Investigation of Vessel Growth and its Impact on Hemodynamics in Patients With Lateral Tunnel Total Cavopulmonary Connection

2012 ◽  
Author(s):  
Maria Restrepo ◽  
Lucia Mirabella ◽  
Elaine Tang ◽  
Chris Haggerty ◽  
Mark A. Fogel ◽  
...  
Keyword(s):  
Heart Defects ◽  
Fontan Procedure ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Total Cavopulmonary Connection ◽  
Lateral Tunnel ◽  
Vessel Growth ◽  
Original Size ◽  
The Right ◽  
Cavopulmonary Connection

Single ventricle heart defects affect 2 per 1000 live births in the US and are lethal if left untreated. The Fontan procedure used to treat these defects consists of a series of palliative surgeries to create the total cavopulmonary connection (TCPC), which bypasses the right heart. In the last stage of this procedure, the inferior vena cava (IVC) is connected to the pulmonary arteries (PA) using one of the two approaches: the extra-cardiac (EC), where a synthetic graft is used as the conduit; and the lateral tunnel (LT) where part of the atrial wall is used along with a synthetic patch to create the conduit. The LT conduit is thought to grow in size in the long term because it is formed partially with biological tissue, as opposed to the EC conduit that retains its original size because it contains only synthetic material. The growth of the LT has not been yet quantified, especially in respect to the growth of other vessels forming the TCPC. Furthermore, the effect of this growth on the hemodynamics has not been elucidated. The objective of this study is to quantify the TCPC vessels growth in LT patients from serial magnetic resonance (MR) images, and to understand its effect on the connection hemodynamics using computational fluid dynamics (CFD).

Hemodynamic Impact of Stenting in the Total Cavopulmonary Connection With Lateral Tunnel Stenosis

2012 ◽  
Author(s):  
Elaine Tang ◽  
Doff B. McElhinney ◽  
Ajit P. Yoganathan
Keyword(s):  
Heart Defects ◽  
Superior Vena ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Total Cavopulmonary Connection ◽  
Lateral Tunnel ◽  
The Us ◽  
Intravascular Stent ◽  
The Right ◽  
Cavopulmonary Connection

2 per 1000 children in the US are born with functionally single ventricle (SV) heart defects. To restore the separate systemic and pulmonary circulations, a Total Cavopulmonary Connection (TCPC) is carried out through a series of surgical steps, which result in the direct connection of the superior vena cava (SVC) and inferior vena cava (IVC) to the pulmonary arteries without an intervening pulmonary ventricle. One way to complete the TCPC is by placing a synthetic patch in the right atrium, forming an intracardiac lateral tunnel (LT) as the final step. As patients grow, some LT pathways become stenosed. The stenosis can impose extra resistance to flow in addition to the TCPC in the SV circulation. One method of treating LT stenosis is by placement of an intravascular stent.

Effect of Flow Pulsatility and Wall Compliance on the Energy Loss in the Total Cavopulmonary Connection

2013 ◽  
Author(s):  
Reza H. Khiabani ◽  
Sulisay Phonekeo ◽  
Harish Srinimukesh ◽  
Elaine Tang ◽  
Mark Fogel ◽  
...  
Keyword(s):  
Energy Loss ◽  
Wall Motion ◽  
Heart Defects ◽  
Superior Vena ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Total Cavopulmonary Connection ◽  
Venous Flow ◽  
The Right ◽  
Cavopulmonary Connection

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. In the current practice, surgical interventions on SVHD patients commonly result in the total cavopulmonary connection (TCPC) [1]. 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 and wall motion may result in complex and unsteady flow patterns in the TCPC. Although vessel wall motion and different degrees of pulsatility have been observed in vivo, non-pulsatile (time-averaged) flow boundary conditions and rigid walls have traditionally been assumed in estimating the TCPC hemodynamic parameters (such as energy loss). Recent studies have shown that these assumptions may result in significant inaccuracies in modeling TCPC hemodynamics [2, 3].

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 Investigation of the Effect of Flow Pulsatility on Power Loss in the Total Cavopulmonary Connection

2011 ◽  
Author(s):  
Elaine Tang ◽  
Reza H. Khiabani ◽  
Christopher M. Haggerty ◽  
Ajit P. Yoganathan
Keyword(s):  
Heart Defects ◽  
Pulmonary Arteries ◽  
Patient Specific ◽  
Total Cavopulmonary Connection ◽  
Unique Challenge ◽  
Venae Cavae ◽  
In Vitro Investigation ◽  
The Right ◽  
Cavopulmonary Connection

Total Cavopulmonary Connection (TCPC) is the most common surgical palliation for single ventricle heart defects. In such connections, venae cavae are connected to the pulmonary arteries, bypassing the right ventricle. The patient-specific anatomical complexity makes characterization and optimization of the fluid mechanics a unique challenge.

Design of a Novel Cavopulmonary Assist Device for Fontan Procedures: CFD, PIV, and Hydraulic Testing

2010 ◽  
Author(s):  
Jeffrey R. Kennington ◽  
Steven Frankel ◽  
Jun Chen ◽  
Mark D. Rodefeld ◽  
Guruprasad A. Giridharan
Keyword(s):  
Inferior Vena ◽  
Fontan Procedure ◽  
Pulmonary Arteries ◽  
Hydraulic Testing ◽  
Assist Device ◽  
Lung Resistance ◽  
Left And Right ◽  
The Right ◽  
Cavopulmonary Connection ◽  
Cavopulmonary Assist Device

Single ventricle heart disease is the leading cause of death for birth defects in children under one years of age [1]. The current surgical procedure requires the use of a shunt for the first stage of the surgery. The following surgeries remove the shunt but cannot be performed on a newborn due to higher lung resistance during the first weeks of life. The overall surgical process, known as the Fontan procedure, results in a reconstructed anatomy where the left and right pulmonary arteries are sutured to the superior and inferior vena cavae (SVC/IVC), hence bypassing the right heart. This anatomy is called a total cavopulmonary connection or TCPC.

scholarly journals Increased Energy Loss Due to Twist and Offset Buckling of the Total Cavopulmonary Connection

2017 ◽  
Vol 11 (2) ◽  
Author(s):  
Gokce Nur Oguz ◽  
Senol Piskin ◽  
Erhan Ermek ◽  
Samir Donmazov ◽  
Naz Altekin ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Energy Loss ◽  
Heart Defects ◽  
Venous Pressure ◽  
Vena Cava ◽  
Three Dimensions ◽  
Total Cavopulmonary Connection ◽  
Torsional Deformation ◽  
Porcine Pericardium ◽  
Cavopulmonary Connection

The hemodynamic energy loss through the surgically implanted conduits determines the postoperative cardiac output and exercise capacity following the palliative repair of single-ventricle congenital heart defects. In this study, the hemodynamics of severely deformed surgical pathways due to torsional deformation and anastomosis offset are investigated. We designed a mock-up total cavopulmonary connection (TCPC) circuit to replicate the mechanically failed inferior vena cava (IVC) anastomosis morphologies under physiological venous pressure (9, 12, 15 mmHg), in vitro, employing the commonly used conduit materials: Polytetrafluoroethylene (PTFE), Dacron, and porcine pericardium. The sensitivity of hemodynamic performance to torsional deformation for three different twist angles (0 deg, 30 deg, and 60 deg) and three different caval offsets (0 diameter (D), 0.5D, and 1D) are digitized in three dimensions and employed in computational fluid dynamic (CFD) simulations to determine the corresponding hydrodynamic efficiency levels. A total of 81 deformed conduit configurations are analyzed; the pressure drop values increased from 80 to 1070% with respect to the ideal uniform diameter IVC conduit flow. The investigated surgical materials resulted in significant variations in terms of flow separation and energy loss. For example, the porcine pericardium resulted in a pressure drop that was eight times greater than the Dacron conduit. Likewise, PTFE conduit resulted in a pressure drop that was three times greater than the Dacron conduit under the same venous pressure loading. If anastomosis twist and/or caval offset cannot be avoided intraoperatively due to the anatomy of the patient, alternative conduit materials with high structural stiffness and less influence on hemodynamics can be considered.

scholarly journals Case Report: An Anomalous Left Hepatic Venous Connection in a Patient With Unexpected Cyanosis

2021 ◽  
Vol 9 ◽  
Author(s):  
Fanyan Luo ◽  
Haisong Bu
Keyword(s):  
Rural Areas ◽  
Treatment Time ◽  
Superior Vena ◽  
Vena Cava ◽  
Total Cavopulmonary Connection ◽  
Blood Oxygen Saturation ◽  
Tunnel Technique ◽  
Cardiac Lesions ◽  
The Right ◽  
Cavopulmonary Connection

An anomalous left hepatic venous (LHV) connection is an extremely rare cardiac malformation, and left hepatic venous route abnormalities not associated with other cardiac lesions do not require surgical treatment because they are physiologically benign. However, when venous route abnormalities exist with associated cardiac lesions, the conduct of the cardiac surgical repair must accommodate the abnormal venous anatomy, especially in total cavopulmonary connection patients. Herein, we present a rare case of a 7-year-old Chinese boy about 1 year post bilateral superior vena cava pulmonary anastomosis who presented with severe cyanosis and was referred to our department. However, the patient showed an unexpected gradual decrease in blood oxygen saturation to 60–70% after the extracardiac total cavopulmonary connection (ETCPC) operation. Emergency echocardiography and computed tomography confirmed that the LHV entered the right atrium. Subsequently, the patient undergone completion of a staged TCPC with intra-atrial tunnel technique. This illustrative report highlights the essence of improving the preoperative accurate diagnosis to avoid unplanned reoperation in China, especially for the remote rural areas of eastern countries where the level of health care and services is relatively backward. Failure to identify anomalous LHV connection, in this case, will delay effective treatment past the optimal treatment time.

A Hemi Fontan Operation Performed by an Engineer: Considerations on Virtual Surgery

2013 ◽  
Author(s):  
Giovanni Biglino ◽  
Ethan Kung ◽  
Adam Dorfman ◽  
Andrew M. Taylor ◽  
Edward Bove ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Fontan Operation ◽  
Hybrid Approach ◽  
Pulmonary Arteries ◽  
Virtual Surgery ◽  
Extracardiac Conduit ◽  
Lateral Tunnel ◽  
The Right ◽  
Cavopulmonary Connection

Single ventricle circulation, characterized at birth by a rudimentary or absent left or right ventricle, presents a challenging and life-threatening physiological scenario. Surgical palliation aims to restore the balance between systemic and pulmonary blood flow and is staged, each of the three stages presenting the surgeon with different options: - Stage 1 (Norwood procedure) involves different types of shunting to source pulmonary blood flow, or recently a hybrid approach [1]; - Stage 2 can involve a superior cavopulmonary connection (Glenn operation) or patching between the right atrium and the pulmonary arteries (Hemi Fontan operation [2]); - Stage 3 involves a total cavopulmonary connection with extracardiac conduit or lateral tunnel, or with novel alternatives such as the Y-graft [3].

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.

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