The delayed effects of irreversible electroporation ablation on nerves

Abstract

To evaluate the delayed effects of irreversible electroporation (IRE) ablation on nerves. The study was approved by the institutional animal care and use committee. CT-guided IRE-ablation (electric field per distance, 1,500 V/cm; pulse length, 70 μs; number of pulses, 90) of 6 sciatic nerves was performed in 6 pigs that were euthanized 2 months after ablation. The sciatic nerves were harvested immediately after euthanasia for histopathological evaluation. Sections from selected specimens were stained with haematoxylin and eosin (H&E), Masson's trichrome (MT) method for collagen, and immunohistochemistry was performed for S100 and neurofilaments (markers for Schwann cells and axons, respectively). All nerves showed a preserved endoneural architecture and presence of numerous small calibre axons associated with Schwann cell hyperplasia, consistent with axonal regeneration. A fibrous scar was observed in the adjacent muscle tissue, confirming ablation at the site examined. After IRE-ablation of nerves, the preservation of the architecture of the endoneurium and the proliferation of Schwann cells may enable axonal regeneration as demonstrated after 2 months in this study.