Electrical Field and Temperature Model of Nonthermal Irreversible Electroporation in Heterogeneous Tissues

Abstract

Nonthermal irreversible electroporation (NTIRE) is a new minimally invasive surgical technique that is part of the emerging field of molecular surgery, which holds the potential to treat diseases with unprecedented accuracy. NTIRE utilizes electrical pulses delivered to a targeted area, producing irreversible damage to the cell membrane. Because NTIRE does not cause thermal damage, the integrity of all other molecules, collagen, and elastin in the targeted area is preserved. Previous theoretical studies have only examined NTIRE in homogeneous tissues; however, biological structures are complex collections of diverse tissues. In order to develop electroporation as a precise treatment in clinical applications, realistic models are necessary. Therefore, the purpose of this study was to refine electroporation as a treatment by examining the effect of NTIRE in heterogeneous tissues of the prostate and breast. This study uses a two-dimensional finite element solution of the Laplace and bioheat equations to examine the effects of heterogeneities on electric field and temperature distribution. Three different heterogeneous structures were taken into account: nerves, blood vessels, and ducts. The results of this study demonstrate that heterogeneities significantly impact both the temperature and electrical field distribution in surrounding tissues, indicating that heterogeneities should not be neglected. The results were promising. While the surrounding tissue experienced a high electrical field, the axon of the nerve, the interior of the blood vessel, and the ducts experienced no electrical field. This indicates that blood vessels, nerves, and lactiferous ducts adjacent to a tumor treated with electroporation will survive, while the cancerous lesion is ablated. This study clearly demonstrates the importance of considering heterogeneity in NTIRE applications.

Feasibility of a Modified Biopsy Needle for Irreversible Electroporation Ablation and Periprocedural Tissue Sampling

“…The shape and extent of this isoline represented the expected ablation zone, which was used to compare the effects of variations in the electrode geometry between the treatment cohorts. Simulation techniques reported here mirror prior work by Daniels et al[18] and Davalos et al[19]. …”

Elimination of Purkinje Fibers by Electroporation Reduces Ventricular Fibrillation Vulnerability

“…We did not formally evaluate ventricular function with echocardiography or strain imaging or perform pathological analysis to assess the impact of IRE. In addition, although IRE is considered nonthermal60, 61, 62 at higher voltages (specifically, 2500 V), we cannot rule out the possibility of a local increase in temperature. Another major limitation also relates to the different conduction properties between the Krebs buffer as opposed to blood, and whether this can be extrapolated to the human is unclear and merits further study.…”

Planning Irreversible Electroporation in the Porcine Kidney: Are Numerical Simulations Reliable for Predicting Empiric Ablation Outcomes?

“…This geometry was then discretized into a FEM mesh, and numerically solved for determining the electric field distribution resulting from the voltage applied between the electrodes. Detailed information on the construction of the model and numerical simulation can be found in prior work[18, 19, 22]. …”