Experimental evaluation of high intensity focused ultrasound for fat reduction of ex vivo porcine adipose tissue

Purpose The present study was stimulated by the continuous growth of commercially available high intensity focused ultrasound (HIFU) systems for fat reduction. Herein, HIFU was utilised for fat ablation using a single-element ultrasonic transducer operating in thermal mode. Methods The custom-made concave transducer that operates at 1.1 MHz was assessed on excised porcine adipose tissue for its ability to reduce fat. Ultrasonic sonications were executed on the adipose tissue utilising acoustical power between 14 and 75 W and sonication time in the range of 1-10 min. The mass of the adipose tissue sample was weighed afore and after ultrasonic sonications and the effect of the sonication on the mass change was recorded. Results Mass change was linearly dependent with either increasing acoustical power or sonication time and was in the range of 0.46-1.9 g. High acoustical power of 62.5 W for a sonication time of 1 min and a power of 75 W for a sonication time of 5 min, respectively resulted in the formation of a lesion or possible cavitation on the piece of excised adipose tissue. Conclusion The study demonstrated the efficacy of the proposed transducer in achieving a reduction of excised fat tissue. The present findings indicate the potential use of the transducer in a HIFU system indicated for the reduction of subcutaneous adipose tissue where increased values of acoustical power can result in increased amounts of fat reduction.