Botulinum Toxin Type A for Preventing Facial Trauma and Hypertrophic Scars: A Meta-Analysis and Trial Sequential Analysis.

[OBJECTIVE] To evaluate the effectiveness and safety of local injection of botulinum toxin type A in preventing hypertrophic scars after facial trauma and surgery using meta-analysis and sequential experimental analysis methods.

[METHOD] Computer retrieval of randomized controlled trials on the prevention of facial scars with botulinum toxin type A from PubMed, EMbase, the Cochrane Library, CNKI, China Biomedical Literature Service System, Wanfang Database, and VIP Chinese Science and Technology Journal Full text Database up to February 2025.

[RESULT] Twelve randomized controlled clinical trials were included, with a total of 644 patients; Type A botulinum toxin injection is superior to the control group in improving patient satisfaction [RR = 6.89; 95% CI (3.20, 14.85); p < 0.0001], Vancouver Scale score [RR = -1.40; 95% CI (-2.73, 0.08); p < 0.0001], visual analog score [RR = 1.41; 95% CI (0.26, 2.56); p = 0.02], scar width [RR = -0.14; 95% CI (-0.17, -0.10); p < 0.0001], and the difference is significant; The incidence of adverse events [RR = 0.38; 95% CI (0.18, 0.84); p = 0.02] and recurrence rate [RR = 0.17; 95% CI (0.04, 0.81); p < 0.03] were lower than those in the control group, and no serious adverse reactions occurred; Sensitivity analysis showed that the results were relatively robust, sequential analysis of the experiment showed that the benefits were conclusive, and Begg's and Egger's tests showed no publication bias.

[CONCLUSION] Type A botulinum toxin injection has a certain therapeutic effect on hypertrophic scars without significant side effects. However, the accuracy and stability of its therapeutic effect still require more high-quality research verification.