School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia.
School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia; Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor, Malaysia.
Comput Biol Med. 2021 Jan;128:104112. doi: 10.1016/j.compbiomed.2020.104112. Epub 2020 Nov 11.
Infusion of saline prior to radiofrequency ablation (RFA) is known to enlarge the thermal coagulation zone. The abundance of ions in saline elevate the electrical conductivity of the saline-saturated region. This promotes greater electric current flow inside the tissue, which increases the amount of RF energy deposition and subsequently enlarges the coagulation zone. In theory, infusion of higher concentration of saline should lead to larger coagulation zone due to the greater number of ions. Nevertheless, existing studies on the effects of concentration on saline-infused RFA have been conflicting, with the exact role of saline concentration yet to be fully elucidated. In this paper, computational models of saline-infused RFA were developed to investigate the role of saline concentration on the outcome of saline-infused RFA. The elevation in tissue electrical conductivity was modelled using the microscopic mixture model, while RFA was modelled using the coupled dual porosity-Joule heating model. Results obtained indicated that the presence of a concentration threshold to which no further elevation in tissue electrical conductivity and enlargement in thermal coagulation can occur. This threshold was determined to be at 15% NaCl. Analysis of the Joule heating distribution revealed the presence of a secondary Joule heating site located along the interface between wet and dry tissue. This secondary Joule heating was responsible for the enlargement in coagulation volume and its rapid growth phase during ablation.
在射频消融 (RFA) 之前输注生理盐水已知会扩大热凝固区。盐水中离子的丰富度会提高盐水饱和区域的电导率。这促进了组织内更大的电流流动，从而增加了射频能量的沉积量，并随后扩大了凝固区。理论上，由于离子数量的增加，输注更高浓度的盐水应该会导致更大的凝固区。然而，关于浓度对盐水输注 RFA 影响的现有研究存在冲突，盐水浓度的确切作用尚未完全阐明。在本文中，开发了盐水输注 RFA 的计算模型，以研究盐水浓度对盐水输注 RFA 结果的影响。使用微观混合模型模拟组织电导率的升高，而使用耦合双孔隙焦耳加热模型模拟 RFA。结果表明，存在一个浓度阈值，超过该阈值后，组织电导率和热凝固的增大不会再发生。该阈值被确定为 15%的 NaCl。对焦耳加热分布的分析揭示了在湿组织和干组织之间的界面处存在一个次要的焦耳加热部位。这个次要的焦耳加热是导致凝固体积增大及其在消融过程中的快速增长阶段的原因。
