Intense focused ultrasound for facial tightening: Histologic changes in 11 Patients

Introduction: Intense focused ultrasound (IFUS) is a novel modality for treating skin laxity that produces thermal effects at various depths while sparing the overlying tissue. This study assessed histologic changes and the safety and efficacy of intense focused ultrasound (Doublo^TM, HIRONIC Co., Sungnam, Korea) for tightening of facial skin in Asian patients. Methods: Eleven patients with facial laxity were treated with IFUS and evaluated before and after treatment. Mean age was 46 years (range, 35-64 years). Two available hand-pieces with different focal depths (3 mm and 4.5 mm) were used with three to five passes 1-2 mm apart. Outcome assessment included photographic evaluation by two blinded investigators, skin biopsies before and two months after treatment, and patient satisfaction. Results: Subjective and objective analyses showed 63.6% and 72.7% improvement at the two-month evaluation, respectively. Histologic evaluation by hematoxylin and eosin (H&E) and Masson's trichrome staining showed increased collagen fibers in the lower dermis and between fat layers. Discussion and conclusions: Intense focused ultrasound can be used as a non-invasive skin tightening technique in Asian patients. It induced collagen generation in the dermis and fat layers and was effective and safe in our study population.