An Evaluation of Electrocoagulation and Thermal Diffusion Following Radiofrequency Microneedling Using An In-Vivo Porcine Skin Model.

BACKGROUND Few studies exist that examined the role of radiofrequency microneedling (RFMN) in skin electrocoagulation. This research utilized a porcine model to understand bipolar dermal delivery from an RFMN device. AIMS The objective of this study was to elucidate and compare the dermal thermal effects of a RFMN device producing 1 and 2 MHz signal amplitudes, with respective voltage and current gradients, utilizing noninsulated and insulated needles by examining the histologic effects on porcine skin. METHODS Two separate animal studies were conducted to evaluate the electrocoagulation and thermal diffusion effects using the RFMN device. The electrocoagulation effects were assessed histologically using hematoxylin and eosin (H&E) staining, and heating effects were assessed through thermal imaging. RESULTS Histology results of the thermal injury induced by insulated needles demonstrated that 2 MHz resulted in a narrow and concentrated coagulation zone as compared to 1 MHz. Further, the 1 MHz insulated needle resulted in ovular shaped tissue coagulation as compared to 2 MHz tissue coagulation that was columnar. Finally, full thermal diffusion occurs seconds after the set RF conduction time. CONCLUSION The findings showed that 1 MHz insulated needle produces larger coagulations with an increase in power level, the 1 MHz noninsulated array was comparable to the 2 MHz insulated array with similar histologic features, and heat dissipates seconds after the set conduction time.