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

Correlation between Collagen Type I/III Ratio and Scar Formation in Patients Undergoing Immediate Reconstruction with the Round Block Technique after Breast-Conserving Surgery

The aim of this study was to investigate the relationship between the collagen type I/III ratio and scarring in patients who underwent immediate reconstruction with the round block technique (RBT) after breast conservation surgery. Seventy-eight patients were included, and demographic and clinical characteristics were recorded. The collagen type I/III ratio was measured using immunofluorescence staining and digital imaging, and scarring was assessed using the Vancouver Scar Scale (VSS). The mean VSS scores were 1.92 ± 2.01 and 1.79 ± 1.89, as assessed by two independent plastic surgeons, with good reliability of the scores. A significant positive correlation was found between VSS and the collagen type I/III ratio (r = 0.552, p < 0.01), and a significant negative correlation was found between VSS and the collagen type III content (r = −0.326, p < 0.05). Multiple linear regression analysis showed that the collagen type I/III ratio had a significant positive effect on VSS (β = 0.415, p = 0.028), whereas the collagen type I and collagen type III content had no significant effect on VSS. These findings suggest that the collagen type I/III ratio is associated with scar development in patients undergoing RBT after breast conservation surgery. Further research is needed to develop a patient-specific scar prediction model based on genetic factors affecting the collagen type I/III ratio.

Assessing the Reporting of Harms in Systematic Reviews Focused on the Therapeutic and Cosmetic Uses of Botulinum Toxin

BACKGROUND AND OBJECTIVE

The expanding use of botulinum toxin (BoNT) in medical practice demonstrates the need to highlight whether there is adequate information regarding its safety profile. The aim of our study was to identify completeness of harms reporting for BoNT treatment within systematic reviews (SRs), assess quality of SRs using the AMSTAR-2 tool, and determine the degree of overlap among primary studies within each SR.

METHODS

On May 31, 2022, we searched Embase, Epistemonikos, MEDLINE, and the Cochrane Database of Systematic Reviews for SRs on BoNT therapy. Screening and data extraction were performed in a masked, duplicate fashion. AMSTAR-2 was used to evaluate the methodological quality of included SRs. Corrected covered area (CCA) was calculated for SR dyads.

RESULTS

Of the 90 included SRs, we found that 70 completed less than 50% of harms items. The most reported items were BoNT as a favorable intervention (73/90, 81.1%) and harms as a primary outcome (72/90, 80.0%). The least reported items were grades and severity scales used to classify harms (8/90, 8.9%) and number of treatment discontinuations in each arm (10/90, 11.1%). Eighty-three SRs were rated "critically low" (83/90, 92.2%), while 5 SRs were rated "high" (5/90, 5.6%) via AMSTAR-2 tool. Significant associations were found between completion of harms reporting and: (1) a "critically low" appraisal on AMSTAR-2 tool (p = 0.0060) and (2) whether harms was reported as a primary outcome (p = 0.0001). The total CCA overlap was determined to be 0.8%.

CONCLUSION

Our results demonstrate that harms are underreported within BoNT SRs. Because healthcare professionals often refer to SRs to guide clinical decision making, it is important to continue to explore shortcomings among BoNT literature in future studies.

Histologic Evaluation of the Effects of Folinic Acid Chitosan Hydrogel and Botulinum Toxin A on Wound Repair of Cleft Lip Surgery in Rats

The aim of the present study was to compare the effects of folinic acid chitosan hydrogel and botulinum toxin A on the wound repair of cleft lip surgery in rat animal models. Cleft lip defects were simulated by triangular incisions in the upper lip of 40 Wistar rats. Then, the rats were randomly assigned to four groups: control (CTRL), chitosan hydrogel (CHIT), and folinic acid chitosan hydrogel (FOLCHIT), in which the wounds were covered by a gauze pad soaked in normal saline, chitosan hydrogel, and folinic acid chitosan hydrogel, respectively for 5 min immediately after closure; and botulinum toxin A (BOT) with the injection of 3 units of botulinum toxin A in the wound region. Fibroblast proliferation, collagen deposition, inflammatory cell infiltration, neovascularization, and epithelial proliferation and each parameter were rated on days 14 and 28. Statistical analysis was performed by Kolmogorov-Smirnov test, Shapiro-Wilk test, Kruskal-Wallis, and post-hoc tests (α = 0.05). The mean score for fibroblast proliferation was significantly higher in the FOLCHIT group compared with the BOT group at days 14 and 28 (p < 0.001, p = 0.012, respectively). At day 28, collagen deposition was significantly higher in the FOLCHIT group compared with the BOT group (p = 0.012). No significant difference was observed between the inflammatory infiltration of the study groups at the two time points (p = 0.096 and p = 1.000, respectively). At day 14, vascular proliferation of group FOLCHIT was significantly higher than groups CTRL and CHIT (p = 0.001 and p = 0.006, respectively). The epithelial proliferation in the FOLCHIT group was significantly higher than groups CHIT and CTRL at day 14 (p = 0.006 and p = 0.001, respectively) and day 28 (p = 0.012). In simulated lip cleft defects, topical application of folinic acid induces faster initial regeneration by higher inflammation and cellular proliferation, at the expense of a higher tendency for scar formation by slightly higher fibroblast proliferation and collagen deposition. While injection of botulinum toxin A provides less fibroblast proliferation and collagen deposition, and thus lower potential for scar formation compared with the folinic acid group. Therefore, in wounds of the esthetic zone, such as cleft lip defects, the application of botulinum toxin A shows promising results.

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.

Synergic Effect of Botulinum Toxin Type A and Triamcinolone Alleviates Scar Pruritus by Modulating Epidermal Hyperinnervation: A Preliminary Report

BACKGROUND

Patients often experience scar-related pruritus, which adversely affects quality of life. Triamcinolone acetonide (TAC) is widely used to treat pathologic scars, and botulinum toxin type A (BTX-A) reportedly improves scarring and associated discomfort.

OBJECTIVES

The aim of this study was to investigate the clinical efficacy of combining TAC and BTX-A to reduce scar itch; potential mechanisms were investigated via an animal model.

METHODS

For the clinical study, each scar on a patient was divided into 2 equal parts, with one part receiving TAC/BTX-A and the other TAC alone. Therapeutic interventions were administered over 3 sessions at 4-week intervals. Itch intensity was measured on a visual analog scale before each therapeutic intervention (V1, V2, V3) and 4 weeks after the last intervention (V4). For the animal model, rats were allocated into 5 groups: control, untreated burn, TAC, BTX-A, and TAC/BTX-A. We evaluated alloknesis in the right hind paw and analyzed possible molecular mechanisms.

RESULTS

In humans, TAC/BTX-A significantly reduced scar itch compared with TAC alone at V4 (P = 0.04). In rats, post-burn itch was mitigated at 4 weeks after treatment with TAC, BTX-A, and TAC/BTX-A (P = 0.03, P = 0.0054, and P = 0.0053, respectively). TAC/BTX-A significantly decreased the density of intraepidermal nerve fibers post-burn relative to the untreated burn (P = 0.0008). TAC/BTX-A downregulated the expressions of nerve growth factor and protein transient receptor potential vanilloid subtype 1.

CONCLUSIONS

TAC/BTX-A therapy exhibited enhanced and sustained clinical efficacy in relieving scar itch, possibly via modulating epidermal innervation and expression of transient receptor potential vanilloid subtype 1 .

LEVEL OF EVIDENCE: 2

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

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 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.

Efficacy and safety of Nd:YAG laser alone compared with combined Nd:YAG laser with intralesional steroid or botulinum toxin A in the treatment of hypertrophic scars

The aim of this study is to evaluate the efficacy and safety of Nd:YAG laser alone or in combination with intralesional injection of botulinum toxin type A or intralesional injection of steroid in treatment of hypertrophic scars. This study included 45 patients with hypertrophic scars who were randomly divided into three equal groups. All participants received 4 sessions of Nd:YAG laser at 4-week intervals. Immediately after the laser treatment, patients in group II were assigned to intralesional triamcinolone acetonide, and those in group III were assigned to intralesional botulinum toxin type A. All patients were followed up monthly for 3 months after the last session for any recurrence, or side effects. Clinical evaluation of the cases was done by Vancouver Scar Scale. Hypertrophic scars in the three groups showed a significant improvement (p < 0.001) compared with before treatment in all variables (except for pigmentation) and also a significant improvement in pruritus, pain, and patient relief. The highest percentage of improvements was seen in patients treated with Nd:YAG laser combined with intralesional steroid in all variables according to Vancouver Scar Scale. The degree of improvement was negatively correlated with the patients' age. The three treatment modalities were effective, safe with minimal side effects. Nd:YAG laser followed by intralesional injection of Triamcinolone acetonide had the highest percentage of Vancouver Scar Scale reduction. Combination therapy of Nd:YAG laser with intralesional injection of either Triamcinolone acetonide or Botox revealed better results than using Nd:YAG as a single therapeutic modality for HTS.

Refinements of the application of paramedian forehead flap in nasal defects repair in Asian patients

BACKGROUND

Due to the relatively higher tendency of postsurgery scars, insufficient cartilage support, and low surgical acceptability, nasal defect repair with forehead flap in Asian patients needs further study.

OBJECTIVE

We aim to determine the necessity of tissue expansion, timing of pedicle division, and the importance of cartilage scaffold reinforcement and scar prevention at the donor site during nasal reconstruction in Asian patients with paramedian forehead flap.

METHODS

A retrospective analysis was performed on patients who underwent nasal reconstruction with forehead flap at our hospital from January 2013 to January 2018. The demographical information, surgery details, and postoperative complications of all patients were recorded. The reconstructed nose, scars, and eyebrow deformities were evaluated by digital photographs, and the overall satisfaction of the patients was documented.

RESULTS

The study included 15 patients (7 males and 8 females). All nasal defects involved at least two aesthetic units and included seven full-thickness defects. Only one patient underwent two revision operations. Complications like hematoma, infection, and necrosis were not detected, except in one patient with partial necrosis of the flap. All patients were satisfied with the reconstructed nose and did not report any respiratory dysfunction. No obvious scars or eyebrow deformities were observed.

CONCLUSION

Three-stage full-thickness forehead flap should be used to repair nasal defects in Asian patients, with immediate cartilage scaffold reconstruction at stage one and reinforcement at stage two. Botox injection into the forehead can refine the scar.