Abstract No. 328 The Efficacy of Innovative Clustered Electrodes in Irreversible Electroporation: A Preclinical Study in A Porcine Liver Model

Parallel placement of electrodes at an exact distance is crucial for irreversible electroporation (IRE). The most common cause of high current issues is needle placement with convergence or divergence. The aim of this study is to assess the feasibility of newly designed clustered electrodes and evaluate the ablation zone in porcine liver models. Furthermore, the ablation zone was assessed following IRE using an ultrashort pulse width of 10 μs, along with an increase in the number of pulses. The EPO system (The Standard Co., S. Korea) was utilized for IRE. A total of 18 IRE procedures were performed on the livers of 14 pigs, guided by ultrasound and fluoroscopy during open laparotomy. Clustered electrodes with a fixed distance of either 1.5 or 2 cm, in double-type (n=14) or triple-type (n=4) configurations, were employed. IRE procedures were conducted using pulse widths ranging from 70 to 90 μs, with 90 to 180 pulses and at 2500 volts. Additionally, IRE was performed on four livers using ultrashort pulse width (10 μs) and 630 to 1260 pulse numbers. One day after the procedures, the livers were harvested, and histopathological examination was conducted. On fluoroscopy, needle placements were confirmed to be parallel in all experiments, and no high current issues were encountered. Average ablation zones were observed to range from 2.6 × 1.6 × 2.9 cm in the double-type configuration and 2.6 × 2.7 × 3.1 cm in the triple-type clustered electrodes, respectively. In the case of IRE with an ultrashort pulse width and increased pulse numbers, the resulting ablation zone was 2.5 ×1 × 1.5 × 1.5 cm in double type, 2.7 × 2.6 × 3.0 cm in triple type respectively, comparable to that achieved with IRE using a regular pulse width. Histopathologic finding revealed marked dilation of the liver sinusoidal spaces, with hepatic necrosis and multiple neutrophil infiltrates. The effectiveness of the newly designed clustered electrodes for irreversible electroporation (IRE) is highlighted by their capacity to facilitate precise and parallel electrode placement. This development has the potential to streamline the process of needle placement during IRE, potentially reducing procedure times. IRE with an ultrashort pulse width, along with an increased number of pulses, demonstrated a comparable ablation zone.