Estudo do efeito da associação da terapia de fotobiomodulação e a aplicação intralesional de corticóide no pré e pós-operatório da exérese de queloides: um estudo controlado, randomizado e duplo-cego

Abstract

Keloid-type scars are characterized by excessive proliferation of fibroblasts and the breakdown of the balance between collagen production and degradation, with its increase in the dermis. The most studied treatment after keloid removal is the intralesional application of corticosteroid alone or associated in the pre and postoperative period. Photobiomodulation (PBM) with blue light has shown in vitro studies a decrease in the speed of multiplication and the number of fibroblasts as well as TGF-β, which could be a low-cost, non-invasive alternative with no side effects to be associated with the most recommended treatment. Therefore, the objective of this study was to evaluate the effect of blue light associated with corticosteroid treatment in the pre and postoperative period of keloid excision. A randomized, controlled, and double-blind clinical trial was conducted divided into two groups: 1) Control (N=2): intralesional application of corticosteroid (IAC) in the pre and postoperative period of keloid excision and placebo PBM and 2) PBM associated with IAC (N=2) in the pre and postoperative period of keloid excision (active PBM). The PBM was performed in a punctual manner, in contact, on the keloid in the preoperative period (5 sessions) and on the remaining scar in the postoperative period (8 sessions) using blue LED (470nm, 400mW, 4J per point, being 10 linear points with a space of 1cm between them). In parallel, an in vitro study was carried out using fibroblasts of the L929 lineage submitted to PBM with the same parameters and radiant energies of 4, 6, and 8J for viability analysis by the MTT technique, analyzed at 24 and 48h post-irradiation. The patients answered three questionnaires, one for quality of life assessment (Qualifibro-UNIFESP), one to determine skin phototype (FITZPATRICK), and one for scar satisfaction assessment (PSAQ), and the team of plastic surgeons filled out the Vancouver questionnaire for scar assessment (VSS), all were answered at the beginning of treatment and at 01, 03, and 06 months after surgery. The removed keloid was sent for histopathological analyses including staining with picrosirius red for collagen area analysis. All data were submitted to statistical analysis. Results: There was a difference in quality of life in the PBM group in the first month of the protocol, and in all patients in the postoperative period evaluated by Qualifibro. There was no significant difference in the analysis of the collagen area in patients submitted to PBM or placebo. There was greater satisfaction by the PSAQ-BR in the PBM group in the preoperative period. The in vitro results showed that the LED did not alter the viability of fibroblasts after 24 and 48h, with no differences identified between the control group and the irradiated ones. Conclusion: Despite not having had a significant difference between the groups in the scar quality item (VSS) and in the quality of life and satisfaction evaluations (Qualifibro/PSAQ-BR), analyzing individually we can conclude that there was an improvement in scar quality and clinically there was a significant improvement, as well as patient satisfaction in all periods analyzed.