Autologous Lipofilling Improves Clinical Outcome in Patients With Symptomatic Dermal Scars Through Induction of a Pro-Regenerative Immune Response

BACKGROUND: Autologous lipofilling is emerging procedure to augment and possibly reverse dermal scars and to reduce scar-related pain, but its efficacy and mechanisms are poorly understood.OBJECTIVES: To test the hypothesis that repeated lipografts reverse dermal scars by re-initiation of wound healing.METHODS: In a prospective, non-placebo controlled clinical study, 27 adult patients with symptomatic scars were given two lipofilling treatments at 3-month intervals. As primary outcome, clinical effects were measured using the patient and observer scar assessment scale (POSAS). Scar biopsies were taken before and after treatments to assess scar remodeling at a cellular level.RESULTS: Twenty patients completed the study. Patients' scars improved after lipofilling. The total POSAS scores (combined patient and observer scores) decreased from 73.2±14.7 points pre-treatment to 46.1±14.0 and 32.3±13.2 after the first and second treatment, respectively. Patient POSAS scores decreased from 37.3±8.8 points to 27.2±11.3 and 21.1±11.4 points, whereas Observer POSAS scores decreased from 35.9±9.5 points, which decreased to 18.9±6.0 and 11.3±4.5 points after the first and second lipofilling treatment, respectively. After each lipofilling treatment, T-lymphocytes, mast cells and M2 macrophages had invaded scar tissue and associated was increased vascularization. In addition, the scar-associated epidermis showed increase in epidermal cell proliferation which was akin to normal skin. Moreover, lipofilling treatment caused normalization of the extracellular matrix (ECM) organization towards that of normal skin.CONCLUSIONS: Autologous lipofilling improves clinical outcome of dermal scars through the induction of a pro-regenerative immune response, increased vascularization, and epidermal proliferation and remodeling of scar tissue ECM.