Efficacy and Safety of Botulinum Toxin Type A for Pathological Scar Prevention: A Systematic Review and Meta-Analysis

The objective of this study was to evaluate the efficacy of botulinum toxin type A (BoNT-A) in preventing pathological scars and improving scar quality and to assess treatment safety and patient satisfaction.

Randomized controlled trials and cohort studies identified in PubMed, Scopus, Embase, or Web of Science were included. Outcomes analyzed included scar quality, patient satisfaction, and adverse effects. Statistical analysis was performed using mean differences (MDs) and relative risks (RRs). Risk of bias was assessed with the Risk of Bias 2 and Risk of Bias in Nonrandomized Studies of Interventions tools.

Nineteen studies with a total of 686 patients were included. BoNT-A showed significant improvements in several outcomes. The MD was -1.07 (95% CI, -1.59 to -0.56; P < 0.0001) on the Vancouver Scar Scale and 1.18 (95% CI, 0.94 to 1.42; P < 0.00001) on the visual analog scale. Scar width was reduced, with an MD of -0.21 (95% CI, -0.33 to -0.09; P = 0.0008). In the Stony Brook Scar Evaluation Scale and Patient and Observer Scar Assessment Scale, the differences favored BoNT-A, with MD of 1.64 (95% CI, 0.78 to 2.50; P = 0.0002) and -1.28 (95% CI, -2.02 to -0.53; P = 0.0008), respectively. Patient satisfaction was higher with BoNT-A (RR, 1.83 [95% CI, 1.10 to 3.07]; P = 0.02). Adverse effects were minimal and transient, with no significant differences between groups.

BoNT-A is an effective and safe intervention. Its use reduces the formation of pathological scars and generates high levels of patient satisfaction, without serious adverse effects. However, studies with larger sample sizes and homogeneous designs are required to confirm these findings.