#2-3. RF and HIFU: Mechanism of Action and Efficacy

Figure 4. A study comparing HIFU devices.

Comparison of Two HIFU Devices

This study conducted a split-face comparison of two HIFU devices; Ulthera(USA) and Ultra-Skin(Won TECH, KOR) in Korean patients. Ulthera has three probes; superficial(7.0 MHz with a focal depth of 3.0 mm and Max. source energy of 3 J); intermediate(7.0 MHz with focal depth of 4.5 mm and Max. source energy of 3 J); and low(4.4 MHz with a focal depth of 4.5 mm and Max. source energy of 3 J). Ultra-Skin has two probes; superficial(7.0 MHz with a focal depth of 3.0 mm and Max. source energy of 3 J); and intermediate(4.0 MHz with focal depth of 4.5 mm and Max. source energy of 3J).

Spacing was set at 1.5mm 0.9J in Ulthera and at 1.0mm 1.3J in Ultra-Skin. Transducer was set at 4.4MHz/4.5mm in Ulthera and 4.0MHz/4.5mm in Ultra-Skin. Thermal coagulative zone was set at 17 in Ulthera and 21zone in Ultra-Skin. Split-face comparision of clinical efficacy and satisfaction level showed no significant difference between the two devices.

Conclusion

HIFU and RF treatments have excellent safety profiles but are not without side effects. There were reports of thermal damage, blistering, crusting and PIH associated with these treatments. The risk of such side effects can be reduced with the correct use of contact cooling. The key benefits of the two modalities are the convenience of use and safety. I expect more clinical data on both modalities as new, improved devices continue to be developed.

References

1. Suh DH, Choi JH, Lee SJ, JeongKH, Song KY , Shin MK. Comparative histometric analysis of the effects of high-intensity focused ultrasound and radiofrequency on skin. J Cosmet Laser Ther 2015;17:230-6.

2. Lee S, Kim HJ, Park HJ, Kim HM, Lee SH , Cho SB. Morphometric analysis of high-intensity focused ultrasound-induced lipolysis on cadaveric abdominal and thigh skin. Lasers Med Sci 2017.

3. Sugawara J, Kou S, Kokubo K, Kuroda A, Hashizume Y, Kobayashi S et al. Application for lower facial fat reduction and tightening by static type monopolar 1-MHz radio frequency for body contouring. Lasers Surg Med 2017.

4. Jung HJ, Min J, SeoHM , Kim WS. Comparison of effect between high intense focused ultrasound devices for facial tightening: Evaluator-blinded, split-face study. J Cosmet Laser Ther 2016;18:252-6.

-To be continued