Evaluation of effects of a novel endoscopically applied radiofrequency ablation biliary catheter using an ex-vivo pig liver.

BACKGROUND: The effects of ablation with various settings of powers and times using a newly developed radiofrequency (RF) ablation device, the Habib™ EndoHPB catheter, are not well known. In the present study, we examined the effects of a novel RF ablation catheter using resected fresh pig livers and evaluated the macro- and microscopic effects of RF ablation under various conditions.
MATERIALS AND METHODS: The RF application was performed step by step at 5, 10, 15, and 20 W power and 60, 90, 120 s, respectively. Macroscopic and microscopic findings of the ablation area were evaluated at each setting.
RESULTS: The mean lengths of the short axis of the ablation area at 10 W and 60, 90 and 120 s were 8.0 ± 1.0, 8.3 ± 1.2, and 9.7 ± 0.6 mm, respectively. The mean lengths of the long axis at 10 W power and 60, 90 and 120 s were 20.3 ± 0.6, 21.3 ± 1.6, and 28.3 ± 2.1 mm, respectively. Although the lengths of the short and long axes at 5 and 10 W increased gradually with power, there were no obvious differences in either short or long axis lengths between 15 and 20 W. Of all the settings, only at 5 W and 60 and 90 s did the long axis of the ablation show separate areas around the 2 ring electrodes.
CONCLUSIONS: Although other sequelae including hemorrhage, pancreatitis, acute inflammatory changes, perforation and late fibrosis could not be investigated in our ex-vivo pig model, our study clarified the relationship between ablation powers and times and the effects concerning depth and longitudinal spread of ablation. Although the clinical ablation setting at 7-10 W power and 2 min is suitable, ultimately the ablation power and time should be adjusted according to the size of masses using examples from the present results.