The safety and efficacy of botulinum toxin for management of scars: A systematic review with meta-analysis and trial sequential analysis

Effectiveness of microneedle fractional radiofrequency combined with transcutaneous delivery of botulinum toxin in the management of post-acne scars

BACKGROUND

Post-acne scars are a common sequela of acne, especially prevalent among young people. Delayed treatment not only affects self-perception of beauty but also affects the mental health of patients.

OBJECTIVE

This study aims to investigate the clinical efficacy of microneedle fractional radiofrequency (MFR) combined with botulinum toxin A (BoNT/A) in managing post-acne scars.

METHODS

This retrospective study involved 63 adult patients with post-acne scars, divided into two groups: group 1 (n = 30) and group 2 (n = 33). Group 1 received treatment with MFR combined with transcutaneous delivery of BoNT/A, whereas group 2 received treatment with MFR alone. The study observed the clinical outcomes in both groups.

RESULTS

Based on experimental analysis, the combination of MFR with transcutaneous delivery of BoNT/A demonstrated superior clinical efficacy compared with group 2. There were no significant differences in baseline data or treatment-related pain and adverse reactions between the two groups. However, group 1 exhibited a higher effectiveness rate, lower ECCA score after treatment, higher satisfaction levels, and statistically significant differences compared to group 2.

CONCLUSION

MFR combined with transcutaneous delivery of BoNT/A represents an effective and safe alternative for treating acne scars with minimal side effects and complications.

SUMMARY STATEMENT

Post-acne scars are a common sequela of acne and combination therapy proves beneficial. Microneedle fractional radiofrequency (MFR) combined with transcutaneous delivery of BoNT/A can be considered an effective and safe alternative for the treatment of acne scars with minimal side effects and complications. It works together through microneedles, radiofrequency, and botulinum toxin. MFR combined with transcutaneous delivery of BoNT/A is based on the direct action of MFR on acne scars and the use of microneedle to create a transient skin microchannel, facilitating BoNT/A penetration into the skin.

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

BACKGROUND

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

PURPOSE OF THE STUDY

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 1: therapeutic applications

Objective An evidence-based review on the safety and efficacy of botulinum toxin type-A (BoNTA) in orofacial conditions, focusing on the therapeutic applications and role of BoNTA as an adjuvant treatment.Data source and selection Data was collected using PubMed (Medline), Cochrane Library of Systematic Reviews and Cochrane Central Register of Controlled Trials electronic databases. Having satisfied the search parameters, 32 studies for therapeutic applications and 26 for BoNTA as an adjunctive treatment were included. The quality of relevant studies was assessed using the Best Evidence Topics (BETs) Critical Appraisal Tool.Data extraction The highest level of evidence (LOE) behind BoNTA safety and efficacy was for wound healing and scar management in the orofacial surgery context, where BoNTA was presented as an adjunctive modality. Level-I evidence was controversial for temporomandibular disorders and bruxism. However, it showed promising results for painful temporomandibular disorders of myogenic origin refractory to conservative therapies, and to decrease muscle contraction intensity in sleeping bruxism. There was only one level-II study for persistent recurrent aphthous stomatitis. Data showed limited level-III evidence for orofacial pain conditions (temporomandibular joint recurrent dislocation and pain, burning mouth syndrome or atypical odontalgia), oral cancer complications, or as an adjuvant to maxillofacial and orthognathic surgeries. Benefits of BoNTA in prosthodontics had weak level-IV evidence. No evidence was found among the periodontology field.Conclusion There is growing evidence to support the safety and efficacy of BoNTA in the investigated orofacial pathological conditions, with high levels of satisfaction from the patient and clinician perspective. However, there are some inconsistencies and limited high-quality evidence available. Well-designed controlled clinical trials are necessary to evaluate long-term safety, efficacy and cost-effectiveness before BoNTA is widely adopted with irrefutable evidence-based clinical guidelines.

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.

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 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.

Management of excessive gingival display using botulinum toxin type A: a descriptive study

Botulinum toxin is a protease used by the bacterium Clostridium botulinum that causes chemical denervation of skeletal muscles, producing a temporary weakening of muscle activity. Despite having a transitory effect, the application of botulinum toxin has been identified as an alternative for correcting an excessive gingival display (EGD). However, studies evaluating the maintenance of long-term results of botulinum toxin remain scarce. This study aimed to evaluate the effectiveness and duration of botulinum toxin type A in the treatment of anterior EGD. Botulinum toxin Type A was applied to 15 patients with EGD. The measurement was performed in triplicate, using a Castro Viejo dry point compass, between the central cervical portion of the upper lateral incisors to the lower portion of the upper lip, bilaterally. The measurements were performed before the application of the toxin and repeated on days 7, 14, 90, 120, and 180 after the procedure. The data were analyzed using repeated-measures ANOVA, followed by a Bonferroni. There was a statistically significant reduction between the measurements performed on the Baseline and seven days after the application of the botulinum toxin. After 180 days, approximately one-quarter of the patients in the sample did not presented EGD. Mild adverse effects were reported by 46.7% of the patients. The use of botulinum toxin type A was effective to treat EGD. After 180 days, it was still possible to observe a significant effect compared to the initial gingival exposure.

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 .

Botulinum toxin type A attenuates hypertrophic scar formation via the inhibition of TGF-β1/Smad and ERK pathways

BACKGROUND

Hypertrophic scar is a common complication in would healing process, and how to effectively prevent and treat it has been a hot and difficult research issue. Previous studies have showed that botulinum toxin type A (BTA) has effects on the prevention and treatment of hypertrophic scar, but little is known about the specific mechanisms.

OBJECTIVE

This study aimed to explore the potential mechanisms of BTA on the inhibition of hypertrophic scar formation.

METHODS

Hypertrophic scar-derived human fibroblasts were cultured and then treated with transforming growth factor-β1 (TGF-β1) and various concentrations of BTA. Cell proliferation and viability were measured by CellTiter 96® AQueous One Solution Cell Proliferation Assay and trypan blue staining, respectively. The total amount of collagen was examined using Sirius red staining. Collagen I and Collagen III in the culture supernatant were evaluated by enzyme-linked immunosorbent assay. Reverse transcription-quantitative polymerase chain reaction and Western blot analysis were performed to detect the transcription and translation levels.

RESULTS

Our results revealed that BTA decreased the proliferation of hypertrophic scar-derived human fibroblasts. The mRNA and protein expression levels of alpha-smooth muscle actin, collagen I, and collagen III induced by TGF-β1 were inhibited by BTA in a dose-dependent manner. BTA also inhibited the phosphorylation of Smad2/3 and ERK.

CONCLUSION

BTA decreased the proliferation of fibroblasts and prevented overdeposition of ECM through the inhibition of the TGF-β1/Smad and ERK pathways. The findings of this study provide new scientific reference for the prevention and treatment of hypertrophic scar.

Differential Effects of Extracorporeal Shockwave Therapy and Botulinum Toxin-A Injection on Postburn Contractures and Gait Kinematics in Burn Children

Postburn contracture is a complex and multifactorial problem that requires intensive inputs from the burn care staff. This study endeavored to evaluate the effectiveness of extracorporeal shockwave therapy and botulinum toxin-A for treating the postburn plantar flexion contracture and optimizing ankle kinematics in burn children. Thirty-eight children with burns and plantar flexion contracture were randomized to receive the standard physical rehabilitation program (control group; n = 13), unfocused extracorporeal shockwave therapy (0.2 mJ/mm2) once a week over four consecutive weeks in addition to the standard physical rehabilitation (n = 12), or botulinum toxin-A injection (0.5–2 U/kg/muscle group with maximum dose of 12 U/kg/body weight) once at entry besides the standard physical rehabilitation (n = 13). Dorsiflexion active range of motion and ankle kinematics were measured before and immediately after treatment. The posttreatment dorsiflexion active range of motion increased significantly in the extracorporeal shockwave therapy group (P = .025) and botulinum toxin-A group (P = .04) when compared to the control group. Likewise, the initial stance–dorsiflexion, stance-maximum dorsiflexion, and swing-peak dorsiflexion angle improved significantly in the extracorporeal shockwave therapy group (P ˂ .001, P = .005, and P = .002, respectively) and botulinum toxin-A group (P = .004, P = .012, and P ˂ .001, respectively) compared to the control group. No significant differences were observed between the extracorporeal shockwave therapy and botulinum toxin-A groups with respect to any of the measured variables. To conclude, extracorporeal shockwave therapy and botulinum toxin-A injection could be effectively used to treat postburn plantar flexion contracture and to optimize the ankle kinematics during walking in children, without preference for either of them.