Wound contraction rate in excised and unexcised burn wounds with laser photobiomodulation: Systematic review and meta-analysis of preclinical studies

Introduction: Laser photobiomodulation (laser PBM) is an effective means of accelerating burn wound contraction, however it is still unclear whether laser PBM produces greater benefit when applied directly to excised and unexcised burn wounds. The aim of this systematic review of preclinical studies was to determine the effectiveness of laser PBM in the wound contraction rate in excised and unexcised burn wounds. Materials and methods: A systematic search was conducted in the EMBASE, MEDLINE and LILACS databases. Preclinical studies were included that analysed the effectiveness of laser PBM in burn wound contraction, and assessed wound closure. The SYRCLE risk of bias tool was used. Random effects models were used to estimate the pooled effect. Results: Thirteen studies were included in the qualitative analysis and six in the quantitative analysis. Two weeks after the lesion, laser PBM favoured the wound contraction percentage, increasing the closure rate in excised burn wounds (SMD= 1.34, CI 95% 0.41 to 2.27, 0.41–2.27, I²=0%, = 0%, low certainty of evidence. In unexcised burns, it was uncertain whether laser PBM increased or diminished the wound contraction rate (SMD=1.22(SMD = 1.22 CI 95% −0.05 to 2.49, I²=68%; = 68%; very low certainty of evidence). Conclusions: In the animal model, laser PBM is effective in increasing the wound contraction rate in excised burns. However, due to the low certainty of the evidence, uncertainty remains about the true magnitude of the effect of laser on wound contraction in animals; our results should therefore be interpreted with caution.