Histological damage characteristics and quantitive analysis of porcine skin with non-insulated microneedle radiofrequency.

OBJECTIVE: In recent years, the microneedle radiofrequency (MRF) has been widely used for skin rejuvenation, but histological studies on the immediate trauma caused by different parameters of non-insulated RF microneedles METHODS: The skin of three pigs was treated with different needle depths, pulse widths and energy levels of non-insulated microneedle RF. Samples were collected before, immediately, and 2 weeks after treatment. The immediate histological response of each group was assessed and quantified by hematoxylin and eosin staining, Masson staining and Victoria Blue staining.

RESULTS: In the treatment of non-insulated microneedle RF, different energy levels affected mainly the range of thermal damage (p = 0.044), and different needle depths affected mainly the depth of the cavity (p = 0.022). But the width of the coagulation zone width was determined by different factors. There was no significant difference in the histology of immediate damage caused by different pulse widths. Reepithelialization of the epidermis and basic wound repair can be completed within 2 weeks.

CONCLUSION: Non-insulated RF microneedle therapy is an effective and safe treatment that can stimulate dermal wound healing with less thermal coagulation and a wide range of reversible thermal damage. However, it should be noted that the set needle depth may not correspond to the actual penetration depth, nor to the actual depth of histologic trauma.