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

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

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.

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.

Efficacy and Safety of Verapamil Versus Triamcinolone Acetonide in Treating Keloids and Hypertrophic Scars: A Systematic Review and Meta-Analysis

BACKGROUND

Keloids and hypertrophic scars can affect the appearance and normal function of patients, and may severely affect patients' physical and mental health. Many methods have been used for the treatment of keloids and hypertrophic scars, there is no standardized method so far. The aim of this study was to compare the efficacy and safety of verapamil and triamcinolone acetonide (TAC) in treating keloids and hypertrophic scars.

METHODS

All studies from their inception date up to August 2022 were searched using four databases (PubMed, Cochrane Library, MEDLINE, and EMBASE). The weighted mean differences and the risk ratio were calculated for comparing continuous variables and dichotomous variables, respectively.

RESULTS

A total of nine randomized controlled trials involving 567 patients were identified. This meta-analysis indicated that TAC group showed significantly better effects compared with verapamil group in the reduction of height at 3 and 9 weeks, pliability at 3, 9, and 18 weeks, vascularity at 3, 6, 9, 12, 18, and 24 weeks, whereas verapamil group showed significantly better effects compared with TAC group in the reduction of pliability at 21 and 24 weeks. Verapamil group showed a significantly lower incidence of skin atrophy, telangiectasia, and hypopigmentation compared with TAC group. However, the incidence of burning sensation in verapamil group was higher than that in TAC group.

CONCLUSION

Concerning the treatment of keloids and hypertrophic scars, TAC was more effective than verapamil for improving vascularity; TAC was superior to verapamil in improving height within 9 weeks of treatment; TAC produced superior result for improving pliability within 18 weeks of treatment, whereas verapamil produced superior result between 18 and 24 weeks of treatment. Verapamil had fewer adverse events than TAC and can be used as a safer alternative for the treatment of keloids and hypertrophic scars.

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 .

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.