New methods
Experimental endoscopy
Development of a swine bile duct dilation model using endoclips or a detachable snare under cap-assisted endoscopy

https://doi.org/10.1016/j.gie.2014.03.036Get rights and content

Background

A reproducible large animal model of bile duct dilation for the preclinical testing of new biliary devices and for training endoscopic biliary intervention is required. Surgical methods are mainly used to produce large animal models of biliary obstruction.

Objective

To develop an animal model of bile duct dilation using endoscopic methods and to compare the merits of endoclips and detachable snares for the obstruction of major duodenal papillae.

Design

Proof of concept experimental study.

Settings

Animal laboratory.

Interventions

Endoscopic clipping of the major duodenal papilla or closure of the major duodenal papilla with a detachable snare.

Main Outcome Measurements

Feasibility, efficacy, and safety of endoscopic methods to develop swine models with bile duct dilation were estimated by degree of dilation at the common bile duct (CBD), intrahepatic duct (IHD), and gallbladder (GB).

Results

All animals survived until the end of the experiment. Clipping of the major duodenal papilla and closure of the major duodenal papilla with a detachable snare were performed successfully in all swine. No technical difficulty or adverse event occurred during the procedures. Biliary dilatations in all animals were observed on cholangiograms (mean Δ% of postprocedural and preprocedural maximum diameters: CBD, 301%; IHD, 223.5%; GB, 34.8%). Degree of bile duct dilation in the snare group tended to be greater (CBD, 367.3%; IHD, 298.3%; GB, 47.8%) than in the endoclip group (CBD, 234.7%; IHD, 148.7%; GB, 21.8%), but this difference was not significant. An analysis of degrees of dilation according to location in the biliary tree showed that the GB was not dilated as well as the CBD or IHD.

Limitations

Animal model.

Conclusion

The 2 endoscopic procedures described are effective and safe for creating a swine model of bile duct dilation and could be helpful for training biliary intervention and for endoscopic biliary studies.

Introduction

ERCP has become the first-line procedure for the management of biliary drainage. However, ERCP failure can occur in the setting of an altered bile duct anatomy. During the past few years, EUS-guided biliary drainage has evolved in such a way that in experienced hands it has become an attractive treatment method after failed ERCP.1 However, mastering EUS-BD based on clinical experience is difficult because of the amount of experience required. Furthermore, many new devices have been developed for the treatment of bile duct obstruction.2, 3 Therefore, we considered that an animal model of bile duct obstruction was required to train individuals how to use new devices and as an aid for device development and evaluation.4, 5 The purpose of this study was to determine the feasibility of endoclips or of a detachable snare to obstruct major duodenal papilla for the development of bile duct dilation in an animal model.

Take-home Message

  • A swine model of bile duct dilation was developed based on the use of endoclips or a detachable snare. These endoscopic procedures appear to be comparable with surgical procedures in terms of producing bile duct dilation.

  • A detachable snare is more appropriate than endoclips as a device for bile duct dilation.

Section snippets

Animals

Six miniature pigs (Sus scrofa, mean age 14 months, mean body weight 30 kg) were used. The animals were allocated to 2 groups; 3 animals were allocated to the endoclip model group (group A) and 3 to the detachable snare group (group B). Approval was obtained from our institutional animal care committee before study commencement (MK-IACUC: 130722-001).

Endoclipping of the major duodenal papilla

Endoscopic clipping of the major duodenal papilla was performed using a conventional endoscope (GIF-Q260J; Olympus, Tokyo, Japan) with a fitted

Results

All animals survived until the end of the experiment, and all were included in the analysis. Mean maximum CBD, IHD, and GB diameters before the procedures are summarized in Table 1. No significant difference was observed between the 2 groups. Clipping and closure of the papilla were achieved in all pigs, and no technical difficulties or adverse events were encountered during the procedures (Figs. 1 and 2). No clinical signs of total bile duct obstruction were observed in any animal after the

Discussion

The endoscopic procedures used to produce our animal models have some advantages. Most importantly, the procedures required are straightforward. All endoscopic procedures, including endoclip and detachable snare placement, can be performed without technical difficulty within 30 minutes. We recommend using transparent cap-fitted endoscope for these procedures in the swine model, because it provides comfortable and a wide range of therapeutic techniques in clipping or detachable snare application.

References (14)

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DISCLOSURE: The following author received research support for this study from the Industrial Technology Innovation Program (Advanced Technology Center Program funded by the Korean Ministry of Trade, Industry & Energy and the National Center of Efficacy Evaluation for the Development of Health Products Targeting Digestive Disorders (NCEED): C.-I. Kwon. All other authors disclosed no financial relationships relevant to this publication.

Drs Park and Kwon contributed equally to this article.

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