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.


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.
Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan. itoi@tokyo-med.ac.jp
Takao
T
Itoi
Hiroyuki
H
Isayama
Atsushi
A
Sofuni
Fumihide
F
Itokawa
Miho
M
Tamura
Yusuke
Y
Watanabe
Fuminori
F
Moriyasu
Michel
M
Kahaleh
Nagy
N
Habib
Toshitaka
T
Nagao
Tomohisa
T
Yokoyama
Kazuhiko
K
Kasuya
Hiroshi
H
Kawakami
D000818:Animals; D001652:Bile Ducts; D017115:Catheter Ablation / Q000295:instrumentation*; D004724:Endoscopy; D066298:In Vitro Techniques; D008099:Liver / Q000601:surgery*; D015607:Stents; D034421:Sus scrofa