Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Nov 10, 2015; 7(16): 1222-1229
Published online Nov 10, 2015. doi: 10.4253/wjge.v7.i16.1222
Optimization of the generator settings for endobiliary radiofrequency ablation
Maximilien Barret, Sarah Leblanc, Ariane Vienne, Alexandre Rouquette, Frederic Beuvon, Stanislas Chaussade, Frederic Prat
Maximilien Barret, Sarah Leblanc, Ariane Vienne, Stanislas Chaussade, Frederic Prat, Department of Gastroenterology, Cochin Hospital, 75014 Paris, France
Maximilien Barret, Sarah Leblanc, Ariane Vienne, Alexandre Rouquette, Frederic Beuvon, Stanislas Chaussade, Frederic Prat, Faculty of Medecine, Paris-Descartes University, 75005 Paris, France
Alexandre Rouquette, Frederic Beuvon, Department of Pathology, Cochin Hospital, 75014 Paris, France
Author contributions: Barret M analysed the data and drafted the manuscript; Leblanc S, Vienne A and Prat F conceived and performed the animal experiments; Rouquette A and Beuvon F preformed the histologic study; Chaussade S provided critical revision related to the intellectual content of the manuscript; all authors approved the final version of the article to be published.
Institutional review board statement: Ethical permission from our institutional review board was obtained for participation in the study.
Institutional animal care and use committee statement: The study received approval from our animal care and use committee.
Conflict-of-interest statement: To the best of our knowledge, no conflict of interest exists.
Data sharing statement: Technical appendix, statistical code, and dataset are available from the corresponding author at frederic.prat@aphp.fr.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Frederic Prat, MD, PhD, Department of Gastroenterology, Cochin Hospital, 27, rue du Faubourg St Jacques, 75014 Paris, France. frederic.prat@cch.aphp.fr
Telephone: +33-1-58411945 Fax: +33-1-58411965
Received: February 27, 2015
Peer-review started: March 2, 2015
First decision: June 18, 2015
Revised: July 21, 2015
Accepted: September 7, 2015
Article in press: September 8, 2015
Published online: November 10, 2015
Processing time: 257 Days and 14.2 Hours
Abstract

AIM: To determine the optimal generator settings for endobiliary radiofrequency ablation.

METHODS: Endobiliary radiofrequency ablation was performed in live swine on the ampulla of Vater, the common bile duct and in the hepatic parenchyma. Radiofrequency ablation time, “effect”, and power were allowed to vary. The animals were sacrificed two hours after the procedure. Histopathological assessment of the depth of the thermal lesions was performed.

RESULTS: Twenty-five radiofrequency bursts were applied in three swine. In the ampulla of Vater (n = 3), necrosis of the duodenal wall was observed starting with an effect set at 8, power output set at 10 W, and a 30 s shot duration, whereas superficial mucosal damage of up to 350 μm in depth was recorded for an effect set at 8, power output set at 6 W and a 30 s shot duration. In the common bile duct (n = 4), a 1070 μm, safe and efficient ablation was obtained for an effect set at 8, a power output of 8 W, and an ablation time of 30 s. Within the hepatic parenchyma (n = 18), the depth of tissue damage varied from 1620 μm (effect = 8, power = 10 W, ablation time = 15 s) to 4480 μm (effect = 8, power = 8 W, ablation time = 90 s).

CONCLUSION: The duration of the catheter application appeared to be the most important parameter influencing the depth of the thermal injury during endobiliary radiofrequency ablation. In healthy swine, the currently recommended settings of the generator may induce severe, supratherapeutic tissue damage in the biliary tree, especially in the high-risk area of the ampulla of Vater.

Keywords: Endobiliary radiofrequency ablation; Biliary stricture; Ampullary tumor; Endoscopic retrograde cholangio-pancreatography

Core tip: The use of endoscopic retrograde cholangio-pancreatography-guided endobiliary radiofrequency ablation is expanding quickly, from the clearing of obstructed biliary stents in malignant biliary stenoses, to the treatment of benign biliary strictures. However, the morbidity associated with this procedure remains high, of course because of the severity of the disease treated, but also possibly due to suboptimal generator settings. Therefore, we conducted an animal study in live pigs. We report novel data, highlighting the importance of the effect setting on the generator, and suggesting specific settings for radiofrequency ablation in the ampulla of Vater.