Mathematical modeling of the effect of stent construction during endoluminal IRE for recanalization of an occluded metal stent

Abstract

Background: Intraluminal irreversible electroporation (IRE) can be used for recanalizing occluded metalstents. However, optimal IRE parameters for consistent effects across different stent designs remainunclear. The aim of this study was to simulate the process of stent recanalization in silico by employingfinite element analysis. Methods: A virtual model of an occluded biliary stent with an experimental 3-electrode IRE catheter was developed. Electric field distribution, temperature changes, and potential ablation volumes weresimulated across various parameters: IRE voltage (300 1300 V), stent wire width (0.1 0.5 mm) and stentmesh size (0.7 5.58 mm). Simulations incorporated five representative stent types commonly used inclinical practice. 685 unique simulations were conducted, analyzing 1162 unique values. Results: Higher voltages generally led to larger ablation zones and increased temperatures. Thinnerstent wires and larger mesh sizes also increased the extent of ablation zone. While in-stent ablation waslargely independent of stent design, out-of-stent ablation was significantly impacted by mesh size andtissue thickness between the stent and irreversible electroporation electrodes. Voltages above 1000 Vproduced significant thermal effects, with substantial volumes of tissue heated above 50 °C. Specificstent designs exhibited variations in maximum temperature (72.1 83.1 °C) and ablation volume(8.7 14.7 mm3). Conclusion: Tailored IRE protocols for different stent designs are required due to differences in in- andout-stent ablation volumes. High voltages (>1000 V) induce both thermal and nonthermal ablation mechanisms.

Background: Intraluminal irreversible electroporation (IRE) can be used for recanalizing occluded metalstents. However, optimal IRE parameters for consistent effects across different stent designs remainunclear. The aim of this study was to simulate the process of stent recanalization in silico by employingfinite element analysis. Methods: A virtual model of an occluded biliary stent with an experimental 3-electrode IRE catheter was developed. Electric field distribution, temperature changes, and potential ablation volumes weresimulated across various parameters: IRE voltage (300 1300 V), stent wire width (0.1 0.5 mm) and stentmesh size (0.7 5.58 mm). Simulations incorporated five representative stent types commonly used inclinical practice. 685 unique simulations were conducted, analyzing 1162 unique values. Results: Higher voltages generally led to larger ablation zones and increased temperatures. Thinnerstent wires and larger mesh sizes also increased the extent of ablation zone. While in-stent ablation waslargely independent of stent design, out-of-stent ablation was significantly impacted by mesh size andtissue thickness between the stent and irreversible electroporation electrodes. Voltages above 1000 Vproduced significant thermal effects, with substantial volumes of tissue heated above 50 °C. Specificstent designs exhibited variations in maximum temperature (72.1 83.1 °C) and ablation volume(8.7 14.7 mm3). Conclusion: Tailored IRE protocols for different stent designs are required due to differences in in- andout-stent ablation volumes. High voltages (>1000 V) induce both thermal and nonthermal ablation mechanisms.