Double radiofrequency ablation is more extensive with a spherical zone shape compared to single ablation in a pig liver model.

Objective: We compared the duration of ablation and the area of coagulation necrosis between a single ablation method (SAM) and a double ablation method (DAM) with a 'multitined expandable' electrode (LeVeen 2 cm) for radiofrequency ablation (RFA) using pig liver.

Method: In the SAM group, ablation was completed after the first roll-off. In the DAM group, an additional ablation was performed to achieve a second roll-off.

Influence of large intrahepatic blood vessels on the gross and histological characteristics of lesions produced by radiofrequency ablation in a pig liver model.

Aims: To determine whether the presence of large intrahepatic blood vessels (>/=3 mm) affect radiofrequency (RF)-induced coagulation necrosis, the gross and histological characteristics of RF-ablated areas proximal to or around vessels were examined in normal pig livers.

Methods: An RF ablation treatment using a two-stepwise extension technique produced 12 lesions: six contained vessels (Group A), and the other six were localized around vessels (Group B).

Results: Gross examination revealed that the longest and shortest diameters of the ablated lesions were significantly larger in Group B than in Group A.