Parametric evaluation of impedance curve in radiofrequency ablation: A quantitative description of the asymmetry and dynamic variation of impedance in bovine ex vivo model.

Radiofrequency ablation (RFA) is a treatment for liver tumors with advantages over the traditional treatment of surgical resection. This procedure has the shortest recovery time in early stage tumors. The objective of this study is to parameterize the impedance curve of the RFA procedure in an ex vivo model by defining seven parameters (t1/2, tminimum, tend, Zinitial, Z1/2, Zminimum and Zend).

Roll-Off Displacement in Ex Vivo Experiments of RF Ablation With Refrigerated Saline Solution and Refrigerated Deionized Water.

Objective: The recurrence rate in the treatment of liver tumors using radio frequency ablation (RFA) is often related to incomplete tissue necrosis and consequently the limitation in the ablation volume. This paper proposes an ablation protocol combined with the infusion of saline solution and deionized water aiming at achieving a time displacement in the roll-off occurrence and consequently increasing the volume of ablation.

Methods: An infusion of saline solution and deionized water at 5 and 23  C was performed to evaluate the influence of these liquids on the RFA procedure in ex vivo bovine liver pieces.