Maor Elad, Rubinsky Boris
Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA 94720, USA.
J Biomech Eng. 2010 Mar;132(3):031008. doi: 10.1115/1.4001035.
Tissue ablation finds an increasing use in modern medicine. Nonthermal irreversible electroporation (NTIRE) is a biophysical phenomenon and an emerging novel tissue ablation modality, in which electric fields are applied in a pulsed mode to produce nanoscale defects to the cell membrane phospholipid bilayer, in such a way that Joule heating is minimized and thermal damage to other molecules in the treated volume is reduced while the cells die. Here we present a two-dimensional transient finite element model to simulate the electric field and thermal damage to the arterial wall due to an endovascular NTIRE novel device. The electric field was used to calculate the Joule heating effect, and a transient solution of the temperature is presented using the Pennes bioheat equation. This is followed by a kinetic model of the thermal damage based on the Arrhenius formulation and calculation of the Henriques and Moritz thermal damage integral. The analysis shows that the endovascular application of 90, 100 mus pulses with a potential difference of 600 V can induce electric fields of 1000 V/cm and above across the entire arterial wall, which are sufficient for irreversible electroporation. The temperature in the arterial wall reached a maximum of 66.7 degrees C with a pulse frequency of 4 Hz. Thermal damage integral showed that this protocol will thermally damage less than 2% of the molecules around the electrodes. In conclusion, endovascular NTIRE is possible. Our study sets the theoretical basis for further preclinical and clinical trials with endovascular NTIRE.
组织消融在现代医学中的应用越来越广泛。非热不可逆电穿孔(NTIRE)是一种生物物理现象,是一种新兴的组织消融方式,通过以脉冲模式施加电场,在细胞膜磷脂双分子层上产生纳米级缺陷,从而将焦耳热降至最低,并减少对治疗区域内其他分子的热损伤,同时使细胞死亡。在此,我们提出一个二维瞬态有限元模型,以模拟一种血管内NTIRE新型装置对动脉壁造成的电场和热损伤。利用电场来计算焦耳热效应,并使用彭尼斯生物热方程给出温度的瞬态解。随后基于阿伦尼乌斯公式建立热损伤动力学模型,并计算亨里克斯和莫里茨热损伤积分。分析表明,血管内施加90、100微秒脉冲,电位差为600 V时,可在整个动脉壁上诱导出1000 V/cm及以上的电场,足以实现不可逆电穿孔。动脉壁温度在脉冲频率为4 Hz时最高达到66.7摄氏度。热损伤积分表明,该方案对电极周围分子的热损伤小于2%。总之,血管内NTIRE是可行的。我们的研究为进一步开展血管内NTIRE的临床前和临床试验奠定了理论基础