Evidences of autologous fat grafting for the treatment of keloids and hypertrophic scars / Evidências da lipoenxertia autóloga para o tratamento de queloides e cicatrizes hipertróficas

SUMMARY Introduction Since the 1980s, the use of autologous fat grafting has been growing in plastic surgery. Recently, this procedure has come to be used as a treatment for keloids and hypertrophic scars mainly due to the lack of satisfactory results with other techniques. So far, however, it lacks more consistent scientific evidence to recommend its use. The aim of this study was to review the current state of autologous fat grafting for the treatment of keloids and hypertrophic scars, their benefits and scientific evidences in the literature. Method A review in the Pubmed database was performed using the keywords “fat grafting and scar”, “fat grafting and keloid scar” and “fat grafting and hypertrophic scar.” Inclusion criteria were articles written in English and published in the last 10 years, resulting in 15 studies. Results These articles indicate that autologous fat grafting carried out at sites with pathological scars leads to a reduction of the fibrosis and pain, an increased range of movement in areas of scar contraction, an increase in their flexibility, resulting in a better quality of scars. Conclusion So far, evidences suggest that autologous fat grafting for the treatment of keloids and hypertrophic scars is associated with a better quality of scars, leading to esthetic and functional benefits. However, this review has limitations and these findings should be treated with reservations, since they mostly came from studies with low levels of evidence.

RESUMO Introdução a partir da década de 1980, o uso da lipoenxertia autóloga tem crescido na cirurgia plástica. Recentemente, esse procedimento passou a ser utilizado como tratamento de queloides e cicatrizes hipertróficas, principalmente em decorrência da falta de resultados satisfatórios com outras técnicas. No entanto, até o momento, faltam evidências científicas mais consistentes que recomendem seu uso. O objetivo deste estudo foi realizar uma revisão do estado atual da lipoenxertia autóloga no tratamento de queloides e cicatrizes hipertróficas, os benefícios e as evidências científicas presentes na literatura. Método foi realizada uma revisão na base de dados Pubmed com os descritores “fat grafting and scar”, “fat grafting and keloid scar” e “fat grafting and hypertrofic scar”. Os critérios de inclusão foram artigos escritos em inglês e publicados nos últimos 10 anos, resultando em 15 estudos. Resultados os artigos indicam que a lipoenxertia autóloga realizada em locais com cicatrizes patológicas leva a uma diminuição da fibrose e da dor, à maior amplitude de movimentos em áreas de retração cicatricial, ao aumento de sua maleabilidade, resultando na melhor qualidade das cicatrizes. Conclusão até o momento, as evidências sugerem que a lipoenxertia autóloga para o tratamento das queloides e cicatrizes hipertróficas está associada à uma melhor qualidade das cicatrizes, levando a benefícios estéticos e funcionais. Contudo, esta revisão possui limitações e os acha dos devem ser analisados com ressalvas, já que a maioria provem de estudos com baixos níveis de evidência.

Effects of Hepatocyte Growth Factor on Collagen Synthesis and Matrix Metalloproteinase Production in Keloids

Keloids are pathologic proliferations of the dermal layer of the skin resulting from excessive collagen production and deposition. Hepatocyte growth factor (HGF) increases the expression of matrix metalloproteinase (MMP)-1 and suppresses collagen synthesis to modulate extracellular matrix turnover. To investigate the anti-fibrotic effects of HGF, we examine the mRNA expression of collagen types I and III and matrix metalloproteinase (MMP-1, MMP-3) on human dermal fibroblast (HDF) cell lines and keloid fibroblasts (KFs, n = 5) after adding various amount of HGF protein. We also evaluated the enzymatic activity of MMP-2, MMP-9 by zymograghy. In HDFs treated with TGF-beta1 and HGF protein simultaneously, both type I and III collagen mRNA expression significantly decreased (P < 0.05). Expression of MMP-1, MMP-3 mRNA also decreased. However, the mRNA expression of MMP-1, MMP-3 significantly increased in KFs with increasing amount of HGF in dose dependent manner (P < 0.05). The enzymatic activities of MMP-2 increased with increasing HGF protein in a dose-dependent manner. However, the enzymatic activity of MMP-9 did not change. These results suggest that the anti-fibrotic effects of HGF may have therapeutic effects on keloids by reversing pathologic fibrosis.

Biochemical and dynamic studies of collagen from human normal skin and keloid tissue.

Keloids are exuberant scars, in which collagen, fibronectin and glycosaminoglycans are overdeposited. Biochemical analysis of the collagen isolated from normal skin and keloid tissue by pepsin treatment, indicated an increase in the type III and GAG content. Viscosity measurements of collagen from normal skin and keloid tissue were used in the present study to establish the interaction between collagen and GAG. Physico-chemical properties such as intrinsic viscosity, reduced viscosity and hydrated volume were computed from viscosity measurements. These measurements were also used to determine the denaturation temperature of collagen which was further confirmed by DSC measurements. Chondroitinase has been used in this study to probe the influence of GAG on the physico-chemical characteristic of keloid collagen.