A META-analysis About The Improvement Of Scar Quality By Botulinum Toxin Type A

Background:Scar is the final product of wound repair,when the scars is on the exposed areas such as on the face and neck will seriously affect the appearance of the skin.so,more and more patients hope to improve the quality of scar by plastic surgery.The paralyzing effect of botulinum toxin type A,known as "chemical fixation," has been shown to improve scar quality and promote wound healing.However,the current clinical studies are relatively small,and the available evidence is insufficient to prove the effectiveness of botulinum toxin A in the treatment of scars.Objective:To evaluate the effect of botulinum toxin A on scar quality by meta-analysis and provide evidence base for future scar treatment.Methods:Through keywords and free word made a retrieval strategy,retrieve electronic database: CNKI,Wan Fang Date,VIP,Pub Med,EMbase,Medline and the Cochrane Library,such as the database(time was ended by November 30,2019),Preliminary screening of literature by reading titles and abstracts,and then through read the full article,A randomized controlled trial of botulinum toxin A to improve scar quality was screened according to the inclusion and exclusion criteria of the literature,and then extract the data from the literature,comparing with the curative effect between the experimental group which use of botulinum toxin A in the treatment of scar and the placebo group or blank control group.The process of literature screening and data extraction was performed by two researchers.When they disagreed,the third researcher was asked for advice The evaluation methods included vancouver scar scale(VSS),visual analogue scale(VAS),patient satisfaction,and scar of width.The software Revman5.3 was used for the combined analysis of the results of the included literatures.The combined effect sizes of relative risk(RR)and 95% confidence interval(CI)were used for the binary variables,the combined effect sizes of mean difference(MD)and 95% confidence interval(CI)were used for the continuous variables,and I2 was used for the degree of heterogeneity among the studies.When I2= 0,It is think that there is homogeneity among the different studies,We will use the fixed effect model for data consolidation;Substantial heterogeneity is suggested when I2>50%,and combined statistics by using the random effect model.Results:Through screening,A total of 16 randomized controlled clinical trials(Rcts)were included in this study,including 12 in English and 4 in Chinese,involving 1013 patients.we used the software of Revaman5.3 to combined the data shows: The vancouver scar scale(VSS)score showed that there was A statistical difference between the btx-a group and the control group,and the score of the btx-a group was better[MD=-1.78,95% CI:-2.44,-1.12,P < 0.00001].the outcome of Visual analogue score scale(VAS)indicators combined effect values showed that the effect of BTX-A group was significantly better than that the control group [MD=1.29 95%CI: 1.07,-1.52,P < 0.00001],And it was statistically significant.Observing the patient satisfaction showed that there was a statistical difference between the BTX-A experimental group and the control group,and BTX-A group showed a higher satisfaction with scar[RR=1.21 95% CI :1.10,1.34 P = 0.0001];There was also A statistical difference in scar width between the two groups.The scar width of the BXT-A experimental group was narrower than the scar width of control group MD=-0.14 [95% CI:-0.17,-0.10 P < 0.00001];Eight studies reported mild adverse events,all of them without any treat but get well,there was no serious adverse events were reported.