Experimental model of occluded biliary metal stent recanalization using irreversible electroporation via a tubular catheter.

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.

Chemoembolization for Treatment of Hepatocellular Carcinoma - National Registry-Based Analysis.

BACKGROUND: To evaluate survival benefit in patient undergoing transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) by national registry data analysis and comparison of regions with unequal usage of interventional radiology procedures. MATERIALS AND METHODS: A total of 4,343 patients with primary diagnosis of HCC between 2010-2016 were extracted from the databases of The Czech National Cancer Registry. The analysis was supported by data from the National Registry of Paid Health Services and the Death Records Database. Primary treatment option was categorized as liver resection, ablation, TACE and chemotherapy. The regional data analysis provided information of interventional radiology procedures frequency for primary treatment of HCC. The 14 main regions were symmetrically divided to group with well-developed interventional radiology service and low-developed interventional radiology service according the frequency of stage adjusted interventional radiology procedure usage (< 15%, > 15%). Kaplan-Meier and Cox regression were used for survival and hazard ratios (HR) analyses. RESULTS: Only 1,730 patients had assessed any primary treatment option, 16.5 % (285) were treated by TACE. Median of survival were significantly different in regions with well and low developed interventional radiology service for whole study population (13.2 vs. 6.5 months, p < 0.001), patients treated in regions with well-developed interventional radiology service had lower risk of death during treatment (HR 0.73; 0.66-0.81). The patient treated by TACE had median of survival 15.8 months (13.5-18.1), while the survival was not significantly different in region groups. CONCLUSION: The usage of anticancer therapies based on interventional radiology procedures is a huge factor influences the survival of HCC patient according population-based data. Studies gathering data from cancer register databases can provide further information on treatment effectiveness. This work was created at Masaryk University in the project „Oncological radiological interventions and their benefit in complex oncological treatment, comparison of dedicated oncological treatment results data of the Czech republic II“ (MUNI/A/1574/2018), supported by Ministry of Education, Youth and Sports. This publication was additionally suported by Ministry of Health grant No. 15-32484A. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 1. 3. 2019 Accepted: 4. 3. 2019.