Purpose

To analyse the feasibility of directional ablation using a multi-tine electrode.

Methods

A multi-tine electrode capable of operating in multipolar mode has been used to study the directional ablation. In addition to the basic design, similar to commercially available FDA approved multi-tine electrode, tines have been insulated from each other inside the probe base and tip using a thin insulating material of thickness 0.25 mm. A cylindrical single-compartment model of size 6 cm × 6 cm has been used to model normal liver tissue. The temperature-controlled radiofrequency ablation has been employed to maintain the tine-tips at different temperatures. Electro-thermal simulations have been performed by using a commercial multi-physics software package based on finite element methods. To make this study feasible a new approach to predict the ablations have been proposed and used in this study.

Results

Asymmetric ablation zone with up to 5 mm difference in ablation boundary between the intended and non-intended direction has been observed along the transverse direction. Reduction in ablation up to 5 mm along the axial direction in comparison to the monopolar mode has also been observed.

Conclusion

Multi-tine electrode modified to operate in multipolar mode can create directional ablations of different shapes and can be used to target position and shape specific tumours.

中文翻译：

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使用在多极模式下运行的多齿电极进行射频消融的定向消融：使用有限状态集的计算机模拟研究

目的

分析使用多齿电极定向消融的可行性。

方法

能够在多极模式下运行的多齿电极已用于研究定向消融。除了基本设计之外，类似于市售的FDA批准的多齿电极，齿已在探针基座和尖端内部使用厚度为0.25 mm的薄绝缘材料彼此绝缘。大小为6 cm×6 cm的圆柱形单室模型已用于模拟正常肝组织。温度受控的射频消融已被用于将尖齿尖端保持在不同的温度。电热模拟已通过使用基于有限元方法的商业多物理软件包进行。为使这项研究可行，提出了一种新的预测消融的方法，并在本研究中使用。

结果

沿横向观察到在预期方向和非预期方向之间的消融边界差异最大为5 mm的非对称消融区域。还已经观察到与单极模式相比，沿轴向方向的剥蚀减少了多达5 mm。

结论

修改为可在多极模式下运行的多齿电极可产生不同形状的定向消融，并可用于靶向特定位置和特定形状的肿瘤。