Safety, tolerability, and efficacy evaluation of the SlimME device for circumference reduction

Objective To assess the short‐ and long‐term thermal impact of subclinical and clinical regimens of a single, non‐invasive uniform ultrasound treatment session on subcutaneous adipose tissue (SAT). Study Design Prospective, open‐label, single‐arm, split‐side study. Methods Patients ( n  = 17) were subjected to uniform ultrasound treatment, delivered in a single session with the SlimME device. The device was set to one of four treatment regimens, which differed in their durations and energy fluences during the raise and maintenance phases. Up to six abdominal regions were treated, with six patients receiving a different treatment on each side of the abdomen. Safety was assessed by measuring skin surface temperature, evaluating expected skin responses immediately and 30 min after treatment and via patient ratings of pain and discomfort. Efficacy of raising and then maintaining SAT temperatures at 48°C, was determined by routinely measuring SAT temperatures during the treatment session and by histological analysis of samples collected 7 ( n  = 13) or 90 ( n  = 4) days after treatment. Results Trace to mild erythema was observed in up to 48% of the treated zones, which, in most cases, resolved within 30 minutes. No significant rise in mean skin surface temperature (≤26.5°C) was recorded following any of the four tested regimens. Overall, patients reported tolerability to treatment, with the highest mean pain score registered for the moderate and high intensity regimens (4.4 ± 1.5 and 4.9 ± 1.4, respectively). Mean SAT temperatures did not exceed 48.4 ± 2.5°C and were effectively maintained throughout the maintenance phase of the treatment session. Low‐energy fluence led to localized fat coagulative necrotic lesions, surrounded by subacute rim of inflammation, while high‐energy fluence induced fat coagulative necrosis alongside granulomatous panniculitis, which resolved within 90 days. Conclusion The tested uniform ultrasound regimens elicited SAT temperature elevations, with a subsequent energy‐dependent increase in degree of fat necrosis. At the same time, the unique design spared the surrounding tissue from thermal damage and was associated with minimal discomfort. Taken together, the SlimME device constitutes an effective tool for destruction of stubborn hypodermal fat deposits. Lasers Surg. Med. 50:745–754, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.