Helium Plasma Skin Regeneration: Evaluation of Skin Tissue Effects in a Porcine Model and Comparison to Nitrogen Plasma Skin Regeneration

BACKGROUND AND OBJECTIVES: Helium plasma skin regeneration (PSR) is a novel skin rejuvenation technology with significant differences compared with nitrogen PSR technology but that may exert similar skin tissue effects. Study objectives included a comparison of acute and chronic skin tissue changes among the two plasmas in a porcine animal model. STUDY DESIGN/MATERIALS AND METHODS: In this study, both helium and nitrogen gas plasmas were used to treat the dorsal skin of Yorkshire cross mini pigs with 20% (8.6 J/cm(2)) and 40% (17.8 J/cm(2)) power helium plasma single pass treatment (4 liter gas flow, continuous energy delivery, and linear non‐overlapping passes) compared with high energy nitrogen plasma double pass treatment (PSR3 @ 14.1 J/cm(2): 4.0 J, 2.5 Hz pulse rate, overlapping horizontal, and vertical passes). Acute and chronic skin contraction, maximum acute depth of injury and chronic reparative healing depth were assessed along with representative histopathology in each treatment paradigm. RESULTS: High‐energy nitrogen plasma treatment exhibited greatest mean depth of acute tissue injury 4 hours post‐treatment whereas helium plasma treatment exhibited greater acute skin tissue contraction. Then, 20% and 40% power helium plasma treatment results were each very similar among animals as a percentage of nitrogen plasma treatment results for both depths of acute tissue injury and acute skin tissue contraction. Mean depths of reparative tissue healing were similar among treatment paradigms 30 days after treatment with significant intra‐ and inter‐animal variability observed within each treatment paradigm. Thirty‐day mean skin tissue contraction was greater for helium plasma treatment; however, the data varied significantly between animals in all paradigms. Histopathologic tissue evaluation after 30 days showed similar findings among the treatment paradigms with epidermal hyperplasia, flattening of rete ridges and with regenerative granulation tissue expanding the superficial and papillary dermis. CONCLUSIONS: This study demonstrates modestly reduced depth of the thermal effect, greater skin tissue contraction and similarity of acute and chronic histopathological findings for helium plasma when compared with nitrogen plasma in a porcine animal model. © 2019 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.