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Computational Modeling of the Penn State Fontan Circulation Assist Device. ASAIO J 2022; 68:1513-1522. [PMID: 35421006 DOI: 10.1097/mat.0000000000001708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
To address the increasing number of failing Fontan patients, Penn State University and the Penn State Hershey Medical Center are developing a centrifugal blood pump for long-term mechanical support. Computational fluid dynamics (CFD) modeling of the Penn State Fontan Circulatory Assist Device (FCAD) was performed to understand hemodynamics within the pump and its potential for hemolysis and thrombosis. CFD velocity and pressure results were first validated against experimental data and found to be within the standard deviations of the velocities and within 5% of the pressures. Further simulations performed with a human blood model found that most of the fluid domain was subjected to low shear stress (<50 Pa), with areas of highest stress around the rotor blade tips that increased with pump flow rate and rotor speed (138-178 Pa). However, the stresses compared well to previous CFD studies of commercial blood pumps and remained mostly below common thresholds of hemolysis and platelet activation. Additionally, few regions of low shear rate were observed within the FCAD, signifying minimal potential for platelet adhesion. These results further emphasize the FCAD's potential that has been observed previously in experimental and animal studies.
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Ponnaluri S, Christensen E, Good B, Kubicki C, Deutsch S, Cysyk J, Weiss WJ, Manning KB. Experimental Hemodynamics within the Penn State Fontan Circulatory Assist Device. J Biomech Eng 2021; 144:1129243. [PMID: 34897373 DOI: 10.1115/1.4053210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Indexed: 11/08/2022]
Abstract
For children born with a single functional ventricle, the Fontan operation bypasses the right ventricle by forming a four-way total cavopulmonary connection adapting the existing ventricle for the systemic circulation. However, upon adulthood, many Fontan patients exhibit low cardiac output and elevated venous pressure, eventually requiring a heart transplantation. Despite efforts to develop a Fontan pump or use an existing ventricular assist device for failing Fontan support, there is still no device designed or tested for subpulmonary support. Penn State University is developing a hydrodynamically levitated Fontan circulatory assist device (FCAD) for bridge-to-transplant or destination therapy. The FCAD hemodynamics, at both steady and pulsatile conditions for three pump operating conditions, were quantified using particle image velocimetry to determine the velocity magnitudes and Reynolds normal and shear stresses. Data were acquired at three planes (0 mm and ±25% of the radius) for the inferior and superior vena cavae inlets and the pulmonary artery outlet. The inlets had a blunt velocity profile that became skewed towards the collecting volute as fluid approached the rotor. At the outlet, regardless of the flow condition, a high-velocity jet exited the volute and moved downstream in a helical pattern. Turbulent stresses observed at the volute exit were influenced by the rotor's rotation. Regardless of inlet conditions, the pump demonstrated advantageous behavior for clinical use with a predictable flow field and a low risk of platelet adhesion and hemolysis based on calculated wall shear rates and turbulent stresses, respectively.
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Affiliation(s)
- Sailahari Ponnaluri
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA; Suite 122 Chemical and Biomedical Engineering Building, Penn State University, University Park, PA
| | - Emma Christensen
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA; Suite 122 Chemical and Biomedical Engineering Building, Penn State University, University Park, PA
| | - Bryan Good
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA; Suite 122 Chemical and Biomedical Engineering Building, Penn State University, University Park, PA
| | - Cody Kubicki
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA; Suite 122 Chemical and Biomedical Engineering Building, Penn State University, University Park, PA
| | - Steven Deutsch
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA; Suite 122 Chemical and Biomedical Engineering Building, Penn State University, University Park, PA
| | - Joshua Cysyk
- Department of Surgery, Penn State Hershey Medical Center, PA; H151 Surgery Hershey PA 17033, The Milton S. Hershey Medical Center
| | - William J Weiss
- Department of Surgery, Penn State Hershey Medical Center, PA; H151 Surgery Hershey PA 17033, The Milton S. Hershey Medical Center
| | - Keefe B Manning
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, Department of Surgery, Penn State Hershey Medical Center, PA; Suite 122 Chemical and Biomedical Engineering Building, Penn State University, University Park, PA
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