Invited Response on: Comment on: “Botulinum Toxin Type A Injection for Mammoplasty and Abdominoplasty Scar Management: A Split-Scar Double-Blinded Randomized Controlled Study”

Background Scars are inevitable results of surgical procedures, and prevention of them is still a major problem in the field of cosmetic surgery. Although various studies have been performed on botulinum toxin-A (BoNT‐A) injection for the prevention of hypertrophic scars, the exact mechanism remains unclear. Methods This prospective, double-blinded, randomized study was performed on 19 patients who underwent mammoplasty and abdominoplasty surgery in Razi Hospital from October 2018 to December 2019. Single session of treatment was performed, where XEOMIN was allocated to one half of the scar and 0.9% saline to the control half. 3 and 6 months later, scars were assessed using the modified Stony Brook Scar Evaluation Scale (SBSES). Results In total, 19 patients who completed the study were analyzed. mSBSES at the third month ( P value < 0.001; 3.34 ± 1.59 vs 1.5 ± 1.36) and the sixth month ( P value < 0.001; 4.89 ± 1.83 vs 2.39 ± 1.82) showed a significant difference between the treatment and control groups. In the subset analysis, there was significant difference between BoNT-A and control in all four items including width, height, color, and scar visibility at months 3 and 6, and the BoNT-A-treated sides had higher scores in all items. Conclusion BoNT-A has a significant effect on scar prevention due to mammoplasty and abdominoplasty compared to placebo and results in decreased erythema, height, width and reduces incision line visibility. Moreover, its effect increases significantly over time from months 3 to 6. Level of Evidence II This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .