Echocardiographic assessment of blood flow volume in the superior vena cava and descending aorta in the newborn infant

The bidirectional cavopulmonary anastomosis (BCPA or bidirectional Glenn) is an operation to treat congenital heart diseases of the right heart by diverting the systemic venous return from the superior vena cava to both lungs. The main goal is to provide the correct perfusion to both lungs avoiding an excessive increase in systemic venous pressure. One of the factors which can affect the clinical outcome of the surgically reconstructed circulation is the amount of pulsatile blood flow coming from the main pulmonary artery. The purpose of this work is to analyse the influence of this factor on the BCPA hemodynamics. A 3-D finite element model of the BCPA has been developed to reproduce the flow of the surgically reconstructed district. Geometry and hemodynamic data have been taken from angiocardiogram and catheterization reports, respectively. On the basis of the developed 3-D model, four simulations have been performed with increasing pulsatile blood flow rate from the main pulmonary artery. The results show that hemodynamics in the pulmonary arteries are greatly influenced by the amount of flow through the native main pulmonary artery and that the flow from the superior vena cava allows to have a similar distribution of the blood to both lungs, with a little predilection for the left side, in agreement with clinical postoperative data.

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Use of Superior Vena Cava-Right Pulmonary Artery Anastomosis in Congenital Heart Disease with Decreased Pulmonary Blood Flow

Circulation ◽

10.1161/01.cir.40.6.777 ◽

1969 ◽

Vol 40 (6) ◽

pp. 777-784 ◽

Cited By ~ 3

Author(s):

IRWIN B. BORUCHOW ◽

THOMAS D. BARTLEY ◽

LARRY P. ELLIOTT ◽

MYRON W. WHEAT ◽

L. JEROME KROVETZ ◽

...

Keyword(s):

Congenital Heart Disease ◽

Blood Flow ◽

Heart Disease ◽

Pulmonary Artery ◽

Superior Vena Cava ◽

Pulmonary Blood Flow ◽

Congenital Heart ◽

Superior Vena ◽

Vena Cava ◽

Right Pulmonary Artery

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Hemodynamics Characteristics of a Four-Way Right-Atrium Bypass Connector

Volume 1C, Symposia: Gas-Liquid Two-Phase Flows; Gas and Liquid-Solid Two-Phase Flows; Numerical Methods for Multiphase Flow; Turbulent Flows: Issues and Perspectives; Flow Applications in Aerospace; Fluid Power; Bio-Inspired Fluid Mechanics; Flow Manipulation and Active Control; Fundamental Issues and Perspectives in Fluid Mechanics; Transport Phenomena in Energy Conversion From Clean and Sustainable Resources; Transport Phenomena in Materials Processing and Manufacturing Processes ◽

10.1115/fedsm2017-69470 ◽

2017 ◽

Author(s):

Elizabeth Mack ◽

Alexandrina Untaroiu

Keyword(s):

Blood Flow ◽

Superior Vena Cava ◽

Right Atrium ◽

Superior Vena ◽

Pulmonary Arteries ◽

Vena Cava ◽

Design Parameters ◽

Patient Specific ◽

Optimal Size ◽

The Right

Currently, the surgical procedure followed by the majority of cardiac surgeons to address right ventricular dysfunction is the Fontan procedure, which connects the superior and inferior vena cava directly to the left and right pulmonary arteries bypassing the right atrium. However, this is not the most efficient configuration from a hemodynamics perspective. The goal of this study is to develop a patient-specific 4-way connector to bypass the dysfunctional right ventricle and augment the pulmonary circulation. The 4-way connector is intended to channel the blood flow from the inferior and superior vena cava directly to the right and left pulmonary arteries. By creating a connector with proper hemodynamic characteristics, one can control the jet flow interactions between the inferior and superior vena cava and streamline the flow towards the right and left pulmonary arteries. In this study the focus is on creating a system that can identify the optimal configuration for the 4-way connector for patients from 0–20 years of age. A platform is created in ANSYS that utilizes the DOE function to minimize power-loss and blood damage propensity in the connector based on junction geometries. A CFD model is created to simulate the blood flow through the connector. Then the geometry of the bypass connector is parameterized for DOE process. The selected design parameters include inlet and outlet diameters, radius at the intersection, and length of the connector pathways. The chosen range for each geometric parameter is based on the relative size of the patient’s arteries found in the literature. It was confirmed that as the patient’s age and artery size change, the optimal size and shape of the connector also changes. However, the corner radius did not decrease at the same rate as the opening diameters. This means that creating different sized connectors is not just a matter of scaling the original connector to match the desired opening diameter. However, it was found that power losses within the connector decrease and average and maximum blood traversal time through the connector increased for increasing opening radius. This information could be used to create a more specific relationship between the opening radius and the flow characteristics. So in order to create patient specific connectors, either a new more complicated trend needs to be found or an optimization program would need to be run on each patient’s specific geometry when they need a new connector.

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