Migration resistance of esophageal stents: The role of stent design

Hozhabr Mozafari; Pengfei Dong; Shijia Zhao; Yonghua Bi; Xinwei Han; Linxia Gu

doi:10.1016/j.compbiomed.2018.06.031

Migration resistance of esophageal stents: The role of stent design

Comput Biol Med. 2018 Sep 1:100:43-49. doi: 10.1016/j.compbiomed.2018.06.031. Epub 2018 Jun 28.

Authors

Hozhabr Mozafari¹, Pengfei Dong¹, Shijia Zhao¹, Yonghua Bi², Xinwei Han³, Linxia Gu⁴

Affiliations

¹ Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588-0656, USA.
² Department of Interventional Radiology, The First Affiliated Hospital of Zhengzhou University, Henan Province, China.
³ Department of Interventional Radiology, The First Affiliated Hospital of Zhengzhou University, Henan Province, China. Electronic address: hanxinwei2006@163.com.
⁴ Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588-0656, USA; Department of Interventional Radiology, The First Affiliated Hospital of Zhengzhou University, Henan Province, China; Nebraska Center for Materials and Nanoscience, Lincoln, NE, 68588-0656, USA. Electronic address: lgu2@unl.edu.

PMID: 29975854
DOI: 10.1016/j.compbiomed.2018.06.031

Abstract

Objective: Stenting is one of the major treatments for malignant esophageal cancer. However, stent migration compromises clinical outcomes. A flared end design of the stent diminishes its migration. The goal of this work is to quantitatively characterize stent migration to develop new strategies for better clinical outcomes.

Methods: An esophageal stent with flared ends and a straight counterpart were virtually deployed in an esophagus with asymmetric stricture using the finite element method. The resulted esophagus shape, wall stress, and migration resistance force of the stent were quantified and compared.

Results: The lumen gain for both the flared stent and the straight one exhibited no significant difference. The flared stent induced a significantly larger contact force and thus a larger stress onto the esophagus wall. In addition, more migration resistance force was required to pull the flared stent through the esophagus. This force was inversely related to the occurrence rate of stent migration. A doubled strut diameter also increased the migration resistance force by approximately 56%. An increased friction coefficient from 0.1 to 0.3 also boosted the migration resistance force by approximately 39%.

Summary: The mechanical advantage of the flared stent was unveiled by the significantly increased contact force, which provided the anchoring effect to resist stent migration. Both the strut diameter and friction coefficient positively correlated with the migration resistance force, and thus the occurrence of stent migration.

Keywords: Esophageal stent; Finite element method; Flared; Migration; Stent design.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Esophageal Neoplasms / surgery*
Esophagus / surgery*
Friction
Humans
Models, Biological*
Prosthesis Design*
Prosthesis Failure*
Stents*