250Efficacy of multi-electrode linear irreversible electroporation

Abstract

Abstract Background We investigated the efficacy of linear irreversible electroporation (IRE) ablation in a porcine model. Methods The study was performed in 6 pigs (weight 60-75kg). After median sternotomy and opening of the pericardium, a pericardial cradle was formed and filled with blood. A linear 7 polar 7F electrode catheter with 2.5mm electrodes and 2.5mm inter-electrode spacing was placed in good epicardial contact. A single IRE application was delivered using 50 Joules (J) at 1 site and 100 J at 2 other sites, in random sequence, using a standard monophasic defibrillator connected to all 7 electrodes connected in parallel. The pericardium and thorax were closed and after 3 weeks survival animals were euthanized. 82 histological sections from all 18 electroporation lesions were analyzed. Results A total of seven 50 J and fourteen 100 J epicardial IRE applications were performed. Mean peak voltages at 50 J and 100 J were 1079.2 V ± 81.1 and 1609.5 V ± 56.8, with a mean peak current of 15.4 A ± 2.3 and 20.2 A ± 1.7, respectively. Median depth of the 50J and 100J lesions were 3.2 mm (interquartile range [IQR], 3.1 – 3.6) and 5.5 mm (IQR, 4.6 – 6.6) (P < 0.001), respectively. Median lesion width of the 50J and 100J lesions were 3.9 mm (IQR, 3.7 – 4.8) and 5.4 mm (IQR, 5.0 - 6.3), respectively(P < 0.001). Longitudinal sections showed continuous lesions for 100J lesions. Conclusion Epicardial linear application of IRE pulses is effective in creating continuous deep lesions. Ablation characteristics and lesion size Peak voltageV Peak currentA Peak resistanceΩ SlicesN Depthmm Widthmm 50 J 1079.2 ± 81.1 14.5 ± 2.3 71.8 ± 15.6 26 3.2 (3.1 - 3.6) 3.9 (3.7 - 4.8) 100J 1609.5 ± 56.8 20.2 ± 1.7 80.0 ± 9.5 56 5.5 (4.6 - 6.6) 5.4 (5.0 - 6.3) P-value† <0.001 <0.001 Data is displayed as mean ± SD or median (interquartile range) where appropriate.†assessed by general linear mixed models Abstract Figure. Transversal histological sections