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.

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