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Pigot H, Soltesz K, Steen S. Ex Vivo Working Porcine Heart Model. Methods Mol Biol 2024; 2803:87-107. [PMID: 38676887 DOI: 10.1007/978-1-0716-3846-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2024]
Abstract
Ex vivo working porcine heart models allow for the study of a heart's function and physiology outside the living organism. These models are particularly useful due to the anatomical and physiological similarities between porcine and human hearts, providing an experimental platform to investigate cardiac disease or assess donor heart viability for transplantation. This chapter presents an in-depth discussion of the model's components, including the perfusate, preload, and afterload. We explore the challenges of emulating cardiac afterload and present a historical perspective on afterload modeling, discussing various methodologies and their respective limitations. An actively controlled afterload device is introduced to enhance the model's ability to rapidly adjust pressure in the large arteries, thereby providing a more accurate and dynamic experimental model. Finally, we provide a comprehensive experimental protocol for the ex vivo working porcine heart model.
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Affiliation(s)
- Henry Pigot
- Department of Automatic Control, Lund University, Lund, Sweden.
| | | | - Stig Steen
- Department of Cardiothoracic Surgery, Skåne University Hospital, Lund, Sweden
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2
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Sage AT, Donahoe LL, Shamandy AA, Mousavi SH, Chao BT, Zhou X, Valero J, Balachandran S, Ali A, Martinu T, Tomlinson G, Del Sorbo L, Yeung JC, Liu M, Cypel M, Wang B, Keshavjee S. A machine-learning approach to human ex vivo lung perfusion predicts transplantation outcomes and promotes organ utilization. Nat Commun 2023; 14:4810. [PMID: 37558674 PMCID: PMC10412608 DOI: 10.1038/s41467-023-40468-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 07/26/2023] [Indexed: 08/11/2023] Open
Abstract
Ex vivo lung perfusion (EVLP) is a data-intensive platform used for the assessment of isolated lungs outside the body for transplantation; however, the integration of artificial intelligence to rapidly interpret the large constellation of clinical data generated during ex vivo assessment remains an unmet need. We developed a machine-learning model, termed InsighTx, to predict post-transplant outcomes using n = 725 EVLP cases. InsighTx model AUROC (area under the receiver operating characteristic curve) was 79 ± 3%, 75 ± 4%, and 85 ± 3% in training and independent test datasets, respectively. Excellent performance was observed in predicting unsuitable lungs for transplantation (AUROC: 90 ± 4%) and transplants with good outcomes (AUROC: 80 ± 4%). In a retrospective and blinded implementation study by EVLP specialists at our institution, InsighTx increased the likelihood of transplanting suitable donor lungs [odds ratio=13; 95% CI:4-45] and decreased the likelihood of transplanting unsuitable donor lungs [odds ratio=0.4; 95%CI:0.16-0.98]. Herein, we provide strong rationale for the adoption of machine-learning algorithms to optimize EVLP assessments and show that InsighTx could potentially lead to a safe increase in transplantation rates.
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Affiliation(s)
- Andrew T Sage
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Laura L Donahoe
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Alaa A Shamandy
- Department of Computer Science, University of Toronto, Toronto, ON, Canada
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada
| | - S Hossein Mousavi
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
| | - Bonnie T Chao
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
| | - Xuanzi Zhou
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
| | - Jerome Valero
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
| | - Sharaniyaa Balachandran
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
| | - Aadil Ali
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
| | - Tereza Martinu
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - George Tomlinson
- Department of Medicine, University Health Network, Toronto, ON, Canada
| | - Lorenzo Del Sorbo
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Interdepartmental Division of Critical Care Medicine, Medical and Surgical Intensive Care Unit, University Health Network, Toronto, ON, Canada
| | - Jonathan C Yeung
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Mingyao Liu
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Marcelo Cypel
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Bo Wang
- Department of Computer Science, University of Toronto, Toronto, ON, Canada.
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada.
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
- Vector Institute, Toronto, ON, Canada.
| | - Shaf Keshavjee
- Latner Thoracic Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada.
- Toronto Lung Transplant Program, Ajmera Transplant Centre, University Health Network, Toronto, ON, Canada.
- Department of Surgery, University of Toronto, Toronto, ON, Canada.
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
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3
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Sakota D, Kosaka R, Nagaoka E, Ohuchi K, Tahara T, Arai H, Sakanoue I, McCurry KR, Okamoto T. Left ventricular assist device mode: Co-pulse left ventricular unloading in a working mode of ex vivo heart perfusion. J Heart Lung Transplant 2023; 42:707-715. [PMID: 36931988 DOI: 10.1016/j.healun.2023.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 11/10/2022] [Accepted: 01/14/2023] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND For normothermic ex vivo heart perfusion (EVHP), a resting mode and working mode have been proposed. We newly developed a left ventricular assist device (LVAD) mode that supports heart contraction by co-pulse synchronized LVAD. METHODS Following resting mode during time 0 to 1 hour, pig hearts (n = 18) were perfused in either resting, working, or LVAD mode during time 1 to 5 hour, and then myocardial function was evaluated in working mode at 6 hour. The preservation ratio was defined as the myocardial mechanical function at 330 minute divided by the function at 75 minute. In LVAD mode, LVAD unloaded the pressure and the volume in the left ventricle in the systolic phase. RESULTS The LVAD group was significantly associated with higher preservation ratios in cardiac output (resting, 33 ± 3; working, 35 ± 5; LVAD, 76% ± 5%; p < 0.001), stroke work, dP/dt maximum, and dP/dt minimum compared with the other groups. Glucose consumption was significantly reduced in the resting group. The LVAD group was significantly associated with higher myocardial oxygen consumption (resting, 2.2 ± 0.3; working; 4.6 ± 0.5; LVAD, 6.1 ± 0.5 mL O2/min/100 g, p < 0.001) and higher adenosine triphosphate (ATP) levels (resting, 1.1 ± 0.1; working, 0.7 ± 0.1; LVAD, 1.6 ± 0.2 μmol/g, p = 0.001) compared with the others. CONCLUSION These data suggest that myocardial mechanical function was better preserved in LVAD mode than in resting and working modes. Although our data suggested similar glycolysis activity in the LVAD and working groups, the higher final ATP in the LVAD group might be explained by reduced external work in LVAD.
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Affiliation(s)
- Daisuke Sakota
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
| | - Ryo Kosaka
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Eiki Nagaoka
- Department of Cardiovascular Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Katsuhiro Ohuchi
- Department of Advanced Surgical Technology Research and Development, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tomoki Tahara
- Department of Cardiovascular Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hirokuni Arai
- Department of Cardiovascular Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Ichiro Sakanoue
- Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Cleveland, Ohio; Department of Inflammation and Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; Transplant Center, Cleveland Clinic, Cleveland, Ohio
| | - Kenneth R McCurry
- Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Cleveland, Ohio; Department of Inflammation and Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; Transplant Center, Cleveland Clinic, Cleveland, Ohio
| | - Toshihiro Okamoto
- Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Cleveland, Ohio; Department of Inflammation and Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; Transplant Center, Cleveland Clinic, Cleveland, Ohio.
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Olkowicz M, Ribeiro RVP, Yu F, Alvarez JS, Xin L, Yu M, Rosales R, Adamson MB, Bissoondath V, Smolenski RT, Billia F, Badiwala MV, Pawliszyn J. Dynamic Metabolic Changes During Prolonged Ex Situ Heart Perfusion Are Associated With Myocardial Functional Decline. Front Immunol 2022; 13:859506. [PMID: 35812438 PMCID: PMC9267769 DOI: 10.3389/fimmu.2022.859506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 05/20/2022] [Indexed: 11/13/2022] Open
Abstract
Ex situ heart perfusion (ESHP) was developed to preserve and evaluate donated hearts in a perfused beating state. However, myocardial function declines during ESHP, which limits the duration of perfusion and the potential to expand the donor pool. In this research, we combine a novel, minimally-invasive sampling approach with comparative global metabolite profiling to evaluate changes in the metabolomic patterns associated with declines in myocardial function during ESHP. Biocompatible solid-phase microextraction (SPME) microprobes serving as chemical biopsy were used to sample heart tissue and perfusate in a translational porcine ESHP model and a small cohort of clinical cases. In addition, six core-needle biopsies of the left ventricular wall were collected to compare the performance of our SPME sampling method against that of traditional tissue-collection. Our state-of-the-art metabolomics platform allowed us to identify a large number of significantly altered metabolites and lipid species that presented comparable profile of alterations to conventional biopsies. However, significant discrepancies in the pool of identified analytes using two sampling methods (SPME vs. biopsy) were also identified concerning mainly compounds susceptible to dynamic biotransformation and most likely being a result of low-invasive nature of SPME. Overall, our results revealed striking metabolic alterations during prolonged 8h-ESHP associated with uncontrolled inflammation not counterbalanced by resolution, endothelial injury, accelerated mitochondrial oxidative stress, the disruption of mitochondrial bioenergetics, and the accumulation of harmful lipid species. In conclusion, the combination of perfusion parameters and metabolomics can uncover various mechanisms of organ injury and recovery, which can help differentiate between donor hearts that are transplantable from those that should be discarded.
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Affiliation(s)
- Mariola Olkowicz
- Department of Chemistry, University of Waterloo, Waterloo, ON, Canada
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
| | - Roberto Vanin Pinto Ribeiro
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
- Division of Cardiac Surgery, Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Division of Cardiac Surgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada
| | - Frank Yu
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Juglans Souto Alvarez
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Liming Xin
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Miao Yu
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Roizar Rosales
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Mitchell Brady Adamson
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Ved Bissoondath
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | | | - Filio Billia
- Toronto General Hospital Research Institute (TGHRI), University Health Network, Toronto, ON, Canada
- Ted Roger’s Center for Heart Research, University Health Network, Toronto, ON, Canada
| | - Mitesh Vallabh Badiwala
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, ON, Canada
- Division of Cardiac Surgery, Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Ted Roger’s Center for Heart Research, University Health Network, Toronto, ON, Canada
| | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo, Waterloo, ON, Canada
- *Correspondence: Janusz Pawliszyn,
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5
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Pigot H, Soltesz K, Paskevicius A, Liao Q, Sjöberg T, Steen S. A novel nonlinear afterload for ex vivo heart evaluation: porcine experimental results. Artif Organs 2022; 46:1794-1803. [PMID: 35548921 PMCID: PMC9545718 DOI: 10.1111/aor.14307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/13/2022] [Accepted: 04/29/2022] [Indexed: 11/28/2022]
Abstract
Background Existing working heart models for ex vivo functional evaluation of donor hearts often use cardiac afterloads made up of discrete resistive and compliant elements. This approach limits the practicality of independently controlling systolic and diastolic aortic pressure to safely test the heart under multiple loading conditions. We present and investigate a novel afterload concept designed to enable such control. Methods Six ∼70 kg pig hearts were evaluated in vivo, then ex vivo in left‐ventricular working mode using the presented afterload. Both in vivo and ex vivo, the hearts were evaluated at two exertion levels: at rest and following a 20 μg adrenaline bolus, while measuring aortic pressure and flow, left ventricular pressure and volume, and left atrial pressure. Results The afterload gave aortic pressure waveforms that matched the general shape of the in vivo measurements. A wide range of physiological systolic pressures (93 to 160 mm Hg) and diastolic pressures (73 to 113 mm Hg) were generated by the afterload. Conclusions With the presented afterload concept, multiple physiological loading conditions could be tested ex vivo, and compared with the corresponding in vivo data. An additional control loop from the set pressure limits to the measured systolic and diastolic aortic pressure is proposed to address discrepancies observed between the set limits and the measured pressures.
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Affiliation(s)
- Henry Pigot
- Lund University, Dept Automatic Control, Sweden
| | | | - Audrius Paskevicius
- Lund University, Div. Thoracic Surgery, Dept. Clinical Sciences and Skane° University Hospital, Dept. Cardiothoracic Surgery, Sweden
| | - Qiuming Liao
- Lund University, Div. Thoracic Surgery, Dept. Clinical Sciences and Skane° University Hospital, Dept. Cardiothoracic Surgery, Sweden
| | - Trygve Sjöberg
- Lund University, Div. Thoracic Surgery, Dept. Clinical Sciences and Skane° University Hospital, Dept. Cardiothoracic Surgery, Sweden
| | - Stig Steen
- Lund University, Div. Thoracic Surgery, Dept. Clinical Sciences and Skane° University Hospital, Dept. Cardiothoracic Surgery, Sweden
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6
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Hondjeu ARM, Mashari A, Ramos R, Ruggeri GM, Gellner B, Ribeiro RVP, Hiansen JQ, Yu F, Xin L, Adamson MB, Badiwala MV, Meineri M. Echocardiographic assessment of left ventricular function in ex situ heart perfusion using pump-supported and passive afterload working mode: a pilot study. JOURNAL OF ANESTHESIA, ANALGESIA AND CRITICAL CARE (ONLINE) 2021; 1:20. [PMID: 37386658 DOI: 10.1186/s44158-021-00018-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/29/2021] [Indexed: 07/01/2023]
Abstract
Ex situ heart perfusion (ESHP) has been developed to decrease cold ischemia time and allow metabolic assessment of donor hearts prior to transplantation. Current clinical ESHP systems preserve the heart in an unloaded condition and only evaluate the cardiac metabolic profile. In this pilot study we performed echocardiographic functional assessment using two alternative systems for left ventricular (LV) loading: pump supported afterload working mode (SAM) and passive afterload working modes (PAM). Six hearts were procured from male Yorkshire pigs. During cold ischemia, hearts were mounted on our custom made ESHP circuit and a 3D-printed enclosure for the performance of echocardiography with a standard TEE probe. Following perfusion with Langherdorf mode of the unloaded heart, the system was switched into different working modes to allow LV loading and functional assessment: pump supported (SAM) and passive (PAM). Echocardiographic assessment of left ventricular function in the donor hearts was performed in vivo and at 1 h of ESHP with SAM, after 4.5 h with PAM and after 5.5 h with SAM. We obtained good quality epicardial echocardiographic images at all time points allowing a comprehensive LV systolic assessment. All indices showed a decrease in LV systolic function throughout the trial with the biggest drop after heart harvesting. We demonstrated the feasibility of echocardiographic functional assessment during ESHP and two different working modes. The expected LV systolic dysfunction consisted of a reduction in EF, FAC, FS, and strain throughout the experiment with the most significant decrease after harvesting.
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Affiliation(s)
- Arnaud Romeo Mbadjeu Hondjeu
- Department of Anesthesia and Pain Management, Peter Munk Cardiac Center Toronto General Hospital, University Health Network, Toronto, Canada
| | - Azad Mashari
- Department of Anesthesia and Pain Management, Peter Munk Cardiac Center Toronto General Hospital, University Health Network, Toronto, Canada
| | - Ryan Ramos
- Department of Anesthesia and Pain Management, Peter Munk Cardiac Center Toronto General Hospital, University Health Network, Toronto, Canada
| | - Giulia Maria Ruggeri
- Department of Anesthesia and Pain Management, Peter Munk Cardiac Center Toronto General Hospital, University Health Network, Toronto, Canada
| | - Bryan Gellner
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada
| | - Roberto Vanin Pinto Ribeiro
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Joshua Qua Hiansen
- Department of Anesthesia and Pain Management, Peter Munk Cardiac Center Toronto General Hospital, University Health Network, Toronto, Canada
| | - Frank Yu
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Liming Xin
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Mitchell Brady Adamson
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Mitesh Vallabh Badiwala
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Massimiliano Meineri
- Department of Anesthesia and Pain Management, Peter Munk Cardiac Center Toronto General Hospital, University Health Network, Toronto, Canada.
- Department of Anesthesia and Intensive Care, Herzzentrum Leipzig, Strumpell Strasse 39, 04289, Leipzig, Germany.
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7
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Hatami S, Qi X, White CW, Bozso SJ, Himmat S, Sergi C, Nagendran J, Chung HJ, Nobes DS, Freed DH. The Position of the Heart During Normothermic Ex Situ Heart Perfusion is an Important Factor in Preservation and Recovery of Myocardial Function. ASAIO J 2021; 67:1222-1231. [PMID: 33741785 DOI: 10.1097/mat.0000000000001386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Ex situ heart perfusion (ESHP) is being investigated as a method for the continuous preservation of the myocardium in a semiphysiologic state for subsequent transplantation. Most methods of ESHP position the isolated heart in a hanging (H) state, representing a considerable departure from the in vivo anatomical positioning of the heart and may negatively affect the functional preservation of the heart. In the current study, cardiac functional and metabolic parameters were assessed in healthy pig hearts, perfused for 12 hours, in either an H, or supported (S) position, either in nonworking mode (NWM) or working mode (WM). The cardiac function was best preserved in the S position hearts in WM (median 11 hour cardiac index (CI)/1 hour CI%: working mode perfusion in supported position = 94.77% versus nonworking mode perfusion in supported position = 62.80%, working mode perfusion in H position = 36.18%, nonworking mode perfusion in H position = 9.75%; p < 0.001). Delivery of pyruvate bolus significantly improved the function in S groups, however, only partially reversed myocardial dysfunction in the H heart groups. The hearts perfused ex situ in a semianatomical S position and in physiologic WM had better functional preservation and recovery than the H hearts in non-S position. Optimizing the positional support for the ex situ-perfused hearts may improve myocardial preservation during ESHP.
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Affiliation(s)
- Sanaz Hatami
- From the Department of Surgery, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Alberta Transplant Institute, Edmonton, Alberta, Canada
| | - Xiao Qi
- From the Department of Surgery, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Alberta Transplant Institute, Edmonton, Alberta, Canada
| | - Christopher W White
- Department of surgery, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sabin J Bozso
- From the Department of Surgery, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Alberta Transplant Institute, Edmonton, Alberta, Canada
| | - Sayed Himmat
- From the Department of Surgery, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Alberta Transplant Institute, Edmonton, Alberta, Canada
| | - Consolato Sergi
- Department of Laboratory Medicine and Pathology, Faculty of Medicine, Canada
| | - Jayan Nagendran
- From the Department of Surgery, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Alberta Transplant Institute, Edmonton, Alberta, Canada
- Canadian Donation and Transplantation Research Program, Canada
| | - Hyun-Joong Chung
- Department of Chemical and Materials Engineering Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - David S Nobes
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Darren H Freed
- From the Department of Surgery, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Alberta Transplant Institute, Edmonton, Alberta, Canada
- Canadian Donation and Transplantation Research Program, Canada
- Department of Physiology, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Department of Biomedical Engineering, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
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8
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A Multi-Mode System for Myocardial Functional and Physiological Assessment during Ex Situ Heart Perfusion. THE JOURNAL OF EXTRA-CORPOREAL TECHNOLOGY 2020; 52:303-313. [PMID: 33343033 DOI: 10.1182/ject-2000034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 10/20/2020] [Indexed: 11/20/2022]
Abstract
Ex situ heart perfusion (ESHP) has proven to be an important and valuable step toward better preservation of donor hearts for heart transplantation. Currently, few ESHP systems allow for a convenient functional and physiological evaluation of the heart. We sought to establish a simple system that provides functional and physiological assessment of the heart during ESHP. The ESHP circuit consists of an oxygenator, a heart-lung machine, a heater-cooler unit, an anesthesia gas blender, and a collection funnel. Female Yorkshire pig hearts (n = 10) had del Nido cardioplegia (4°C) administered, excised, and attached to the perfusion system. Hearts were perfused retrogradely into the aortic root for 2 hours before converting the system to an isovolumic mode or a working mode for further 2 hours. Blood samples were analyzed to measure metabolic parameters. During the isovolumic mode (n = 5), a balloon inserted in the left ventricular (LV) cavity was inflated so that an end-diastolic pressure of 6-8 mmHg was reached. During the working mode (n = 5), perfusion in the aortic root was redirected into left atrium (LA) using a compliance chamber which maintained an LA pressure of 6-8 mmHg. Another compliance chamber was used to provide an afterload of 40-50 mmHg. Hemodynamic and metabolic conditions remained stable and consistent for a period of 4 hours of ESHP in both isovolumic mode (LV developed pressure: 101.0 ± 3.5 vs. 99.7 ± 6.8 mmHg, p = .979, at 2 and 4 hours, respectively) and working mode (LV developed pressure: 91.0 ± 2.6 vs. 90.7 ± 2.5 mmHg, p = .942, at 2 and 4 hours, respectively). The present study proposed a novel ESHP system that enables comprehensive functional and metabolic assessment of large mammalian hearts. This system allowed for stable myocardial function for up to 4 hours of perfusion, which would offer great potential for the development of translational therapeutic protocols to improve dysfunctional donated hearts.
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9
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Wang L, MacGowan GA, Ali S, Dark JH. Ex situ heart perfusion: The past, the present, and the future. J Heart Lung Transplant 2020; 40:69-86. [PMID: 33162304 DOI: 10.1016/j.healun.2020.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/30/2020] [Accepted: 10/08/2020] [Indexed: 01/06/2023] Open
Abstract
Despite the advancements in medical treatment, mechanical support, and stem cell therapy, heart transplantation remains the most effective treatment for selected patients with advanced heart failure. However, with an increase in heart failure prevalence worldwide, the gap between donor hearts and patients on the transplant waiting list keeps widening. Ex situ machine perfusion has played a key role in augmenting heart transplant activities in recent years by enabling the usage of donation after circulatory death hearts, allowing longer interval between procurement and implantation, and permitting the safe use of some extended-criteria donation after brainstem death hearts. This exciting field is at a hinge point, with 1 commercially available heart perfusion machine, which has been used in hundreds of heart transplantations, and a number of devices being tested in the pre-clinical and Phase 1 clinical trial stage. However, no consensus has been reached over the optimal preservation temperature, perfusate composition, and perfusion parameters. In addition, there is a lack of objective measurement for allograft quality and viability. This review aims to comprehensively summarize the lessons about ex situ heart perfusion as a platform to preserve, assess, and repair donor hearts, which we have learned from the pre-clinical studies and clinical applications, and explore its exciting potential of revolutionizing heart transplantation.
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Affiliation(s)
- Lu Wang
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom; Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne, United Kingdom
| | - Guy A MacGowan
- Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne, United Kingdom; Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Simi Ali
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John H Dark
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
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10
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Primed Left Ventricle Heart Perfusion Creates Physiological Aortic Pressure in Porcine Hearts. ASAIO J 2020; 66:55-63. [PMID: 30893130 DOI: 10.1097/mat.0000000000000947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This article presents a primed left ventricle heart perfusion method to generate physiologic aortic pressure (AoP) and perform functional assessment. Isolated hearts of male Yorkshire pigs were used to study the hemodynamic behaviors of AoPs generated in the primed left ventricle heart perfusion (n = 6) and conventional (zero-loaded left ventricle) Langendorff perfusion (n = 6). The measurement results show that left ventricular pressure generated in the primed left ventricle heart perfusion is a determinant of physiologic AoP (i.e. systolic and diastolic pressures within physiologic range). The aortic pulse pressure (systolic pressure = 124.5 ± 1.7 mm Hg, diastolic pressure = 87.8 ± 0.9 mm Hg, aortic pulse pressure = 36.7 ± 2.6 mm Hg) from the primed left ventricle heart perfusion represents close match with the in vivo physiologic data. The volume in the left ventricle remains constant throughout the primed left ventricle heart perfusion, which allows us to perform isovolumetric left ventricular pressure measurement in ex vivo heart perfusion (EVHP). Left ventricular contractility measurements (maximum and minimum rates of left ventricular pressure change) were derived for cardiac assessment. In summary, the proposed primed left ventricle heart perfusion method is able to create physiologic AoP and enables left ventricular functional assessment in EVHP in porcine hearts.
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11
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Ribeiro RVP, Alvarez JS, Yu F, Adamson MB, Paradiso E, Hondjeu ARM, Xin L, Gellner B, Degen M, Bissoondath V, Meineri M, Rao V, Badiwala MV. Comparing Donor Heart Assessment Strategies During Ex Situ Heart Perfusion to Better Estimate Posttransplant Cardiac Function. Transplantation 2020; 104:1890-1898. [PMID: 32826843 DOI: 10.1097/tp.0000000000003374] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Ex situ heart perfusion (ESHP) limits ischemic periods and enables continuous monitoring of donated hearts; however, a validated assessment method to predict cardiac performance has yet to be established. We compare biventricular contractile and metabolic parameters measured during ESHP to determine the best evaluation strategy to estimate cardiac function following transplantation. METHODS Donor pigs were assigned to undergo beating-heart donation (n = 9) or donation after circulatory death (n = 8) induced by hypoxia. Hearts were preserved for 4 hours with ESHP while invasive and noninvasive (NI) biventricular contractile, and metabolic assessments were performed. Following transplantation, hearts were evaluated at 3 hours of reperfusion. Spearman correlation was used to determine the relationship between ESHP parameters and posttransplant function. RESULTS We performed 17 transplants; 14 successfully weaned from bypass (beating-heart donation versus donation after circulatory death; P = 0.580). Left ventricular invasive preload recruitable stroke work (PRSW) (r = 0.770; P = 0.009), NI PRSW (r = 0.730; P = 0.001), and NI maximum elastance (r = 0.706; P = 0.002) strongly correlated with cardiac index (CI) following transplantation. Right ventricular NI PRSW moderately correlated to CI following transplantation (r = 0.688; P = 0.003). Lactate levels were weakly correlated with CI following transplantation (r = -0.495; P = 0.043). None of the echocardiography measurements correlated with cardiac function following transplantation. CONCLUSIONS Left ventricular functional parameters, especially ventricular work and reserve, provided the best estimation of myocardial performance following transplantation. Furthermore, simple NI estimates of ventricular function proved useful in this setting. Right ventricular and metabolic measurements were limited in their ability to correlate with myocardial recovery. This emphasizes the need for an ESHP platform capable of assessing myocardial contractility and suggests that metabolic parameters alone do not provide a reliable evaluation.
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Affiliation(s)
- Roberto Vanin Pinto Ribeiro
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Juglans Souto Alvarez
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Frank Yu
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Mitchell Brady Adamson
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Emanuela Paradiso
- Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Arnaud Romeo Mbadjeu Hondjeu
- Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Liming Xin
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
- Department of Mechanical Engineering, University of Toronto, Toronto, Canada
| | - Bryan Gellner
- Department of Mechanical Engineering, University of Toronto, Toronto, Canada
| | - Maja Degen
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Ved Bissoondath
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Massimiliano Meineri
- Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Canada
- Department of Anesthesia, University of Toronto, Toronto, Canada
| | - Vivek Rao
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Mitesh Vallabh Badiwala
- Division of Cardiovascular Surgery, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, Toronto, Canada
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Canada
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12
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Gellner B, Xin L, Ribeiro RVP, Bissoondath V, Lu P, Adamson MB, Yu F, Paradiso E, Zu J, Simmons CA, Badiwala MV. The Implementation of an Adjustable Afterload Module for Ex Situ Heart Perfusion. Cardiovasc Eng Technol 2019; 11:96-110. [PMID: 31797263 DOI: 10.1007/s13239-019-00447-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 11/24/2019] [Indexed: 12/23/2022]
Abstract
PURPOSE Windkessel impedance analysis has proven to be an effective technique for instituting artificial afterload on ex situ hearts. Traditional fixed parameter afterload modules, however, are unable to handle the changing contractile conditions associated with prolonged ex situ heart perfusion. In this paper, an adjustable afterload module is described comprising of three fully adjustable sub-components: a systemic resistor, a proximal resistor and a compliance chamber. METHODS Using a centrifugal pump, the systemic resistor and compliance chamber were subjected to testing across their operating ranges, whereby the predictability of resistance and compliance values was evaluated. The components were then assembled, and the full module tested on three separate porcine hearts perfused for 6 h with success defined by the ability to maintain physiological systolic and diastolic aortic pressures across flow rate variability. RESULTS For both the systemic resistor and compliance chamber, experimental measurements agreed with their theoretical equivalents, with coefficients of determination of 0.99 and 0.97 for the systemic resistor and compliance chamber, respectively. During ex situ perfusion, overall 95% confidence intervals demonstrate that physiological systolic (95-96.21 mmHg) and diastolic (26.8-28.8 mmHg) pressures were successfully maintained, despite large variability in aortic flow. Left ventricular contractile parameters, were found to be in line with those in previous studies, suggesting the afterload module has no detrimental impact on functional preservation. CONCLUSIONS We conclude that due to the demonstrable control of our afterload module, we can maintain physiological aortic pressures in a passive afterload working mode across prolonged perfusion periods, enabling effective perfusion regardless of contractile performance.
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Affiliation(s)
- Bryan Gellner
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, ON, Canada
- Translational Biology & Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada
| | - Liming Xin
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, ON, Canada
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, ON, Canada
- State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing, China
| | - Roberto Vanin Pinto Ribeiro
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Ved Bissoondath
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Pengzhou Lu
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, ON, Canada
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Mitchell B Adamson
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Frank Yu
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Emanuela Paradiso
- Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Jean Zu
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Craig A Simmons
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, ON, Canada.
- Translational Biology & Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada.
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
| | - Mitesh V Badiwala
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
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13
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Gellner B, Xin L, Pinto Ribeiro RV, Bissoondath V, Adamson MB, Yu F, Lu P, Paradiso E, Mbadjeu Hondjeu AR, Simmons CA, Badiwala MV. The implementation of physiological afterload during ex situ heart perfusion augments prediction of posttransplant function. Am J Physiol Heart Circ Physiol 2019; 318:H25-H33. [PMID: 31774696 DOI: 10.1152/ajpheart.00427.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ex situ heart perfusion (ex situ heart perfusion) is an emerging technique that aims to increase the number of organs available for transplantation by augmenting both donor heart preservation and evaluation. Traditionally, ex situ heart perfusion has been performed in an unloaded Langendorff mode, though more recently groups have begun to use pump-supported working mode (PSWM) and passive afterload working mode (PAWM) to enable contractile evaluation during ex situ heart perfusion. To this point, however, neither the predictive effectiveness of the two working modes nor the predictive power of individual contractile parameters has been analyzed. In this article, we use our previously described system to analyze the predictive relevance of a multitude of contractile parameters measured in each working mode. Ten porcine hearts were excised and perfused ex situ in Langendorff mode for 4 h, evaluated using pressure-volume catheterization in both PSWM and PAWM, and transplanted into size-matched recipient pigs. After 3 h, hearts were weaned from cardiopulmonary bypass and evaluated. When correlating posttransplant measurements to their ex situ counterparts, we report that parameters measured in both modes show sufficient power (Spearman rank coefficient > 0.7) in predicting global posttransplant function, characterized by cardiac index and preload recruitable stroke work. For the prediction of specific posttransplant systolic and diastolic function, however, a large discrepancy between the two working modes was observed. With 9 of 10 measured posttransplant parameters showing stronger correlation with counterparts measured in PAWM, it is concluded that PAWM allows for a more detailed and nuanced prediction of posttransplant function than can be made in PSWM.NEW & NOTEWORTHY Ex situ heart perfusion has been proposed as a means to augment the organ donor pool by improving organ preservation and evaluation between donation and transplantation. Using our multimodal perfusion system, we analyzed the impact of using a "passive afterload working mode" for functional evaluation as compared with the more traditional "pump-supported working mode." Our data suggests that passive afterload working mode allows for a more nuanced prediction of posttransplant function in porcine hearts.
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Affiliation(s)
- Bryan Gellner
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada.,Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada
| | - Liming Xin
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Roberto Vanin Pinto Ribeiro
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Ved Bissoondath
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Mitchell B Adamson
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Frank Yu
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Pengzhou Lu
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Emanuela Paradiso
- Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Arnaud Romeo Mbadjeu Hondjeu
- Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Craig A Simmons
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada.,Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Mitesh V Badiwala
- Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
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14
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Hearts Donated After Circulatory Death and Reconditioned Using Normothermic Regional Perfusion Can Be Successfully Transplanted Following an Extended Period of Static Storage. Circ Heart Fail 2019; 12:e005364. [DOI: 10.1161/circheartfailure.118.005364] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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