Development of a Functionally Equivalent Model of the Mitral Valve Chordae Tendineae Through Topology Optimization

Amir H. Khalighi, Bruno V. Rego, Andrew Drach, Robert C. Gorman, Joseph H. Gorman, Michael S. Sacks

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Ischemic mitral regurgitation (IMR) is a currently prevalent disease in the US that is projected to become increasingly common as the aging population grows. In recent years, image-based simulations of mitral valve (MV) function have improved significantly, providing new tools to refine IMR treatment. However, clinical implementation of MV simulations has long been hindered as the in vivo MV chordae tendineae (MVCT) geometry cannot be captured with sufficient fidelity for computational modeling. In the current study, we addressed this challenge by developing a method to produce functionally equivalent MVCT models that can be built from the image-based MV leaflet geometry alone. We began our analysis using extant micron-resolution 3D imaging datasets to first build anatomically accurate MV models. We then systematically simplified the native MVCT structure to generate a series of synthetic models by consecutively removing key anatomic features, such as the thickness variations, branching patterns, and chordal origin distributions. In addition, through topology optimization, we identified the minimal structural complexity required to capture the native MVCT behavior. To assess the performance and predictive power of each synthetic model, we analyzed their performance by comparing the mismatch in simulated MV closed shape, as well as the strain and stress tensors, to ground-truth MV models. Interestingly, our results revealed a substantial redundancy in the anatomic structure of native chordal anatomy. We showed that the closing behavior of complete MV apparatus under normal, diseased, and surgically repaired scenarios can be faithfully replicated by a functionally equivalent MVCT model comprised of two representative papillary muscle heads, single strand chords, and a uniform insertion distribution with a density of 15 insertions/cm 2 . Hence, even though the complete sub-valvular structure is mostly missing in in vivo MV images, we believe our approach will allow for the development of patient-specific complete MV models for surgical repair planning.

Original languageEnglish (US)
Pages (from-to)60-74
Number of pages15
JournalAnnals of Biomedical Engineering
Volume47
Issue number1
DOIs
StatePublished - Jan 15 2019

Fingerprint

Shape optimization
Geometry
Tensors
Redundancy
Muscle
Repair
Aging of materials
Imaging techniques
Planning

Keywords

  • Chordae tendineae
  • Finite element analysis
  • Mitral valve
  • Sub-valvular apparatus
  • Topology optimization

ASJC Scopus subject areas

  • Biomedical Engineering

Cite this

Development of a Functionally Equivalent Model of the Mitral Valve Chordae Tendineae Through Topology Optimization. / Khalighi, Amir H.; Rego, Bruno V.; Drach, Andrew; Gorman, Robert C.; Gorman, Joseph H.; Sacks, Michael S.

In: Annals of Biomedical Engineering, Vol. 47, No. 1, 15.01.2019, p. 60-74.

Research output: Contribution to journalArticle

Khalighi, Amir H. ; Rego, Bruno V. ; Drach, Andrew ; Gorman, Robert C. ; Gorman, Joseph H. ; Sacks, Michael S. / Development of a Functionally Equivalent Model of the Mitral Valve Chordae Tendineae Through Topology Optimization. In: Annals of Biomedical Engineering. 2019 ; Vol. 47, No. 1. pp. 60-74.
@article{f3d31688bb074c3c9e1d477e93f5eebf,
title = "Development of a Functionally Equivalent Model of the Mitral Valve Chordae Tendineae Through Topology Optimization",
abstract = "Ischemic mitral regurgitation (IMR) is a currently prevalent disease in the US that is projected to become increasingly common as the aging population grows. In recent years, image-based simulations of mitral valve (MV) function have improved significantly, providing new tools to refine IMR treatment. However, clinical implementation of MV simulations has long been hindered as the in vivo MV chordae tendineae (MVCT) geometry cannot be captured with sufficient fidelity for computational modeling. In the current study, we addressed this challenge by developing a method to produce functionally equivalent MVCT models that can be built from the image-based MV leaflet geometry alone. We began our analysis using extant micron-resolution 3D imaging datasets to first build anatomically accurate MV models. We then systematically simplified the native MVCT structure to generate a series of synthetic models by consecutively removing key anatomic features, such as the thickness variations, branching patterns, and chordal origin distributions. In addition, through topology optimization, we identified the minimal structural complexity required to capture the native MVCT behavior. To assess the performance and predictive power of each synthetic model, we analyzed their performance by comparing the mismatch in simulated MV closed shape, as well as the strain and stress tensors, to ground-truth MV models. Interestingly, our results revealed a substantial redundancy in the anatomic structure of native chordal anatomy. We showed that the closing behavior of complete MV apparatus under normal, diseased, and surgically repaired scenarios can be faithfully replicated by a functionally equivalent MVCT model comprised of two representative papillary muscle heads, single strand chords, and a uniform insertion distribution with a density of 15 insertions/cm 2 . Hence, even though the complete sub-valvular structure is mostly missing in in vivo MV images, we believe our approach will allow for the development of patient-specific complete MV models for surgical repair planning.",
keywords = "Chordae tendineae, Finite element analysis, Mitral valve, Sub-valvular apparatus, Topology optimization",
author = "Khalighi, {Amir H.} and Rego, {Bruno V.} and Andrew Drach and Gorman, {Robert C.} and Gorman, {Joseph H.} and Sacks, {Michael S.}",
year = "2019",
month = "1",
day = "15",
doi = "10.1007/s10439-018-02122-y",
language = "English (US)",
volume = "47",
pages = "60--74",
journal = "Annals of Biomedical Engineering",
issn = "0090-6964",
publisher = "Springer Netherlands",
number = "1",

}

TY - JOUR

T1 - Development of a Functionally Equivalent Model of the Mitral Valve Chordae Tendineae Through Topology Optimization

AU - Khalighi, Amir H.

AU - Rego, Bruno V.

AU - Drach, Andrew

AU - Gorman, Robert C.

AU - Gorman, Joseph H.

AU - Sacks, Michael S.

PY - 2019/1/15

Y1 - 2019/1/15

N2 - Ischemic mitral regurgitation (IMR) is a currently prevalent disease in the US that is projected to become increasingly common as the aging population grows. In recent years, image-based simulations of mitral valve (MV) function have improved significantly, providing new tools to refine IMR treatment. However, clinical implementation of MV simulations has long been hindered as the in vivo MV chordae tendineae (MVCT) geometry cannot be captured with sufficient fidelity for computational modeling. In the current study, we addressed this challenge by developing a method to produce functionally equivalent MVCT models that can be built from the image-based MV leaflet geometry alone. We began our analysis using extant micron-resolution 3D imaging datasets to first build anatomically accurate MV models. We then systematically simplified the native MVCT structure to generate a series of synthetic models by consecutively removing key anatomic features, such as the thickness variations, branching patterns, and chordal origin distributions. In addition, through topology optimization, we identified the minimal structural complexity required to capture the native MVCT behavior. To assess the performance and predictive power of each synthetic model, we analyzed their performance by comparing the mismatch in simulated MV closed shape, as well as the strain and stress tensors, to ground-truth MV models. Interestingly, our results revealed a substantial redundancy in the anatomic structure of native chordal anatomy. We showed that the closing behavior of complete MV apparatus under normal, diseased, and surgically repaired scenarios can be faithfully replicated by a functionally equivalent MVCT model comprised of two representative papillary muscle heads, single strand chords, and a uniform insertion distribution with a density of 15 insertions/cm 2 . Hence, even though the complete sub-valvular structure is mostly missing in in vivo MV images, we believe our approach will allow for the development of patient-specific complete MV models for surgical repair planning.

AB - Ischemic mitral regurgitation (IMR) is a currently prevalent disease in the US that is projected to become increasingly common as the aging population grows. In recent years, image-based simulations of mitral valve (MV) function have improved significantly, providing new tools to refine IMR treatment. However, clinical implementation of MV simulations has long been hindered as the in vivo MV chordae tendineae (MVCT) geometry cannot be captured with sufficient fidelity for computational modeling. In the current study, we addressed this challenge by developing a method to produce functionally equivalent MVCT models that can be built from the image-based MV leaflet geometry alone. We began our analysis using extant micron-resolution 3D imaging datasets to first build anatomically accurate MV models. We then systematically simplified the native MVCT structure to generate a series of synthetic models by consecutively removing key anatomic features, such as the thickness variations, branching patterns, and chordal origin distributions. In addition, through topology optimization, we identified the minimal structural complexity required to capture the native MVCT behavior. To assess the performance and predictive power of each synthetic model, we analyzed their performance by comparing the mismatch in simulated MV closed shape, as well as the strain and stress tensors, to ground-truth MV models. Interestingly, our results revealed a substantial redundancy in the anatomic structure of native chordal anatomy. We showed that the closing behavior of complete MV apparatus under normal, diseased, and surgically repaired scenarios can be faithfully replicated by a functionally equivalent MVCT model comprised of two representative papillary muscle heads, single strand chords, and a uniform insertion distribution with a density of 15 insertions/cm 2 . Hence, even though the complete sub-valvular structure is mostly missing in in vivo MV images, we believe our approach will allow for the development of patient-specific complete MV models for surgical repair planning.

KW - Chordae tendineae

KW - Finite element analysis

KW - Mitral valve

KW - Sub-valvular apparatus

KW - Topology optimization

UR - http://www.scopus.com/inward/record.url?scp=85053385659&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85053385659&partnerID=8YFLogxK

U2 - 10.1007/s10439-018-02122-y

DO - 10.1007/s10439-018-02122-y

M3 - Article

C2 - 30187238

AN - SCOPUS:85053385659

VL - 47

SP - 60

EP - 74

JO - Annals of Biomedical Engineering

JF - Annals of Biomedical Engineering

SN - 0090-6964

IS - 1

ER -