The delayed effects of irreversible electroporation ablation on nerves.

Abstract

OBJECTIVE: To evaluate the delayed effects of irreversible electroporation (IRE) ablation on nerves. METHODS: 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). RESULTS: 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. CONCLUSION: 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.