Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
Radiology. 2011 Aug;260(2):421-7. doi: 10.1148/radiol.11103505. Epub 2011 Jun 3.
To evaluate whether irreversible electroporation (IRE) has the potential to damage nerves in a porcine model and to compare histopathologic findings after IRE with histopathologic findings after radiofrequency ablation (RFA).
This study was approved by the institutional animal care and use committee. Computed tomography (CT)-guided IRE of 11 porcine sciatic nerves was performed in nine pigs, and histopathologic analysis was performed on the day of ablation or 3, 6, or 14 days after ablation. In addition, acute RFA of six porcine sciatic nerves was performed in six pigs that were harvested on the day of ablation. All nerves and associated muscles and tissues were assessed for histopathologic findings consistent with athermal or thermal injury, respectively, such as axonal swelling, axonal fragmentation and loss, Wallerian degeneration, inflammatory infiltrates, Schwann cell proliferation, and coagulative necrosis. The percentage of fascicles affected was recorded.
All nerves had an axonal injury. The percentage of affected nerve fascicles after IRE was 50%-100%. Axonal swelling and perineural inflammatory infiltrates were detectable at every time point after ablation. Axonal fragmentation and loss, macrophage infiltration, and Schwann cell proliferation were found 6 and 14 days after ablation. Distal Wallerian axonal degeneration was observed 14 days after ablation. The endoneurium and perineurium architecture remained intact in all cases. RFA specimens at the day of ablation revealed acute coagulative necrosis associated with intense basophilic staining of extracellular matrix, including collagen of the perineurium and epineurium consistent with thermal injury.
IRE has the potential to damage nerves and may result in axonal swelling, fragmentation, and distal Wallerian degeneration. However, preservation of endoneurium architecture and proliferation of Schwann cells may suggest the potential for axonal regeneration. In contrast, RFA leads to thermal nerve damage, causing protein denaturation, and suggests a much lower potential for regeneration.
评估不可逆电穿孔（IRE）是否有可能在猪模型中损伤神经，并比较IRE 后的组织病理学发现与射频消融（RFA）后的组织病理学发现。
本研究获得机构动物护理和使用委员会批准。在 9 只猪中进行了 11 个坐骨神经的 CT 引导下 IRE，并在消融当天或消融后 3、6 或 14 天进行了组织病理学分析。此外，在 6 只猪中进行了 6 个坐骨神经的急性 RFA，这些猪在消融当天进行了收获。所有神经及其相关的肌肉和组织均评估了各自的与非热或热损伤一致的组织病理学发现，如轴突肿胀、轴突碎裂和丢失、Wallerian 变性、炎症浸润、施万细胞增殖和凝固性坏死。记录受影响的神经束的百分比。
所有神经均有轴突损伤。IRE 后受影响的神经束百分比为 50%-100%。消融后每个时间点均可检测到轴突肿胀和神经周围炎症浸润。消融后 6 天和 14 天发现轴突碎裂和丢失、巨噬细胞浸润和施万细胞增殖。消融后 14 天观察到远端 Wallerian 轴突变性。所有情况下，神经内膜和神经外膜结构均保持完整。消融当天的 RFA 标本显示与细胞外基质（包括神经外膜和神经内膜的胶原）强烈嗜碱性染色相关的急性凝固性坏死，提示热损伤。
IRE 有可能损伤神经，并可能导致轴突肿胀、碎裂和远端 Wallerian 变性。然而，神经内膜结构的保留和施万细胞的增殖可能提示有轴突再生的潜力。相比之下，RFA 导致热神经损伤，引起蛋白质变性，提示再生的潜力要低得多。
