Effect of Flow Pulsatility on 2nd Stage Fontan Hemodynamics: An In Vitro Investigation

2009 ◽  
Author(s):  
Christopher M. Haggerty ◽  
Lakshmi P. Dasi ◽  
Jessica Kanter ◽  
Ajit P. Yoganathan
Keyword(s):  
Congenital Heart ◽  
Single Ventricle ◽  
Heart Defects ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Second Stage ◽  
In Vitro Investigation

The Fontan procedure [1] is the staged, palliative surgical approach used to treat patients suffering from single ventricle congenital heart defects. The second stage of this procedure involves the connection of the superior vena cava (SVC) to the pulmonary arteries (PAs) in either an end-to-side (known as the Bi-Directional Glenn (BDG)) or side-to-side (or Hemi-Fontan (HF)) fashion. Because of obvious disparities at the connection site, there are understandable differences in the fluid dynamics between the two geometries.

Optimization of an Idealized Y-Graft for the Fontan Procedure Using CFD and a Derivative-Free Optimization Algorithm

2009 ◽  
Author(s):  
Weiguang Yang ◽  
Jeffrey A. Feinstein ◽  
V. Mohan Reddy ◽  
Alison L. Marsden
Keyword(s):  
Heart Defects ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Survival Rates ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Protein Losing Enteropathy ◽  
Second Stage ◽  
Derivative Free Optimization ◽  
Derivative Free

The Fontan procedure is a surgery performed to treat patients with single ventricle congenital heart defects. The Fontan is the final of three surgical stages. The first stage consists of aortic reconstruction, in a Norwood procedure or variant thereof. In the second stage, the Bidirectional Glenn procedure, the superior vena cava (SVC) is disconnected from the heart and redirected into the pulmonary arteries (PAs). In the third and final stage, the inferior vena cava (IVC) is connected to PAs via a straight Gore-Tex tube, forming a T-shaped junction. Although early survival rates following the Fontan procedure can exceed 90%, significant morbidity remains after surgery including venous hemodynamic abnormalities, diminished exercise capacity, thromboembolic complications, protein-losing enteropathy, heart transplant etc. [1].

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

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.

Effect of Flow Pulsatility on Modeling the Total Cavopulmonary Hemodynamics: A Numerical Investigation

2012 ◽  
Author(s):  
Reza H. Khiabani ◽  
Maria Restrepo ◽  
Elaine Tang ◽  
Diane De Zélicourt ◽  
Mark Fogel ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Heart Defects ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Venous Flow ◽  
Surgical Interventions ◽  
The Right

Single Ventricle Heart Defects (SVHD) are present in 2 per 1000 live births in the US. SVHD are characterized by cyanotic mixing between the de-oxygenated blood from the systemic circulation return and the oxygenated blood from the pulmonary arteries. Palliative surgical repairs (Fontan procedure) are performed to bypass the right ventricle in these patients. In current practice, the surgical interventions commonly result in the total cavopulmonary connection (TCPC). In this configuration the systemic venous returns (inferior vena cava, IVC, and superior vena cava, SVC) are directly routed to the right and left pulmonary arteries (RPA and LPA), bypassing the right heart. The resulting anatomy has complex and unsteady hemodynamics characterized by flow mixing and flow separation. Pulsation of the inlet venous flow during a cardiac cycle results in complex and unsteady flow patterns in the TCPC. Although various degrees of pulsatility have been observed in vivo, non-pulsatile (time-averaged) flow boundary conditions have traditionally been assumed in modeling TCPC hemodynamics, and only recently have pulsatile conditions been incorporated without completely characterizing their effect or importance. In this study, 3D numerical simulations were performed to predict TCPC hemodynamics with both pulsatile and non-pulsatile boundary conditions and to investigate the accuracy of applying non-pulsatile boundary conditions. Flow structures, energy dissipation rate and pressure drop were compared under rest and estimated exercise conditions. The results show that TCPC hemodynamics can be strongly influenced by the presence of pulsatile flow. However, there exists a minimum pulsatility threshold, identified by defining a weighted pulsatility index (wPI), above which the influence is significant.

Comparison of Clinical and Simulation Results for the Stanford Y-Graft Fontan Pilot Trial

2012 ◽  
Author(s):  
Weiguang Yang ◽  
Jeffrey A. Feinstein ◽  
V. Mohan Reddy ◽  
Frandics P. Chan ◽  
Alison L. Marsden
Keyword(s):  
Inferior Vena ◽  
Single Ventricle ◽  
Heart Defects ◽  
Fontan Procedure ◽  
Pilot Trial ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Extracardiac Conduit ◽  
Lateral Tunnel ◽  
Third Stage

Without surgical palliation, single ventricle heart defects are uniformly fatal. A three-staged surgical repair is typically performed on these patients, who are otherwise severely cyanotic. In the third stage, the Fontan procedure, the inferior vena cava (IVC) is connected to the pulmonary arteries (PAs) via a lateral tunnel or extracardiac conduit. Following Fontan completion, deoxygenated blood from the upper and lower body is redirected to the PAs, bypassing the heart.

In Vitro Study of Pulmonary Vascular Resistance in Fontan Circulation With Respiration Effects

2012 ◽  
Author(s):  
Marija Vukicevic ◽  
Timothy A. Conover ◽  
Jian Zhou ◽  
Tain-Yen Hsia ◽  
Richard S. Figliola
Keyword(s):  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Heart Defects ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Fontan Operation ◽  
Venous Pressure ◽  
Pulmonary Arteries ◽  
Pulmonary Regurgitation ◽  
Vena Cava

The Fontan operation is the final stage of palliative surgery for children born with single ventricle heart defects. The most common configuration is called total cavopulmonary connection (TCPC), wherein the inferior vena cava and superior vena cava are anastomosed directly to the pulmonary arteries; therefore the pulmonary circulation is driven by venous pressure only. The Fontan procedure, although successful in the early postoperative period, with time can decrease in efficiency or even fail within several years after the operation. The reasons of different clinical outcomes for some of the Fontan patients are not clear enough, even though it is commonly accepted that certain factors such as low pulmonary vascular resistance and proper shape and size of the TCPC construction are crucial for the succesful long term outcomes. Accordingly, one of the major problems is the increase in pulmonary vascular resistance due to altered hemodynamics after the surgery, causing venous hypertension and respiratory-dependent pulmonary regurgitation [1]. The main pulmonary arteries may also see increased resistance due to congenital malformations, surgical scarring, or deliberate surgical banding. Thus, the consequence of the increased pulmonary vascular resistance at both proximal and distal locations with respect to the TCPC junction, and its effect on the systemic pressures and flow rates, is the main objective of this study.

Kawashima by Fenestrated Hemi-Fontan for Palliation Following Prior Stage I Norwood Operation

2018 ◽  
Vol 9 (4) ◽  
pp. 451-453 ◽  
Author(s):  
Jenny E. Zablah ◽  
Michael Ross ◽  
Neil Wilson ◽  
Brian Fonseca ◽  
Max B. Mitchell
Keyword(s):  
Single Ventricle ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Venous Blood ◽  
Young Infant ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Stage I ◽  
Azygos Continuation ◽  
Cavopulmonary Shunt

Single ventricle patients with interrupted inferior vena cava (IVC) and azygos continuation to the superior vena cava (SVC) are typically palliated with a bidirectional cavopulmonary shunt (BCPS), known as the Kawashima operation in this setting. Because the volume of venous blood directed to the pulmonary arteries is substantially greater in the presence of interrupted IVC, Kawashima procedures are commonly delayed to older age compared to other single ventricle patients undergoing BCPS. We report two young infant single ventricle patients with interrupted IVC and azygos continuation to the SVC who underwent stage I Norwood procedures for initial palliation. In both cases, a fenestrated hemi-Fontan procedure achieved successful Kawashima circulations.

Customization of the Fontan Y-Graft: Are Unequal Branches Necessary for Optimal Hepatic Flow Distribution?

2011 ◽  
Author(s):  
Weiguang Yang ◽  
Jeffrey A. Feinstein ◽  
Irene E. Vignon-Clementel ◽  
Shawn C. Shadden ◽  
Alison L. Marsden
Keyword(s):  
Heart Diseases ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Flow Distribution ◽  
Shunt Insertion ◽  
Second Stage ◽  
Clinical Complications ◽  
Surgical Complexity

Due to surgical complexity and clinical complications, single ventricle defects are among the most severe and challenging congenital heart diseases to treat. Patients usually undergo a three-staged surgery. The first stage consists of shunt insertion and 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.

Abstract 405: A Personalized, 3D Printed in vitro Model of Vascular Anastomosis in Single Ventricle Heart Defects

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Martin L Tomov ◽  
Bowen Jing ◽  
Akaash Kumar ◽  
Katherine Do ◽  
Alexander Cetnar ◽  
...  
Keyword(s):  
Complex Disease ◽  
Single Ventricle ◽  
Heart Defects ◽  
Pulmonary Arteries ◽  
High Risk Population ◽  
Catheterization Laboratory ◽  
Cardiac Catheterization Laboratory ◽  
Advanced Planning ◽  
Vitro Model

Single ventricle physiology is a complex disease state requiring multiple open-heart surgeries to achieve stable hemodynamics. For patients with abnormalities in the pulmonary arteries (PAs), these must be remedied before the patient can be a candidate for such palliations. Transcatheter techniques could rescue this subset of single ventricle patients through intervascular PA connections, allowing a high-risk population to ultimately achieve stable pulmonary blood flow. However, there is currently no in vitro platform to model transcatheter processes for anastomosis, particularly to palliate single ventricle defects. This project utilizes 3D bioprinting and perfusion bioreactor technologies to develop a functional in vitro biological device to model severely stenotic PAs of single ventricle patients. Human endothelial (ECs) & smooth muscle (SMCs) cells embedded in extracellular matrix bioink are used in a multi-material bioprinting approach to create 3D bilayer vascular structures with controlled geometry and flow. In collaboration with CHOA Cardiac Catheterization Laboratory , stent devices are deployed in the printed model to re-establish intervascular connection. Healthy, stenotic, and stented tissues are cultured via a bioreactor and analyzed for flow hemodynamics by echo PIV and 4D MR imaging. Cell viability, proliferation, and endothelialization of printed vessels, plus EC-SMC interplay were closely monitored pre- and post- anastomosis, to identify the effect of geometry and flow on cellular overgrowth. This advanced planning enables a subset of single ventricle patients, otherwise not eligible, to ultimately accept further palliative strategies.

Superior Vena Cava Banding to Facilitate Unilateral Bidirectional Glenn Operation in Patients With Single Ventricle Heart Disease and Bilateral Superior Caval Veins

2016 ◽  
Vol 8 (2) ◽  
pp. 215-219 ◽  
Author(s):  
Matthew C. Schwartz ◽  
David Nykanen ◽  
William DeCampli ◽  
Kamal Pourmoghadam
Keyword(s):  
Heart Disease ◽  
Congenital Heart ◽  
Single Ventricle ◽  
Superior Vena ◽  
Vena Cava ◽  
Novel Technique ◽  
Bidirectional Glenn ◽  
Increased Risk ◽  
Bridging Vein ◽  
Cavopulmonary Connection

Staged palliation to achieve a total cavopulmonary connection is a common treatment strategy in patients with single ventricle congenital heart disease. Patients with bilateral superior caval veins (bilateral SVC) often require the creation of bilateral superior cavopulmonary connections as part of the staged palliation, and these patients are at increased risk of morbidity. We describe a novel technique used in two patients with bilateral SVC and very small (1-2 mm) bridging vein that encouraged bridging vein growth and facilitated creation of a unilateral superior cavopulmonary connection.

scholarly journals In search of “hepatic factor:” Lack of evidence for ALK1 ligands BMP9 and BMP10

2020 ◽  
Author(s):  
Teresa L. Capasso ◽  
Sara M. Trucco ◽  
Morgan Hindes ◽  
Tristin Schwartze ◽  
Jamie L. Bloch ◽  
...  
Keyword(s):  
Single Ventricle ◽  
Venous Return ◽  
Superior Vena ◽  
Plasma Concentrations ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Systemic Circulation ◽  
Pulmonary Vasculature ◽  
Morphogenetic Protein ◽  
Bone Morphogenetic Protein 9

AbstractIn children with single ventricle physiology, the Glenn procedure is performed to redirect venous return from the superior vena cava directly to the pulmonary arteries and route venous return from the inferior vena cava exclusively to the systemic circulation. Although this surgery successfully palliates the hemodynamic stress experienced by the single ventricle, patients frequently develop pulmonary arteriovenous malformations (PAVMs). Interestingly, PAVMs may regress upon rerouting of hepatic venous effluent to the pulmonary vasculature, suggesting the presence of a circulating “hepatic factor” that is required to prevent PAVMs. Here, we test the hypothesis that hepatic factor is bone morphogenetic protein 9 (BMP9) and/or BMP10. These circulating ligands are produced by the liver and activate endothelial endoglin (ENG)/ALK1 signaling, and mutations in ENG and ALK1 cause hereditary hemorrhagic telangiectasia, a genetic disease associated with AVM development. However, we found no within-subject variation in BMP9, BMP10, or BMP9/10 plasma concentrations when sampled from five cardiovascular sites, failing to support the idea that the Glenn would limit access of these ligands to the lung vasculature. Unexpectedly, however, we found a significant decrease in all three ligand concentrations in Glenn cases versus controls. Our findings suggest that BMP9/BMP10/ENG/ALK1 signaling may be decreased in the Glenn vasculature but fail to implicate these ligands as hepatic factor.

Sign in / Sign up

Export Citation Format

Share Document