Abstract

Purpose

To demonstrate the feasibility of irreversible electroporation (IRE) for treating biliary metal stent occlusion in an experimental liver model.

Methods and materials

IRE was performed using an expandable tubular IRE-catheter placed in nitinol stents in the porcine liver. A 3-electrode IRE-catheter was connected to an IRE-generator and one hundred 100μs pulses of constant voltage (300, 650, 1000, and 1300 V) were applied. Stent occlusion was simulated by insertion of liver tissue both ex vivo (n = 94) and in vivo in 3 pigs (n = 14). Three scenarios of the relationship between the stent, electrodes, and inserted tissue (double contact, single contact, and stent mesh contact) were studied. Electric current was measured and resistance and power calculated. Pigs were sacrificed 72 h post-procedure. Harvested samples (14 experimental, 13 controls) underwent histopathological analysis.

Results

IRE application was feasible at 300 and 650 V for the single and double contact setup in both ex vivo and in vivo studies. Significant differences in calculated resistance between double contact and single contact settings were observed (ex-vivo p ˂ 0.0001, in-vivo p = 0.02; Mann–Whitney). A mild temperature increase of the surrounding liver parenchyma was noted with increasing voltage (0.9–5.9 °C for 300–1000 V). The extent of necrotic changes in experimental samples in vivo correlated with the measured electric current (r² = 0.39, p = 0.01). No complications were observed during or after the in-vivo procedure.

Conclusion

Endoluminal IRE using an expandable tubular catheter in simulated metal stent occlusion is feasible. The relationship of active catheter electrodes to stent ingrowth tissue can be estimated based on resistance values.

中文翻译：

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不可逆电穿孔通过管状导管对胆道金属支架再通的实验模型

摘要

目的

为了证明不可逆电穿孔（IRE）在实验性肝模型中治疗胆道金属支架阻塞的可行性。

方法和材料

使用放置在猪肝中镍钛合金支架中的可膨胀管状IRE导管进行IRE。将三电极IRE导管连接到IRE发生器，并施加100个100μs恒定电压（300、650、1000和1300 V）脉冲。支架闭塞进行模拟由肝组织两者的插入离体（Ñ  = 94）和在体内在3头猪（Ñ  = 14）。研究了支架，电极和插入的组织之间的关系的三种情况（双接触，单接触和支架网状接触）。测量电流并计算电阻和功率。手术72小时后处死猪。收集的样品（14个实验样品，13个对照样品）进行了组织病理学分析。

结果

对于离体和体内研究中的单触点和双触点设置，IRE应用在300和650 V下都是可行的。观察到两次接触和单次接触设置之间的计算电阻存在显着差异（离体p˂0.0001，体内p  = 0.02； Mann-Whitney）。随着电压的升高（300-1000 V，0.9-5.9°C），周围的肝实质温和升高。体内实验样品中坏死变化的程度与测得的电流相关（r ² = 0.39，p  = 0.01）。在体内手术期间或之后未观察到并发症。

结论

在模拟的金属支架阻塞中使用可膨胀的管状导管进行腔内IRE是可行的。有源导管电极与支架向内生长组织的关系可以基于阻力值进行估算。