Irreversible electroporation: Treatment effect is susceptible to local environment and tissue properties

Eliel Ben-David*, Muneeb Ahmed, Mohammad Faroja, Marwan Moussa, Ayelet Wandel, Jacob Sosna, Liat Appelbaum, Isaac Nissenbaum, S. Nahum Goldberg

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

99 Scopus citations

Abstract

Purpose: To study the effects of the surrounding electrical microenvironment and local tissue parameters on the electrical parameters and outcome of irreversible electroporation (IRE) ablation in porcine muscle, kidney, and liver tissue. Materials and Methods: Animal Care and Use Committee approval was obtained, and National Institutes of Health guidelines were followed. IRE ablation (n = 90) was applied in muscle (n = 44), kidney (n = 28), and liver (n = 18) tissue in 18 pigs. Two electrodes with tip exposure of 1.5-2 cm were used at varying voltages (1500-3000 V), pulse repetitions (n = 70-100), pulse length (70-100 μsec), and electrode spacing (1.5-2 cm). In muscle tissue, electrodes were placed exactly parallel, in plane, or perpendicular to paraspinal muscle fibers; in kidney tissue, in the cortex or adjacent to the renal medulla; and in liver tissue, with and without metallic or plastic plates placed 1-2 cm from electrodes. Ablation zones were determined at gross pathologic (90-120 minutes after IRE) and immunohistopathologic examination (6 hours after) for apoptosis and heat-shock protein markers. Multivariate analysis of variance with multiple comparisons and/or paired t tests and regression analysis were used for analysis. Results: Mean (6 standard deviation) ablation zones in muscle were 6.2 cm ± 0.3 × 4.2 cm ± 0.3 for parallel electrodes and 4.2 cm ± 0.8 × 3.0 cm ± 0.5 for in-plane application. Perpendicular orientation resulted in a cross-shaped zone. Orientation significantly affected IRE current applied (28.5-31.7A for parallel, 29.5-39.7A for perpendicular; P = .003). For kidney cortex, ovoid zones of 1.5 cm 6 0.1 × 0.5 cm ± 0.0 to 2.5 cm ± 0.1 × 1.3 cm ± 0.1 were seen. Placement of electrodes less than 5 mm from the medullary pyramids resulted in treatment effect arcing into the collecting system. For liver tissue, symmetric 2.7 cm ± 0.2 × 1.4 cm ± 0.3 coagulation areas were seen without the metallic plate but asymmetric coagulation was seen with the metallic plate. Conclusion: IRE treatment zones are sensitive to varying electrical conductivity in tissues. Electrode location, orientation, and heterogeneities in local environment must be considered in planning ablation treatment.

Original languageAmerican English
Pages (from-to)738-747
Number of pages10
JournalRadiology
Volume269
Issue number3
DOIs
StatePublished - Dec 2013
Externally publishedYes

Fingerprint

Dive into the research topics of 'Irreversible electroporation: Treatment effect is susceptible to local environment and tissue properties'. Together they form a unique fingerprint.

Cite this