Tightening effects of high-intensity focused ultrasound on body skin and subdermal tissue: a pilot study

Abstract

BackgroundHigh-intensity focused ultrasound (HIFU) has been introduced as a new treatment modality for skin tightening through application mainly to the face and neck. ObjectivesThis pilot study assessed the efficacy and safety of HIFU for body tightening in Asian females. MethodsSix Asian female adults were enrolled in this pilot study. All subjects were treated with HIFU to the both cheek, upper arm, lower abdomen, thigh and calf using the following probes: 7 MHz, 1.5 mm focal depth; 2 MHz, 3.0 mm focal depth; 2 MHz, 4.5 mm focal depth; 2 MHz, 6.0 mm focal depth and 2 MHz, 9.0 mm focal depth. Three blinded independent dermatologists assessed results using the Investigator Global Aesthetic Improvement Scale (GAIS) using paired pre- and post-treatment (week 4) standardized photographs. Also, we evaluated skin elasticity at all treated sites using a cutometer. Participants used the subject GAIS to assess their clinical improvement after treatment and rated their pain using a visual analogue scale (VAS) immediately, 1 and 4 weeks after treatment. ResultsThe three blinded evaluators judged all treated sites as showing clinical improvement 4 weeks after treatment. Skin elasticity measured via cutometer was significantly improved 4 weeks after treatment at all treated sites (P < 0.05). All patients scored themselves subjectively as more than improved' on the GAIS. Immediately after treatment the mean VAS score was 5.17 2.48, but no pain was reported at weeks 1 and 4. No permanent adverse effects were observed during the follow-up period. ConclusionFor body tightening, we applied HIFU using transducers with a lower frequency and deep focal depth to effectively deliver ultrasound energy to skin tissues. HIFU appears to be a safe and effective treatment modality for dermal and subdermal tightening.