The effects of irreversible electroporation on tissue, in vivo

Abstract

Irreversible electroporation (IRE) is a new tissue ablation technique in which micro to millisecond electrical pulses are delivered to undesirable tissue to produce cell necrosis through irreversible cell membrane permeabilization, which leads to changes in the cell homeostasis. A unique attribute of IRE is that it affects only the cell membrane and no other structure in the tissue. This report summarizes findinsg on IRE tissue ablation methodology in the pig liver, and provides short results on short and long term histopathology of IRE ablated tissue and discusses the clinical implications of the findings. Among the major findings are the observation that cell ablation occurs to the margin of the treated lesion with several cells thickness resolution. There appears to be complete ablation to the margin of blood vessels without compromising the functionality of the blood vessels, which suggests that IRE is a promising method for treatment of tumors near blood vessels (a significant challenge with current ablation methods). Consistent with the mechanism of action of IRE on the cell membrane only, we show that the structure of bile ducts, blood vessels and connective tissues remains intact with IRE. We report extremely rapid resolution of lesions, within two weeks, which is consistent with retention of vasculature. We also document tentative evidence for an immunological response to the ablated tissue. Last, we show that mathematical predictions with the Laplace equation can be used in treatment planning. The IRE tissue ablation technique, as characterized in this report, may become an important new tool in the surgeon armamentarium.