Tratamento a laser para estrias de distensão: revisão bibliográfica / Laser treatment for stretch marks: a literature review

Estrias de distensão são cicatrizes na derme que constrangem os pacientes e oferecem desafios ao tratamento clínico. Resultam do rápido estiramento da pele, frequentemente presente em adolescentes, gestantes, obesos e indivíduos com rápida mudança de peso. Apresentam-se inicialmente como placas eritematosas e edemaciadas (estrias rubras) e, conforme amadurecem, tornam-se esbranquiçadas e atróficas (estrias albas), devido à degradação e reorganização de fibras de elastina e de colágeno. Atualmente, lasers representam modalidade terapêutica não invasiva emergente, que já demonstrou sucesso na redução da vascularização excessiva das estrias rubras, e no estímulo à produção de colágeno e elastina nas albas. Foi realizada revisão da literatura no PubMed referente ao tratamento de estrias atróficas com laser de janeiro de 2000 até dezembro de 2016. Os autores encontraram 28 artigos que se enquadraram nos critérios de inclusão. Existem poucos estudos clínicos randomizados avaliando a eficácia ao longo prazo e a segurança de aparelhos à base de energia. Baseado em casos clínicos e revisões sistemáticas, ambos os lasers - ablativo e não ablativo - fracionados demonstraram melhora modesta do aspecto das estrias distensas. Há tendência a sugestão do laser não ablativo fracionado de 1.540 nanômetro como sendo opção de primeira escolha para tratamento das estrias distensas. Porém, estudos futuros devem focar em desenhos de pesquisa com duração mais longa, medidas objetivas e padronizadas da avaliação dos resultados como biópsias e estudos moleculares, que demonstrem aumento nas fibras elásticas e fibras de colágeno, que correlacionem com a melhora do aspecto clínico das estrias após aplicação de lasers com parâmetros sistematizados.

Stretch marks are scars on the dermis that cause patients to be self-conscious and that pose challenges in clinical treatment. They result from rapid stretching of the skin and often observed in adolescents, pregnant women, obese individuals, and people experiencing rapid change in weight. They initially appear as erythematous and edematous plaques (red striae), and as they mature, they become whitish and atrophic (striae alba) due to the degradation and reorganization of elastin and collagen fibers. Currently, laser treatment is an emerging noninvasive therapeutic modality that is successful in reducing the excessive vascularization of red striae and in stimulating the production of collagen and elastin in the alba. In the present literature review, PubMed was searched for articles on the treatment of atrophic striations with laser that were published from January 2000 to December 2016. The authors have found 28 articles that met the inclusion criteria. Only few randomized clinical trials have evaluated the long-term efficacy and safety of energybased treatments. Based on clinical cases and systematic reviews, both ablative and non-ablative fractional lasers caused moderate improvement in the appearance of distending striae. The 1540-nm non-ablative fractional laser is more likely to be considered the first-line treatment for stretch marks. However, future studies should focus on research with longer duration, studies with objective and standardized measures for the evaluation of results, such as biopsy results, and molecular studies showing an increase in elastic and collagen fibers that correlate to the improvement in the clinical appearance of the striae after using lasers with systematized parameters.

Evaluation of an ablative and non-ablative laser procedure in the treatment of striae distensae.

Background: Striae distensae or stretch marks are atrophic linear dermal scars with epidermal atrophy. There are many therapeutic options for management, but no consistently effective modality is available yet. Objective: We compared the efficacy of 1064 nm long pulse (LP) Nd: YAG laser and 2940 nm variable square pulse (VSP) erbium: YAG laser in the treatment of striae distensae. Methods: Twenty female volunteers (Fitzpatrick skin types II-V) aged between 20 and 40 years with striae (3 patients with the rubra type and 17 with the alba type) were enrolled in the study. The duration of striae ranged from 4 months to 12 years. Lesions were located on the abdomen in all patients except one patient who had striae on the arms and two patients with striae in the lumbar region. Treatments were randomly allocated to both sides of the body in each patient, one side being treated with VSP erbium: YAG laser and the opposite side with LP Nd: YAG laser. All subjects were treated monthly for a total of three treatments. Two 3-mm punch biopsies were obtained from six subjects, both of the same striae, one before the first treatment and one 4 weeks after the last session. Results: Response was evaluated clinically by photographic comparison and was found to be poor in 17 subjects, both on the LP Nd: YAG laser treated side and VSP erbium YAG laser treated side. All these patients had mature lesions (striae distensae alba). Three subjects had a moderate response on both sides; these patients' striae were immature (striae distensae rubra). Histologically, elastic fibers were slightly increased in post-treatment samples compared with pretreatment skin biopsies. Conclusion: We observed no satisfactory clinical improvement in striae distensae alba lesions although histopathological changes were seen. We suggest that variable square pulse Er: YAG and long pulse Nd: YAG lasers are not useful in the treatment of striae distensae alba.