Catheter–tissue contact optimizes pulsed electric field ablation with a large area focal catheter

Abstract

IntroductionPulsed electric field (PEF) ablation relies on the intersection of a critical voltage gradient with tissue to cause cell death. Field‐based lesion formation with PEF technologies may still depend on catheter–tissue contact (CTC). The purpose of this study was to assess the impact of CTC on PEF lesion formation with an investigational large area focal (LAF) catheter in a preclinical model.MethodsPEF ablation via a 10‐spline LAF catheter was used to create discrete right ventricle (RV) lesions and atrial lesion sets in 10 swine (eight acute, two chronic). Local impedance (LI) was used to assess CTC. Lesions were assigned to three cohorts using LI above baseline: no tissue contact (NTC: ≤∆10 Ω, close proximity to tissue), low tissue contact (LTC: ∆11–29 Ω), and high tissue contact (HTC: ≥∆30 Ω). Acute animals were infused with triphenyl tetrazolium chloride (TTC) and killed ≥2 h post‐treatment. Chronic animals were remapped 30 days post‐index procedure and stained with infused TTC.ResultsMean (± SD) RV treatment sizes between LTC (n = 14) and HTC (n = 17) lesions were not significantly different (depth: 5.65 ± 1.96 vs. 5.68 ± 2.05 mm, p = .999; width: 15.68 ± 5.22 vs. 16.98 ± 4.45 mm, p = .737), while mean treatment size for NTC lesions (n = 6) was significantly smaller (1.67 ± 1.16 mm depth, 5.97 ± 4.48 mm width, p < .05). For atrial lesion sets, acute and chronic conduction block were achieved with both LTC (N = 7) and HTC (N = 6), and NTC resulted in gaps.ConclusionsPEF ablation with a specialized LAF catheter in a swine model is dependent on CTC. LI as an indicator of CTC may aid in the creation of consistent transmural lesions in PEF ablation.

A New Hope for the Treatment of Atrial Fibrillation: Application of Pulsed-Field Ablation Technology

“…Some researchers have also found that the PFA technology has better transmural damage ability than thermogenic ablation and can effectively block the reconnection of pulmonary veins compared with other ablation methods. At the same time, researchers have found that the PFA technique has better transmural damage ability than thermal ablation, and the lesion area has a high degree of consistency in regional width, homogeneous tissue fibrosis in the region, and is able to block the reconnection of the pulmonary veins more effectively than other ablation methods [ 35 , 43 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ].…”

“…The results showed that both left and right atrial ablation lesions were permeable to the wall, with a maximum thickness of 8–12 mm of ablated tissue, and sectioned histology revealed a highly uniform width of the lesion area and no arrhythmias or other complications during the procedure. A similar study was conducted by Doshi et al [ 53 ] where PFA ablation was performed on 10 pigs and the experimental pigs were divided into two subgroups: 8 experimental pigs were debrided 2 h after ablation and 2 experimental pigs were debrided 30 days after ablation. The permeability of each lesion was examined using staining.…”