Exploring feedback-controlled versus open-circuit electrochemical lipolysis in ex vivo and in vivo porcine fat: A feasibility study.

OBJECTIVES: Minimally invasive fat sculpting techniques are becoming more widespread with the development of office-based devices and therapies. Electrochemical lipolysis (ECLL) is a needle-based technology that uses direct current (DC) to electrolyze tissue water creating acid and base in situ. In turn, fat is saponified and adipocyte cell membrane lysis occurs. The electrolysis of water can be accomplished using a simple open-loop circuit (V-ECLL) or by incorporating a feedback control circuit using a potentiostat (P-ECLL). A potentiostat utilizes an operational amplifier with negative feedback to allow users to precisely control voltage at specific electrodes. To date, the variation between the two approaches has not been studied. The aim of this study was to assess current and charge transfer variation and lipolytic effect created by the two approaches in an in vivo porcine model. METHODS: Charge transfer measurements from ex vivo V-ECLL and P-ECLL treated porcine skin and fat were recorded at -1 V P-ECLL, -2 V P-ECLL, -3 V P-ECLL, and -5 V V-ECLL each for 5 min to guide dosimetry parameters for in vivo studies. In follow-up in vivo studies, a sedated female Yorkshire pig was treated with both V-ECLL and P-ECLL across the dorsal surface over a range of dosimetry parameters, including -1.5 V P-ECLL, -2.5 V P-ECLL, -3.5 V P-ECLL, and 5 V V-ECLL each treated for 5 min. Serial biopsies were performed at baseline before treatment, 1, 2, 7, 14, and 28 days after treatment. Tissue was examined using fluorescence microscopy and histology to compare the effects of the two ECLL approaches. RESULTS: Both V-ECLL and P-ECLL treatments induced in-vivo fat necrosis evident by adipocyte membrane lysis, adipocyte denuclearization, and an acute inflammatory response across a 28-day longitudinal study. However, -1.5 V P-ECLL produced a smaller spatial necrotic effect compared to 5 V V-ECLL. In addition, 5 V V-ECLL produced a comparable necrotic effect to that of -2.5 V and -3.5 V P-ECLL. CONCLUSIONS: V-ECLL and P-ECLL at the aforementioned dosimetry parameters both achieved fat necrosis by adipocyte membrane lysis and denuclearization. The -2.5 V and -3.5 V P-ECLL treatments created spatially similar fat necrotic effects when compared to the 5 V V-ECLL treatment. Quantitatively, total charge transfer between dosimetry parameters suggests that -2.5 V P-ECLL and 5 V V-ECLL produce comparable electrochemical reactions. Such findings suggest that a low-voltage closed-loop potentiostat-based system is capable of inducing fat necrosis to a similar extent compared to that of a higher voltage direct current system.