Effects of stent sizing on endothelial and vessel wall stress

Potential mechanisms for in-stent restenosis

Henry Y. Chen, James Hermiller, Anjan Sinha, Michael Sturek, Luoding Zhu, Ghassan S. Kassab

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

Stent sizing and apposition have been shown to be important determinants of clinical outcome. This study evaluates the mechanical effects of undersizing and oversizing of stents on endothelial wall shear stress (WSS) and vessel wall stress to determine a possible biomechanical mechanism of in-stent restenosis and thrombosis. Three-dimensional computational models of stents, artery, and internal fluid were created in a computer-assisted design package, meshed, and solved in finite element and computational fluid dynamic packages. The simulation results show that the effects of various degrees of undersizing on WSS, WSS gradient, and oscillatory shear index were highly nonlinear. As the degree of undersizing increased, the heterogeneity of WSS became smaller. The WSS distribution for the 20% undersizing was smooth and uniform, whereas the 5% case was very heterogeneous. The combination of lower WSS and higher WSS gradient and oscillatory shear index in the 5% undersized case may induce neointimal hyperplasia or thrombosis. Additionally, the oversizing simulation results show that the maximum intramural wall stress of the 20% oversizing case is significantly larger than the maximum stress for the 10% and zero oversizing cases. Edge stress concentration was observed, consistent with the restenosis typically observed in this region. This study demonstrates that proper sizing of stent is important for reducing the hemodynamic and mechanical disturbances to the vessel wall. Furthermore, the present findings may be used to improve stent design to reduce endothelial flow disturbances and intramural wall stress concentrations.

Original languageEnglish
Pages (from-to)1686-1691
Number of pages6
JournalJournal of Applied Physiology
Volume106
Issue number5
DOIs
StatePublished - May 2009

Fingerprint

Stents
Thrombosis
Computer-Aided Design
Hydrodynamics
Hyperplasia
Arteries
Hemodynamics

Keywords

  • Intimial hyperplasia
  • Oversizing
  • Shear stress
  • Undersizing

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Effects of stent sizing on endothelial and vessel wall stress : Potential mechanisms for in-stent restenosis. / Chen, Henry Y.; Hermiller, James; Sinha, Anjan; Sturek, Michael; Zhu, Luoding; Kassab, Ghassan S.

In: Journal of Applied Physiology, Vol. 106, No. 5, 05.2009, p. 1686-1691.

Research output: Contribution to journalArticle

Chen, Henry Y. ; Hermiller, James ; Sinha, Anjan ; Sturek, Michael ; Zhu, Luoding ; Kassab, Ghassan S. / Effects of stent sizing on endothelial and vessel wall stress : Potential mechanisms for in-stent restenosis. In: Journal of Applied Physiology. 2009 ; Vol. 106, No. 5. pp. 1686-1691.
@article{b14da6b7f8884794a9bfcb18c1cfd413,
title = "Effects of stent sizing on endothelial and vessel wall stress: Potential mechanisms for in-stent restenosis",
abstract = "Stent sizing and apposition have been shown to be important determinants of clinical outcome. This study evaluates the mechanical effects of undersizing and oversizing of stents on endothelial wall shear stress (WSS) and vessel wall stress to determine a possible biomechanical mechanism of in-stent restenosis and thrombosis. Three-dimensional computational models of stents, artery, and internal fluid were created in a computer-assisted design package, meshed, and solved in finite element and computational fluid dynamic packages. The simulation results show that the effects of various degrees of undersizing on WSS, WSS gradient, and oscillatory shear index were highly nonlinear. As the degree of undersizing increased, the heterogeneity of WSS became smaller. The WSS distribution for the 20{\%} undersizing was smooth and uniform, whereas the 5{\%} case was very heterogeneous. The combination of lower WSS and higher WSS gradient and oscillatory shear index in the 5{\%} undersized case may induce neointimal hyperplasia or thrombosis. Additionally, the oversizing simulation results show that the maximum intramural wall stress of the 20{\%} oversizing case is significantly larger than the maximum stress for the 10{\%} and zero oversizing cases. Edge stress concentration was observed, consistent with the restenosis typically observed in this region. This study demonstrates that proper sizing of stent is important for reducing the hemodynamic and mechanical disturbances to the vessel wall. Furthermore, the present findings may be used to improve stent design to reduce endothelial flow disturbances and intramural wall stress concentrations.",
keywords = "Intimial hyperplasia, Oversizing, Shear stress, Undersizing",
author = "Chen, {Henry Y.} and James Hermiller and Anjan Sinha and Michael Sturek and Luoding Zhu and Kassab, {Ghassan S.}",
year = "2009",
month = "5",
doi = "10.1152/japplphysiol.91519.2008",
language = "English",
volume = "106",
pages = "1686--1691",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "5",

}

TY - JOUR

T1 - Effects of stent sizing on endothelial and vessel wall stress

T2 - Potential mechanisms for in-stent restenosis

AU - Chen, Henry Y.

AU - Hermiller, James

AU - Sinha, Anjan

AU - Sturek, Michael

AU - Zhu, Luoding

AU - Kassab, Ghassan S.

PY - 2009/5

Y1 - 2009/5

N2 - Stent sizing and apposition have been shown to be important determinants of clinical outcome. This study evaluates the mechanical effects of undersizing and oversizing of stents on endothelial wall shear stress (WSS) and vessel wall stress to determine a possible biomechanical mechanism of in-stent restenosis and thrombosis. Three-dimensional computational models of stents, artery, and internal fluid were created in a computer-assisted design package, meshed, and solved in finite element and computational fluid dynamic packages. The simulation results show that the effects of various degrees of undersizing on WSS, WSS gradient, and oscillatory shear index were highly nonlinear. As the degree of undersizing increased, the heterogeneity of WSS became smaller. The WSS distribution for the 20% undersizing was smooth and uniform, whereas the 5% case was very heterogeneous. The combination of lower WSS and higher WSS gradient and oscillatory shear index in the 5% undersized case may induce neointimal hyperplasia or thrombosis. Additionally, the oversizing simulation results show that the maximum intramural wall stress of the 20% oversizing case is significantly larger than the maximum stress for the 10% and zero oversizing cases. Edge stress concentration was observed, consistent with the restenosis typically observed in this region. This study demonstrates that proper sizing of stent is important for reducing the hemodynamic and mechanical disturbances to the vessel wall. Furthermore, the present findings may be used to improve stent design to reduce endothelial flow disturbances and intramural wall stress concentrations.

AB - Stent sizing and apposition have been shown to be important determinants of clinical outcome. This study evaluates the mechanical effects of undersizing and oversizing of stents on endothelial wall shear stress (WSS) and vessel wall stress to determine a possible biomechanical mechanism of in-stent restenosis and thrombosis. Three-dimensional computational models of stents, artery, and internal fluid were created in a computer-assisted design package, meshed, and solved in finite element and computational fluid dynamic packages. The simulation results show that the effects of various degrees of undersizing on WSS, WSS gradient, and oscillatory shear index were highly nonlinear. As the degree of undersizing increased, the heterogeneity of WSS became smaller. The WSS distribution for the 20% undersizing was smooth and uniform, whereas the 5% case was very heterogeneous. The combination of lower WSS and higher WSS gradient and oscillatory shear index in the 5% undersized case may induce neointimal hyperplasia or thrombosis. Additionally, the oversizing simulation results show that the maximum intramural wall stress of the 20% oversizing case is significantly larger than the maximum stress for the 10% and zero oversizing cases. Edge stress concentration was observed, consistent with the restenosis typically observed in this region. This study demonstrates that proper sizing of stent is important for reducing the hemodynamic and mechanical disturbances to the vessel wall. Furthermore, the present findings may be used to improve stent design to reduce endothelial flow disturbances and intramural wall stress concentrations.

KW - Intimial hyperplasia

KW - Oversizing

KW - Shear stress

KW - Undersizing

UR - http://www.scopus.com/inward/record.url?scp=66349132501&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=66349132501&partnerID=8YFLogxK

U2 - 10.1152/japplphysiol.91519.2008

DO - 10.1152/japplphysiol.91519.2008

M3 - Article

VL - 106

SP - 1686

EP - 1691

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 5

ER -