V originále
Purpose: To compare electrical and thermal parameters of irreversible electroporation (IRE) and high-frequency irreversible electroporation (H-FIRE) using tubular electrode prototype in biliary metal stent. Material and methods: 3-electrode tubular catheter prototype was placed inside metallic biliary stent in ex vivo porcine liver model. 3 scenarios of stent occlusion using 2±1 mm thick piece of liver parenchyma were simulated. Only 2 electrodes were active in each time. IRE were performed by one hundred pulses at voltages 300V, 650V, 1000V and 1300V with 100 us pulse length. H-FIRE is a newer modifcation of electroporation methods using, in our case, 100 us burst of alternating polarity pulses of 2,5; 5; 10 and 25 us length, pause between pulses 0,5, 1 and 1,5 seconds with the same voltages as IRE. Values of electric current were measured. Thermal efects were monitored by infrared thermal imaging camera. Results: IRE and H-FIRE procedures were feasible in all settings with simulated obstruction of the voltages of 300 and 650V and in most of the cases with 1000 V. In higher voltages the safety limit of generator (12A) were exceeded. No signifcant diference in heating between IRE and H-FIRE was observed (p=0,49, Mann-Whitney). Maximal temperature increase in both methods was 7°C at 1000 V in model with one electrode in direct in contact with the stent and the other one with simulated obstruction. Conclusion: No signifcant diferences in thermal efects between IRE and H-FIRE delivering comparable amount of energy in metal stent were observed.