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López-Martínez S, Simón C, Santamaria X. Normothermic Machine Perfusion Systems: Where Do We Go From Here? Transplantation 2024; 108:22-44. [PMID: 37026713 DOI: 10.1097/tp.0000000000004573] [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: 04/08/2023]
Abstract
Normothermic machine perfusion (NMP) aims to preserve organs ex vivo by simulating physiological conditions such as body temperature. Recent advancements in NMP system design have prompted the development of clinically effective devices for liver, heart, lung, and kidney transplantation that preserve organs for several hours/up to 1 d. In preclinical studies, adjustments to circuit structure, perfusate composition, and automatic supervision have extended perfusion times up to 1 wk of preservation. Emerging NMP platforms for ex vivo preservation of the pancreas, intestine, uterus, ovary, and vascularized composite allografts represent exciting prospects. Thus, NMP may become a valuable tool in transplantation and provide significant advantages to biomedical research. This review recaps recent NMP research, including discussions of devices in clinical trials, innovative preclinical systems for extended preservation, and platforms developed for other organs. We will also discuss NMP strategies using a global approach while focusing on technical specifications and preservation times.
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Affiliation(s)
- Sara López-Martínez
- Carlos Simon Foundation, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Carlos Simón
- Carlos Simon Foundation, Centro de Investigación Príncipe Felipe, Valencia, Spain
- Department of Obstetrics and Gynecology, Universidad de Valencia, Valencia, Spain
- Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX
| | - Xavier Santamaria
- Carlos Simon Foundation, Centro de Investigación Príncipe Felipe, Valencia, Spain
- INCLIVA Biomedical Research Institute, Valencia, Spain
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Zarnitz L, Doorschodt BM, Ernst L, Hosseinnejad A, Edgworth E, Fechter T, Theißen A, Djudjaj S, Boor P, Rossaint R, Tolba RH, Bleilevens C. Taurine as Antioxidant in a Novel Cell- and Oxygen Carrier-Free Perfusate for Normothermic Machine Perfusion of Porcine Kidneys. Antioxidants (Basel) 2023; 12:antiox12030768. [PMID: 36979015 PMCID: PMC10045130 DOI: 10.3390/antiox12030768] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Donor organ-shortage has resulted in the increased use of marginal grafts; however, normothermic machine perfusion (NMP) holds the potential for organ viability assessment and restoration of marginal grafts prior to transplantation. Additionally, cell-, oxygen carrier-free and antioxidants-supplemented solutions could potentially prevent adverse effects (transfusion reactions, inflammation, hemolysis), associated with the use of autologous packed red blood cell (pRBC)-based perfusates. This study compared 6 h NMP of porcine kidneys, using an established pRBC-based perfusate (pRBC, n = 7), with the novel cell- and oxygen carrier-free organ preservation solution Ecosol, containing taurine (Ecosol, n = 7). Despite the enhanced tissue edema and tubular injury in the Ecosol group, related to a suboptimal molecular mass of polyethylene glycol as colloid present in the solution, functional parameters (renal blood flow, intrarenal resistance, urinary flow, pH) and oxygenation (arterial pO2, absence of hypoxia-inducible factor 1-alpha) were similar to the pRBC group. Furthermore, taurine significantly improved the antioxidant capacity in the Ecosol group, reflected in decreased lactate dehydrogenase, urine protein and tubular vacuolization compared to pRBC. This study demonstrates the feasibility of 6 h NMP using a taurine containing, cell- and oxygen carrier-free perfusate, achieving a comparable organ quality to pRBC perfused porcine kidneys.
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Affiliation(s)
- Laura Zarnitz
- Department of Anesthesiology, Medical Faculty, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Benedict M Doorschodt
- Institute for Laboratory Animal Science and Experimental Surgery, Faculty of Medicine, RWTH Aachen University, 52074 Aachen, Germany
| | - Lisa Ernst
- Institute for Laboratory Animal Science and Experimental Surgery, Faculty of Medicine, RWTH Aachen University, 52074 Aachen, Germany
| | - Aisa Hosseinnejad
- DWI-Leibniz-Institute for Interactive Materials e.V., 52056 Aachen, Germany
| | - Eileen Edgworth
- Department of Anesthesiology, Medical Faculty, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Tamara Fechter
- Department of Anesthesiology, Medical Faculty, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Alexander Theißen
- Department of Anesthesiology, Medical Faculty, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Sonja Djudjaj
- Institute of Pathology & Division of Nephrology, Medical Faculty, RWTH Aachen, 52074 Aachen, Germany
| | - Peter Boor
- Institute of Pathology & Division of Nephrology, Medical Faculty, RWTH Aachen, 52074 Aachen, Germany
| | - Rolf Rossaint
- Department of Anesthesiology, Medical Faculty, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - René H Tolba
- Institute for Laboratory Animal Science and Experimental Surgery, Faculty of Medicine, RWTH Aachen University, 52074 Aachen, Germany
| | - Christian Bleilevens
- Department of Anesthesiology, Medical Faculty, University Hospital RWTH Aachen, 52074 Aachen, Germany
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Lepoittevin M, Giraud S, Kerforne T, Allain G, Thuillier R, Hauet T. How to improve results after DCD (donation after circulation death). Presse Med 2022; 51:104143. [PMID: 36216034 DOI: 10.1016/j.lpm.2022.104143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/29/2022] [Indexed: 11/09/2022] Open
Abstract
The shortage of organs for transplantation has led health professionals to look for alternative sources of donors. One of the avenues concerns donors who have died after circulatory arrest. This is a special situation because the organs from these donors are exposed to warm ischaemia-reperfusion lesions that are unavoidable during the journey of the organs from the donor to the moment of transplantation in the recipient. We will address and discuss the key issues from the perspective of team organization, legislation and its evolution, and the ethical framework. In a second part, the avenues to improve the quality of organs will be presented following the itinerary of the organs between the donor and the recipient. The important moments from the point of view of therapeutic strategy will be put into perspective. New connections between key players involved in pathophysiological mechanisms and implications for innate immunity and injury processes are among the avenues to explore. Technological developments to improve the quality of organs from these recipients will be analyzed, such as perfusion techniques with new modalities of temperatures and oxygenation. New molecules are being investigated for their potential role in protecting these organs and an analysis of potential prospects will be proposed. Finally, the important perspectives that seem to be favored will be discussed in order to reposition the use of deceased donors after circulatory arrest. The use of these organs has become a routine procedure and improving their quality and providing the means for their evaluation is absolutely inevitable.
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Affiliation(s)
- Maryne Lepoittevin
- Unité UMR U1082, F-86000 Poitiers, France; Faculté de Médecine et de Pharmacie, Université de Poitiers, F-86000 Poitiers, France
| | - Sébastien Giraud
- Unité UMR U1082, F-86000 Poitiers, France; Service de Biochimie, Pôle Biospharm, Centre Hospitalier Universitaire, 2 rue de la Milétrie, CS 90577, 86021 Poitiers Cedex, France
| | - Thomas Kerforne
- Unité UMR U1082, F-86000 Poitiers, France; Faculté de Médecine et de Pharmacie, Université de Poitiers, F-86000 Poitiers, France; CHU Poitiers, Service de Réanimation Chirurgie Cardio-Thoracique et Vasculaire, Coordination des P.M.O., F-86021 Poitiers, France
| | - Géraldine Allain
- Unité UMR U1082, F-86000 Poitiers, France; Faculté de Médecine et de Pharmacie, Université de Poitiers, F-86000 Poitiers, France; CHU Poitiers, Service de Chirurgie Cardiothoracique et Vasculaire, F-86021 Poitiers, France
| | - Raphaël Thuillier
- Unité UMR U1082, F-86000 Poitiers, France; Faculté de Médecine et de Pharmacie, Université de Poitiers, F-86000 Poitiers, France; Service de Biochimie, Pôle Biospharm, Centre Hospitalier Universitaire, 2 rue de la Milétrie, CS 90577, 86021 Poitiers Cedex, France
| | - Thierry Hauet
- Unité UMR U1082, F-86000 Poitiers, France; Faculté de Médecine et de Pharmacie, Université de Poitiers, F-86000 Poitiers, France; Fédération Hospitalo-Universitaire « Survival Optimization in Organ Transplantation », CHU de Poitiers, 2 rue de la Milétrie - CS 90577, 86021 Poitiers Cedex, France.
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Preoperative Function Assessment of Ex Vivo Kidneys with Supervised Machine Learning Based on Blood and Urine Markers Measured during Normothermic Machine Perfusion. Biomedicines 2022; 10:biomedicines10123055. [PMID: 36551812 PMCID: PMC9776285 DOI: 10.3390/biomedicines10123055] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/13/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Establishing an objective quality assessment of an organ prior to transplantation can help prevent unnecessary discard of the organ and reduce the probability of functional failure. In this regard, normothermic machine perfusion (NMP) offers new possibilities for organ evaluation. However, to date, few studies have addressed the identification of markers and analytical tools to determine graft quality. In this study, function and injury markers were measured in blood and urine during NMP of 26 porcine kidneys and correlated with ex vivo inulin clearance behavior. Significant differentiation of kidneys according to their function could be achieved by oxygen consumption, oxygen delivery, renal blood flow, arterial pressure, intrarenal resistance, kidney temperature, relative urea concentration, and urine production. In addition, classifications were accomplished with supervised learning methods and histological analysis to predict renal function ex vivo. Classificators (support vector machines, k-nearest-neighbor, logistic regression and naive bayes) based on relevant markers in urine and blood achieved 75% and 83% accuracy in the validation and test set, respectively. A correlation between histological damage and function could not be detected. The measurement of blood and urine markers provides information of preoperative renal quality, which can used in future to establish an objective quality assessment.
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HBOC-301 in Porcine Kidney Normothermic Machine Perfusion and the Effect of Vitamin C on Methemoglobin Formation. Antioxidants (Basel) 2022; 11:antiox11071329. [PMID: 35883821 PMCID: PMC9311674 DOI: 10.3390/antiox11071329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 06/30/2022] [Accepted: 07/05/2022] [Indexed: 11/30/2022] Open
Abstract
Normothermic machine perfusion (NMP) of kidneys in combination with an optimized perfusate composition may increase donor organ preservation quality, especially in the case of marginal donor grafts. Optimization of currently employed perfusates is still a subject of present research. Due to the advantages of being cell-free, easy to store, and having minimal antigenicity, hemoglobin-based oxygen carriers, such as HBOC-301 (Oxyglobin®, Hemoglobin Oxygen Therapeutics LLC, Souderton, PA, USA), offer an alternative to the commonly used perfusates based on packed red blood cells (pRBC). As previously described, using HBOC results in formation of methemoglobin (metHb) as an adverse effect, inducing hypoxic conditions during the perfusion. As a potential counterpart to metHb formation, the application of the antioxidant ascorbic acid (VitC) is of high interest. Therefore, this study was conducted in four experimental groups, to compare the effect of NMP with (1) HBOC or (3) pRBC, and additionally examine a beneficial effect of VitC in both groups (2) HBOC + VitC and (4) pRBC + VitC. All groups were subjected to NMP for 6 h at a pressure of 75 mmHg. Kidneys in the HBOC groups had a significantly lower renal blood flow and increasing intrarenal resistance, with reduced renal function in comparison to the pRBC groups, as demonstrated by significantly lower creatinine clearance and higher fractional sodium excretion rates. Clinical chemistry markers for tissue damage (LDH, lactate) were higher in the HBOC groups, whereas no significant histological differences were observed. Although the application of VitC decreased oxidative stress levels, it was not able to significantly increase the outcome parameters mentioned above in either group. This study demonstrated that HBOC-301 is inferior to pRBCs in our porcine kidney NMP model, independent of additional VitC administration. Oxidative stress and fragmentation of the hemoglobin polymers could be detected as a possible reason for these results, hence further research, focusing on the use of cell-free oxygen carriers that do not exhibit this complex of issues, is required.
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Lepoittevin M, Giraud S, Kerforne T, Barrou B, Badet L, Bucur P, Salamé E, Goumard C, Savier E, Branchereau J, Battistella P, Mercier O, Mussot S, Hauet T, Thuillier R. Preservation of Organs to Be Transplanted: An Essential Step in the Transplant Process. Int J Mol Sci 2022; 23:ijms23094989. [PMID: 35563381 PMCID: PMC9104613 DOI: 10.3390/ijms23094989] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 12/23/2022] Open
Abstract
Organ transplantation remains the treatment of last resort in case of failure of a vital organ (lung, liver, heart, intestine) or non-vital organ (essentially the kidney and pancreas) for which supplementary treatments exist. It remains the best alternative both in terms of quality-of-life and life expectancy for patients and of public health expenditure. Unfortunately, organ shortage remains a widespread issue, as on average only about 25% of patients waiting for an organ are transplanted each year. This situation has led to the consideration of recent donor populations (deceased by brain death with extended criteria or deceased after circulatory arrest). These organs are sensitive to the conditions of conservation during the ischemia phase, which have an impact on the graft’s short- and long-term fate. This evolution necessitates a more adapted management of organ donation and the optimization of preservation conditions. In this general review, the different aspects of preservation will be considered. Initially done by hypothermia with the help of specific solutions, preservation is evolving with oxygenated perfusion, in hypothermia or normothermia, aiming at maintaining tissue metabolism. Preservation time is also becoming a unique evaluation window to predict organ quality, allowing repair and/or optimization of recipient choice.
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Affiliation(s)
- Maryne Lepoittevin
- Biochemistry Department, CHU Poitiers, 86021 Poitiers, France; (M.L.); (S.G.); (R.T.)
- Faculty of Medicine and Pharmacy, University of Poitiers, 86073 Poitiers, France;
- INSERM U1313, IRMETIST, 86021 Poitiers, France; (B.B.); (L.B.)
| | - Sébastien Giraud
- Biochemistry Department, CHU Poitiers, 86021 Poitiers, France; (M.L.); (S.G.); (R.T.)
- Faculty of Medicine and Pharmacy, University of Poitiers, 86073 Poitiers, France;
- INSERM U1313, IRMETIST, 86021 Poitiers, France; (B.B.); (L.B.)
| | - Thomas Kerforne
- Faculty of Medicine and Pharmacy, University of Poitiers, 86073 Poitiers, France;
- INSERM U1313, IRMETIST, 86021 Poitiers, France; (B.B.); (L.B.)
- Cardio-Thoracic and Vascular Surgery Intensive Care Unit, Coordination of P.M.O., CHU Poitiers, 86021 Poitiers, France
| | - Benoit Barrou
- INSERM U1313, IRMETIST, 86021 Poitiers, France; (B.B.); (L.B.)
- Sorbonne Université Campus Pierre et Marie Curie, Faculté de Médecine, 75005 Paris, France
- Service Médico-Chirurgical de Transplantation Rénale, APHP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
| | - Lionel Badet
- INSERM U1313, IRMETIST, 86021 Poitiers, France; (B.B.); (L.B.)
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Faculté de Médecine, Campus Lyon Santé Est, Université Claude Bernard, 69622 Lyon, France
- Service d’Urologie et Transplantation, Hospices Civils de Lyon, Hôpital Edouard-Herriot, 69003 Lyon, France
| | - Petru Bucur
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service de Chirurgie Digestive et Endocrinienne, Transplantation Hépatique, CHU de Tours, 37170 Chambray les Tours, France
- Groupement d’Imagerie Médicale, CHU de Tours, 37000 Tours, France
- University Hospital Federation SUPORT Tours Poitiers Limoges, 86021 Poitiers, France
| | - Ephrem Salamé
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service de Chirurgie Digestive et Endocrinienne, Transplantation Hépatique, CHU de Tours, 37170 Chambray les Tours, France
- Groupement d’Imagerie Médicale, CHU de Tours, 37000 Tours, France
- University Hospital Federation SUPORT Tours Poitiers Limoges, 86021 Poitiers, France
| | - Claire Goumard
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service de Chirurgie Digestive, Hépato-Bilio-Pancréatique et Transplantation Hépatique, APHP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Eric Savier
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service de Chirurgie Digestive, Hépato-Bilio-Pancréatique et Transplantation Hépatique, APHP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Julien Branchereau
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service d’Urologie et de Transplantation, CHU de Nantes, 44000 Nantes, France
| | - Pascal Battistella
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service de Cardiologie et Maladies Vasculaires, CHU de Montpellier, CEDEX 5, 34295 Montpellier, France
| | - Olaf Mercier
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service de Chirurgie Thoracique et Cardio-Vasculaire, Centre Chirurgical Marie LANNELONGUE, 92350 Le Plessis Robinson, France
| | - Sacha Mussot
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- Service de Chirurgie Thoracique et Cardio-Vasculaire, Centre Chirurgical Marie LANNELONGUE, 92350 Le Plessis Robinson, France
| | - Thierry Hauet
- Biochemistry Department, CHU Poitiers, 86021 Poitiers, France; (M.L.); (S.G.); (R.T.)
- Faculty of Medicine and Pharmacy, University of Poitiers, 86073 Poitiers, France;
- INSERM U1313, IRMETIST, 86021 Poitiers, France; (B.B.); (L.B.)
- Société Francophone de Transplantation et de l’Ecole Francophone pour le Prélèvement Multi-Organes, 75013 Paris, France; (P.B.); (E.S.); (C.G.); (E.S.); (J.B.); (P.B.); (O.M.); (S.M.)
- University Hospital Federation SUPORT Tours Poitiers Limoges, 86021 Poitiers, France
- Correspondence:
| | - Raphael Thuillier
- Biochemistry Department, CHU Poitiers, 86021 Poitiers, France; (M.L.); (S.G.); (R.T.)
- Faculty of Medicine and Pharmacy, University of Poitiers, 86073 Poitiers, France;
- INSERM U1313, IRMETIST, 86021 Poitiers, France; (B.B.); (L.B.)
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Improved Normothermic Machine Perfusion After Short Oxygenated Hypothermic Machine Perfusion of Ischemically Injured Porcine Kidneys. Transplant Direct 2021; 7:e653. [PMID: 33490378 PMCID: PMC7817286 DOI: 10.1097/txd.0000000000001108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 10/17/2020] [Accepted: 10/21/2020] [Indexed: 12/15/2022] Open
Abstract
Supplemental Digital Content is available in the text. Background. In an era where global kidney shortage has pushed the field of transplantation towards using more marginal donors, modified kidney preservation techniques are currently being reviewed. Some techniques require further optimization before implementation in full scale transplantation studies. Using a porcine donation after circulatory death kidney model, we investigated whether initial kidney hemodynamics improved during normothermic machine perfusion if this was preceded by a short period of oxygenated hypothermic machine perfusion (oxHMP) rather than static cold storage (SCS). Methods. Kidneys subjected to 75 minutes of warm ischemia were randomly assigned to either SCS (n = 4) or SCS + oxHMP (n = 4), with a total cold storage time of 240 minutes. Cold preservation was followed by 120 minutes of normothermic machine perfusion with continuous measurement of hemodynamic parameters and renal function. Results. oxHMP preserved kidneys maintained significantly lower renal resistance throughout the normothermic machine perfusion period compared to SCS kidneys (P < 0.001), reaching lowest levels at 60 minutes with means of 0.71 ± 0.35 mm Hg/mL/min/100 g (SCS) and 0.45 ± 0.15 mm Hg/mL/min/100 g (oxHMP). Accordingly, the oxHMP group had a higher mean renal blood flow versus SCS kidneys (P < 0.001). oxHMP kidneys had higher oxygen consumption during normothermic machine perfusion compared to SCS preserved kidneys (P < 0.001). Creatinine clearance remained similar between groups (P = 0.665). Conclusions. Preceding oxHMP significantly improved initial normothermic machine perfusion hemodynamics and increased total oxygen consumption. With the long period of warm ischemia, immediate kidney function was not observed, reflected by the findings of low creatinine clearance in both groups.
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In Vitro/Ex Vivo Models for the Study of Ischemia Reperfusion Injury during Kidney Perfusion. Int J Mol Sci 2020; 21:ijms21218156. [PMID: 33142791 PMCID: PMC7662866 DOI: 10.3390/ijms21218156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/20/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
Oxidative stress is a key element of ischemia–reperfusion injury, occurring during kidney preservation and transplantation. Current options for kidney graft preservation prior to transplantation are static cold storage (CS) and hypothermic machine perfusion (HMP), the latter demonstrating clear improvement of preservation quality, particularly for marginal donors, such as extended criteria donors (ECDs) and donation after circulatory death (DCDs). Nevertheless, complications still exist, fostering the need to improve kidney preservation. This review highlights the most promising avenues of in kidney perfusion improvement on two critical aspects: ex vivo and in vitro evaluation.
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Kim YJ, Kim KG. Development of an Optimized Deep Learning Model for Medical Imaging. JOURNAL OF THE KOREAN SOCIETY OF RADIOLOGY 2020; 81:1274-1289. [PMID: 36237706 PMCID: PMC9431842 DOI: 10.3348/jksr.2020.0171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/01/2020] [Accepted: 11/02/2020] [Indexed: 11/22/2022]
Abstract
최근, 의료 영상 분야에서 딥러닝은 가장 활발하게 연구되고 있는 기술 중 하나이다. 충분한 데이터와 최신의 딥러닝 알고리즘은 딥러닝 모델의 개발에 중요한 요소이다. 하지만 일반화된 최적의 딥러닝 모델을 개발하기 위해서는 데이터의 양과 최신의 딥러닝 알고리즘 외에도 많은 것을 고려해야 한다. 데이터 수집부터 가공, 전처리, 모델의 학습 및 검증, 경량화까지 모든 과정이 딥러닝 모델의 성능에 영향을 미칠 수 있기 때문이다. 본 종설에서는 의료 영상에 최적화된 딥러닝 모델을 위해 개발 과정 각각에서 고려해야 할 중요한 요소들을 살펴보고자 한다.
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Affiliation(s)
- Young Jae Kim
- Department of Biomedical Engineering, Gachon University, Incheon, Korea
| | - Kwang Gi Kim
- Department of Biomedical Engineering, Gachon University, Incheon, Korea
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