Efficacy of the Neodymium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Keloid and Hypertrophic Scars: A Systematic Review and Meta-analysis

Keloid and hypertrophic scars are the most common types of pathological scars. They can cause itching, pain, erythema, and psychological stress due to cosmetic problems, decreasing the quality of life for affected individuals. The neodymium-doped yttrium aluminum garnet (Nd:YAG) multipurpose laser is used to treat pathological scars, and studies have shown that the Nd:YAG laser can markedly improve scarring.We performed a meta-analysis to evaluate the efficacy of the Nd:YAG laser in the treatment of keloid and hypertrophic scars.A literature search of PubMed, Web of Science, Scopus, Cochrane, Embase, CNKI, and Wanfang was performed between January 1st, 2010, and July 14th, 2021. The Vancouver Scar Scale (VSS) was used to evaluate treatment outcomes. We used the R version 4.0.0 software for statistical analysis.The Nd:YAG laser improved the condition of keloid and hypertrophic scars and reduced VSS score (mean difference [MD]: 2.96, 95% confidence interval [CI]: 2.08-3.84, plt; 0.01). There was no obvious difference in the results between regions. A subgroup analysis by scar type revealed that the curative effect of the Nd:YAG laser on keloid scars (MD: 2.02, 95% CI: 0.58-4.63, p = 0.10) was less marked compared with that on hypertrophic scars (MD: 3.05, 95% CI: 1.58-4.52, plt; 0.01). With the combined use of the Nd:YAG laser and other treatment methods, a more significant change in VSS score was noted (MD: 4.28, 95% CI: 2.07-6.49).This meta-analysis showed that the Nd:YAG laser can improve the condition of keloid and hypertrophic scars and effectively reduce VSS score. Moreover, the curative effect of this approach on keloid scars is less marked compared with that on hypertrophic scars.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.