ORIGINAL ARTICLE Evaluation of effects of a novel endoscopically applied radiofrequency ablation biliary catheter using an ex-vivo pig liver Takao Itoi • Hiroyuki Isayama • Atsushi Sofuni • Fumihide Itokawa • Miho Tamura • Yusuke Watanabe • Fuminori Moriyasu • Michel Kahaleh • Nagy Habib • Toshitaka Nagao • Tomohisa Yokoyama • Kazuhiko Kasuya • Hiroshi Kawakami Published online: 25 October 2011 Ó Japanese Society of Hepato-Biliary-Pancreatic Surgery and Springer 2011 Abstract Background The effects of ablation with various settings of powers and times using a newly developed radiofre- quency (RF) ablation device, the Habib TM 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 per- formed 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 hemor- rhage, pancreatitis, acute inflammatory changes, perfora- tion 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 con- cerning 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. T. Itoi (&) Á A. Sofuni Á F. Itokawa Á F. Moriyasu Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan e-mail: itoi@tokyo-med.ac.jp H. Isayama Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan M. Tamura Á Y. Watanabe Tokyo Medical University, Tokyo, Japan M. Kahaleh Department of Gastroenterology, Well Cornell Medical Center, New York, NY, USA N. Habib Department of Surgery and Cancer, Imperial College London, London, UK T. Nagao Department of Pathology, Tokyo Medical University, Tokyo, Japan T. Yokoyama Department of Clinical Oncology, Tokyo Medical University, Tokyo, Japan K. Kasuya Third Department of Surgery, Tokyo Medical University, Tokyo, Japan H. Kawakami Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Sapporo, Japan 123 J Hepatobiliary Pancreat Sci (2012) 19:543–547 DOI 10.1007/s00534-011-0465-7