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Karner B, Escher A, Schorn T, Narayanaswamy K, Sachweh J, Laufer G, Hübler M, Zimpfer D, Granegger M. Anatomical Compliance of Cavopulmonary Assist Device Designs: A Virtual Fitting Study in Fontan Patients. ASAIO J 2023; 69:1016-1024. [PMID: 37902686 DOI: 10.1097/mat.0000000000002013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023] Open
Abstract
Several device designs for cavopulmonary mechanical circulatory support (MCS) are under investigation, however, challenged by the Fontan population's heterogeneity in size, cardiovascular and thoracic anatomy. This study aimed to preclinically assess the anatomical compliance of proposed device designs in silico. Representative double- and single-outlet cavopulmonary assist device (CPAD) designs were virtually implanted into CT imaging data of 10 patients previously palliated with total cavopulmonary connection (TCPC) for functionally univentricular hearts. Anatomical device compatibility was characterized concerning pump proximity to cardiovascular, respiratory and thoracic structures, as well as pump in- and outflow graft configuration. In 10 Fontan patients with a median age of 10.4 years (interquartile range [IQR] 5.0-15.3 years) and a median body surface area of 1.09 m2 (IQR 0.76-1.28 m2), implantation of a double-outlet CPAD was feasible in 1 patient (10%). In all other, adverse device intersection with the trachea and (neo-)aorta, or posterior pulmonary artery outflow graft kinking were observed. A single-outlet design permitted enhanced device mobilization adapting to individual anatomical conditions, resulting in device fit in nine of 10 patients (90%). Despite vast anatomical variations among single ventricle patients, a single-outlet device design may provide intracorporeal cavopulmonary MCS to a broad spectrum of failing Fontan patients.
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Affiliation(s)
- Barbara Karner
- From the Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
- Division of Cardiac Surgery, Department of Surgery, Medical University Graz, Graz, Austria
| | - Andreas Escher
- From the Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Therese Schorn
- From the Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | | | - Jörg Sachweh
- Department of Congenital and Pediatric Heart Surgery, Children's Heart Clinic, University Heart & Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Günther Laufer
- From the Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Michael Hübler
- Department of Congenital and Pediatric Heart Surgery, Children's Heart Clinic, University Heart & Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Daniel Zimpfer
- From the Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
- Division of Cardiac Surgery, Department of Surgery, Medical University Graz, Graz, Austria
| | - Marcus Granegger
- From the Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
- Biofluid Mechanics Laboratory, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Zwischenberger JB, Breetz KA, Ballard-Croft C, Wang D. Failing Fontan cardiovascular support: Review. J Card Surg 2022; 37:5257-5261. [PMID: 36321714 PMCID: PMC9812883 DOI: 10.1111/jocs.17094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 09/17/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Although all congenital heart defects (CHD) present unique challenges, univentricular CHD are especially challenging given the difficulty of passively perfusing pulmonary blood flow. Three surgical procedures are required within the first years of life, with the final completing a Fontan circulation in which the inferior vena cava is connected to the pulmonary artery and previously connected superior vena cava. This allows passive venous return to the pulmonary circulation then flow into the single ventricle for systemic circulation. METHODS Although a Fontan provides successful palliation for two to three decades, many complications can arise as pulmonary resistance must remain low to allow adequate forward flow. Eventually, the failing Fontan circulation requires temporary support as the patient awaits a heart transplant. We reviewed PubMed, Google Scholar, and U. Kentucky library for different techniques evaluated to support a failing Fontan circulation. RESULTS Multiple technologies have been developed as a bridge to transplant to decrease morbidity. Innovative types of extracorporeal membrane oxygenation, ventricular assist devices, and total artificial hearts have been attempted in laboratory settings as well as in Fontan patients with varying degrees of success. This article emphasizes the strengths and weaknesses of each technology in the context of Fontan physiology. CONCLUSION The end game for these patients remains a heart transplant. Without easy access to donors, each of the options discussed is a potential bridge to limit morbidity and mortality until a suitable donor heart becomes available.
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Affiliation(s)
| | | | | | - Dongfang Wang
- University of Kentucky, Department of Surgery, Division of Surgical Research
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Onder A, Yapici R, Incebay O. An experimental performance comparison of Newtonian and non-Newtonian fluids on a centrifugal blood pump. Proc Inst Mech Eng H 2022; 236:399-405. [PMID: 35014554 DOI: 10.1177/09544119211057626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The use of substitute fluid with similar rheological properties instead of blood is important due to ethical concerns and high blood volume consumption in pump performance test before clinical applications. The performance of a centrifugal blood pump with hydrodynamic journal bearing is experimentally tested using Newtonian 40% aqueous glycerin solution (GS) and non-Newtonian aqueous xanthan gum solution of 600 ppm (XGS) as working fluids. Experiments are performed at four different rotational speeds which are 2700, 3000, 3300, and 3600 rpm; experiments using GS reach between 8.5% and 37.2% higher head curve than experiments using the XGS for every rotational speed. It was observed that as the rotational speed and flow rate increase, the head curve difference between GS and XGS decreases. This result can be attributed to the friction reduction effect when using XGS in experiments at high rotation speed and high flow rate. Moreover, due to different fluid viscosities, differences in hydraulic efficiency were observed for both fluids. This study reveals that the use of Newtonian fluids as working fluids is not sufficient to determine the actual performance of a blood pump, and the performance effects of non-Newtonian fluids are remarkably important in pump performance optimizations.
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Affiliation(s)
- Ahmet Onder
- Mechanical and Metal Technologies Department, Technical Sciences Vocational School, Konya Technical University, Konya, Turkey
| | - Rafet Yapici
- Mechanical Engineering Department, Faculty of Engineering and Natural Science, Konya Technical University, Konya, Turkey
| | - Omer Incebay
- Mechanical Engineering Department, Faculty of Engineering and Natural Science, Konya Technical University, Konya, Turkey
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Computational fluid dynamic simulations of a cavopulmonary assist device for failing Fontan circulation. J Thorac Cardiovasc Surg 2019; 158:1424-1433.e5. [PMID: 31005303 DOI: 10.1016/j.jtcvs.2019.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 01/13/2019] [Accepted: 03/02/2019] [Indexed: 01/23/2023]
Abstract
OBJECTIVES Adult patients who have undergone the Fontan procedure are highly vulnerable to gradual, progressive circulatory failure, and options to reverse this situation are few. A cavopulmonary assist device could decongest the venous and lymphatic systems, overcome elevated pulmonary vascular resistance, increase cardiac output, and support some of these patients to heart transplant. This study characterizes the performance and challenges of a novel multilumen cannula coupled to an external blood pump proposed as a potential Fontan cavopulmonary assist strategy. METHODS Computational fluid dynamic simulations were conducted for 3 extracardiac Fontan geometries consisting of 1 idealized model and 2 patient-specific models. A range of physiologic flow rates and pump assist levels were simulated to calculate the pressure gain provided by the multilumen cannula. Hemolysis index was estimated for the idealized model with Lagrangian particle tracking and 2 variations of the power-law. Wall shear stresses were also examined. RESULTS Pressure gains up to 4 and 9 mm Hg were achieved for the idealized and patient-specific models, respectively. Pressure gains increased with both higher cardiac output and larger pump intake through the external pump. Flow-weighted hemolysis show hemoglobin damage levels to be several times lower than the 2% threshold at the highest pump intake flow cases. Wall shear stress predictions depict elevated areas in the pulmonary vessels and regions of the cannula device. CONCLUSIONS The cannula tested in this study shows promise as a percutaneous option to bridge support in some patients with a failing extracardiac Fontan. Limitations identified will be addressed in future design iterations and in ongoing experimental tests.
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Buratto E, Shi WY, Ye XT, Konstantinov IE. Ventricular assist devices for the failing univentricular circulation. Expert Rev Med Devices 2017; 14:449-459. [DOI: 10.1080/17434440.2017.1332523] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Edward Buratto
- Department of Cardiac Surgery, The Royal Children’s Hospital, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
- Murdoch Children’s Research Institute, Melbourne, Australia
| | - William Y. Shi
- Department of Cardiac Surgery, The Royal Children’s Hospital, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
- Murdoch Children’s Research Institute, Melbourne, Australia
| | - Xin Tao Ye
- Department of Cardiac Surgery, The Royal Children’s Hospital, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
- Murdoch Children’s Research Institute, Melbourne, Australia
| | - Igor E. Konstantinov
- Department of Cardiac Surgery, The Royal Children’s Hospital, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
- Murdoch Children’s Research Institute, Melbourne, Australia
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Abstract
In this Editor's Review, articles published in 2016 are organized by category and briefly summarized. We aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, the International Society for Mechanical Circulatory Support, the International Society for Pediatric Mechanical Cardiopulmonary Support, and the Vienna International Workshop on Functional Electrical Stimulation, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We were pleased to publish our second Virtual Issue in April 2016 on "Tissue Engineering in Bone" by Professor Tsuyoshi Takato. Our first was published in 2011 titled "Intra-Aortic Balloon Pumping" by Dr. Ashraf Khir. Other peer-reviewed Special Issues this year included contributions from the 11th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion edited by Dr. Akif Ündar and selections from the 23rd Congress of the International Society for Rotary Blood Pumps edited by Dr. Bojan Biocina. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.
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An Observation from Liver Biopsies Two Decades Post-Fontan. Pediatr Cardiol 2016; 37:1119-22. [PMID: 27160101 DOI: 10.1007/s00246-016-1403-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/22/2016] [Indexed: 10/21/2022]
Abstract
This brief report describes an observation from liver biopsy results in nonfailing Fontan patients, currently in their second postoperative decade. In three patients, with either atriopulmonary or atrioventricular connections and functional left ventricles, we found no portal fibrosis. In contrast, we found portal fibrosis in three clinically similar, nonfailing Fontan patients with lateral tunnel connections and functional left ventricles. We recognize the results may be secondary to chance; nevertheless, we speculate about possible relevancy.
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