Intrapulmonary Vein Ablation Without Stenosis: A Novel Balloon‐Based Direct Current Electroporation Approach

Abstract

BackgroundCurrent thermal ablation methods for atrial fibrillation, including radiofrequency and cryoablation, have a suboptimal success rate. To avoid pulmonary vein (PV) stenosis, ablation is performed outside of the PV, despite the importance of triggers inside the vein. We previously reported on the acute effects of a novel direct current electroporation approach with a balloon catheter to create lesions inside the PVs in addition to the antrum. In this study, we aimed to determine whether the effects created by this nonthermal ablation method were associated with irreversible lesions and whether PV stenosis or other adverse effects occurred after a survival period.Methods and ResultsInitial and survival studies were performed in 5 canines. At the initial study, the balloon catheter was inflated to contact the antrum and interior of the PV. Direct current energy was delivered between 2 electrodes on the catheter in ECG‐gated 100 μs pulses. A total of 10 PVs were treated demonstrating significant acute local electrogram diminution (mean amplitude decrease of 61.2±19.8%). After the survival period (mean 27 days), computed tomography imaging showed no PV stenosis. On histologic evaluation, transmural, although not circumferential, lesions were seen in each treated vein. No PV stenosis or esophageal injury was present.ConclusionsIrreversible, transmural lesions can be created inside the PV without evidence of stenosis after a 27‐day survival period using this balloon‐based direct current ablation approach. These early data show promise for an ablation approach that could directly treat PV triggers in addition to traditional PV antrum ablation.

Ablation Modalities for Therapeutic Intervention in Arrhythmia-Related Cardiovascular Disease: Focus on Electroporation

“…With the oesophagus lying near the heart, the avoidance of trauma here is also a major concern of electrophysiologists. Similar findings were reported in a canine model, with subjects showing no signs of oesophageal injury [ 93 ]. In a porcine model, Neven et al reported no disruption to oesophagus architecture, even with purposeful targeting of the adventitia [ 94 ].…”

“…Another major difference between IRE and thermal catheter-based procedures is the time taken to perform the procedure. From a practical perspective, IRE procedures require significantly less time, energy and number of applications of energy in comparison to those of RF or cryoablation [ 3 , 59 , 72 , 78 , 93 ]. In the FIRE and ICE trial, studies by Reddy et al, on the isolation of PVs, highlighted a notable difference in mean total procedure time for IRE (92.2 min) compared to RF and cryoablation procedure times, which required 141 and 124 min, respectively [ 78 ].…”

AC Pulsed Field Ablation Is Feasible and Safe in Atrial and Ventricular Settings: A Proof-of-Concept Chronic Animal Study

“…Tissue specificity was not an investigative target or our study; nevertheless, we did obtain contained lesions and no observable peripheral damage to the pericardium, esophagus, or lungs. This feature of PFA was extensively investigated in animal models, specifically for coronary vessels ( Neven et al, 2014 ), phrenic nerves ( van Driel et al, 2015 ), and pulmonary veins ( van Driel et al, 2014 ; Witt et al, 2018 ).…”

Feasibility of selective cardiac ventricular electroporation

“…One animal experienced an idioventricular rhythm of fascicular origin, this dissipated spontaneously and did not recur. Considering all published preclinical [8,10,[47][48][49] and the recent first in human clinical data [50], it is reasonable to deduce that that direct cardiac IRE delivery within the ventricle or atrium (epicardial or endocardium) is reasonably safe (when timed with R wave).…”

“…While reversible electroporation has been studied since the 1980s [1][2][3][4], the concept of irreversible electroporation is relatively new and proposed by Davlaos in 2005 [5] in a landmark paper highlighting the power of electric fields to produce tissue ablation without detrimental thermal effects. While much of the initial focus on the irreversible effects of PEFs was oncological, Hong [6] and later Wittkampf [7,8], explored cardiac applications which lead to the emergence of PEFs as a novel cardiac ablation modality [9][10][11][12].…”