Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Ablation Techniques D-PO02 - Poster Session II (ID 47) Poster

D-PO02-164 - Preliminary Feasibility Of Synergistic Electroporation-electrolysis For Cardiac Ablation (ID 1039)

Abstract

Background: Ablation treatment of cardiac arrhythmias has relied on thermal ablation, which may limit efficacy, speed and risk. Electroporation is emerging in cardiac ablation as a fast, non-thermal and tissue-specific alternative. Successful irreversible electroporation (IRE) ablation in tumours has spurred similar use of kilovolt pulses in cardiac ablation. However, such high voltages in the heart pose technical, clinical and regulatory challenges. Electroporation-Electrolysis ablation (E2) is a novel ablation technique that uses low-voltage reversible electroporation augmented with cytotoxic electrolysis in a single pulse.
Objective: The objective was to define the feasibility of E2 ablation by examining E2 dose versus depth and continuity of ablation in a thigh muscle model.
Methods: Specialised electrodes and a custom E2 pulse generator were developed based on numerical and in vitro models of electrical fields and electrolytic pH fronts. E2 ablation effects were examined in the sheep thigh muscle model of cardiac ablation using 3 anesthetised non-paralysed animals. Arrays of four 5 x 12mm trapezoidal electrodes were applied to muscle in custom jigs for accurate tissue excision and consistent pressure. We applied single or double, non-arcing, monophasic bipolar pulses decaying from 350-500V for 40-100ms. Animals were sacrificed 1hr after the last pulse.
Results: E2 pulses resulted in peak currents of 4,4A-9,2A with no arcing, delivering 22J-42J, producing mild-moderate thigh and buttock contractions. For the most successful E2 dose of 350V decaying for 100ms, H&E of muscle excised 1-5hrs post-pulse showed muscle fibre disintegration for a continuous depth of 4-5mm with vasculature spared, corresponding to calculated field strengths of 140-350V/cm. No complications occurred.
Conclusion: E2 achieves consistent muscle tissue ablation acutely to 4mm depth at far lower field strengths than IRE, making it potentially more suitable for ablation of atrial fibrillation. Further investigations will address cardiac muscle, chronic effects and the safety profile of the electrolytic component.
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