Efficacy of fractional CO 2 laser therapy combined with hyaluronic acid dressing for treating facial atrophic acne scars: a systematic review and meta-analysis of randomized controlled trials

The present work aimed to systematically identify the efficacy and safety of fractional carbon dioxide (CO 2 ) laser plus hyaluronic acid (HA) dressing in dealing with facial atrophic acne scars. Randomized controlled trials (RCTs) concerning fractional CO 2 laser in combination with HA dressing for treating atrophic acne scars were screened in 8 electronic databases (containing PubMed, Embase, the Cochrane Library, Web of Science, China National Knowledge Internet, Wanfang, Sinomed as well as VIP). Besides, for the purpose of evaluating the risk of bias of the enrolled RCTs, the Cochrane Collaboration tool was adopted. Statistical analysis was completed using Revman5.3 software and Stata 14.0 software. Meanwhile, the quality of evidence was assessed by the GRADE system. Finally, 6 studies involving 623 patients were enrolled. According to the findings in this study, compared with fractional CO 2 laser alone, fractional CO 2 laser therapy combined with HA dressing reduced the scores of ECCA (échelle d’évaluation clinique des cicatrices d’acné) grading scale (MD=-3.37,95% CI [-5.03, -1.70], P <0.0001), shortened the time of crust formation (MD=-0.42,95% CI [-0.80, -0.04], P =0.03) and the time of crust removal(MD=-1.31,95% CI [-1.67, -0.95], P <0.00001), enhanced patient satisfaction (RR=1.85, 95% CI [1.44, 2.38], P <0.00001). All the reported adverse events including hyperpigmentation, erythema, edema, mild itching, and slight burning pain were controllable. In addition, fractional CO 2 laser combined with HA dressing therapy had a lower incidence of hyperpigmentation than fractional CO 2 laser alone (RR=0.37, 95% CI [0.23, 0.61], P <0.0001). The level of evidence for outcomes was classified to be low to moderate. According to our findings, fractional CO 2 laser combined with HA dressing is efficacious and safe option for facial atrophic acne scars. Nevertheless, more high-quality trials are required for further verification in the future.