Basic Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 7, 2019; 25(25): 3207-3217
Published online Jul 7, 2019. doi: 10.3748/wjg.v25.i25.3207
Silicone-covered biodegradable magnesium stent for treating benign esophageal stricture in a rabbit model
Kai Yang, Jun Cao, Tian-Wen Yuan, Yue-Qi Zhu, Bi Zhou, Ying-Sheng Cheng
Kai Yang, Bi Zhou, Ying-Sheng Cheng, Department of Radiological Intervention, Shanghai Sixth People's Hospital East Campus Affiliated to Shanghai University of Medicine & Health Sciences, Shanghai 201306, China
Kai Yang, Bi Zhou, Ying-Sheng Cheng, Department of Radiological Intervention, Shanghai Sixth People's Hospital East Campus Affiliated to Shanghai Jiao Tong University, Shanghai 201306, China
Jun Cao, Tian-Wen Yuan, Department of Tumor Intervention, Dahua Hospital, Shanghai 200237, China
Yue-Qi Zhu, Department of Radiological Intervention, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai 200233, China
Author contributions: Yang K and Cao J contributed equally to this study; Yang K, Cheng YS, and Cao J designed all the experiments; Yang K, Yuan TW, and Zhu YQ performed the research; Zhou B contributed analytic tools; Yang K and Cao J wrote the paper.
Supported by the National Natural Science Foundation of China, No. 81371659, No. 81571773, and No. 81771943; and Shanghai Municipal Health and Family Planning Commission, No. 201640191.
Institutional animal care and use committee statement: All experimental protocols were approved by the Animal Research Council of Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University and followed the guidelines of the International Committee of Animal Care (US National Institutes of Health and European Commission).
Conflict-of-interest statement: The authors declare no conflicts of interest.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
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: Ying-Sheng Cheng, MD, PhD, Academic Fellow, Doctor, Department of Radiological Intervention, Shanghai Sixth People's Hospital East Campus Affiliated to Shanghai Jiao-tong University, No. 222, West Huanhu No. 3 Road, Shanghai 201306, China. chengyingsheng@hotmail.com
Telephone: +86-21-38297858 Fax: +86-21-38297706
Received: March 6, 2019
Peer-review started: March 7, 2019
First decision: April 8, 2019
Revised: May 14, 2019
Accepted: June 7, 2019
Article in press: June 8, 2019
Published online: July 7, 2019
Processing time: 121 Days and 22.5 Hours
ARTICLE HIGHLIGHTS
Research background

Stent insertion has been widely used as an effective alternative to improve the quality of life of patients with benign esophageal strictures (BES). However, the metallic stents implantation is associated with some severe complications, such as migration, tissue ingrowth, and instent restenosis. Stents made from biodegradable alloy or polymer are able to provide enough force to tear the benign stricture of the esophagus, as well as reduce complications caused by stents.

Research motivation

Magnesium alloy stents are a good candidate because of biological safety, but they show a poor corrosion resistance and a quick loss of mechanical support in vivo. Silicone coating could prolong degradation time of magnesium alloy and enhance the support force of magnesium alloy stents.

Research objectives

The aim of the present study was to evaluate the technique feasibility and therapeutic effect of and tissue response to silicone-covered bio-degradable magnesium stent insertion into the benign esophageal stricture in rabbits.

Research methods

The silicone-covered magnesium stent was made of the magnesium alloy wires through cross-linked mesh, and was fabricated by covering with a silicone membrane. The mechanical testing demonstrated that silicone-covered magnesium stent possessed good flexibility and elasticity, and could provide adequate support in vivo. Fifteen rabbits underwent silicone-covered biodegradable magnesium stent insertion into the benign esophageal stricture under fluo-roscopic guidance (stent group). The wall reconstruction and tissue reaction of stenotic esophagus were compared with those of six stenosis esophagus models (control group). Esoph-agography was performed at 1, 2, and 3 wk after stent insertion.

Research results

Histological examination revealed that the inflammation scores at 4 wk in the BES rabbits with stent implantation (stent group) were similar to those in the control rabbits (control group). Both the epithelial and smooth muscle cell layers were significantly thinner in the stent group than in the control group. The smooth muscle actin layer in the muscle layer was thinner in the stent group than in the control group. Without causing severe injury or collagen deposition, im-plantation of silicone-covered magnesium stent provided reliable support for at least 2 wk in rabbits.

Research conclusions

The present study demonstrated that insertion of silicone-covered magnesium esophageal stent is a promising approach for treating benign esophageal stricture without causing severe injury or tissue reaction.

Research perspectives

The silicone-covered magnesium stent can provide reliable support for at least 1 wk, however, reliable support of the silicone-covered biodegradable magnesium for 2 wk is not enough and associated with high migration rates. There are still some limitations in this study. Further study is needed to reduce the biodegradation rate and prolong the support time. Longer follow-up study is required for determining the efficacy, optimal insertion time, and tissue responses.