Randomized Controlled Trial
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 21, 2019; 25(19): 2373-2382
Published online May 21, 2019. doi: 10.3748/wjg.v25.i19.2373
New antireflux plastic stent for patients with distal malignant biliary obstruction
Xiang-Lei Yuan, Bin Wei, Lian-Song Ye, Chun-Cheng Wu, Qing-Hua Tan, Ming-Hong Yao, Yu-Hang Zhang, Xian-Hui Zeng, Yan Li, Yu-Yan Zhang, Bing Hu
Xiang-Lei Yuan, Lian-Song Ye, Chun-Cheng Wu, Qing-Hua Tan, Yu-Hang Zhang, Xian-Hui Zeng, Yan Li, Yu-Yan Zhang, Bing Hu, Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Bin Wei, Department of Gastroenterology, the First Hospital of Xi’an City, Xi’an 710002, Shaanxi Province, China
Ming-Hong Yao, Department of Epidemiology and Health Statistics, West China School of Public Health, Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Hu B, Yuan XL and Ye LS designed this study; Hu B, Yuan XL, Wu CC, and Tan QH recruited the patients, performed the clinical investigations, and treated the patients; Yuan XL, Wei B, Ye LS, Zhang YH, Zeng XH, Li Y, and Zhang YY participated in trial coordination and monitoring; Yuan XL and Wu CC performed data collection and management; Yuan XL and Yao MH contributed to the statistical analyses; Hu B, Wu CC, and Tan QH analyzed and interpreted the data; Yuan XL and Wei B drafted the manuscript; Hu B, Ye LS, Tan QH, Zhang YH, Zeng XH, Li Y, and Zhang YY critically revised the manuscript; all authors approved the final version of the manuscript for publication.
Supported by the Sichuan Province Science and Technology Department, China, No. 2017SZ0009.
Institutional review board statement: The study protocol was approved by the China Ethics Committee of Registering Clinical Trials (Number: ChiECRCT-20150069; date of approval: December 13, 2015).
Clinical trial registration statement: The trial was registered with Chinese Clinical Trial Registry (Number: ChiCTR-IIR-16007869; date of registration: February 1, 2016).
Informed consent statement: Informed consent was obtained from all patients involved in this study.
Conflict-of-interest statement: Professor Bing Hu is one of the inventors of the antireflux plastic stent. He has worked in collaboration with Micro-Tech (Nanjing) Co. Ltd., Nanjing, China to develop the stent. No free device was offered for this study. The authors disclose no conflicts of interest.
Data sharing statement: No additional unpublished 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/
Corresponding author: Bing Hu, MD, Professor, Department of Gastroenterology, West China Hospital, Sichuan University, No. 37, Guo Xue Xiang, Wuhou District, Chengdu 610041, Sichuan Province, China. hubingnj@163.com
Telephone: +86-18980601278
Received: March 14, 2019
Peer-review started: March 14, 2019
First decision: March 27, 2019
Revised: March 28, 2019
Accepted: April 19, 2019
Article in press: April 20, 2019
Published online: May 21, 2019
Research background

Endoscopic biliary stenting has become an established palliative treatment for patients with unresectable malignant biliary obstruction (MBO). However, stent occlusion is considered to be the most frequent delayed adverse event of stent placement. Since duodenobiliary reflux is discussed to be a major risk factor of stent occlusion, in recent years, the design of plastic stents with an anti-reflux valve has been an attractive idea for prolonging stent patency, unfortunately without convincing results and therefore limiting their use in clinical practice.

Research motivation

To reduce duodenobiliary reflux and thereby prolonging stent patency, we developed a new antireflux plastic stent (ARPS) with a “duckbilled” valve attached to the duodenal end of the stent. We presumed that this valve could simulate the opening and closing function of the duck’s bill. This geometry allows unimpaired antegrade bile flow into the duodenum, while it closes instantly when the intestinal pressure increases, thereby preventing the reflux of duodenal contents.

Research objectives

In this study, we compared the patency of ARPSs with that of traditional plastic stents (TPSs) in patients with unresectable distal MBO. The results of the study will guide the treatment of unresectable distal MBO in the future.

Research methods

From February 2016 to December 2017, consecutive patients with extrahepatic MBO were recruited in our randomized clinical trial. Eligible patients were assigned to receive either an ARPS or a TPS in a randomized manner. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The duration of stent patency, the rates of technical and clinical success, adverse events, and patient survival were documented. All data were analyzed statistically to evaluate the efficacy and safety of this new ARPS.

Research results

During the study period, 89 patients were screened for eligibility. Of these, 51 patients were excluded; thus, 38 patients were randomized to receive ARPSs or TPSs (19 per group). Stent insertion was technically successful in all patients. No significant differences were noted in the rates of clinical success, the rates of early or late adverse events, or patient survival. There was a significant difference when comparing the duration of stent patency, which was significantly longer in the ARPS group than in the TPS group.

Research conclusions

This new ARPS is safe and effective for the palliation of unresectable distal MBO, and has a significantly longer stent patency compared with TPS. This ARPS may be an alternative option for the treatment of unresectable distal MBO.

Research perspectives

Multiple center studies with larger samples are expected in the future to confirm and strengthen our results.