Experimental study of single-pin puncture asymmetrical hydroablation using a conformational radiofrequency ablation electrode inex vivoox liver

Abstract

The aim of this study was to evaluate the feasibility of single-pin puncture asymmetrical hydroablation in liver using the multipole cluster conformable radiofrequency ablation electrode. The conformable electrode used in this study consists of both a main electrode in a central cannula and a circle of subelectrodes comprising two groups of six subelectrodes located on opposite sides (A and B) of the circle. The two subelectrode groups can be extended to different lengths independently of one another, resulting in asymmetrical shapes. Ablation experiments were performed using ex vivo ox liver. The experiments included six groups based on six potential electrode deployments in which the subelectrodes on sides A and B were fully extended, half extended or fully retracted. After ablation, the transverse diameters of the resulting necrotic tissue from sides A and B were measured. The experiment was conducted in 12 separate sites for each group. When the subelectrodes were arranged symmetrically (either fully extended or half extended on both sides), the mean transverse diameter of necrotic tissue was similar for both sides A and B. When the subelectrodes were arranged asymmetrically, the fully extended side showed a significantly greater mean transverse diameter of necrotic tissue than the half extended or fully retracted side. In this study, the WHK 3-8-4 multipole cluster conformable radiofrequency ablation electrode was able to produce both symmetrical and asymmetrical necrotic tissue patterns in the liver. The size and shape of the ablation can be altered by both withdrawing and extending the subelectrodes to different lengths.