Aycock Kenneth N, Campelo Sabrina N, Davalos Rafael V
Bioelectromechanical Systems Lab, Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Virginia Tech Department of Biomedical Engineering and Mechanics, 320 Kelly Hall, 325 Stanger Street, Blacksburg, VA 24061.
J Heat Transfer. 2022 Mar 1;144(3):031206. doi: 10.1115/1.4053199. Epub 2022 Jan 18.
Irreversible electroporation (IRE), also referred to as nonthermal pulsed field ablation (PFA), is an attractive focal ablation modality for solid tumors and cardiac tissue due to its ability to destroy aberrant cells with limited disruption of the underlying tissue architecture. Despite its nonthermal cell death mechanism, application of electrical energy results in Joule heating that, if ignored, can cause undesired thermal injury. Engineered thermal mitigation (TM) technologies including phase change materials (PCMs) and active cooling (AC) have been reported and tested as a potential means to limit thermal damage. However, several variables affect TM performance including the pulsing paradigm, electrode geometry, PCM composition, and chosen active cooling parameters, meaning direct comparisons between approaches are lacking. In this study, we developed a computational model of conventional bipolar and monopolar probes with solid, PCM-filled, or actively cooled cores to simulate clinical IRE treatments in pancreatic tissue. This approach reveals that probes with integrated PCM cores can be tuned to drastically limit thermal damage compared to existing solid probes. Furthermore, actively cooled probes provide additional control over thermal effects within the probe vicinity and can altogether abrogate thermal damage. In practice, such differences in performance must be weighed against the increased time, expense, and effort required for modified probes compared to existing solid probes.
不可逆电穿孔(IRE),也被称为非热脉冲场消融(PFA),是一种针对实体肿瘤和心脏组织具有吸引力的局部消融方式,因为它能够在对底层组织结构破坏有限的情况下破坏异常细胞。尽管其细胞死亡机制是非热的,但电能的应用会导致焦耳热,如果被忽视,可能会造成不期望的热损伤。包括相变材料(PCM)和主动冷却(AC)在内的工程热缓解(TM)技术已被报道并作为限制热损伤的潜在手段进行了测试。然而,几个变量会影响TM性能,包括脉冲模式、电极几何形状、PCM成分和所选的主动冷却参数,这意味着缺乏不同方法之间的直接比较。在本研究中,我们开发了一种传统双极和单极探针的计算模型,其核心为实心、填充PCM或主动冷却,以模拟胰腺组织中的临床IRE治疗。该方法表明,与现有的实心探针相比,集成PCM核心的探针可以进行调整以大幅限制热损伤。此外,主动冷却探针可对探针附近的热效应提供额外控制,并可完全消除热损伤。在实际应用中,与现有的实心探针相比,这种性能差异必须与改进探针所需增加的时间、费用和工作量相权衡。