Effects of Parallel Contact Cooling on Pulsed-Type, Bipolar Radiofrequency-Induced Tissue Reactions in an in vivo Porcine Model

• Published in: Clinical, cosmetic and investigational dermatology Vol. 17; pp. 125 - 135
• Main Authors: Cho, Sung Bin, Lee, Yea-Jin, Kang, Sun Young, Choi, Min, Kim, Bora, Ahn, Jin-Chul
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01.01.2024; Dove; Dove Medical Press
• Subjects: alternating current; bipolar; Care and treatment; gated pulse; Original Research; Pain; parallel contact cooling; porcine model; radiofrequency; Skin; thermoelectric cooling; tissue reaction; South Korea; tissue reaction; porcine model; radiofrequency; bipolar; alternating current; gated pulse; thermoelectric cooling; parallel contact cooling
• ISSN: 1178-7015; 1178-7015
• DOI: 10.2147/CCID.S446814

Skin cooling during laser or radiofrequency (RF) treatments is a method to minimize thermal damage to the epidermis, reduce pain, and decrease post-treatment downtime. We evaluated the effect of parallel contact cooling (PCC) on RF-induced thermal reactions in minipig skin in vivo after bipolar microneedling RF treatment. RF treatments were administered at frequencies of 0.5, 1, and 2 MHz with single (500 ms), six (1000 ms), and ten (5000 ms) sub-pulse packs to minipig skin with or without PCC. Subsequently, thermometric imaging and histology were used to analyze skin reactions to RF. Thermometric images showed that PCC promptly lowered skin temperature in the RF-treated area, with this effect persisting for over 60s. Regardless of the PCC, RF treatments lasting for 500 ms with a single pulse pack resulted in peri-electrode coagulative necrosis (PECN) zones and inter-electrode non-necrotic thermal reaction (IENT) zones in the dermis. In contrast, treatment lasting 5000 ms with 10 sub-pulse packs produced distinct IENT without notable PECN over a wide dermal area. Skin specimens obtained at 1 h and 3, 7, and 14 days after PCC-assisted RF treatments showed a higher degree of thermal tissue reactions in the deeper dermal regions compared to those after RF treatments without PCC. PCC-assisted RF treatment, utilizing an invasive bipolar microneedling device, enhanced RF-induced skin reactions in the mid to deep dermis while preserving the epidermis and upper papillary dermis from excessive thermal tissue injury.