Interventional Planning for Endovascular Revision of a Lateral Tunnel Fontan: A Patient-Specific Computational Analysis

IntroductionA 2-year-old female with hypoplastic left heart syndrome (HLHS)-variant, a complex congenital heart defect (CHD) characterized by the underdevelopment of the left ventricle, presented with complications following single ventricle palliation. Diagnostic work-up revealed elevated Fontan pathway pressures, as well as significant dilation of the inferior Fontan pathway with inefficient swirling flow and hepatic venous reflux. Due to the frail condition of the patient, the clinical team considered an endovascular revision of the Fontan pathway. In this work, we performed a computational fluid dynamics (CFD) analysis informed by data on anatomy, flow, and pressure to investigate the hemodynamic effect of the endovascular Fontan revision.MethodsA patient-specific anatomical model of the Fontan pathway was constructed from magnetic resonance imaging (MRI) data using the cardiovascular modeling software CardiovasculaR Integrated Modeling and SimulatiON (CRIMSON). We first created and calibrated a pre-intervention 3D-0D multi-scale model of the patient’s circulation using fluid-structure interaction (FSI) analyses and custom lumped parameter models (LPMs), including the Fontan pathway, the single ventricle, arterial and venous systemic, and pulmonary circulations. Model parameters were iteratively tuned until simulation results matched clinical data on flow and pressure. Following calibration of the pre-intervention model, a custom bifurcated endograft was introduced into the anatomical model to virtually assess post-intervention hemodynamics.ResultsThe pre-intervention model successfully reproduced the clinical hemodynamic data on regional flow splits, pressures, and hepatic venous reflux. The proposed endovascular repair model revealed increases of mean and pulse pressure at the inferior vena cava (IVC) of 6 and 29%, respectively. Inflows at the superior vena cava (SVC) and IVC were each reduced by 5%, whereas outflows at the left pulmonary artery (LPA) and right pulmonary artery (RPA) increased by 4%. Hepatic venous reflux increased by 6%.ConclusionOur computational analysis indicated that the proposed endovascular revision would lead to unfavorable hemodynamic conditions. For these reasons, the clinical team decided to forgo the proposed endovascular repair and to reassess the management of this patient. This study confirms the relevance of CFD modeling as a beneficial tool in surgical planning for single ventricle CHD patients.

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NUMERICAL STUDY OF BIDIRECTIONAL GLENN WITH UNILATERAL PULMONARY ARTERY STENOSIS

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519414500560 ◽

2014 ◽

Vol 14 (04) ◽

pp. 1450056 ◽

Cited By ~ 1

Author(s):

XI ZHAO ◽

YOUJUN LIU ◽

JINLI DING ◽

FAN BAI ◽

XIAOCHEN REN ◽

...

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Pulmonary Artery ◽

Superior Vena Cava ◽

Superior Vena ◽

Vena Cava ◽

Artery Stenosis ◽

Patient Specific ◽

Pulmonary Artery Stenosis ◽

Bidirectional Glenn

Purpose: Hypoplastic left heart syndrome (HLHS) is a congenital heart disease and is usually associated with pulmonary artery stenosis. The superior vena cava-to-pulmonary artery (bidirectional Glenn) shunt is used primarily as a staging procedure to the total cava-to-pulmonary connection for single-ventricle complex. When HLHS coexists with pulmonary artery stenosis, the surgeons then face a multiple problem. This leads to high demand of optimized structure of Glenn surgery. The objective of this article is to investigate the influence of various anastomotic structures and the direction of superior vena cava (SVC) in Glenn on hemodynamics under pulse inflow conditions and try to find an optimal structure of SVC in Glenn surgery with unilateral pulmonary artery stenosis.Method: First, 3D patient-specific models were constructed from medical images of a HLHS patient before any surgery by using the commercial software Mimics, and another software Free-form was used to deform the reconstructed models in the computer. Four 3D patient-specific Glenn models were constructed: model-1 (normal Glenn), model-2 (lean the SVC back to the stenotic pulmonary artery), model-3 (lean the SVC towards the stenotic pulmonary artery), model-4 (add patch at junction of the SVC toward stenosis at pulmonary artery). Second, a lumped parameter model (LPM) was established to predict boundary conditions for computational fluid dynamics (CFD). In addition, numerical simulations were conducted using CFD through the finite volume method. Finally, hemodynamic parameters were obtained and evaluated.Results: It was showed that model-4 have relatively balanced vena cava blood perfusion into the left pulmonary artery (LPA) and right pulmonary artery (RPA), this may be due to less helical flow and the patch at junction of the SVC. Near stenosis of pulmonary artery, model-4 performed with the higher wall shear stress (WSS), which would benefit endothelial cell function and gene expression. In addition, results showed that model-4 performed with the lower oscillatory shear index (OSI) and wall shear stress gradient (WSSG), which would decrease the opportunity of vascular intimal hyperplasia.Conclusion: It is benefited that surgeons adds patch at junction of the SVC towards stenosis at pulmonary artery. These results can impact the surgical design and planning of the Glenn surgery with unilateral pulmonary artery stenosis.

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Hepatic Venous Blood Flow Distribution in the Total Cavopulmonary Connection: Patient-Specific Anatomical Models

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176392 ◽

2007 ◽

Cited By ~ 2

Author(s):

Lakshmi Dasi ◽

Kerem Pekkan ◽

Kevin Whitehead ◽

Mark Fogel ◽

Ajit Yoganathan

Keyword(s):

Single Ventricle ◽

Venous Blood ◽

Vena Cava ◽

Flow Distribution ◽

Experimental Models ◽

Cfd Modeling ◽

Normal Lung ◽

Patient Specific ◽

Circulation System ◽

Venous Blood Flow

CFD modeling of the anatomical pathways (TCPC) created by the palliative single-ventricle heart defect surgeries is an area studied by several research groups [1–5]. To the best of our knowledge except Walker et al. (in idealized experimental models) [6], all studies focused on the prediction of hydrodynamic power losses or dissipation function and ignored venous hepatic flow distribution to the left and right lungs. Hepatic flow coming from the inferior vena cava (IVC) transports essential growth factors that are required for normal lung growth. Inadequate IVC blood distribution also cause protein loosing enteropathy [7], a serious complex pathology leading to total failure of the surgically created single-ventricle circulation system. Early TCPC configurations distributing the hepatic flow unidirectionaly to one of the lungs [8] were promptly discontinued from the operating rooms and replaced with “+” shaped connections for these reasons, Fig 1.

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Virtual Design for the Fontan Procedure: From Idealized to Patient Specific Models Using CFD and Derivative-Free Optimization

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19683 ◽

2010 ◽

Author(s):

Weiguang Yang ◽

Guillaume Troianowski ◽

Alexandre Birolleau ◽

Irene Vignon-Clementel ◽

Jeffrey A. Feinstein ◽

...

Keyword(s):

Single Ventricle ◽

Heart Defects ◽

Superior Vena ◽

Fontan Procedure ◽

Pulmonary Arteries ◽

Vena Cava ◽

Patient Specific ◽

Virtual Design ◽

Modeling Tools ◽

Patient Specific Modeling

Single ventricle congenital heart defects are among the most challenging for pediatric cardiologists to treat. Children born with these defects are cyanotic, and these conditions are nearly uniformly fatal without treatment. A series of surgeries is performed to palliate single ventricle defects. The first stage consists of aortic reconstruction in a Norwood procedure. In the second stage, the Bidirectional Glenn procedure, the superior vena cava (SVC) is disconnected from the heart and redirected into the pulmonary arteries (PA’s). In the third and final stage, the Fontan procedure, the inferior vena cava (IVC) is connected to the PA’s via a straight Gore-Tex tube, forming a T-shaped junction with or without offset. Patient specific modeling tools provide a means to evaluate new designs with the goal of lowering long-term morbidity and improving patients’ quality of life.

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Comparison of Particle Image Velocimetry and Phase Contrast MRI in a Patient-Specific Extracardiac Total Cavopulmonary Connection

Journal of Biomechanical Engineering ◽

10.1115/1.2900725 ◽

2008 ◽

Vol 130 (4) ◽

Cited By ~ 19

Author(s):

Hiroumi D. Kitajima ◽

Kartik S. Sundareswaran ◽

Thomas Z. Teisseyre ◽

Garrett W. Astary ◽

W. James Parks ◽

...

Keyword(s):

Particle Image Velocimetry ◽

Pulmonary Artery ◽

Phase Contrast ◽

Particle Image ◽

Vena Cava ◽

Patient Specific ◽

Flow Structures ◽

Total Cavopulmonary Connection ◽

Image Velocimetry ◽

Cavopulmonary Connection

Particle image velocimetry (PIV) and phase contrast magnetic resonance imaging (PC-MRI) have not been compared in complex biofluid environments. Such analysis is particularly useful to investigate flow structures in the correction of single ventricle congenital heart defects, where fluid dynamic efficiency is essential. A stereolithographic replica of an extracardiac total cavopulmonary connection (TCPC) is studied using PIV and PC-MRI in a steady flow loop. Volumetric two-component PIV is compared to volumetric three-component PC-MRI at various flow conditions. Similar flow structures are observed in both PIV and PC-MRI, where smooth flow dominates the extracardiac TCPC, and superior vena cava flow is preferential to the right pulmonary artery, while inferior vena cava flow is preferential to the left pulmonary artery. Where three-component velocity is available in PC-MRI studies, some helical flow in the extracardiac TCPC is observed. Vessel cross sections provide an effective means of validation for both experiments, and velocity magnitudes are of the same order. The results highlight similarities to validate flow in a complex patient-specific extracardiac TCPC. Additional information obtained by velocity in three components further describes the complexity of the flow in anatomic structures.

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