Comparison of Efficacy of Intradermal Stromal Vascular Fraction Injection Versus Saline Injection in the Treatment of Atrophic Acne Scar: A 10-Week, Prospective, Randomized, Split-Face, Single-Blind Controlled Trial.

INTRODUCTION

Management of atrophic acne scars remains challenging, and conventional treatments often yield suboptimal or inconsistent outcomes. Stromal vascular fraction (SVF), a cell-rich fraction derived from adipose tissue, has recently gained attention as a promising regenerative therapy. Several previous studies have reported benefits of SVF when combined with other treatment modalities; however, its stand-alone efficacy for atrophic acne scars has not been clearly investigated. In addition, molecular evidence supporting the regenerative effects of SVF in acne scar treatment remains limited.

METHODS

This randomized, evaluator-blinded, split-face clinical trial was conducted in 14 patients with bilateral facial atrophic acne scars. One side was treated with intradermal SVF injection, while the contralateral side received normal saline (NS). Clinical outcomes were assessed using scar counts, Évaluation Clinique des Cicatrices d'Acne (ECCA) scores, Scar Global Assessment (SGA) scores, and standardized photography at baseline, 5 weeks, and 10 weeks. Skin biopsies were analyzed via immunohistochemistry for markers of epidermal regeneration (cytokeratin 14, cytokeratin 15, p63, integrin β1) and dermal remodeling (collagen I, elastin, vimentin).

RESULTS

At 10 weeks after initial treatment, the SVF-treated side showed a significantly greater reduction in total scar count compared to the NS-treated side (56.4% vs. 13.2%, p < 0.001). Scar subtype analysis revealed that all scar types (ice pick, boxcar, and rolling) responded more favorably to SVF treatment, with large effect sizes (Cohen's d > 0.99). ECCA and SGA scores were also significantly decreased on the SVF-treated side. Immunohistochemical analysis revealed marked upregulation of epidermal progenitor markers and increased deposition of collagen I, elastin, and vimentin in the SVF-treated tissue.

CONCLUSION

We clinically demonstrated that SVF injection improves atrophic acne scars and simultaneously revealed its regenerative mechanisms involving epidermal and dermal remodeling. This supports the use of SVF as an evidence-based treatment modality for atrophic acne scars.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier, NCT07094958.