal vascular fraction gel on hypertrophic scars in the rabbit ear model

BACKGROUND AND OBJECTIVES

Botulinum toxin type A (BTA) is often used for wrinkles and muscle convulsive diseases due to its blocking of the transmission of nerve impulses. Stromal vascular fraction gel (SVF-gel) prepared from adipose tissue has novel effects on skin depression and poor texture. Both BTA and SVF-gel are proved to possess anti-scar potential. This study aimed to assess and compare their therapeutic effects on hypertrophic scars.

MATERIALS AND METHODS

The rabbit ear scar model was established and treated with BTA and SVF-gel, alone or in combination. Gross evaluation using Manchester Scar Scale (MSS) was conducted immediately, 4 and 8 weeks after initial treatment. After tissue sample harvest, histological and Western blot analyses were performed.

RESULTS

All the treatments alleviated scar hyperplasia in different degrees by inhibiting fibroblast activation (Ki-67, α-SMA), tissue inflammation (CD45, IL-1β) and the transforming growth factor-β1 (TGF-β1)/Smad3 pathway. Despite an excellent anti-inflammatory effect, improvement of scar appearance and pathological characteristics in SVF-gel-contained groups was not as good as that in BTA-only group, which might be related to the retention of M2-type macrophages (CD163 +) and partial maintenance of TGF-β1 expression.

CONCLUSION

Our data suggest that BTA has better anti-scar efficacy than SVF-gel, and the combination of these two treatments shows no obvious combinatorial effect.

Efficacy of Botulinum Toxin Type A for Prevention of Post-Mastectomy Scar in Transmen: A Prospective, Randomized Study

BACKGROUND

Subcutaneous mastectomies in transmen have been gaining popularity. However, post-operative scars are an inevitable consequence. Recently, Botulinum neurotoxin A (BoNT-A) has shown positive effects in scar prevention. The objective of this study is to investigate the effectiveness of BoNT-A in scar prevention.

METHODS

Fifteen patients who had undergone subcutaneous mastectomy were included. At 14 days post-surgery, either incoBoNT-A or a placebo was injected into the scar on each side. The primary outcome assessment measured the scar's severity using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). The secondary outcome assessment evaluated the scar's color using a standard measurement device. Outcome assessments were conducted until 6 months post-surgery.

RESULTS

There were significantly lower VSS scores in the BoNT-A group compared to the placebo at the end of the study (7.43 ± 0.26 vs. 8.82 ± 0.26, p < 0.001). The objective assessment revealed a statistically significant decrease in redness values in the BoNT-A group compared to the placebo at 3 and 6 months.

CONCLUSION

BoNT-A has demonstrated effectiveness in scar prevention by reducing the severity of postoperative scar formation and improving overall scar appearance.

Current and Future Developments in Wound Healing

Poor wound healing on the face and neck can lead to significant morbidity and dissatisfaction in facial plastic surgery. With current advances in wound healing management and commercially available biologic and tissue-engineered products, there are several options available to optimize acute wound healing and treat delayed or chronic wounds. This article summarizes some of the key principals and recent developments in wound healing research in addition to potential future advancements in the field of soft tissue wound healing.

The Impact of Botulinum Toxin Injection on the Outcomes of Breast Surgeries: A Systematic Review and Meta-Analysis

BACKGROUND

Breast surgeries aim to restore the natural appearance of the breasts with acceptable functional and cosmetic outcomes. However, these surgical procedures may be associated with considerable adverse events. The present systematic review and meta-analysis was designed to reveal the functional and aesthetic outcomes of botulinum toxins (BTX) injection in patients subjected to breast surgeries.

METHODS

A literature review was performed up to 21 September 2022. All clinical studies included patients older than 18 years old and treated with BTX injection for breast surgeries were included.

RESULTS

The present study included 12 articles, encompassing 496 patients. The average dosage of BTX injection ranged from 20 to 100 units. Injecting BTX significantly reduced the mean post-operative opioid analgesics usage (SMD -1.577; 95% -2.087, -1.067; P < 0.001) and the risk of severe animation deformity (RR 12.37; 95% 1.76, 86.66; P = 0.01). There was a statistically significant higher mean expansion volume per visit in the BTX injection group (SMD 1.166; 95% 0.313, 2.018; P = 0.007). There was no statistically significant impact of BTX injection on the risk of surgical site infection (RR 0.59; 95% 0.15, 2.34; P = 0.45) and seroma (RR 0.51; 95% 0.03, 10.15; P = 0.66).

CONCLUSIONS

The present study revealed the potential benefits of BTX injection in breast surgeries. This included reduced post-operative analgesics, as well as the risk of severe animation deformity. This was accomplished with increased expansion volume per visit and a similar risk of BTX injection-related complications.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Current Research of Botulinum Toxin Type A in Prevention and Treatment on Pathological Scars

BACKGROUND

Dermatologists have been looking for ways to improve wound healing and postoperative scar appearance. The safety and efficacy of botulinum toxin type A (BTXA) in the prevention and treatment on pathological scars have become the current research hotspot since it was approved by the US FDA in medical cosmetology in 2002.

PURPOSE

This article aims to provide an overview of the clinical research, limitations, and application prospects of BTXA in the prevention and treatment of traumatic or postoperative pathological scars, which can provide a reference and better understanding of relevant studies.

METHODS

The current research progress was summarized and discussed, with new problems and research ideas being proposed ranging from the molecular mechanism of BTXA in preventing and treating pathological scars to its clinical application via investigation and reference research.

RESULTS

BTXA is effective in relieving itching and pain associated with pathological scars, limiting scar hyperplasia along with preventing scar contracture, but the specific mechanism is still not clear.

CONCLUSION

Most of the clinicians have confirmed the clinical effectiveness of BTXA in the prevention and treatment of pathological scars, yet its mode of action and combination therapy need more research.

Botulinum Toxin Type A for the Treatment of Skin Ulcers: A Review Article

The normal biological wound healing process consists of three precisely and highly programmed phases that require optimal conditions including internal and external factors. Any negative factors that disrupt the sequence or time frame of the healing mechanism can result in a non-healing wound or chronic ulcers. Botulinum neurotoxin A (BoNT-A) which is generally known as anti-contraction of muscles has been reported as a successful treatment in various types of chronic ulcers. The aim of this study is to review the outcome of treatment with BoNT-A for chronic skin ulcers. The results demonstrated some positive effects of BoNT-A on chronic ulcers. Ischemic ulcers secondary to Raynaud’s phenomenon seem to be the most promising type of ulcers that have benefited from BoNT-A. The rationale behind using BoNT-A to fasten the wound healing process is also discussed. Further clinical trial studies should be conducted to affirm the efficacy of wound healing using BoNT-A administration.

A Systematic Review And Meta-Analysis: Botulinum Toxin A Effect on Postoperative Facial Scar Prevention

BACKGROUND

Postoperative facial scarring can be a significant psychological burden for patients to carry after surgery, often resulting in prolonged mental health dysfunction. Currently, there is no established method to prevent facial scar formation; however, there are several methods to prevent facial scar hyperplasia and improve scar quality. Botulinum toxin A (BTA) has been widely used due to its properties of muscle paralysis and known success in plastic surgery and cosmetology. This meta-analysis aimed to evaluate the efficacy of BTA in preventing postoperative facial scar hyperplasia and improving scar quality.

METHODS

PubMed, MEDLINE, EMBASE, web of science, and Cochrane libraries were searched for randomized controlled trials (RCTs) (published before May 2021) wherein BTA was used for the treatment of facial scars. The efficacy and safety of BTA were evaluated by the following scales: the Vancouver Scar Scale (VSS), Visual Analog Scale (VAS), Observer Scar Assessment Scale (OSAS), Patient Scar Assessment Scale (PSAS), and Stony Brook Scar Evaluation Scale (SBSES); the BTA effect on scar width and complications was also assessed.

RESULTS

Ten RCTs involving 114 cases were included. Through quantitative analysis, the BTA injection group had a higher VAS score, lower VSS score, lower OSAS score, and smaller scar width. However, no significant difference was noted in the incidence of postoperative complications between the two groups.

CONCLUSIONS

This meta-analysis demonstrated that BTA can safely improve the appearance of postoperative facial scars by significantly inhibiting scar hyperplasia and improving scar quality.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The effect of botulinum toxin A in unilateral cleft lip scar: comparison of results with different sites of injection

Botulinum toxin type A (BTA) injections into the subjacent orbicularis oris muscle have been shown to improve appearance and produce narrower cheiloplasty scars. This study was performed to determine the effect of BTA injected at different sites on the unilateral cleft lip scar and cleft side nostril width. A double-blind, randomized prospective trial was conducted involving 64 consecutive patients with unilateral cleft lip undergoing primary cheiloplasty between September 2016 and January 2019. The patients were randomized to receive BTA injections either into the subjacent orbicularis oris muscle (4 points group) or into the bilateral nasolabial fold region (6 points group) during cheiloplasty. The scars were assessed by photographic scar width measurements and Vancouver scar scale assessment tool. The cleft side nostril width was compared to the non-cleft side width. Fifty-six patients completed the trial, 24 in the 4 points group and 31 in the 6 points group. There was no significant difference in scar width or nostril width measurements between the groups at the end of follow-up. The Vancouver scar scale assessment was also similar between the groups. There was no significant difference in scar width or nostril width measurements after cleft lip repair between patients treated with botulinum toxin injections to the subjacent orbicularis oris muscle and patients treated with injections in the nasolabial region.

Efficacy and safety of botulinum toxin type A for postoperative scar prevention and wound healing improvement: A systematic review and meta-analysis

BACKGROUND

Botulinum toxin type A (BTXA) has shown underlying effects for wound healing improvement. New small clinical trials keep emerging every year and updated evidence-based information is warranted. This study aimed to evaluate the efficacy and safety of BTXA for preventing scarring.

METHODS

Four databases were searched to recruit randomized clinical trials (RCTs) which compared the surgical wounds treated with BTXA vs. those treated with placebo or blank control. The outcomes were primarily quantified by measures including the Vancouver Scar Scale (VSS), Visual Analog Scale (VAS), Stony Brook Scar Evaluation Scales (SBSES), modified SBSES (mSBSES), and scar width. Patients' satisfaction and adverse events were also reported.

RESULTS

In total, 16 RCTs involving 671 cases (510 patients) were included. The outcome showed significant superiority of BTXA in VSS (mean difference [MD] = -1.32, 95% confidence interval [CI]: -2.00 to -0.65, p = 0.0001), VAS (MD = 1.29, 95% CI: 1.05-1.52, p < 0.00001), SBSES or mSBSES (MD = -0.18, 95% CI: -0.27 to -0.10, p < 0.0001), scar width (MD = -0.18, 95% CI: -0.27 to -0.10, p < 0.0001), and patients' satisfaction (risk ratio [RR] = 1.25, 95% CI: 1.06-1.49, p = 0.01). No significant difference of adverse events incidence was observed (RR = 1.46 95% CI: 0.64-3.33, p = 0.36).

CONCLUSIONS

Botulinum toxin type A is effective and safe for postoperative scar prevention and wound healing improvement, especially for facial wounds of Asians. Further studies should manage to standardize the treatment algorithm, while mSBSES is recommended for scar assessment.

Efficacy of Botulinum Toxin A for Scar Prevention After Breast Augmentation: A Randomized Double-Blind Intraindividual Controlled Trial

BACKGROUND

Botulinum toxin A benefits postsurgical scar prevention by reducing wound edge tension and inhibiting in vitro scar tissue fibrosis.

OBJECTIVE

To investigate the efficacy of botulinum toxin Type A (BTX) in improving inframammary scar appearance after primary breast augmentation.

MATERIALS AND METHODS

A prospective, double-blinded, randomized controlled trial was performed with 27 participants receiving primary augmentation mammoplasty with inframammary incisions. After skin closure, intradermal injections of BTX were administered to 1 (treated) side of the inframammary incision. The contralateral side was the control. Scars were evaluated at 3 months, 6 months, and 9 months using the Patient and Observer Scar Assessment Scale and multispectral imaging analysis.

RESULTS

Overall, 22 patients completed the study. There were no significant subjective differences between the treated and control sides except the patient's treated side had significantly higher scores than the control side at 9 months. The treated side showed significantly smaller scar widths at 6 months and 9 months (p < .001) and better scar surface textures at 9 months (p = .003) than the control side.

CONCLUSION

Subjectively, intradermal BTX injection immediately after breast augmentation skin closure caused no significant differences. Objectively, scar width and texture significantly improved at 6 months and 9 months.

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

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

Botulinum Toxin to Improve Lower Blepharoplasty Scar: A Double-Blinded, Randomized, Vehicle-Controlled Clinical Trial

BACKGROUND

Lower blepharoplasty is a common cosmetic operation that relies on minimal postoperative scarring, but Asian patients are at higher risk than Caucasians for hypertrophic and/or widened scars. Botulinum toxin type A (BTX) injections are widely employed to alleviate dynamic facial rhytids and also can improve scar quality by reducing scar tension. The authors assessed whether simultaneous transcutaneous lower blepharoplasty and BTX injections could improve subciliary scar quality.

OBJECTIVES

The objective of this study was to assess whether simultaneous transcutaneous lower blepharoplasty and BTX injections could improve subciliary scar quality.

METHODS

This is a prospective, randomized, vehicle-controlled, double-blinded clinical trial. Between May 2015 and May 2018, 40 adults who underwent bilateral transcutaneous lower blepharoplasties were randomized to receive BTX (n = 20) or vehicle (normal saline; n = 20) injections into the lateral orbicularis oculi muscle immediately after wound closure. Vancouver Scar Scale, Visual Analogue Scale, and photographic scar width measurements at 3 reference points were recorded at the final clinical follow-up.

RESULTS

Thirty-seven patients completed the trial. Vancouver Scar Scale and Visual Analogue Scale scores in the experimental and vehicle control groups were similar, but scar widths in the experimental group at all measured points were significantly narrower than in the vehicle control group (P < 0.001, P = 0.027, and P < 0.001 at each measured point, respectively).

CONCLUSIONS

Transcutaneous lower blepharoplasty scars in Asians can be significantly narrowed by simultaneous BTX injections without additional complications.

LEVEL OF EVIDENCE 4

Current Advances in Hypertrophic Scar and Keloid Management

Hypertrophic scars and keloids are caused by excessive tissue response to dermal injury due to local fibroblast proliferation and collagen overproduction. This response occurs because of pathologic wound healing due to dysregulation in the inflammatory, proliferative, and/or remodeling phase. Patients with hypertrophic scars or keloids report reduced quality of life, physical status, and psychological health. Hypertrophic scars or keloids will develop in 30 to 90% of individuals, and despite their prevalence, treatment remains a challenge. Of the treatments currently available for hypertrophic scars and keloids few have been adequately supported by studies with appropriate experimental design. Here, we aim to review the available literature to provide up-to-date information on the etiology, epidemiology, histology, pathophysiology, prevention, and management options available for the treatment of hypertrophic scars and keloids and highlight areas where further research is required.

Clinical Outcomes Following the Early Application of Multimodal Scar Programs for Facial Incisional Wounds

BACKGROUND

Even though scars are major issues for patients who undergo facial lacerations, programs for their prevention and early management are not well established. The purpose of this study was to evaluate the clinical outcomes of prophylactic scar assessments and early scar interventions in patients with lacerations.

PATIENTS AND METHODS

A total of 116 patients underwent suture line and scar prevention treatment in the emergency room from 2014 to 2015. In the retrospective study, 46 patients who met all the criteria were included in the study. They were assigned to one of the following two scar prevention programs: the standard scar program for prevention, which included taping, silicone sheets, and ointments, and the multimodality scar program for treatment, which included triamcinolone, botulinum toxins, or CO₂ fractional lasers. The patterns of early scar program were investigated for the standard scar prevention program and the multimodality scar management program, and we evaluated the scar assessment scores of the patients at 3 and 6 months.

RESULTS

Scar scores for the patients who received multimodality scar management showed statistically significant improvements in Patient Scar Assessment (PSA) scales, Stony Brook Scar Evaluation Scales (SBSES), Vancouver Scar Scale (VSS) scores, and Visual Analog Scar (VAS) scales (the p values were 0.008, 0.007, 0.017, and 0.01, respectively).

CONCLUSION

The multimodality scar program is more effective for scar prevention than the standard scar program.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Botulinum Toxin for a Better Scar in Cleft Lip Surgery: A Prospective Randomized Control Trial

INTRODUCTION

An unsightly scar following cleft repair can undo the good work of even an experienced surgeon. A functioning orbicularis oris muscle beneath the lip scar maintains a zone of dynamic tension resulting in a stretched scar. Botulinum toxin type A (BTA) can be used to create a temporary paralysis of the orbicularis muscle during the healing phase. This may lead to better scar formation after a cleft lip repair.

METHOD

The present prospective randomized control trial enrolled 28 infants with unilateral cleft lip undergoing primary lip repair. They were randomized to receive injection of either BTA (botox group) or normal saline (control group) intraoperatively into adjacent orbicularis oris muscle immediately after completion of cleft lip repair. Blinded experts reassessed the scar after 6 months. Objective assessment was undertaken employing Visual Analogue Scale (VAS), Vancouver Scar Scale (VSS), and photographic scar width measurements.

RESULTS

Twenty-two subjects were able to complete a follow-up duration of 6 months. Children in the BTA (Botox Group) had a statistically significantly better VAS score and lesser scar width compared to the control group. However, the difference in the VSS score between both groups was not statistically significant. On comparing patients with cleft lip alone with cleft lip and palate, no statistically significant difference was found in VAS, VSS, and scar width. There were no complications associated with the use of botulinum toxin A.

CONCLUSIONS

Botulinum toxin type A injection is a safe and effective addition to improve scar appearance following cleft lip repair. There was improvement in appearance of the scar in terms of width, but no improvement was seen in the scar pigmentation. The scar outcome is independent of cleft lip classification.

The effect of botulinum toxin injection dose on the appearance of surgical scar

Early postoperative injection of botulinum toxin type A (BTxA) can reduce surgical scar hypertrophy. BTxA injection at different time points is associated with different levels of efficacy, but the efficacy of different doses of BTxA for scar management has not investigated. The purpose of this study was to investigate the effect of different doses of BTxA administered early after surgery on scar improvement through a split-scar experiment. The study included 22 patients who underwent surgery between September 2019 and October 2020. High- and low-dose BTxA was randomly administered into each half of the surgical wound closure immediately after surgery. One half of the incision was injected with a low dose (4 U) of BTxA, and the other half was injected with a high dose (8 U). The scars were then evaluated at postoperative 6 months using the modified Stony Brook Scar Evaluation Scale (mSBSES), and patient satisfaction was evaluated using the Visual Analogue Scale (VAS). The occurrence of complications or adverse events was also recorded. Twenty patients completed the study and were analyzed. Compared with the low-dose sides, the high-dose sides had significantly better mSBSES scores and significantly higher VAS scores (p < 0.01, respectively). No serious adverse reactions or post-injection complications were observed. Immediately after the operation, high-dose BTxA (that is within the therapeutic range) injection improved the appearance of postoperative scar more than low-dose injection.

The Efficacy of Drug Injection in the Treatment of Pathological Scar: A Network Meta-analysis

BACKGROUND

Pathological scars mainly include hyperplastic scars and keloids, and there is no uniform treatment standard for the treatment of pathological scar in clinic now. Drug injection in the treatment of pathological scar is widely used because of its advantages of less trauma and simple operation. Therefore, we used a network meta-analysis to compare the curative effect of four kinds of drugs which are commonly used in the treatment of pathological scar such as botulinum toxin type A, corticosteroids (including diprospan and triamcinolone acetonide (TAC)), verapamil and 5-fluorouracil (5-FU), systematically. It is hoped that our study will provide evidence for the choice of drugs in the treatment of pathological scar by injection.

METHODS

Relevant articles from Wanfang, VIP, CNKI, PubMed, Cochrane Library and Embase databases were extracted by us. They were included into a network meta-analysis to compare the four kinds of drugs which are commonly used in the treatment of pathological scar.

RESULTS

The network meta-analysis included a total of 1513 patients from 23 studies. Through meta-analysis, we found that the efficacy of botulinum toxin type A combined with corticosteroid drugs was best in the treatment of pathological scar by injection. There was no significant difference between botulinum toxin type A, corticosteroids combined with 5 Fu, verapamil and 5-FU. The efficacy of corticosteroids combined with 5-FU was better than that of corticosteroids alone and verapamil alone, but there was no significant difference between them and 5-FU. Further, the order of efficacy predicted by the SUCRA curve was as follows: botulinum toxin type A combined with corticosteroids > corticosteroids combined with 5-FU > botulinum toxin type A > corticosteroids > 5-FU > verapamil. Moreover, no publication bias was found in the funnel diagram.

CONCLUSION

In the injection treatment of pathological scar, we recommend the combined injection of two drugs, especially botulinum toxin type A combined with corticosteroids. The effective treatment of botulinum toxin type A combined with corticosteroids in the treatment of pathological scar is as follows: Patients were treated once monthly with intralesional injection of TAC (0.1 ml/cm3) mixed with botulinum toxin type A (2.5 IU/cm3) for a total of 3 treatments. However, there are still limitations in this network meta-analysis, and its conclusion still needs to be further confirmed by more randomized controlled trials.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Botulinum Toxin Type A Injection for Mammoplasty and Abdominoplasty Scar Management: A Split-Scar Double-Blinded Randomized Controlled Study

BACKGROUND

Scars are inevitable results of surgical procedures, and prevention of them is still a major problem in the field of cosmetic surgery. Although various studies have been performed on botulinum toxin-A (BoNT-A) injection for the prevention of hypertrophic scars, the exact mechanism remains unclear.

METHODS

This prospective, double-blinded, randomized study was performed on 19 patients who underwent mammoplasty and abdominoplasty surgery in Razi Hospital from October 2018 to December 2019. Single session of treatment was performed, where XEOMIN was allocated to one half of the scar and 0.9% saline to the control half. 3 and 6 months later, scars were assessed using the modified Stony Brook Scar Evaluation Scale (SBSES).

RESULTS

In total, 19 patients who completed the study were analyzed. mSBSES at the third month (P value < 0.001; 3.34 ± 1.59 vs 1.5 ± 1.36) and the sixth month (P value < 0.001; 4.89 ± 1.83 vs 2.39 ± 1.82) showed a significant difference between the treatment and control groups. In the subset analysis, there was significant difference between BoNT-A and control in all four items including width, height, color, and scar visibility at months 3 and 6, and the BoNT-A-treated sides had higher scores in all items.

CONCLUSION

BoNT-A has a significant effect on scar prevention due to mammoplasty and abdominoplasty compared to placebo and results in decreased erythema, height, width and reduces incision line visibility. Moreover, its effect increases significantly over time from months 3 to 6.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effect of botulinum toxin type A for treating hypertrophic scars: A split-scar, double-blind randomized controlled trial

BACKGROUND

Hypertrophic scars (HS) are a challenging disorder that mostly develops during wound-healing process following skin injuries.

METHODS

A split-scar, double-blind randomized controlled trial was held to assess the safety and efficacy of botulinum toxin type A (BTA) injection in hypertrophic scars (HS). Thirty patients with old scars (range: 1-15 years) were treated, with sides randomized to receive treatment with either BTA or 0.9% normal saline once monthly for three consecutive months. Scars were assessed using the Vancouver scar scale (VSS) along with digital photograph standardization.

RESULTS

Twenty-one subjects completed the study. The mean VSS score for the BTA-treated half of the scars decreased from 7.29 ± 2.327 before injection to 5.33 ± 2.41 following injection which was highly significant (P = .01). For the control half, the mean VSS decreased insignificantly from 7.29 ± 2.327 before injection to 7.10 ± 2.234 following injection (P = .104).

CONCLUSION

Clinical and cosmetic improvement was demonstrated significantly among the BTA-treated group. BTA can be an additional and useful tool for improving scar outcomes.

Botulinum toxin type A as a novel method of preventing cleft lip scar hypertrophy-A literature review

BACKGROUND

Cleft lip is a congenital development defect. Primary cleft lip repair leads to cleft scar formation. The resulting scar often undergoes hypertrophy, which negatively affects the facial esthetics, function, and patient's mental health. One of the methods used in scar therapy described in recent years is botulinum toxin injections The aim of this work is to present current knowledge about the impact of botulinum toxin A on cleft lip scar appearance and its effect on scar hypertrophy.

METHODS

The literature search was conducted in the English language via the PubMed and Google Scholar databases.

RESULTS

The results show injections seem to be a promising method in cleft lip scar management. However, future studies, especially randomized controlled trials, are necessary to assess the effect of BoNT-A compared with placebo and to determine the optimal dosages and injection schemes for BoNT-A treatment in cleft lip patients.

Efficacy and Safety of Botulinum Toxin Type A in Preventing Postoperative Scars and Improving the Cosmetic Appearance of Scars: A Systematic Review and Meta-Analysis

BACKGROUND

Scars with poor cosmesis that develop after wound healing may affect normal life.

OBJECTIVE

To assess the efficacy and safety of botulinum toxin type A (BTXA) in preventing postoperative hypertrophic scars or keloids.

METHODS

A systematic review was performed by searching the PubMed, Cochrane Library, and EMBASE databases from their inception date up to February 2020 for randomized controlled trials (RCTs) evaluating the efficacy of BTXA in preventing hypertrophic scars or keloids. The primary outcome measures included the Vancouver Scar Scale (VSS) score, Visual Analog Scale (VAS) score, scar width, patient satisfaction, and adverse events.

RESULTS

Twelve RCTs involving 497 cases (372 patients) were included. The meta-analysis showed significant differences in the VAS score (weighted mean difference [WMD] = 1.31, 95% CI = 1.06 to 1.55, P < .00001), VSS score (WMD = -1.02, 95% CI = -1.72 to -0.32, P = .004), scar width (WMD = -0.18, 95% CI = -0.29 to -0.08, P = .0008), and patient satisfaction (relative risk = 1.25, 95% CI = 1.06-1.49, P = .01). Four studies reported trivial adverse events.

CONCLUSIONS

This meta-analysis showed that BTXA was more effective than the control treatment in preventing postoperative scars and improving the cosmetic appearance of facial scars for East Asians, and no serious adverse events were found during the follow-up period. However, there was insufficient evidence to support the use of BTXA for the prevention of scars in patients from other ethnic groups and regions or scars in non-facial areas.

Electrospun Biomaterials in the Treatment and Prevention of Scars in Skin Wound Healing

Electrospinning is a promising method for the rapid and cost-effective production of nanofibers from a wide variety of polymers given the high surface area morphology of these nanofibers, they make excellent wound dressings, and so have significant potential in the prevention and treatment of scars. Wound healing and the resulting scar formation are exceptionally well-characterized on a molecular and cellular level. Despite this, novel effective anti-scarring treatments which exploit this knowledge are still clinically absent. As the process of electrospinning can produce fibers from a variety of polymers, the treatment avenues for scars are vast, with therapeutic potential in choice of polymers, drug incorporation, and cell-seeded scaffolds. It is essential to show the new advances in this field; thus, this review will investigate the molecular processes of wound healing and scar tissue formation, the process of electrospinning, and examine how electrospun biomaterials can be utilized and adapted to wound repair in the hope of reducing scar tissue formation and conferring an enhanced tensile strength of the skin. Future directions of the research will explore potential novel electrospun treatments, such as gene therapies, as targets for enhanced tissue repair applications. With this class of biomaterial gaining such momentum and having such promise, it is necessary to refine our understanding of its process to be able to combine this technology with cutting-edge therapies to relieve the burden scars place on world healthcare systems.

Efficacy of Botulinum Toxin Type A in Improving Scar Quality and Wound Healing: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Botulinum toxin type A-induced "chemoimmobilization" has long been utilized for improved scar quality and wound healing; however, current evidence is limited to small studies, and evidence-based information is inadequate to make well-informed decisions.

OBJECTIVES

The purpose of this study was to evaluate the efficacy of botulinum toxin type A (BTA) to improve scars and wound healing.

METHODS

The authors searched databases, including Pubmed, Embase, and Cochrane Library, to identify randomized clinical trials (RCTs) that compared outcomes of surgical scars and wounds treated with BTA vs those treated with blank or placebo controls. The Visual Analog Scale, Vancouver Scar Score, scar width, and reported patient satisfaction were utilized in evaluating outcomes. Adverse events were also recorded.

RESULTS

Eleven RCTs involved a total of 486 cases (374 patients). Quantitative synthesis suggested that compared with the control group, patients in the BTA treatment group had significantly higher Visual Analog Scale scores (mean difference [MD] = 1.30, 95% confidence interval [CI]: 1.05 to 1.55), lower Vancouver Scar Scores (MD = -1.62, 95% CI: -2.49 to -0.75, P = 0.0003), and thinner scars (MD = -0.15, 95% CI: -0.20 to -0.11, P < 0.00001). Patient satisfaction was higher in the BTA group than in the control group (risk ratio: 1.25, 95% CI: 1.06 to 1.49, P = 0.01). Trivial adverse events were reported.

CONCLUSIONS

This meta-analysis of RCTs provides reliable evidence that BTA injection is superior to placebo or blank control group in improving scar quality and wound healing in the face and neck for Asians, and negative outcomes for BTA treatment in these patients include only trivial adverse events. However, inadequate evidence supports utilization of BTA in Caucasians for primary surgical scars or for scars in locations other than the face and neck. Further studies on the standardized injection regimen and technique of BTA are warranted for clinical practice.

LEVEL OF EVIDENCE: 1

Comparison of botulinum toxin type A and aprotinin monotherapy with combination therapy in healing of burn wounds in an animal model

Burns are one of the most common injuries that are complicated by many challenges including infection, severe inflammatory response, excessive expression of proteases, and scar formation. The aim of this study was to investigate the effect of botulinum toxin type A (BO) and aprotinin (AP) separately or in combination (BO-AP) in healing process. Four burn wounds were created in each rat and randomly filled with silver sulfadiazine (SSD), BO, AP and BO-AP. The rats were euthanized after 7, 14, and 28 days, and their harvested wound samples were evaluated by gross pathology, histopathology, gene expression, biochemical testing, and scanning electron microscopy. Both BO and AP significantly reduced expression of interleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1) at the 7th post wounding day. Moreover, they inhibited scar formation by reducing the TGF-β1 level and increasing basic fibroblast growth factor (bFGF) at the 28th day. AP by decreasing protease production showed more effective role than BO in wound regeneration. AP increased tissue organization and maturation and improved cosmetic appearance of wounds, at 28 days. The best results gained when combination of BO and AP were used in healing of burn wounds. Treatment by BO-AP significantly subsided inflammation compared to the BO, AP, and SSD treated wounds. Treatment with BO-AP also reduced collagen density and led to minimal scar formation. Combination of botulinum toxin type A and aprotinin considerably increased structural and functional properties of the healing wounds by reducing scar formation and decreasing production of proteases.

Appropriate Timing of Early Postoperative Botulinum Toxin Type A Injection for Thyroidectomy Scar Management: A Split-Scar Study

BACKGROUND

Botulinum toxin type A (BTxA) injection is effective for surgical scar prevention. Although some studies have aimed to confirm the efficacy of BTxA injection at different time points, none has been conducted to determine the most appropriate timing of injection for scar management. The authors predicted that the injection of BTxA at different times during the wound healing process would cause differing scar quality improvement and clarify unknown molecular mechanisms.

METHODS

The study included adults who underwent thyroidectomy. All patients received paralesional BTxA injections on the day of the surgery on either the right or left side of the operative site. The same dose was injected on the noninjected side by means of the same method after 2 weeks. At 2, 4, 12, and 24 weeks postoperatively, the modified Stony Brook Scar Evaluation Scale, visual analogue scale, and erythema index were used for objective, subjective, and quantitative evaluations of the scar. At week 24 postoperatively, a quantitative scar assessment was performed with respect to the erythema index, skin elasticity, melanin index, and friction.

RESULTS

On objective evaluation of the scar and patient satisfaction at 24 weeks postoperatively, the operation-day injection side showed better outcomes than the 2-week-postoperative injection side. These differences were significant from postoperative week 4. In the final quantitative scar assessment at postoperative week 24, significant improvements were observed in the erythema index and skin elasticity.

CONCLUSION

These results suggest that immediate postoperative BTxA injection is more effective for thyroidectomy scar management in terms of erythema, skin elasticity, and patient satisfaction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

The use of botulinum toxin in keloid scar management: a literature review

INTRODUCTION

Administration of botulinum toxin is an increasingly popular procedure in the medical and aesthetic field. There is emerging evidence that it can influence fibroblast activity and minimise tension around the scar by virtue of muscular chemoimmobilisation. This review aims to explore the current evidence base behind the treatment of keloid scars with botulinum toxin.

METHODS

A detailed literature review was conducted using PubMed Medline, Embase and Web of Science databases. Manuscripts were appraised and classified in accordance with the Joanna Briggs Institute Levels of Evidence by an independent consultant in evidence synthesis. The results of this search are presented in descending order of evidence for botulinum toxin as a primary management agent as well as a secondary adjunct following extralesional keloid excision.

DISCUSSION

On the basis of level 1 evidence, botulinum toxin appears to be equivalent to triamcinolone in producing a short-term reduction in keloidal volume, height and vascularity. A number of level 1 and 2 studies also suggest that botulinum toxin may be particularly helpful in alleviating symptoms of keloid associated pain and itch. There are currently limited studies appraising the value of botulinum toxin in the postoperative management of keloid scars.

CONCLUSION

Botulinum toxin may represent a promising agent in the management of keloid scars. However, further research involving large-scale studies with comparative designs and long-term follow-up is warranted to delineate the value of this therapeutic modality in scar management protocols.

Keloids: Current and emerging therapies

Keloids are pathological scars that grow over time and extend beyond the initial site of injury after impaired wound healing. These scars frequently recur and rarely regress. They are aesthetically disfiguring, can cause pain, itching, discomfort as well as psychological stress, often affecting quality of life. Many treatment modalities, including surgical and non-surgical, have been explored and have been reported to be beneficial; however, none have been absolutely satisfactory or optimal for the treatment of all keloid subtypes to date. This poses a major challenge to clinicians. Often, a combinational therapeutic approach appears to offer the best results with higher patient satisfaction compared to monotherapy. The aetiopathogenesis of keloids is not fully elucidated; however, with recent advances in molecular biology and genetics, insight is being gained on the complex process of scar formation and hence new therapeutic and management options for keloids. In this paper, we explore the literature and summarise the general concepts surrounding keloid development and review both current (corticosteroids, surgical excision, silicone-based products, pressure therapy, radiotherapy, cryotherapy, laser therapy, imiquimod and 5-fluorouracil) and emerging (stem cell therapy, mitomycin C, verapamil, interferons, bleomycin, botulinum toxin type A and angiotensin-converting enzyme inhibitors) treatments. Increased knowledge and understanding in this area may potentially lead to the discovery and development of novel therapeutic options that are more efficacious for all keloid types.

LAY SUMMARY

Keloids are problematic scars that are difficult to treat and manage. The aetiopathogenesis of keloids is not clear; however, recent advances in molecular biology and genetics are beginning to shed light on the underlying mechanisms implicated in keloid scar formation which will hopefully lead to the development of treatment options for all keloid types. This review summarises current and emerging therapies.

Effectiveness and Safety of Botulinum Toxin Type A Injection for Scar Prevention: A Systematic Review and Meta-analysis

BACKGROUND

The role of active scar prevention in postoperative scar management is important. Botulinum toxin type A (BTXA) has been shown to improve postoperative scars in the past decades. The aim of this systematic review and meta-analysis was to evaluate the effectiveness and safety of BTXA injection for scar prevention.

METHODS

The authors searched the databases of Medicine, Embase, the Cochrane Library, Web of Science, and CINAHL from inception through November 2018 for randomized controlled trials (RCTs) reporting the use of BTXA in scar prevention. The outcomes were the visual analogue scale (VAS) score, Vancouver Scar Scale score, scar width, patient satisfaction and adverse events.

RESULTS

A total of nine RCTs were identified in this systematic review and meta-analysis. The VAS score was significantly higher in the BTXA group than in the control group (weighted mean difference (WMD) = 1.32, 95% confidence interval (CI) = 1.06-1.58, P < 0.00001). The Vancouver Scar Scale score was significantly lower in the BTXA group (WMD = - 1.25, 95% CI = - 2.23 to - 0.26, P = 0.01). The scar width was also significantly smaller in the BTXA group (WMD = - 0.18, 95% CI = - 0.24 to - 0.12, P < 0.00001). There was a significant difference in terms of patient satisfaction between the BTXA group and the control group (relative risk (RR) = 1.38, 95% CI = 1.09-1.74, P = 0.007). Only two studies reported complications, and other studies reported no complications during the follow-up period.

CONCLUSIONS

This systematic review and meta-analysis demonstrates that BTXA injection can reduce scar width in wounds and improve the overall appearance of postoperative scars and suggests that BTXA may be a safety therapy for scar prevention.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Histologic Evaluation of Healing Lip Defects Treated With Injected Onabotulinum Toxin A and Topical Mitomycin C

OBJECTIVE

Using an experimental rat model, the efficacy of injected Onabotulinum Toxin A (BoNT-A) versus topical Mitomycin C in surgical wound healing of rat lip defects was evaluated.

METHODS AND MATERIALS

Sixty-seven male Wister rats received a triangular cut (7 × 7 × 4 mm) on their upper lip. Then they were divided randomly into 4 equal groups: group A (topical Mitomycin C plus injected BoNT-A); group B (topical Mitomycin C); group C or control group (saline solution) and group D (injected (BoNT-A). After 3 months, the animals were euthanized and scars were evaluated using hematoxylin and eosin and Masson's trichrome.For qualitative analysis, inflammatory cell density, new capillary formation, fibroblast proliferation, and collagen deposition were reported using relative ranks from 0 to 3 (absence, mild, moderate, marked). Data were analyzed by post hoc and Kruskal-Wallis tests. The significance level was P < 0.05.

RESULT

Mean collagen deposition values and fibroblast proliferation in the 4 groups showed statistically significant differences with each other (P value < 0.001). A significant difference between group A and controls existed for fibroblast proliferation (median 1 versus 2, P value < 0.001); also, collagen deposition (median 1 versus 2, P value < 0.001). A significant difference existed between the control and group D (median 2 versus 1, P value = 0.004); also, group A and B (median 1 versus 2, P value = 0.002) for collagen deposition. However, no significant differences existed between the 4 groups regarding inflammatory cells and angiogenesis (P value > 0.05).

CONCLUSION

Local injection of BoNT-A plus Mitomycin C followed by BoNT-A alone provided less collagen formation and fibroblastic proliferation in the healing lip defect in a rat model.

Botulinum toxin type A suppresses pro-fibrotic effects via the JNK signaling pathway in hypertrophic scar fibroblasts

Hypertrophic scar is a dermal fibroproliferative disease characterized by the overproduction and deposition of extracellular matrix, and the hyperproliferation and enhanced angiogenesis of fibroblasts, along with their enhanced differentiation to myofibroblasts. Botulinum toxin type A shows potential for prevention of hypertrophic scar formation; however, its effectiveness in attenuating skin fibrosis and the related mechanism are unclear. In this study, human scar fibroblasts were cultured and stimulated with botulinum toxin type A, and the changes in fibroblast proliferation, migration, and protein expression of pro-fibrotic factors were evaluated with colorimetric, scratch, and enzyme-linked immunosorbent assays and western blotting, respectively. Botulinum toxin type A treatment decreased the proliferation and migration of human scar fibroblasts compared with those of untreated controls. Protein expression levels of pro-fibrotic factors (transforming growth factor β1, interleukin-6, and connective tissue growth factor) were also inhibited by botulinum toxin type A, whereas the JNK phosphorylation level was increased. Activation of the JNK pathway demonstrated the inhibitory effects of the toxin on human scar fibroblast proliferation and production of pro-fibrotic factors, suggesting that the suppressive effects of botulinum toxin type A are closely associated with JNK phosphorylation. Overall, this study showed that botulinum toxin type A has a suppressive effect on extracellular matrix production and scar-related factors in human scar fibroblasts in vitro, and that regulation of JNK signaling plays an important role in this process. Our results provide a theoretical basis, at the cellular level, for the therapeutic use of botulinum toxin type A.

Clinical trial to evaluate the efficacy of botulinum toxin type A injection for reducing scars in patients with forehead laceration: A double-blinded, randomized controlled study

BACKGROUND

Botulinum toxin type A (BoNTA) is known to prevent fibroblast proliferation and expression of transforming growth factor beta 1 (TGF-β1). It also induces temporary muscle paralysis and decreases tension vectors. Fibroblasts induce scar contracture and hypertrophy by producing collagen fibers in wound healing processes. The aim of this study is to identify the effect of BoNTA on the scar formation.

METHODS

Forty-five patients with forehead laceration were enrolled in this study and randomized into 2 groups with or without injection of BoNTA. When the patients presented to the clinic to remove the stitches, BoNTA was injected to the BoNTA group with 24 patients and saline was injected to the control group with 21 patients. The BoNTA was injected on dermal layer with 5 IU/cm. After that, follow-up was done in 1, 3, and 6 months. The scars were analyzed with the patient and observer scar assessment scale, Stony Brook scar evaluation scales (SBSESs), and visual analog scale (VAS) and analyzed with independent T-test, along with clinical photographs, cutometer, and biopsies.

RESULTS

In all scar scales, the scores changed into favorable direction in both groups and the changes were larger in BoNTA group compared with the control group. On SBSES and VAS, better improvements on BoNTA group showed statistical significance. Skin biopsy showed less collagen deposition on dermal layer in BoNTA group.

CONCLUSION

Improvement of aesthetic, functional, and emotional aspect of the scar formation in the groups treated with BoNTA was illustrated. The application of BoNTA may be expanded to prevent hypertrophic scar after trauma, burns, or operations.

[Postoperative care and options for scar treatment in eyelid surgery]

Oculoplastic surgery places special demands on postoperative care because of the functional importance of the eyelids for the ocular surface. We present an overview of postoperative care after surgical eyelid interventions. All options, limits and the scientific evidence are discussed with a special focus on the treatment of postoperative edema, analgesia, infection prophylaxis and scar treatment.

Prevention of esophageal stricture after endoscopic resection

Stricture formation after esophageal endoscopic resection has a negative impact on patients' quality of life because it causes dysphagia and requires multiple endoscopic dilations. Various methods by which to prevent stricture have recently been developed and reported. Among these methods, local steroid injection is the most commonly used and is currently considered the standard method for noncircumferential resection. However, local steroid injection has a limited effect on circumferential resection. Thus, oral steroid administration is used for such cases because it may have a stronger effect than local injection. Steroid treatment, both by local injection and oral administration, is effective and low-cost; however, it may cause fragility of the esophageal wall, resulting in adverse events such as perforation during balloon dilatation. Many innovative approaches have been developed, such as tissue-shielding methods with polyglycolic acid, tissue engineering approaches with autologous oral mucosal epithelial cell sheet transplantation, and stent insertion. These methods may be promising, but they are limited by a scarcity of data. Further investigations are needed to confirm the efficacy of these methods.