The efficacy of external ultrasound-assisted liposuction: A randomized controlled trial

BACKGROUND. Use of high-intensity, high-frequency external ultrasound befor e liposuction has been reported to enhance the ease of fat extraction, incr ease the amount of fat extracted, and decrease patient discomfort during li posuction. OBJECTIVE. The purpose of this study was to compare the effect of applicati on of high-intensity continuous wave ultrasound to extremely low-intensity ultrasound (placebo) prior to tumescent liposuction. METHODS. A total of 19 patients (25 sites) completed the double-blind study . We used a split treatment area design so that each patient could serve as their own control. After tumesing the treatment area, a 3 W/cm(2) continuo us wave 1 MHz ultrasound was applied for 10 minutes. The placebo control wa s treated with 0.3 W/cm(2) 1 MHz for 10 minutes. Traditional tumescent lipo suction followed ultrasound application. Doctors completed a visual analog scale rating the following: rate of extraction, degree of resistance to can nula movement, and color of fat. Patients also completed a questionnaire af ter the procedure and at 1 month postoperatively. Histologic samples of the fat treated with external ultrasound were taken from two patients. RESULTS. In 14 of 19 patients the doctors graded either no difference betwe en treatment and control sides or found a better response on the nontreated side in rate of fat removal and resistance to cannula advancement giving a P value of .0096. Only 5 of 19 aspirates were graded as differing in redne ss between treatment and control sides. Four of these were more red on the control side and one was more red on the treatment side. Therefore 15 of 19 had no better result with treatment, giving a P value of .0022. Seven pati ents graded the sensation during suctioning and/or postoperative course as better on the control side, four graded these variables as better on the tr eatment side, four showed no difference between the two sides, and four had mixed results. This gives only 4 of the 19 patients showing any advantage in treatment with a P value of .0022. CONCLUSIONS. When the placebo effect is eliminated, there is no advantage t o the application of external ultrasound prior to liposuction.