0018-9294 (c) 2019 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TBME.2019.2954122, IEEE Transactions on Biomedical Engineering TBME-01508-2018.R3 1 Abstract Objective: To demonstrate the feasibility of a single electrode and grounding pad approach for delivering high frequency irreversible electroporation treatments (H-FIRE) in in-vivo hepatic tissue. Methods: Ablations were created in porcine liver under surgical anesthesia by adminstereing high frequency bursts of 0.5–5.0 μs pulses with amplitudes between 1.1–1.7kV in the absence of cardiac synchronization or intraoperative paralytics. Finite element simulations were used to determine the electric field strength associated with the ablation margins (ELethal) and predict the ablations feasible with next generation electronics. Results: All animals survived the procedures for the protocol duration without adverse events. ELethal of 2550, 1650, and 875V/cm were found for treatments consisting of 100x bursts containing 0.5μs pulses and 25, 50, and 75μs of energized-time per burst, respectively. Treatments with 1μs pulses consisting of 100 bursts with 100μs energized-time per burst resulted in ELethal of 650V/cm. Conclusion: A single electrode and grounding pad approach was successfully used to create ablations in hepatic tissue. This technique has the potential to reduce challenges associated with placing multiple electrodes in anatomically challenging environments. Significance: H-FIRE is an in situ tumor ablation approach in which electrodes are placed within or around a targeted region to deliver high voltage electrical pulses. Electric fields generated around the electrodes induce irrecoverable cell membrane damage leading to predictable cell death in the relative absence of thermal damage. The sparing of architectural integrity means H-FIRE offers potential advantages compared to thermal ablation modalities for ablating tumors near critical structures. Index Terms— Irreversible electroporation, pulsed electric fields, microwave and radiofrequency ablation alternative I. INTRODUCTION nergy mediated tumor ablation is an alternative definitive therapy to resection for the treatment of primary and metastatic hepatic tumors. Thermal ablation (radiofrequency and microwave ablation [RFA/MWA]) represent the mainstays of liver tumor ablation therapy[1, 2], with MWA largely superseding RFA as the ablative modality of choice[3-5]. Thermal ablation has similar oncological outcomes to resection in appropriately selected patients[6, 7]. However, thermal ablation is not without limits. Since tissue destruction is indiscriminate in the near-field ablation zone, there is significant risk for non-tumor tissue loss and damage to critical structures, meaning patients with underlying liver dysfunction have a higher incidence of liver-related complications[5, 8]. Irreversible electroporation (IRE; commercially available as NanoKnife [NK-IRE], Angiodynamics Inc., Latham, NY) has the potential to overcome some of the technical challenges associated with RFA/MWA, including sparing of vascular and biliary integrity[9-11]. Thus, NK-IRE can be a useful approach in patients with decreased functional hepatic reserve, treating metastatic disease in which RFA/MWA is not possible, and treating tumors on (or adjacent to) major biliary or vascular pedicles, hepatic veins, or the vena cava[12-14]. Simplified Non-Thermal Tissue Ablation With A Single Insertion Device Enabled By Bipolar High-Frequency Pulses Matthew R. DeWitt # , Eduardo L. Latouche # , Jacob Kaufman, Christopher C. Fesmire, Jacob H. Swet, Russel C. Kirks, Erin H. Baker, Dionisios Vrochides, David A. Iannitti, Iain H. McKillop, Rafael V. Davalos, Michael B. Sano * E Fig. 1. H-FIRE treatment for single electrode IRE. Schematics of (A) monopolar NK-IRE pulses with two electrode delivery scheme and (B) H-FIRE bursts with a single inserted electrode. (C) Two electrode delivery leads to oblong lesions and (D) a single electrode results in semi- This is the author's version of an article that has been published in this journal. Changes were made to this version by the publisher prior to publication. The final version of record is available at http://dx.doi.org/10.1109/TBME.2019.2954122 Copyright (c) 2019 IEEE. Personal use is permitted. For any other purposes, permission must be obtained from the IEEE by emailing pubs-permissions@ieee.org. Authorized licensed use limited to: to IEEExplore provided by University Libraries | Virginia Tech. Downloaded on February 17,2020 at 14:56:18 UTC from IEEE Xplore. Restrictions apply.