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

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Elizabeth Mack ◽  
Alexandrina Untaroiu
Keyword(s):  
Superior Vena Cava ◽  
Right Atrium ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Right Ventricular Dysfunction ◽  
Patient Specific ◽  
Optimal Size ◽  
Size Change

Currently, the surgical procedure followed by the majority of cardiac surgeons to address right ventricular dysfunction is the Fontan procedure, which connects the superior vena cava and inferior vena cava (IVC) directly to the left and right pulmonary arteries (LPA and RPA, respectively) bypassing the right atrium. The goal of this study is to develop a patient-specific four-way connector to bypass the dysfunctional right ventricle and augment the pulmonary circulation. The four-way connector was intended to channel the blood flow from the inferior and superior vena cava directly to the RPA and LPA. 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 toward the RPA and LPA. The focus for this study was on creating a system that could identify the optimal configuration for the four-way connector for patients from 0 to 20 years of age. A platform was created in ANSYS that utilized the design of experiments (DOE) function to minimize power-loss and blood damage propensity in the connector based on junction geometries. 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. 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.

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

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.

Hemodynamics Characteristics of a Four-Way Right-Atrium Bypass Connector With an Optimized Central Diverter

2018 ◽  
Author(s):  
Elizabeth Mack ◽  
Jakin Jagani ◽  
Alexandrina Untaroiu
Keyword(s):  
Pulmonary Artery ◽  
Inferior Vena Cava ◽  
Stagnation Point ◽  
Superior Vena Cava ◽  
Right Atrium ◽  
Power Loss ◽  
Inferior Vena ◽  
Superior Vena ◽  
Fontan Procedure ◽  
Vena Cava

The most common surgical procedure used to treat right ventricular heart failure is the Fontan procedure, which connects the superior vena cava and the inferior vena cava directly to the left and right pulmonary arteries bypassing the right atrium. Many studies have been performed to improve the Fontan procedure. Research has been done on a four-way connector that can both passively and actively improve flow characteristics of the junction between the Superior Vena Cava (SVC), Inferior Vena Cava (IVC), Left Pulmonary Artery (LPA) and Right Pulmonary Artery (RPA), using an optimized connector and dual propeller system. However, the configuration of these devices do not specify propeller motor placement and has a stagnation point in the center of the connector. This study focuses on creating a housing for the motor in the center of the connector to reduce the stagnation area and further stabilize the propellers. To do this, we created a program in ANSYS that utilizes the design-of-experiment (DOE) function to minimize power-loss and stagnation points in the connector for a given geometry. First, a CFD model is created to simulate the blood flow inside the connector with different housing geometries. The shape and size of the housing are used as parameters for the DOE process. In this study, an enhanced central composite design technique is used to discretize the design space. The objective functions in the DOE are red blood cell residence time and power loss. It was confirmed that the addition of the housing did decrease the size of the stagnation point. In fact, the housing added in stabilizing the flow through the connector by creating a more defined flow path. Because the flowrates from the IVC and SVC are not the same, the best configuration for the housing was found to be asymmetric along the axis of the pulmonary artery. While this is a continuation of previous studies, the creation of an optimized housing for the motors for the propellers makes implementation of the propeller idea more viable in a real life situation. The added stability of the propellers provided by the housing can also decrease the risk of propeller failure due to rotordynamic instability.

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.

scholarly journals P649 Before and after: sinus venosus atrial septal defect

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
I Marco Clement ◽  
R Eiros ◽  
R Dalmau ◽  
T Lopez ◽  
G Guzman ◽  
...  
Keyword(s):  
Atrial Septal Defect ◽  
Left Atrium ◽  
Atrial Flutter ◽  
Superior Vena Cava ◽  
Right Atrium ◽  
Septal Defect ◽  
Superior Vena ◽  
Pulmonary Veins ◽  
Vena Cava ◽  
The Right

Abstract Introduction The diagnosis of sinus venosus atrial septal defect (SVASD) is complex and requires special imaging. Surgery is the conventional treatment; however, transcatheter repair may become an attractive option. Case report A 60 year-old woman was admitted to the cardiology department with several episodes of paroxysmal atrial flutter, atrial fibrillation and atrioventricular nodal reentrant tachycardia. She reported a 10-year history of occasional palpitations which had not been studied. A transthoracic echocardiography revealed severe right ventricle dilatation and moderate dysfunction. Right volume overload appeared to be secondary to a superior SVASD with partial anomalous pulmonary venous drainage. A transesophageal echocardiography confirmed the diagnosis revealing a large SVASD of 16x12 mm (Figure A) with left-right shunt (Qp/Qs 2,2) and two right pulmonary veins draining into the right superior vena cava. Additionally, it demonstrated coronary sinus dilatation secondary to persistent left superior vena cava. CMR and cardiac CT showed right superior and middle pulmonary veins draining into the right superior vena cava 18 mm above the septal defect (Figures B and C). After discussion in clinical session, a percutaneous approach was planned to correct the septal defect and anomalous pulmonary drainage. For this purpose, anatomical data obtained from CMR and CT was needed to plan the procedure. During the intervention two stents graft were deployed in the right superior vena cava. The distal stent was flared at the septal defect level so as to occlude it while redirecting the anomalous pulmonary venous flow to the left atrium (Figure D). Control CT confirmed the complete occlusion of the SVASD without residual communication from pulmonary veins to the right superior vena cava or the right atrium (Figure E). Anomalous right superior and middle pulmonary veins drained into the left atrium below the stents. Transthoracic echocardiographies showed progressive reduction of right atrium and ventricle dilatation. The patient also underwent successful ablation of atrial flutter and intranodal tachycardia. She is currently asymptomatic, without dyspnea or arrhythmic recurrences. Conclusions In this case, multimodality imaging played a key role in every stage of the clinical process. First, it provided the diagnosis and enabled an accurate understanding of the patient’s anatomy, particularly of the anomalous pulmonary venous connections. Secondly, it allowed a transcatheter approach by supplying essential information to guide the procedure. Finally, it assessed the effectiveness of the intervention and the improvement in cardiac hemodynamics during follow-up. Abstract P649 Figure.

TYPES OF CORRECTION OF THE SUPRACARDIAC FORM OF PARTIAL ABNORMAL DRAINAGE OF THE PULMONARY VEINS. WARDEN PROCEDURE

2021 ◽  
pp. 28-31
Author(s):  
Inkar Sagatov ◽  
Nurzhan Dosmailov
Keyword(s):  
Left Atrium ◽  
Superior Vena Cava ◽  
Right Atrium ◽  
Superior Vena ◽  
Pulmonary Veins ◽  
Vena Cava ◽  
Artificial Circulation ◽  
The Right

The article describes the types of correction of the supracardial form of abnormal drainage of the pulmonary veins. One of the methods of correcting this defect is the Warden operation, which includes: after sternotomy, connection of artificial circulation, cardioplegia, the superior vena cava is cut off, the proximal end is sutured. Next, a right atriotomy is performed, an anastomosis is formed using an autopericardial patch between the abnormal drainage and the left atrium through the ASD. Then an anastomosis is formed between the auricle of the right atrium and the distal end of the superior vena cava. As a result, blood from the abnormal pulmonary veins begins to drain into the left atrium through the ASD.

Persistent left superior vena cava and its clinical correlation - A cadaveric study

2021 ◽  
Vol 12 (4) ◽  
pp. 118-121
Author(s):  
Sachendra Kumar Mittal ◽  
Rekha Parashar ◽  
Pankaj Kumar Singh ◽  
Leena Jadon
Keyword(s):  
Superior Vena Cava ◽  
Right Atrium ◽  
Superior Vena ◽  
Vena Cava ◽  
Medical Sciences ◽  
Left Superior Vena Cava ◽  
Persistent Left Superior Vena ◽  
Male Cadaver ◽  
The Right ◽  
Brachiocephalic Veins

Background: Presented is a case of persistent left superior vena cava draining into the right atrium through coronary sinus and finally opens into right atrium. Abnormalities of the vascular system are more commonly seen due to its importance in circulation. Persistent left superior vena cava is rare but important congenital vascular anomaly. It results when the left superior cardinal vein caudal to the innominate vein fails to regress.The venous anomaly of a persistent left superior vena cava (PLSVC) affects 0.3%–0.5% of the general population. Normally the superior vena cava is a single vascular structure formed by the union of right and left brachiocephalic veins which are in turn formed by the union of internal jugular and subclavian veins of corresponding side, draining the head and neck as well as the superior extremity. Aims and Objective: To evaluate the accuracy of persistent left superior vena cava and to find out the opening of PLSVC and formations of both SVC. Materials and Methods: During routine dissection of Thorax, we have opened the thoracic cage and take out the Heart. during that we found separate SVC and then we did the study on this PLSVC in the Department of Anatomy, Jaipur National University Institute for Medical Sciences and Research Centre (JNUIMSRC) Jaipur and National Institute of Medical Sciences and Research (NIMS & R). Results: We found persistent left superior vena cava in two cadavers out of 30 cadavers (6.66%) one was 64-year-old male cadaver and another 72-year-old male cadaver. Both the vena cavae were formed as of brachiocephalic veins of the corresponding side. The persistent left superior vena cava opened into the enlarged coronary sinus that drained into the right atrium between the opening of inferior vena cava and right atrio-ventricular orifice. Conclusion: It has important clinical implications in certain clinical interventions. It may complicate placementof cardiac catheters or pacemaker leads.

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