Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Apr 27, 2020; 12(4): 138-148
Published online Apr 27, 2020. doi: 10.4240/wjgs.v12.i4.138
Newly developed self-expandable Niti-S MD colonic metal stent for malignant colonic obstruction
Yuki Miyasako, Toshio Kuwai, Sauid Ishaq, Kanae Tao, Hirona Konishi, Ryoichi Miura, Yuki Sumida, Kazutaka Kuroki, Yuzuru Tamaru, Ryusaku Kusunoki, Atsushi Yamaguchi, Hirotaka Kouno, Hiroshi Kohno
Yuki Miyasako, Toshio Kuwai, Kanae Tao, Hirona Konishi, Ryoichi Miura, Yuki Sumida, Kazutaka Kuroki, Yuzuru Tamaru, Ryusaku Kusunoki, Atsushi Yamaguchi, Hirotaka Kouno, Hiroshi Kohno, Department of Gastroenterology, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, Kure 737-0023, Japan
Sauid Ishaq, Gastroenterology Department, Russells Hall Hospital, Birmingham City University, Birmingham B17 9BE, United Kingdom
Sauid Ishaq, St George’s University, University Centre Grenada, West Indies, Grenada
Author contributions: Miyasako Y drafted the manuscript, collected and interpreted data, planned the study, and approved the final draft submitted; Kuwai T drafted the manuscript, planned and conducted the study, interpreted data, and approved the final draft submitted; Ishaq S drafted the manuscript, conducted the study, and approved the final draft submitted; Tao K, Konishi H, Miura R, Sumida Y, Kuroki K, Tamaru Y, Kusunoki R, Yamaguchi A, Kouno H, and Kohno H collected data and approved the final draft submitted.
Institutional review board statement: The study was approved by the Institutional Review Board Ethics Committee of the National Hospital Organization Kure Medical Center and Chugoku Cancer Center.
Informed consent statement: All participants provided informed consent to the procedure and data collection.
Conflict-of-interest statement: There are no conflicts of interest to declare.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: Toshio Kuwai, MD, PhD, Chief Doctor, Department of Gastroenterology, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, 3-1 Aoyamacho, Kure 737-0023, Japan. kuwai.toshio.ur@mail.hosp.go.jp
Received: December 21, 2019
Peer-review started: December 21, 2019
First decision: January 15, 2020
Revised: January 21, 2020
Accepted: March 25, 2020
Article in press: March 25, 2020
Published online: April 27, 2020
Processing time: 123 Days and 19.5 Hours
ARTICLE HIGHLIGHTS
Research background

The most serious adverse event of colonic stenting is perforation. The Niti-S D type stent could be ideal to reduce risk of perforation due to its structure with weaker axial force. Stents are deployed using a standard colonoscope, which can pose a challenge while overcoming sharp angles. Smaller caliber colonoscopes could be ideal for easy maneuverability, facilitating scope advancement and cecal intubation where the standard colonoscope has failed. The main drawback of using small caliber colonoscope is its small channel of 9.2 mm, that would only allow 9Fr delivery catheter available only with stents of diameter 18 mm that has less radial force to overcome obstruction. Stents with greater radial force are 22 mm that require larger channel standard colonoscope.

Research motivation

We would like to develop a new colonic stent that maintains the structure with low axial force of the conventional Niti-S D type and takes additional radial force with 22-mm diameter, but that requires 9Fr delivery system, hence can be deployed using smaller caliber colonoscope.

Research objectives

We evaluated the efficacy and safety of the newly developed “Niti-S MD type” colonic stent.

Research methods

This single-center retrospective observational study with endoscopic self-expandable metallic stents placed between November 2011 and December 2018, and we evaluated the short-term outcomes including success rates and adverse events.

Research results

The technical and clinical success rate of the Niti-S MD type was 100%, and its perforation rate was 0%.

Research conclusions

Our preliminary data suggested that the newly developed “Niti-S MD type” colonic stent was feasible and safe.

Research perspectives

The stent might have a potential to be an ideal one that offers high radial force and can be deployed with small caliber colonoscope. Larger prospective studies and randomized comparison trials are warranted to evaluate and compare this new stent with available conventional colonic stents.