The Efficacy and Safety of Botulinum Toxin Injections in Preventing Postoperative Scars and Improving Scar Quality: A Systematic Review and Meta-Analysis.

[BACKGROUND] Scars exposed on the body surface lead to a large psychological burden on patients. However, no satisfactory scar treatments exist. Botulinum toxin type A is a neurotoxin that has been widely applied in the plastic and cosmetic surgery field. The purpose of this meta-analysis was to assess the efficacy and safety of botulinum toxin in scar management.

[METHODS] PubMed, the Cochrane Library, EMBASE, MEDLINE, and Web of Science were searched for randomized controlled trials that evaluated the efficacy of botulinum toxin injections in preventing postoperative scars and improving scars quality and were published prior to Dec. 29, 2020. The outcome indicators were the visual analog scale score, Vancouver scar scale score, Stony Brook scar evaluation scales score, scar width, patient self-assessment results, and complications.

[RESULTS] Seventeen randomized controlled trials with a total of 633 cases were identified in this meta-analysis. The quantitative synthesis results showed that compared with the control group, the botulinum toxin group had a significantly lower VSS score (MD = -0.97, 95%CI = -1.56 to -0.39, p = 0.001), higher VAS score (MD = 1.26, 95%CI = 1.04 to 1.47, p < 0.00001), thinner scar width (MD = -0.25, 95%CI = -0.37 to -0.12, p < 0.0001) and higher patient satisfaction (RR = 3.38 95%CI = 1.45 to 7.89, p = 0.005). There were no significant differences between the two groups in the number of adverse events.

[CONCLUSIONS] This meta-analysis demonstrated that botulinum toxin injections can significantly improve cosmetic appearance and postoperative scar quality. At the therapeutic dose, no significant complications were observed, indicating that botulinum toxin injections are safe.

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