Kosmetische Medizin 2-2010: 84 – 92

Characterization of Non-thermal Focused Ultrasound for Non-invasive Selective Fat Cell Disruption (Lysis): Technical and Pre-clinical Assessment

SPENCER A. BROWN1, LIOR GREENBAUM2, STELLA SHTUKMASTER2, YEHUDA ZADOK2,
SHMUEL BEN-EZRA2 AND LEONID KUSHKULEY2

1 Plastic Surgery Department, The University of Texas Southwestern Medical Center at Dallas, 1801 Inwood Road, Dallas , TX 75390
2 UltraShape Inc., 2 HaCarmel St., Yoqneam, Israel (P.O.B.: 80), Zip code: 20692

KEY WORDS: Ultrasound, adipose tissue, lipolysis, porcine model, Schlieren

SUMMARY:
Goal: Summarize the ongoing laboratory and pre-clinical data generated to support the safety and effectiveness of a novel non-thermal focused ultrasound technology for non-invasive fat reduction for the purpose of body contouring.

Methods: A series of experiments were conducted with the UltraShape Contour I System : 1) 3-D acoustic field distribution measured by hydrophone in a water bath; 2) the real-time 2-D acoustic field was assessed using optical visualization by a Schlieren system; 3) comparison of 3-D and Schlieren results in tissue-mimicking gel phantoms and in frozen specimens of porcine subcutaneous fat; 4) a porcine in vivo preclinical model was used to test safety, selectivity and efficacy by histological staining of excised skin and subcutaneous fat specimens.

Results: Real-time imaging of acoustic field distribution obtained by the Schlieren system, as well as real-time ultrasound visualization, demonstrated the capability of the Contour I System for producing stable cavitation both in water and in the gel phantoms. The area where the effect was visible corresponded to the focal area of energy delivered by the system transducer, as measured by the hydrophone. No effect was observed at the surface of the transducer. Histologically stained specimens of skin and subcutaneous fat that were excised from porcine studies (n = 14) following treatments (n = 31) demonstrated discrete holes in the subcutaneous fat compartment. Staining in the target treatment areas showed fat cell lysis and no observable cellular destruction of adjacent blood vessels, nerves and connective tissue. No epidermal or dermal changes were observed clinically or histologically.