UNC - NCSU Joint Department of Biomedical Engineering, Raleigh, NC, USA.
Ann Biomed Eng. 2021 Jan;49(1):191-202. doi: 10.1007/s10439-020-02524-x. Epub 2020 May 15.
Thermal tissue injury is an unintended consequence in current irreversible electroporation treatments due to the induction of Joule heating during the delivery of high voltage pulsed electric fields. In this study active temperature control measures including internal electrode cooling and dynamic energy delivery were investigated as a process for mitigating thermal injury during treatment. Ex vivo liver was used to examine the extent of thermal injury induced by 5000 V treatments with delivery rates up to five times faster than current clinical practice. Active internal cooling of the electrode resulted in a 36% decrease in peak temperature vs. non-cooled control treatments. A temperature based feedback algorithm (electro-thermal therapy) was demonstrated as capable of maintaining steady state tissue temperatures between 30 and 80 °C with and without internal electrode cooling. Thermal injury volumes of 2.6 cm were observed for protocols with 60 °C temperature set points and electrode cooling. This volume reduced to 1.5 and 0.1 cm for equivalent treatments with 50 °C and 40 °C set points. Finally, it was demonstrated that the addition of internal electrode cooling and active temperature control algorithms reduced ETT treatment times by 84% (from 343 to 54 s) vs. non-cooled temperature control strategies with equivalent thermal injury volumes.
热组织损伤是当前不可逆电穿孔治疗中一种意外的后果，这是由于在施加高压脉冲电场时产生焦耳加热。在这项研究中，主动温度控制措施，包括内部电极冷却和动态能量传递，被研究作为减轻治疗过程中热损伤的一种方法。离体肝被用于检查在 5000 V 治疗下诱导的热损伤程度，其输送速度比当前临床实践快五倍。与非冷却对照治疗相比，主动内部电极冷却使峰值温度降低了 36%。基于温度的反馈算法（电热治疗）被证明能够在有和没有内部电极冷却的情况下将组织温度稳定在 30 到 80°C 之间。对于具有 60°C 温度设定点和电极冷却的协议，观察到的热损伤体积为 2.6 cm。对于具有 50°C 和 40°C 设定点的等效治疗，该体积减少到 1.5 和 0.1 cm。最后，证明了内部电极冷却和主动温度控制算法的添加将 ETT 治疗时间减少了 84%（从 343 秒减少到 54 秒），而具有等效热损伤体积的非冷却温度控制策略则没有。
