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

Abstract

BACKGROUND: High-intensity focused ultrasound (HIFU) has been introduced as a new treatment modality for skin tightening through application mainly to the face and neck. OBJECTIVES: This pilot study assessed the efficacy and safety of HIFU for body tightening in Asian females. METHODS: Six 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. RESULTS: The 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. CONCLUSION: For 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.