Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2015; 21(28): 8629-8635
Published online Jul 28, 2015. doi: 10.3748/wjg.v21.i28.8629
Newly designed “pieced” stent in a rabbit model of benign esophageal stricture
Jin Liu, Liang Shang, Ji-Yong Liu, Cheng-Yong Qin
Jin Liu, Ji-Yong Liu, Cheng-Yong Qin, Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, Shandong Province, China
Liang Shang, Department of General Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, Shandong Province, China
Author contributions: Liu J carried out the study, analyzed and interpreted the data, and drafted the manuscript; Shang L assisted with the endoscopic operation and analyzed the data; Qin CY participated in the experimental design and supervised the study; Liu JY participated in the technical support and endoscopic operation; All authors read and approved the final manuscript.
Supported by A grant from the Graduate Innovation Foundation of Shandong University, China, No. yyx10129.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of Shandong Provincial Hospital affiliated to Shandong University.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Shandong Provincial Hospital Affiliated to Shandong University (IACUC protocol number: 2013-004).
Conflict-of-interest statement: The funding source had no role in the design, implementation or analysis of this study. Dr. Ji-Yong Liu and Dr. Jin Liu own the patent for the detachable “pieced” stent (patent No. ZL201110323099.5). Dr. Cheng-Yong Qin and Dr. Liang Shang have no conflicts of interest or financial ties to disclose.
Data sharing statement: No additional data are available.
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: Cheng-Yong Qin, MD, Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, No. 324 Jingwu Road, Jinan 250021, Shandong Province, China. usera9598@163.com
Telephone: +86-18-653170640 Fax: +86-531-87060315
Received: February 5, 2015
Peer-review started: February 6, 2015
First decision: March 10, 2015
Revised: March 26, 2015
Accepted: May 2, 2015
Article in press: May 4, 2015
Published online: July 28, 2015
Processing time: 174 Days and 20.2 Hours
Abstract

AIM: To investigate a newly designed stent and its dilatation effect in a rabbit model of benign esophageal stricture.

METHODS: Thirty-four New Zealand white rabbits underwent a corrosive injury in the middle esophagus for esophageal stricture formation. Thirty rabbits with a successful formation of esophageal strictures were randomly allocated into two groups. The control group (n = 15) was implanted with a conventional stent, and the study group (n = 15) was implanted with a detachable “pieced” stent. The study stent (30 mm in length, 10 mm in diameter) was composed of three covered metallic pieces connected by surgical suture lines. The stent was collapsed by pulling the suture lines out of the mesh. Two weeks after stricture formation, endoscopic placement of a conventional stent or the new stent was performed. Endoscopic extraction was carried out four weeks later. The extraction rate, ease of extraction, migration, complications, and survival were evaluated.

RESULTS: Stent migration occurred in 3/15 (20%) animals in the control group and 2/15 (13%) animals in the study group; the difference between the two groups was not statistically significant. At the end of four weeks, the remaining stents were successfully extracted with the endoscope in 100% (11/11) of the animals in the study group, and 60% (6/10) of the animals in the control group; this difference was statistically significant (P < 0.05). There was no difference in the mean number of follow-up days between the control and study groups (25.33 vs 25.85). Minor bleeding was reported in five cases in the study group and four in the control group. There were no severe complications directly associated with stent implantation or extraction in either of the two groups.

CONCLUSION: In this experimental protocol of benign esophageal strictures, the novel “pieced” stent demonstrated a superior removal rate with a similar migration rate compared to a conventional stent.

Keywords: Animal experimentation; Detachable “pieced” stent; Endoscopic procedure; Esophageal stricture; Stent removal

Core tip: At present, esophageal stent retrieval may be a difficult and traumatic procedure because of tissue adhesion and the stent’s radial force. Currently, all types of stents used in clinical practice retain some of the radial force during the removal procedure. We designed a novel type of stent that has a detachable property and no radial force during removal procedure. We investigated the efficacy and removal feasibility of the stent in an animal model, and we anticipate that it could be used in humans in the future.