A Meta-analysis Of Botulinum Toxin Type A In The Prevention And Treatment Of Facial Hypertrophic Scars

Objective: To evaluate the efficacy of botulinum toxin A(Botulinum toxin type A,BTX-A)in the prevention and treatment of facial hypertrophic scars by meta analysis.Methods:We searched CNKI,Wanfang,Pub Med,Cochrane library,Embase,Ovid,Web of science and other databases by computer.Then we collected the randomized controlled trials on the prevention and treatment of facial hypertrophic scars which used botulinum toxin A published from the database to October 2020.The incomplete data were searched by hand.According to the principle of PICOS,the inclusion and exclusion criteria were established and the literature was screened,the relevant data were extracted.We evaluated The quality of studies and used the Revman 5.4.1software to perform meta-analysis of the results.The outcome indexes were the Vancouver Scar Scale(VSS)score,the visual analogue scale(VAS)score and scar width.Results: 528 articles were searched.According to the inclusion and exclusion criteria and quality evaluation,a total of 10 articles were included,of which 9 were in English and 1 in Chinese.A total of 10 randomized controlled trials were conducted,including 349 patients and 461 scars.The results showed that the VSS score of BTX-A group was better than control group(weighted mean difference(WMD)=-0.95,95%CI=-1.62 to-0.28,P=0.005),and the VAS score of BTX-A group was better than control group(WMD=1.16,95%CI=0.94 to 1.39,P<0.00001).The scar width in the BTX-A group was smaller than that in the control group,and the difference was statistically significant(WMD=-0.15,95%CI=-0.19 to-0.11,P<0.00001).Conclusion:This study shows that botulinum toxin type A can improve the quality of scars and effectively prevent the occurrence of facial hypertrophic scars.The number of literatures included in this study is limited,so we need to conduct more high-quality basic research and clinical trials on botulinum toxin type A in the prevention and treatment of facial hypertrophic scars to prove the clinical value.