scholarly journals Characterization of the Ejector Pump Performance for the Assisted Bidirectional Glenn Procedure

Fluids ◽  
2022 ◽  
Vol 7 (1) ◽  
pp. 31
Author(s):  
Dongjie Jia ◽  
Mahdi Esmaily
Keyword(s):  
Superior Vena ◽  
Vena Cava ◽  
Mechanical Efficiency ◽  
Algebraic Model ◽  
Cfd Simulations ◽  
Dimensional Parameter ◽  
Bidirectional Glenn ◽  
Added Benefit ◽  
Computational Fluid Dynamics Cfd ◽  
Ejector Pump

This study introduces an algebraic model informed by computational fluid dynamics (CFD) simulations to investigate the performance of the assisted bidirectional Glenn (ABG) operation on a broad range of conditions. The performance of this operation, as measured by the superior vena cava (SVC) pressure, depends on the nozzle area in its ejector pump and the patient’s pulmonary vascular resistance (PVR). Using the developed algebraic model to explore this two-dimensional parameter space shows that the ejector pump can create a pressure difference between the pulmonary artery and the SVC as high as 5 mmHg. The lowest SVC pressure is produced at a nozzle area that decreases linearly with the PVR such that, at PVR =4.2 (Wood units-m2), there is no added benefit in utilizing the ejector pump effect (optimal nozzle area is zero, corresponding to the bidirectional Glenn circulation). At PVR =2 (Wood units-m2), the SVC pressure can be lowered to less than 4 mmHg by using an optimal nozzle area of ≈2.5 mm2. Regardless of the PVR, adding a 2 mm2 nozzle to the baseline bidirectional Glenn boosts the oxygen saturation and delivery by at least 15%. The SVC pressure for that 2 mm2 nozzle remains below 14 mmHg for all PVRs less than 7 Wood units-m2. The mechanical efficiency of the optimal designs consistently remains below 30%, indicating the potential for improvement in the future. A good agreement is observed between the algebraic model and high-fidelity CFD simulations.

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.

NUMERICAL STUDY OF BIDIRECTIONAL GLENN WITH UNILATERAL PULMONARY ARTERY STENOSIS

2014 ◽  
Vol 14 (04) ◽  
pp. 1450056 ◽  
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.

scholarly journals Decompression of superior vena cava during bidirectional Glenn shunt

2009 ◽  
Vol 12 (2) ◽  
pp. 146 ◽  
Author(s):  
Venugopal Kulkarni ◽  
Ravikiran Mudunuri ◽  
Krishnaprasad Mulavisala ◽  
RJagannath Byalal
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Glenn Shunt ◽  
Bidirectional Glenn ◽  
Bidirectional Glenn Shunt

An Efficient Assisted Bidirectional Glenn Design With Lowered Superior Vena Cava Pressure for Stage-One Single Ventricle Patients

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Dongjie Jia ◽  
Matthew Peroni ◽  
Tigran Khalapyan ◽  
Mahdi Esmaily
Keyword(s):  
Superior Vena Cava ◽  
Single Ventricle ◽  
Superior Vena ◽  
Vena Cava ◽  
Bidirectional Glenn ◽  
Pulmonary Flow ◽  
Optimization Study ◽  
Shaped Nozzle ◽  
The Right ◽  
Brachiocephalic Veins

Abstract Recently, the assisted bidirectional Glenn (ABG) procedure has been proposed as an alternative to the modified Blalock–Taussig shunt (mBTS) operation for neonates with single-ventricle physiology. Despite success in reducing heart workload and maintaining sufficient pulmonary flow, the ABG also raised the superior vena cava (SVC) pressure to a level that may not be tolerated by infants. To lower the SVC pressure, we propose a modified version of the ABG (mABG), in which a shunt with a slit-shaped nozzle exit is inserted at the junction of the right and left brachiocephalic veins. The proposed operation is compared against the ABG, the mBTS, and the bidirectional Glenn (BDG) operations using closed-loop multiscale simulations. Both normal (2.3 Wood units-m2) and high (7 Wood units-m2) pulmonary vascular resistance (PVR) values are simulated. The mABG provides the highest oxygen saturation, oxygen delivery, and pulmonary flow rate in comparison to the BDG and the ABG. At normal PVR, the SVC pressure is significantly reduced below that of the ABG and the BDG (mABG: 4; ABG: 8; BDG: 6; mBTS: 3 mmHg). However, the SVC pressure remains high at high PVR (mABG: 15; ABG: 16; BDG: 12; mBTS: 3 mmHg), motivating an optimization study to improve the ABG hemodynamics efficiency for a broader range of conditions in the future. Overall, the mABG preserves all advantages of the original ABG procedure while reducing the SVC pressure at normal PVR.

scholarly journals Decompression of superior vena cava during bidirectional Glenn shunt: A simple but risky technique

2012 ◽  
Vol 15 (1) ◽  
pp. 90 ◽  
Author(s):  
PraveenKumar Neema ◽  
Sethuraman Manikandan ◽  
SubrataK Singha ◽  
RameshChandra Rathod
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Glenn Shunt ◽  
Bidirectional Glenn ◽  
Bidirectional Glenn Shunt

A Modified Technique of Venoatrial Bypass in Bidirectional Glenn Shunt

1996 ◽  
Vol 4 (1) ◽  
pp. 23-24 ◽  
Author(s):  
Manisha Lal ◽  
Tek Singh Mahant
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Modified Technique ◽  
Glenn Shunt ◽  
Bidirectional Glenn ◽  
Modified Method ◽  
Bidirectional Glenn Shunt ◽  
Facial Edema

Clamping of the superior vena cava, while constructing a bidirectional Glenn shunt in patients with a single superior vena cava, may lead to an unacceptable rise in proximal venous pressure. Between January 1993 and March 1994, 7 patients underwent bidirectional Glenn shunt at our institution. Of these 7, 4 had a single superior vena cava and required venoatrial bypass. This was carried out with interposition of a roller pump. Central venous pressure was maintained at 13 to 30 mm Hg (mean 23.5 mm Hg) and arterial pressure at 60 to 74 mm Hg (mean 64 mm Hg). Postoperatively, no facial edema or neuropsychological disturbance was detected. This modified method is more effective than simple venoatrial bypass and less extensive than a cardiopulmonary bypass.

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