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Khalil A, Quaglia A, Gélat P, Saffari N, Rashidi H, Davidson B. New Developments and Challenges in Liver Transplantation. J Clin Med 2023; 12:5586. [PMID: 37685652 PMCID: PMC10488676 DOI: 10.3390/jcm12175586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/15/2023] [Accepted: 08/26/2023] [Indexed: 09/10/2023] Open
Abstract
Liver disease is increasing in incidence and is the third most common cause of premature death in the United Kingdom and fourth in the United States. Liver disease accounts for 2 million deaths globally each year. Three-quarters of patients with liver disease are diagnosed at a late stage, with liver transplantation as the only definitive treatment. Thomas E. Starzl performed the first human liver transplant 60 years ago. It has since become an established treatment for end-stage liver disease, both acute and chronic, including metabolic diseases and primary and, at present piloting, secondary liver cancer. Advances in surgical and anaesthetic techniques, refined indications and contra-indications to transplantation, improved donor selection, immunosuppression and prognostic scoring have allowed the outcomes of liver transplantation to improve year on year. However, there are many limitations to liver transplantation. This review describes the milestones that have occurred in the development of liver transplantation, the current limitations and the ongoing research aimed at overcoming these challenges.
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Affiliation(s)
- Amjad Khalil
- Liver Unit, Wellington Hospital, London NW8 9TA, UK
- Centre for Surgical Innovation, Organ Regeneration and Transplantation, University College London, London NW3 2PS, UK
- Clinical Service of HPB Surgery and Liver Transplantation, Royal Free Hospital, London NW3 2QG, UK
| | - Alberto Quaglia
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Pierre Gélat
- Division of Surgery and Interventional Science, University College London, London NW3 2PS, UK
| | - Nader Saffari
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK
| | - Hassan Rashidi
- Institute of Child Health, University College London, London WC1N 1EH, UK;
| | - Brian Davidson
- Liver Unit, Wellington Hospital, London NW8 9TA, UK
- Centre for Surgical Innovation, Organ Regeneration and Transplantation, University College London, London NW3 2PS, UK
- Clinical Service of HPB Surgery and Liver Transplantation, Royal Free Hospital, London NW3 2QG, UK
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De Stefano N, Navarro-Tableros V, Roggio D, Calleri A, Rigo F, David E, Gambella A, Bassino D, Amoroso A, Patrono D, Camussi G, Romagnoli R. Human liver stem cell-derived extracellular vesicles reduce injury in a model of normothermic machine perfusion of rat livers previously exposed to a prolonged warm ischemia. Transpl Int 2021; 34:1607-1617. [PMID: 34448268 PMCID: PMC9291857 DOI: 10.1111/tri.13980] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 01/11/2023]
Abstract
Livers from donors after circulatory death (DCD) are a promising option to increase the donor pool, but their use is associated with higher complication rate and inferior graft survival. Normothermic machine perfusion (NMP) keeps the graft at 37°C, providing nutrients and oxygen supply. Human liver stem cell‐derived extracellular vesicles (HLSC‐EVs) are able to reduce liver injury and promote regeneration. We investigated the efficacy of a reconditioning strategy with HLSC‐EVs in an experimental model of NMP. Following total hepatectomy, rat livers were divided into 4 groups: (i) healthy livers, (ii) warm ischemic livers (60 min of warm ischemia), (iii) warm ischemic livers treated with 5 × 108 HLSC‐EVs/g‐liver, and (iv) warm ischemic livers treated with a 25 × 108 HLSC‐EVs/g‐liver. NMP lasted 6 h and HLSC‐EVs (Unicyte AG, Germany) were administered within the first 15 min. Compared to controls, HLSC‐EV treatment significantly reduced transaminases release. Moreover, HLSC‐EVs enhanced liver metabolism by promoting phosphate utilization and pH self‐regulation. As compared to controls, the higher dose of HLSC‐EV was associated with significantly higher bile production and lower intrahepatic resistance. Histologically, this group showed reduced necrosis and enhanced proliferation. In conclusion, HLSC‐EV treatment during NMP was feasible and effective in reducing injury in a DCD model with prolonged warm ischemia.
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Affiliation(s)
- Nicola De Stefano
- General Surgery 2U, Liver Transplantation Center, AOU Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
| | - Victor Navarro-Tableros
- 2i3T - Società per la gestione dell'incubatore di imprese e per il trasferimento tecnologico dell'Università degli Studi di Torino, Scarl. - Molecular Biotechnology Center (MBC), Turin, Italy
| | - Dorotea Roggio
- General Surgery 2U, Liver Transplantation Center, AOU Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
| | - Alberto Calleri
- General Surgery 2U, Liver Transplantation Center, AOU Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
| | - Federica Rigo
- General Surgery 2U, Liver Transplantation Center, AOU Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
| | - Ezio David
- Pathology Unit, Molinette Hospital, AOU Città della Salute e della Scienza di Torino, Turin, Italy
| | - Alessandro Gambella
- Pathology Unit, Molinette Hospital, AOU Città della Salute e della Scienza di Torino, Turin, Italy
| | - Daniela Bassino
- S.C. Banca del Sangue e Immunoematologia, AOU Città della Salute e della Scienza di Torino, Turin, Italy
| | - Antonio Amoroso
- Regional Transplantation Center, Piedmont, AOU Città della Salute e della Scienza di Torino, Turin, Italy
| | - Damiano Patrono
- General Surgery 2U, Liver Transplantation Center, AOU Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
| | - Giovanni Camussi
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Renato Romagnoli
- General Surgery 2U, Liver Transplantation Center, AOU Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
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Papatheodoridi M, Mazza G, Pinzani M. Regenerative hepatology: In the quest for a modern prometheus? Dig Liver Dis 2020; 52:1106-1114. [PMID: 32868215 DOI: 10.1016/j.dld.2020.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 12/11/2022]
Abstract
As liver-related morbidity and mortality is rising worldwide and orthotopic liver transplantation (OLT) remains the only standard-of-care for end-stage liver disease or acute liver failure, shortage of donor organs is becoming more prominent. Importantly, advances in regenerative Hepatology and liver bioengineering are bringing new hope to the possibility of restoring impaired hepatic functionality in the presence of acute or chronic liver failure. Hepatocyte transplantation and artificial liver-support systems were the first strategies used in regenerative hepatology but have presented various types of efficiency limitations restricting their widespread use. In parallel, liver bioengineering has been a rapidly developing field bringing continuously novel advancements in biomaterials, three dimensional (3D) scaffolds, cell sources and relative methodologies for creating bioengineered liver tissue. The current major task in liver bioengineering is to build small implantable liver mass for treating inherited metabolic disorders, bioengineered bile ducts for congenital biliary defects and large bioengineered liver organs for transplantation, as substitutes to donor-organs, in cases of acute or acute-on-chronic liver failure. This review aims to summarize the state-of-the-art and upcoming technologies of regenerative Hepatology that are emerging as promising alternatives to the current standard-of care in liver disease.
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Affiliation(s)
- Margarita Papatheodoridi
- Sheila Sherlock Liver Unit, Institute for Liver and Digestive Health, University College London, London, United Kingdom
| | - Giuseppe Mazza
- Sheila Sherlock Liver Unit, Institute for Liver and Digestive Health, University College London, London, United Kingdom
| | - Massimo Pinzani
- Sheila Sherlock Liver Unit, Institute for Liver and Digestive Health, University College London, London, United Kingdom.
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Squires JE, Soltys KA, McKiernan P, Squires RH, Strom SC, Fox IJ, Soto-Gutierrez A. Clinical Hepatocyte Transplantation: What Is Next? CURRENT TRANSPLANTATION REPORTS 2017; 4:280-289. [PMID: 29732274 DOI: 10.1007/s40472-017-0165-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Purpose of review Significant recent scientific developments have occurred in the field of liver repopulation and regeneration. While techniques to facilitate liver repopulation with donor hepatocytes and different cell sources have been studied extensively in the laboratory, in recent years clinical hepatocyte transplantation (HT) and liver repopulation trials have demonstrated new disease indications and also immunological challenges that will require the incorporation of a fresh look and new experimental approaches. Recent findings Growth advantage and regenerative stimulus are necessary to allow donor hepatocytes to proliferate. Current research efforts focus on mechanisms of donor hepatocyte expansion in response to liver injury/preconditioning. Moreover, latest clinical evidence shows that important obstacles to HT include optimizing engraftment and limited duration of effectiveness, with hepatocytes being lost to immunological rejection. We will discuss alternatives for cellular rejection monitoring, as well as new modalities to follow cellular graft function and near-to-clinical cell sources. Summary HT partially corrects genetic disorders for a limited period of time and has been associated with reversal of ALF. The main identified obstacles that remain to make HT a curative approach include improving engraftment rates, and methods for monitoring cellular graft function and rejection. This review aims to discuss current state-of-the-art in clinical HT and provide insights into innovative approaches taken to overcome these obstacles.
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Affiliation(s)
- James E Squires
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States
| | - Kyle A Soltys
- Thomas E. Starzl Transplant Institute, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States
| | - Patrick McKiernan
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States
| | - Robert H Squires
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States
| | - Stephen C Strom
- Karolinska Institutet, Department of Laboratory Medicine, Division of Pathology, Stockholm, Sweden
| | - Ira J Fox
- Department of Surgery, Children's Hospital of Pittsburgh of UPMC, and McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Uygun BE, Izamis ML, Jaramillo M, Chen Y, Price G, Ozer S, Yarmush ML. Discarded Livers Find a New Life: Engineered Liver Grafts Using Hepatocytes Recovered From Marginal Livers. Artif Organs 2016; 41:579-585. [PMID: 27862079 DOI: 10.1111/aor.12781] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/19/2016] [Accepted: 05/11/2016] [Indexed: 12/14/2022]
Abstract
Treatment for end-stage liver failure is restricted by the critical shortage of donor organs; about 4000 people die in the USA while waiting for a transplantable organ. This situation has been a major driving force behind the rise of tissue engineering to build artificial tissues/organs. Recent advancements in creating transplantable liver grafts using decellularized liver scaffolds bring the field closer to clinical translation. However, a source of readily available and highly functional adult hepatocytes in adequate numbers for regenerative liver therapies still remains unclear. Here, we describe a new method to utilize discarded livers to make transplantable new liver grafts. We show that marginal donor livers damaged due to warm ischemia could be treated with machine perfusion to yield 39 million viable hepatocytes per gram of liver, similar to fresh livers, and these cells could be used to repopulate decellularized liver matrix (DLM) scaffolds to make transplantable liver grafts. The hepatocytes from recovered livers sustained their characteristic epithelial morphology while they exhibited slightly lower protein synthesis functions both in plate cultures and in recellularized liver grafts. The dampened protein synthesis was attributed to residual endoplasmic reticulum stress found in recovered cells. The results here represent a unique approach to reengineer transplantable liver grafts solely from discarded organs.
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Affiliation(s)
- Basak E Uygun
- Department of Surgery, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, MA
| | - Maria-Louisa Izamis
- Department of Surgery, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, MA
| | - Maria Jaramillo
- Department of Surgery, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, MA
| | - Yibin Chen
- Department of Surgery, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, MA
| | - Gavrielle Price
- Department of Surgery, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, MA
| | - Sinan Ozer
- Department of Surgery, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, MA
| | - Martin L Yarmush
- Department of Surgery, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Burns Hospital, Boston, MA.,Department of Biomedical Engineering, Rutgers University, Piscataway, NJ, USA
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Izamis ML, Perk S, Calhoun C, Uygun K, Yarmush ML, Berthiaume F. Machine perfusion enhances hepatocyte isolation yields from ischemic livers. Cryobiology 2015; 71:244-55. [PMID: 26188080 PMCID: PMC4584189 DOI: 10.1016/j.cryobiol.2015.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 06/03/2015] [Accepted: 07/14/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND High-quality human hepatocytes form the basis of drug safety and efficacy tests, cell-based therapies, and bridge-to-transplantation devices. Presently the only supply of cells derives from an inadequate pool of suboptimal disqualified donor livers. Here we evaluated whether machine perfusion could ameliorate ischemic injury that many of these livers experience prior to hepatocyte isolation. METHODS Non-heparinized female Lewis rat livers were exposed to an hour of warm ischemia (34°C) and then perfused for 3h. Five different perfusion conditions that utilized the cell isolation apparatus were investigated, namely: (1) modified Williams Medium E and (2) Lifor, both with active oxygenation (95%O(2)/5%CO(2)), as well as (3) Lifor passively oxygenated with ambient air (21%O(2)/0.04%CO(2)), all at ambient temperatures (20 ± 2°C). At hypothermic temperatures (5 ± 1°C) and under passive oxygenation were (4) University of Wisconsin solution (UW) and (5) Vasosol. Negative and positive control groups comprised livers that had ischemia (WI) and livers that did not (Fresh) prior to cell isolation, respectively. RESULTS Fresh livers yielded 32 ± 9 million cells/g liver while an hour of ischemia reduced the cell yield to 1.6 ± 0.6 million cells/g liver. Oxygenated Williams Medium E and Lifor recovered yields of 39 ± 11 and 31 ± 2.3 million cells/g liver, respectively. The passively oxygenated groups produced 15 ± 7 (Lifor), 13 ± 7 (Vasosol), and 10 ± 6 (UW)million cells/g liver. Oxygenated Williams Medium E was most effective at sustaining pH values, avoiding the accumulation of lactate, minimizing edematous weight gain and producing bile during perfusion. CONCLUSIONS Machine perfusion results in a dramatic increase in cell yields from livers that have had up to an hour of warm ischemia, but perfusate choice significantly impacts the extent of recovery. Oxygenated Williams Medium E at room temperature is superior to Lifor, UW and Vasosol, largely facilitated by its high oxygen content and low viscosity.
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Affiliation(s)
- Maria-Louisa Izamis
- Center for Engineering in Medicine/Surgical Services, Massachusetts General Hospital, Harvard Medical School, and Shriners Burns Hospital, 51 Blossom Street, Boston, MA 02114, United States.
| | - Sinem Perk
- Center for Engineering in Medicine/Surgical Services, Massachusetts General Hospital, Harvard Medical School, and Shriners Burns Hospital, 51 Blossom Street, Boston, MA 02114, United States.
| | - Candice Calhoun
- Center for Engineering in Medicine/Surgical Services, Massachusetts General Hospital, Harvard Medical School, and Shriners Burns Hospital, 51 Blossom Street, Boston, MA 02114, United States.
| | - Korkut Uygun
- Center for Engineering in Medicine/Surgical Services, Massachusetts General Hospital, Harvard Medical School, and Shriners Burns Hospital, 51 Blossom Street, Boston, MA 02114, United States.
| | - Martin L Yarmush
- Center for Engineering in Medicine/Surgical Services, Massachusetts General Hospital, Harvard Medical School, and Shriners Burns Hospital, 51 Blossom Street, Boston, MA 02114, United States; Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854, United States.
| | - François Berthiaume
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854, United States.
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Izamis ML, Efstathiades A, Keravnou C, Leen EL, Averkiou MA. Dynamic contrast-enhanced ultrasound of slaughterhouse porcine livers in machine perfusion. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:2217-2230. [PMID: 25023101 DOI: 10.1016/j.ultrasmedbio.2014.03.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 03/28/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
The aim of this study was to enable investigations into novel imaging and surgical techniques by developing a readily accessible, versatile liver machine perfusion system. Slaughterhouse pig livers were used, and dynamic contrast-enhanced ultrasound was introduced to optimize the procurement process and provide real-time perfusion monitoring. The system comprised a single pump, oxygenator, bubble trap and two flowmeters for pressure-controlled perfusion of the vessels using an off-the-shelf perfusate at room temperature. Successful livers exhibited homogeneous perfusion in both the portal vein and hepatic artery with dynamic contrast-enhanced ultrasound, which correlated with stable oxygen uptake, bile production and hepatic resistance and normal histology at the end of 3 h of perfusion. Dynamic contrast-enhanced ultrasound revealed perfusion abnormalities invisible to the naked eye, thereby providing context to the otherwise systemic biochemical/hemodynamic measurements and focal biopsy findings. The model developed here is a simple, cost-effective approach for stable ex vivo whole-organ machine perfusion.
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Affiliation(s)
- Maria-Louisa Izamis
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | | | - Christina Keravnou
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | - Edward L Leen
- Department of Medicine, Imperial College, London, United Kingdom
| | - Michalakis A Averkiou
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus.
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BMP type II receptors have redundant roles in the regulation of hepatic hepcidin gene expression and iron metabolism. Blood 2014; 124:2116-23. [PMID: 25075125 DOI: 10.1182/blood-2014-04-572644] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Expression of hepcidin, the hepatic hormone controlling iron homeostasis, is regulated by bone morphogenetic protein (BMP) signaling. We sought to identify which BMP type II receptor expressed in hepatocytes, ActR2a or BMPR2, is responsible for regulating hepcidin gene expression. We studied Bmpr2 heterozygous mice (Bmpr2(+/-)), mice with hepatocyte-specific deficiency of BMPR2, mice with global deficiency of ActR2a, and mice in which hepatocytes lacked both BMPR2 and ActR2a. Hepatic hepcidin messenger RNA (mRNA) levels, serum hepcidin and iron levels, and tissue iron levels did not differ in wild-type mice, Bmpr2(+/-) mice, and mice in which either BMPR2 or ActR2a was deficient. Deficiency of both BMP type II receptors markedly reduced hepatic hepcidin gene expression and serum hepcidin levels leading to severe iron overload. Iron injection increased hepatic hepcidin mRNA levels in mice deficient in either BMPR2 or ActR2a, but not in mice deficient in both BMP type II receptors. In addition, in mouse and human primary hepatocytes, deficiency of both BMPR2 and ActR2a profoundly decreased basal and BMP6-induced hepcidin gene expression. These results suggest that BMP type II receptors, BMPR2 and ActR2a, have redundant roles in the regulation of hepatic hepcidin gene expression and iron metabolism.
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Supercooling enables long-term transplantation survival following 4 days of liver preservation. Nat Med 2014; 20:790-3. [PMID: 24973919 PMCID: PMC4141719 DOI: 10.1038/nm.3588] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/27/2014] [Indexed: 12/28/2022]
Abstract
The realization of long–term human organ preservation will have groundbreaking effects on the current practice of transplantation. Herein we present a novel technique based on sub–zero non–freezing tissue preservation and extracorporeal machine perfusion that allows transplantation of rat livers preserved for up to 4 days, thereby tripling the viable preservation duration.
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Izamis ML, Efstathiades A, Keravnou C, Georgiadou S, Martins PN, Averkiou MA. Effects of air embolism size and location on porcine hepatic microcirculation in machine perfusion. Liver Transpl 2014; 20:601-11. [PMID: 24478135 DOI: 10.1002/lt.23838] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Accepted: 01/05/2014] [Indexed: 02/07/2023]
Abstract
The handling of donor organs frequently introduces air into the microvasculature, but little is known about the extent of the damage caused as a function of the embolism size and distribution. Here we introduced embolisms of different sizes into the portal vein, the hepatic artery, or both during the flushing stage of porcine liver procurement. The outcomes were evaluated during 3 hours of machine perfusion and were compared to the outcomes of livers with no embolisms. Dynamic contrast-enhanced ultrasound (DCEUS) was used to assess the perfusion quality, and it demonstrated that embolisms tended to flow mostly into the left lobe, occasionally into the right lobe, and rarely into the caudate lobe. Major embolisms could disrupt the flow entirely, whereas minor embolisms resulted in reduced or heterogeneous flow. Embolisms occasionally migrated to different regions of the same lobe and, regardless of their size, caused a general deterioration in the flow over time. Histological damage resulted primarily when both vessels of the liver were compromised, whereas bile production was diminished in livers that had arterial embolisms. Air embolisms produced a dose-dependent increase in vascular resistance and a decline in oxygen consumption. This is the first article to quantify the impact of air embolisms on microcirculation in an experimental model, and it demonstrates that air embolisms have the capacity to degrade the integrity of donor organs. The extent of organ damage is strongly dependent on the size and distribution of air embolisms. The diagnosis of embolism severity can be safely and easily made with DCEUS.
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Affiliation(s)
- Maria-Louisa Izamis
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
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Izamis ML, Tolboom H, Uygun B, Berthiaume F, Yarmush ML, Uygun K. Resuscitation of ischemic donor livers with normothermic machine perfusion: a metabolic flux analysis of treatment in rats. PLoS One 2013; 8:e69758. [PMID: 23922793 PMCID: PMC3724866 DOI: 10.1371/journal.pone.0069758] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/16/2013] [Indexed: 12/15/2022] Open
Abstract
Normothermic machine perfusion has previously been demonstrated to restore damaged warm ischemic livers to transplantable condition in animal models. However, the mechanisms of recovery are unclear, preventing rational optimization of perfusion systems and slowing clinical translation of machine perfusion. In this study, organ recovery time and major perfusate shortcomings were evaluated using a comprehensive metabolic analysis of organ function in perfusion prior to successful transplantation. Two groups, Fresh livers and livers subjected to 1 hr of warm ischemia (WI) received perfusion for a total preservation time of 6 hrs, followed by successful transplantation. 24 metabolic fluxes were directly measured and 38 stoichiometrically-related fluxes were estimated via a mass balance model of the major pathways of energy metabolism. This analysis revealed stable metabolism in Fresh livers throughout perfusion while identifying two distinct metabolic states in WI livers, separated at t = 2 hrs, coinciding with recovery of oxygen uptake rates to Fresh liver values. This finding strongly suggests successful organ resuscitation within 2 hrs of perfusion. Overall perfused livers regulated metabolism of perfusate substrates according to their metabolic needs, despite supraphysiological levels of some metabolites. This study establishes the first integrative metabolic basis for the dynamics of recovery during perfusion treatment of marginal livers. Our initial findings support enhanced oxygen delivery for both timely recovery and long-term sustenance. These results are expected to lead the optimization of the treatment protocols and perfusion media from a metabolic perspective, facilitating translation to clinical use.
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Affiliation(s)
- Maria-Louisa Izamis
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Hospitals for Children, Boston, Massachusetts, United States of America
| | - Herman Tolboom
- Division of Cardiac and Vascular Surgery, University Hospital Zurich, Zurich, Switzerland
| | - Basak Uygun
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Hospitals for Children, Boston, Massachusetts, United States of America
| | - Francois Berthiaume
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, United States of America
| | - Martin L. Yarmush
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Hospitals for Children, Boston, Massachusetts, United States of America
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, United States of America
| | - Korkut Uygun
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and the Shriners Hospitals for Children, Boston, Massachusetts, United States of America
- * E-mail:
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