Effectiveness and Safety of Botulinum Toxin Type A Injection for Scar Prevention: A Systematic Review and Meta-analysis

Background: Hypertrophic scar is a common complication in would healing process, and how to effectively prevent and treat it has been a hot and difficult research issue.Previous studies have showed that botulinum toxin type A (BTA) has effects on the prevention and treatment of hypertrophic scar, but little is known about the specific mechanisms.Objective: This study aimed to explore the potential mechanisms of BTA on the inhibition of hypertrophic scar formation.Methods: Hypertrophic scar-derived human fibroblasts were cultured and then treated with transforming growth factor-β1 (TGF-β1) and various concentrations of BTA. Cell proliferation and viability were measured by CellTiter 96® AQueous One Solution Cell Proliferation Assay and trypan blue staining, respectively. The total amount of collagen was examined using Sirius red staining. Collagen I and Collagen III in the culture supernatant were evaluated by enzyme-linked immunosorbent assay.Reverse transcription-quantitative polymerase chain reaction and Western blot analysis were performed to detect the transcription and translation levels.Results: Our results revealed that BTA decreased the proliferation of hypertrophic scar-derived human fibroblasts. The mRNA and protein expression levels of alphasmooth muscle actin, collagen I, and collagen III induced by TGF-β1 were inhibited by BTA in a dose-dependent manner. BTA also inhibited the phosphorylation of Smad2/3 and ERK. Conclusion:BTA decreased the proliferation of fibroblasts and prevented overdeposition of ECM through the inhibition of the TGF-β1/Smad and ERK pathways. The findings of this study provide new scientific reference for the prevention and treatment of hypertrophic scar.

Section: Introductionmentioning

confidence: 99%

Botulinum toxin type A attenuates hypertrophic scar formation via the inhibition of TGF‐β1/Smad and ERK pathways

Yang

Zheng

et al. 2020

“…Although the frontal wound can be successfully closed, the tension in the frontal donor site after suturing inevitably increases with a higher the risk of scar hyperplasia. Previous studies have shown that injection of botulinum toxin type A (Botox) can inhibit the contraction of the frontal muscle and reduce the muscle tension, and thus prevent scar hyperplasia . We injected Botox into the frontal donor site 1 week after removing the stitches for some patients and did not observe any scar hyperplasia 6 months after surgery. Reuse the tissue trimmed during flap thinning to increase local protrusion.The forehead flap will inevitably retract to some extent after transfer, and the contracture of surgical scar may also lead to local depression .…”

Section: Discussionmentioning

confidence: 87%

Refinements of the application of paramedian forehead flap in nasal defects repair in Asian patients

Zhang

Liu

Wang

et al. 2019

Background Due to the relatively higher tendency of postsurgery scars, insufficient cartilage support, and low surgical acceptability, nasal defect repair with forehead flap in Asian patients needs further study. Objective We aim to determine the necessity of tissue expansion, timing of pedicle division, and the importance of cartilage scaffold reinforcement and scar prevention at the donor site during nasal reconstruction in Asian patients with paramedian forehead flap. Methods A retrospective analysis was performed on patients who underwent nasal reconstruction with forehead flap at our hospital from January 2013 to January 2018. The demographical information, surgery details, and postoperative complications of all patients were recorded. The reconstructed nose, scars, and eyebrow deformities were evaluated by digital photographs, and the overall satisfaction of the patients was documented. Results The study included 15 patients (7 males and 8 females). All nasal defects involved at least two aesthetic units and included seven full‐thickness defects. Only one patient underwent two revision operations. Complications like hematoma, infection, and necrosis were not detected, except in one patient with partial necrosis of the flap. All patients were satisfied with the reconstructed nose and did not report any respiratory dysfunction. No obvious scars or eyebrow deformities were observed. Conclusion Three‐stage full‐thickness forehead flap should be used to repair nasal defects in Asian patients, with immediate cartilage scaffold reconstruction at stage one and reinforcement at stage two. Botox injection into the forehead can refine the scar.

“…Within last 5 years, the employment of BTXA in scars at various sites has been evaluated intensively using multifarious tools and, accordingly, several quantitative meta‐analyses have been conducted since the first narrative systemic review published in 2015, providing inadequate supportive evidence to the usage of BTXA 65 48 Wang et al, 66 and Guo et al 47 in 2019, including 9, 9, and 11 RCT studies, respectively. Although they all drew a positive conclusion that BTXA was an effective and safe adjunctive agent for wound healing improvement, the emergence of some new RCTs with partially negative results 34,45 and a focus on mammoplasty and abdominoplasty scars 44 endows updated quantitative analysis with significance.…”

Section: Discussionmentioning

confidence: 99%

Efficacy and safety of botulinum toxin type A for postoperative scar prevention and wound healing improvement: A systematic review and meta‐analysis

Huang

2021

Postoperative wound healing is permanently of great concern to both surgeons and patients because pathological scars, including hypertrophic scars and keloids, profoundly affect an individual's physical and psychological well-being by causing pruritus, ulceration, pain, and contractures. Normal scar formation is an overlapping and orderly process involving hemostasis, inflammation, proliferation, and remodeling phases. 1 Although the pathogenesis of abnormal scar formation remains obscure, it is believed to be attributed to an