Multicenter Efficacy Trial of a Percutaneous Radiofrequency System for the Reduction of Glabellar Lines.

BACKGROUND: Bipolar percutaneous radiofrequency (RF) is an established method for ablation of distal peripheral branches of the facial nerve to produce weakness of the corrugator muscle. Recent developments to the Serene RF system (Serene Medical, Inc., Pleasanton, CA) allowing for safer and more predictable results highlighted a need for prospective clinical data. OBJECTIVES: The authors sought to assess the ability of percutaneous RF to safely improve the appearance of dynamic glabellar lines for a minimum of 3 months and up to 1 year. METHODS: This prospective study enrolled 78 patients across 5 centers in the United States. The most distal branches of the medial and lateral facial nerve innervation to the brow depressor/corrugator complex were treated. Follow-up was at 3 days by telephone and in-office at 7 days and 3, 6, 9, and 12 months posttreatment. Patients were evaluated employing the Merz scale for dynamic glabellar lines. RESULTS: At 3 months, 93.6% of patients had a ≥1-point Merz scale improvement in dynamic glabellar lines based on independent, blinded review. Sustained ≥2-point improvement was present in 60% and 20% of patients at 3 and 12 months, respectively. Overall satisfaction remained >60% through 6 months and >50% at 12 months. All device- or procedure-related adverse events were mild (90%) or moderate (10%) and resolved without medical intervention. CONCLUSIONS: Bipolar percutaneous RF may be adopted in conjunction with surgery or as an office-based procedure where it can serve as a minimally invasive alternative to, or in concert with, Botulinum Toxin A therapy.

Pilot clinical study of a novel minimally invasive bipolar microneedle radiofrequency device.

BACKGROUND AND OBJECTIVES: Noninvasive bipolar and monopolar radiofrequency (RF) deep dermal heating devices have previously been described. A novel minimally invasive RF device employing a bipolar microneedle electrode system is introduced and its resultant thermal effects on human skin in vivo were characterized for the first time. STUDY DESIGN/MATERIALS AND METHODS: An investigational 35 W RF device was configured to operate in bipolar mode delivering energy directly within the dermis using 5 microneedle electrode pairs with real-time feedback of tissue temperature for treatment control. Superficial cooling was achieved using a Peltier device. A range of pulse durations between 1 and 25 seconds, and lesion temperatures between 60 and 80 degrees C were tested in vivo on 15 human subjects. Thermal effects were assessed histologically using either hematoxylin & eosin (H&E) or nitroblue-tetrazoliumchloride (NBTC) staining. Treatment effects and adverse events were also monitored clinically. RESULTS: The investigational bipolar RF device delivered controlled heating within dermal tissue. Histological staining with H&E revealed the presence of zones of denatured collagen within the reticular dermis. Lesions were generated at preselected temperatures between 60 and 80 degrees C. Fractional lesions separated by zones of sparing as well as contiguous lesion patterns were demonstrated. Histological staining with H&E and NBTC revealed sparing of adnexal structures and adipose tissue. No major adverse events were observed. CONCLUSIONS: A novel fractional RF device utilizing a minimally invasive bipolar microneedle delivery system for the treatment of human tissue was developed. Treatment of 15 human subjects illustrated the controlled creation of dermally located thermal coagulation zones, herein known as radiofrequency thermal zones. We discovered that varying the pulse length allowed for fractional sparing of dermal tissue. To our knowledge, this is the first report to describe use of a direct real-time temperature and impedance feedback system to control energy delivery during deep dermal heating.