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1.
Liver Transpl ; 30(1): 30-45, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38109282

RESUMO

Normothermic machine perfusion (NMP) enables pretransplant assessment of high-risk donor livers. The VITTAL trial demonstrated that 71% of the currently discarded organs could be transplanted with 100% 90-day patient and graft survivals. Here, we report secondary end points and 5-year outcomes of this prospective, open-label, phase 2 adaptive single-arm study. The patient and graft survivals at 60 months were 82% and 72%, respectively. Four patients lost their graft due to nonanastomotic biliary strictures, one caused by hepatic artery thrombosis in a liver donated following brain death, and 3 in elderly livers donated after circulatory death (DCD), which all clinically manifested within 6 months after transplantation. There were no late graft losses for other reasons. All the 4 patients who died during the study follow-up had functioning grafts. Nonanastomotic biliary strictures developed in donated after circulatory death livers that failed to produce bile with pH >7.65 and bicarbonate levels >25 mmol/L. Histological assessment in these livers revealed high bile duct injury scores characterized by arterial medial necrosis. The quality of life at 6 months significantly improved in all but 4 patients suffering from nonanastomotic biliary strictures. This first report of long-term outcomes of high-risk livers assessed by normothermic machine perfusion demonstrated excellent 5-year survival without adverse effects in all organs functioning beyond 1 year (ClinicalTrials.gov number NCT02740608).


Assuntos
Transplante de Fígado , Idoso , Humanos , Constrição Patológica/etiologia , Fígado/cirurgia , Transplante de Fígado/efeitos adversos , Preservação de Órgãos , Perfusão , Estudos Prospectivos , Qualidade de Vida
2.
Nature ; 557(7703): 50-56, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29670285

RESUMO

Liver transplantation is a highly successful treatment, but is severely limited by the shortage in donor organs. However, many potential donor organs cannot be used; this is because sub-optimal livers do not tolerate conventional cold storage and there is no reliable way to assess organ viability preoperatively. Normothermic machine perfusion maintains the liver in a physiological state, avoids cooling and allows recovery and functional testing. Here we show that, in a randomized trial with 220 liver transplantations, compared to conventional static cold storage, normothermic preservation is associated with a 50% lower level of graft injury, measured by hepatocellular enzyme release, despite a 50% lower rate of organ discard and a 54% longer mean preservation time. There was no significant difference in bile duct complications, graft survival or survival of the patient. If translated to clinical practice, these results would have a major impact on liver transplant outcomes and waiting list mortality.


Assuntos
Aloenxertos/fisiologia , Transplante de Fígado/métodos , Fígado/fisiologia , Preservação de Órgãos/métodos , Temperatura , Coleta de Tecidos e Órgãos/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aloenxertos/patologia , Aloenxertos/fisiopatologia , Aloenxertos/normas , Ductos Biliares/patologia , Ductos Biliares/fisiologia , Ductos Biliares/fisiopatologia , Feminino , Sobrevivência de Enxerto , Humanos , Tempo de Internação , Fígado/enzimologia , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Preservação de Órgãos/efeitos adversos , Perfusão , Análise de Sobrevida , Doadores de Tecidos/provisão & distribuição , Coleta de Tecidos e Órgãos/efeitos adversos , Resultado do Tratamento , Listas de Espera , Adulto Jovem
3.
J Hepatol ; 78(6): 1181-1198, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37208105

RESUMO

With the increasing number of accepted candidates on waiting lists worldwide, there is an urgent need to expand the number and the quality of donor livers. Dynamic preservation approaches have demonstrated various benefits, including improving liver function and graft survival, and reducing liver injury and post-transplant complications. Consequently, organ perfusion techniques are being used in clinical practice in many countries. Despite this success, a proportion of livers do not meet current viability tests required for transplantation, even with the use of modern perfusion techniques. Therefore, devices are needed to further optimise machine liver perfusion - one promising option is to prolong machine liver perfusion for several days, with ex situ treatment of perfused livers. For example, stem cells, senolytics, or molecules targeting mitochondria or downstream signalling can be administered during long-term liver perfusion to modulate repair mechanisms and regeneration. Besides, today's perfusion equipment is also designed to enable the use of various liver bioengineering techniques, to develop scaffolds or for their re-cellularisation. Cells or entire livers can also undergo gene modulation to modify animal livers for xenotransplantation, to directly treat injured organs or to repopulate such scaffolds with "repaired" autologous cells. This review first discusses current strategies to improve the quality of donor livers, and secondly reports on bioengineering techniques to design optimised organs during machine perfusion. Current practice, as well as the benefits and challenges associated with these different perfusion strategies are discussed.


Assuntos
Transplante de Fígado , Animais , Transplante de Fígado/métodos , Preservação de Órgãos/métodos , Fígado , Perfusão/métodos , Bioengenharia
4.
Liver Transpl ; 28(5): 794-806, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34619014

RESUMO

Normothermic machine perfusion (NMP) allows objective assessment of donor liver transplantability. Several viability evaluation protocols have been established, consisting of parameters such as perfusate lactate clearance, pH, transaminase levels, and the production and composition of bile. The aims of this study were to assess 3 such protocols, namely, those introduced by the teams from Birmingham (BP), Cambridge (CP), and Groningen (GP), using a cohort of high-risk marginal livers that had initially been deemed unsuitable for transplantation and to introduce the concept of the viability assessment sensitivity and specificity. To demonstrate and quantify the diagnostic accuracy of these protocols, we used a composite outcome of organ use and 24-month graft survival as a surrogate endpoint. The effects of assessment modifications, including the removal of the most stringent components of the protocols, were also assessed. Of the 31 organs, 22 were transplanted after a period of NMP, of which 18 achieved the outcome of 24-month graft survival. The BP yielded 94% sensitivity and 50% specificity when predicting this outcome. The GP and CP both seemed overly conservative, with 1 and 0 organs, respectively, meeting these protocols. Modification of the GP and CP to exclude their most stringent components increased this to 11 and 8 organs, respectively, and resulted in moderate sensitivity (56% and 44%) but high specificity (92% and 100%, respectively) with respect to the composite outcome. This study shows that the normothermic assessment protocols can be useful in identifying potentially viable organs but that the balance of risk of underuse and overuse varies by protocol.


Assuntos
Transplante de Fígado , Sobrevivência de Enxerto , Humanos , Fígado , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Doadores Vivos , Preservação de Órgãos/métodos , Perfusão/métodos
5.
Liver Transpl ; 28(11): 1716-1725, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35662403

RESUMO

In situ normothermic regional perfusion (NRP) and ex situ normothermic machine perfusion (NMP) aim to improve the outcomes of liver transplantation (LT) using controlled donation after circulatory death (cDCD). NRP and NMP have not yet been compared directly. In this international observational study, outcomes of LT performed between 2015 and 2019 for organs procured from cDCD donors subjected to NRP or NMP commenced at the donor center were compared using propensity score matching (PSM). Of the 224 cDCD donations in the NRP cohort that proceeded to asystole, 193 livers were procured, resulting in 157 transplants. In the NMP cohort, perfusion was commenced in all 40 cases and resulted in 34 transplants (use rates: 70% vs. 85% [p = 0.052], respectively). After PSM, 34 NMP liver recipients were matched with 68 NRP liver recipients. The two cohorts were similar for donor functional warm ischemia time (21 min after NRP vs. 20 min after NMP; p = 0.17), UK-Donation After Circulatory Death risk score (5 vs. 5 points; p = 0.38), and laboratory Model for End-Stage Liver Disease scores (12 vs. 12 points; p = 0.83). The incidence of nonanastomotic biliary strictures (1.5% vs. 2.9%; p > 0.99), early allograft dysfunction (20.6% vs. 8.8%; p = 0.13), and 30-day graft loss (4.4% vs. 8.8%; p = 0.40) were similar, although peak posttransplant aspartate aminotransferase levels were higher in the NRP cohort (872 vs. 344 IU/L; p < 0.001). NRP livers were more frequently allocated to recipients suffering from hepatocellular carcinoma (HCC; 60.3% vs. 20.6%; p < 0.001). HCC-censored 2-year graft and patient survival rates were 91.5% versus 88.2% (p = 0.52) and 97.9% versus 94.1% (p = 0.25) after NRP and NMP, respectively. Both perfusion techniques achieved similar outcomes and appeared to match benchmarks expected for donation after brain death livers. This study may inform the design of a definitive trial.


Assuntos
Carcinoma Hepatocelular , Doença Hepática Terminal , Neoplasias Hepáticas , Transplante de Fígado , Aspartato Aminotransferases , Doença Hepática Terminal/cirurgia , Sobrevivência de Enxerto , Humanos , Transplante de Fígado/métodos , Preservação de Órgãos/métodos , Perfusão/métodos , Índice de Gravidade de Doença
6.
Int J Mol Sci ; 22(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34299142

RESUMO

The increasing disparity between the number of patients listed for transplantation and the number of suitable organs has led to the increasing use of extended criteria donors (ECDs). ECDs are at increased risk of developing ischaemia reperfusion injury and greater risk of post-transplant complications. Ischaemia reperfusion injury is a major complication of organ transplantation defined as the inflammatory changes seen following the disruption and restoration of blood flow to an organ-it is a multifactorial process with the potential to cause both local and systemic organ failure. The utilisation of machine perfusion under normothermic (37 degrees Celsius) and hypothermic (4-10 degrees Celsius) has proven to be a significant advancement in organ preservation and restoration. One of the key benefits is its ability to optimise suboptimal organs for successful transplantation. This review is focused on examining ischaemia reperfusion injury and how machine perfusion ameliorates the graft's response to this.


Assuntos
Sobrevivência de Enxerto , Transplante de Fígado/métodos , Fígado/irrigação sanguínea , Preservação de Órgãos/métodos , Perfusão , Traumatismo por Reperfusão/terapia , Animais , Humanos
7.
Curr Opin Organ Transplant ; 26(2): 121-132, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33650995

RESUMO

PURPOSE OF REVIEW: To summarize key studies in liver preservation published over the last 3 years and evaluate benefits and limitations of the different perfusion techniques. Selected experimental applications that may be translated to the clinical use will be also discussed. RECENT FINDINGS: Normothermic machine perfusion (NMP) has transitioned into clinical practice. Viability assessment is a reliable tool for clinical decision-making, and safety of the back-to-base approach has facilitated adoption of the technology. Data supporting well tolerated use of declined livers after NMP and new protocols selecting complex recipients aim to improve access to suitable organs. Hypothermic machine perfusion (HMP) is showing promising clinical results by decreasing biliary complications in recipients' receiving organs donated after circulatory death (DCD) and improving early graft function in extended criteria organs. Long-term data of HMP on DCD livers shows improved graft survival over standard SCS. Novel approaches utilizing sequential HMP--NMP or ischaemia-free preservation aim to improve outcomes of extended criteria organs. SUMMARY: Machine perfusion for organ transplantation has become an established technique but the field is rapidly evolving. Ongoing research focuses on evaluation of the intervention efficacy and finding optimal indications to use each perfusion strategy according to graft type and clinical scenario.


Assuntos
Transplante de Fígado , Preservação de Órgãos , Sobrevivência de Enxerto , Humanos , Fígado , Transplante de Fígado/efeitos adversos , Perfusão
8.
Int J Mol Sci ; 21(5)2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32106626

RESUMO

Liver ischaemia-reperfusion injury (IRI) is an intrinsic part of the transplantation process and damages the parenchymal cells of the liver including hepatocytes, endothelial cells and cholangiocytes. Many biomarkers of IRI have been described over the past two decades that have attempted to quantify the extent of IRI involving different hepatic cellular compartments, with the aim to allow clinicians to predict the suitability of donor livers for transplantation. The advent of machine perfusion has added an additional layer of complexity to this field and has forced researchers to re-evaluate the utility of IRI biomarkers in different machine preservation techniques. In this review, we summarise the current understanding of liver IRI biomarkers and discuss them in the context of machine perfusion.


Assuntos
Transplante de Fígado/métodos , Traumatismo por Reperfusão/diagnóstico , Animais , Biomarcadores/metabolismo , Endotelina-1/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Humanos , Interleucinas/metabolismo , Transplante de Fígado/efeitos adversos , Transplante de Fígado/instrumentação , MicroRNAs/metabolismo , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo
10.
Liver Transpl ; 25(7): 1007-1022, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30821045

RESUMO

Strategies to increase the use of steatotic donor livers are required to tackle the mortality on the transplant waiting list. We aimed to test the efficacy of pharmacological enhancement of the lipid metabolism of human livers during ex situ normothermic machine perfusion to promote defatting and improve the functional recovery of the organs. Because of steatosis, 10 livers were discarded and were allocated either to a defatting group that had the perfusate supplemented with a combination of drugs to enhance lipid metabolism or to a control group that received perfusion fluid with vehicle only. Steatosis was assessed using tissue homogenate and histological analyses. Markers for lipid oxidation and solubilization, oxidative injury, inflammation, and biliary function were evaluated by enzyme-linked immunosorbent assay, immunohistochemistry, and in-gel protein detection. Treatment reduced tissue triglycerides by 38% and macrovesicular steatosis by 40% over 6 hours. This effect was driven by increased solubility of the triglycerides (P = 0.04), and mitochondrial oxidation as assessed by increased ketogenesis (P = 0.008) and adenosine triphosphate synthesis (P = 0.01) were associated with increased levels of the enzymes acyl-coenzyme A oxidase 1, carnitine palmitoyltransferase 1A, and acetyl-coenzyme A synthetase. Concomitantly, defatted livers exhibited enhanced metabolic functional parameters such as urea production (P = 0.03), lower vascular resistance, lower release of alanine aminotransferase (P = 0.049), and higher bile production (P = 0.008) with a higher bile pH (P = 0.03). The treatment down-regulated the expression of markers for oxidative injury as well as activation of immune cells (CD14; CD11b) and reduced the release of inflammatory cytokines in the perfusate (tumor necrosis factor α; interleukin 1ß). In conclusion, pharmacological enhancement of intracellular lipid metabolism during normothermic machine perfusion decreased the lipid content of human livers within 6 hours. It also improved the intracellular metabolic support to the organs, leading to successful functional recovery and decreased expression of markers of reperfusion injury.


Assuntos
Fígado Gorduroso/patologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Transplante de Fígado , Preservação de Órgãos/métodos , Perfusão/métodos , Coleta de Tecidos e Órgãos/métodos , Aloenxertos/metabolismo , Aloenxertos/patologia , Antracenos , Butiratos/farmacologia , Colforsina/farmacologia , Fígado Gorduroso/diagnóstico , Fígado Gorduroso/metabolismo , Estudos de Viabilidade , Feminino , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Nicotinamida Fosforribosiltransferase/farmacologia , Preservação de Órgãos/instrumentação , Perfusão/instrumentação , Perileno/análogos & derivados , Perileno/farmacologia , Soluções Farmacêuticas/farmacologia , Compostos de Fenilureia/farmacologia , Traumatismo por Reperfusão/diagnóstico , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/prevenção & controle , Tiazóis/farmacologia , Coleta de Tecidos e Órgãos/efeitos adversos
11.
Liver Transpl ; 25(4): 545-558, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30919560

RESUMO

Parameters of retrieval surgery are meticulously documented in the United Kingdom, where up to 40% of livers are donation after circulatory death (DCD) donations. This retrospective analysis focuses on outcomes after transplantation of DCD livers, retrieved by different UK centers between 2011 and 2016. Donor and recipient risk factors and the donor retrieval technique were assessed. A total of 236 DCD livers from 9 retrieval centers with a median UK DCD risk score of 5 (low risk) to 7 points (high risk) were compared. The majority used University of Wisconsin solution for aortic flush with a median hepatectomy time of 27-44 minutes. The overall liver injury rate appeared relatively high (27.1%) with an observed tendency toward more retrieval injuries from centers performing a quicker hepatectomy. Among all included risk factors, the UK DCD risk score remained the best predictor for overall graft loss in the multivariate analysis (P < 0.001). In high-risk and futile donor-recipient combinations, the occurrence of liver retrieval injuries had negative impact on graft survival (P = 0.023). Expectedly, more ischemic cholangiopathies (P = 0.003) were found in livers transplanted with a higher cumulative donor-recipient risk. Although more biliary complications with subsequent graft loss were found in high-risk donor-recipient combinations, the impact of the standardized national retrieval practice on outcomes after DCD liver transplantation was minimal.


Assuntos
Rejeição de Enxerto/epidemiologia , Hepatectomia/estatística & dados numéricos , Transplante de Fígado/efeitos adversos , Padrões de Prática Médica/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Adenosina/farmacologia , Adulto , Idoso , Aloenxertos/irrigação sanguínea , Aloenxertos/efeitos dos fármacos , Aloenxertos/cirurgia , Alopurinol/farmacologia , Feminino , Glutationa/farmacologia , Sobrevivência de Enxerto , Hepatectomia/efeitos adversos , Hepatectomia/métodos , Hepatectomia/normas , Humanos , Insulina/farmacologia , Fígado/irrigação sanguínea , Fígado/efeitos dos fármacos , Fígado/cirurgia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Preservação de Órgãos/métodos , Preservação de Órgãos/normas , Preservação de Órgãos/estatística & dados numéricos , Soluções para Preservação de Órgãos/farmacologia , Guias de Prática Clínica como Assunto , Padrões de Prática Médica/normas , Rafinose/farmacologia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/métodos , Obtenção de Tecidos e Órgãos/normas , Reino Unido/epidemiologia
12.
Liver Transpl ; 25(10): 1503-1513, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31206217

RESUMO

Clinical adoption of normothermic machine perfusion (NMP) may be facilitated by simplifying logistics and reducing costs. This can be achieved by cold storage of livers for transportation to recipient centers before commencing NMP. The purpose of this study was to assess the safety and feasibility of post-static cold storage normothermic machine perfusion (pSCS-NMP) in liver transplantation. In this multicenter prospective study, 31 livers were transplanted. The primary endpoint was 30-day graft survival. Secondary endpoints included the following: peak posttransplant aspartate aminotransferase (AST), early allograft dysfunction (EAD), postreperfusion syndrome (PRS), adverse events, critical care and hospital stay, biliary complications, and 12-month graft survival. The 30-day graft survival rate was 94%. Livers were preserved for a total of 14 hours 10 minutes ± 4 hours 46 minutes, which included 6 hours 1 minute ± 1 hour 19 minutes of static cold storage before 8 hours 24 minutes ± 4 hours 4 minutes of NMP. Median peak serum AST in the first 7 days postoperatively was 457 U/L (92-8669 U/L), and 4 (13%) patients developed EAD. PRS was observed in 3 (10%) livers. The median duration of initial critical care stay was 3 days (1-20 days), and median hospital stay was 13 days (7-31 days). There were 7 (23%) patients who developed complications of grade 3b severity or above, and 2 (6%) patients developed biliary complications: 1 bile leak and 1 anastomotic stricture with no cases of ischemic cholangiopathy. The 12-month overall graft survival rate (including death with a functioning graft) was 84%. In conclusion, this study demonstrates that pSCS-NMP was feasible and safe, which may facilitate clinical adoption.


Assuntos
Sobrevivência de Enxerto , Transplante de Fígado/efeitos adversos , Preservação de Órgãos/métodos , Perfusão/métodos , Complicações Pós-Operatórias/epidemiologia , Adolescente , Adulto , Idoso , Aloenxertos/irrigação sanguínea , Temperatura Baixa , Doença Hepática Terminal/diagnóstico , Doença Hepática Terminal/cirurgia , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Fígado/irrigação sanguínea , Transplante de Fígado/métodos , Masculino , Pessoa de Meia-Idade , Preservação de Órgãos/efeitos adversos , Perfusão/efeitos adversos , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Isquemia Quente/efeitos adversos , Adulto Jovem
13.
Transpl Infect Dis ; 21(3): e13092, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30972849

RESUMO

Hepatic arterial aortic conduits can be used as an alternative means of revascularizing the donor liver when the native recipient hepatic artery (HA) cannot be used. Cytomegalovirus (CMV) is a common Herpesviridae infection in patients who have undergone solid organ transplants. It can be asymptomatic but may cause fever and invasive disease affecting any organ system. Here we describe the first case in the literature of an aortic conduit aneurysm and concurrent CMV viremia following liver transplantation. We speculate on a causative role for CMV in the development of the aneurysm.


Assuntos
Aneurisma Aórtico/virologia , Infecções por Citomegalovirus/complicações , Fístula do Sistema Digestório/virologia , Transplante de Fígado/efeitos adversos , Colo/diagnóstico por imagem , Citomegalovirus , Artéria Hepática/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Transplante de Órgãos , Fatores de Risco , Tomografia Computadorizada por Raios X , Viremia
14.
Semin Liver Dis ; 38(3): 252-259, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30041277

RESUMO

While majority of liver transplants worldwide continue to be performed using deceased donor organs, the demands for donor livers continues to exceed the current supply. In an attempt to maximize the number of potentially usable donor livers and expand the current donor pool, there is intense global research by various groups exploring the role of machine perfusion in the liver transplantation, particularly with respect to the machine perfusion of extended-criteria liver donors. In this review, the authors summarize the current field of machine perfusion strategies as applied to deceased donor liver transplantation and how therapeutic targeting of the liver sinusoidal endothelial cell may improve the quality of donor livers.


Assuntos
Células Endoteliais/transplante , Transplante de Fígado/métodos , Fígado/cirurgia , Preservação de Órgãos/métodos , Perfusão/métodos , Traumatismo por Reperfusão/prevenção & controle , Doadores de Tecidos/provisão & distribuição , Animais , Seleção do Doador , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Sobrevivência de Enxerto , Humanos , Fígado/metabolismo , Fígado/patologia , Transplante de Fígado/efeitos adversos , Preservação de Órgãos/efeitos adversos , Preservação de Órgãos/instrumentação , Perfusão/efeitos adversos , Perfusão/instrumentação , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Fatores de Risco , Transdução de Sinais , Resultado do Tratamento , Listas de Espera
15.
Am J Transplant ; 18(10): 2384-2399, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29947472

RESUMO

Long-standing research has shown that increased lipid content in donor livers is associated with inferior graft outcomes posttransplant. The global epidemic that is obesity has increased the prevalence of steatosis in organ donors, to the extent that it has become one of the main reasons for declining livers for transplantation. Consequently, it is one of the major culprits behind the discrepancy between the number of donor livers offered for transplantation and those that go on to be transplanted. Steatotic livers are characterized by poor microcirculation, depleted energy stores because of an impaired capacity for mitochondrial recovery, and a propensity for an exaggerated inflammatory response following reperfusion injury culminating in poorer graft function postoperatively. Ex situ machine perfusion, currently a novel method in graft preservation, is showing great promise in providing a tool for the recovery and reconditioning of marginal livers. Hence, reconditioning these steatotic livers using machine perfusion has the potential to increase the number of liver transplants performed. In this review, we consider the problematic issues associated with fatty livers in the realm of transplantation and discuss pharmacological and nonpharmacological options that are being developed to enhance recovery of these organs using machine perfusion and defatting strategies.


Assuntos
Gorduras/metabolismo , Fígado Gorduroso/fisiopatologia , Transplante de Fígado , Doadores Vivos/provisão & distribuição , Preservação de Órgãos/métodos , Perfusão , Humanos
16.
J Hepatol ; 68(3): 456-464, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29155020

RESUMO

BACKGROUND & AIMS: Primary non-function and ischaemic cholangiopathy are the most feared complications following donation-after-circulatory-death (DCD) liver transplantation. The aim of this study was to design a new score on risk assessment in liver-transplantation DCD based on donor-and-recipient parameters. METHODS: Using the UK national DCD database, a risk analysis was performed in adult recipients of DCD liver grafts in the UK between 2000 and 2015 (n = 1,153). A new risk score was calculated (UK DCD Risk Score) on the basis of a regression analysis. This is validated using the United Network for Organ Sharing database (n = 1,617) and our own DCD liver-transplant database (n = 315). Finally, the new score was compared with two other available prediction systems: the DCD risk scores from the University of California, Los Angeles and King's College Hospital, London. RESULTS: The following seven strongest predictors of DCD graft survival were identified: functional donor warm ischaemia, cold ischaemia, recipient model for end-stage liver disease, recipient age, donor age, previous orthotopic liver transplantation, and donor body mass index. A combination of these risk factors (UK DCD risk model) stratified the best recipients in terms of graft survival in the entire UK DCD database, as well as in the United Network for Organ Sharing and in our own DCD population. Importantly, the UK DCD Risk Score significantly predicted graft loss caused by primary non-function or ischaemic cholangiopathy in the futile group (>10 score points). The new prediction model demonstrated a better C statistic of 0.79 compared to the two other available systems (0.71 and 0.64, respectively). CONCLUSIONS: The UK DCD Risk Score is a reliable tool to detect high-risk and futile combinations of donor-and-recipient factors in DCD liver transplantation. It is simple to use and offers a great potential for making better decisions on which DCD graft should be rejected or may benefit from functional assessment and further optimization by machine perfusion. LAY SUMMARY: In this study, we provide a new prediction model for graft loss in donation-after-circulatory-death (DCD) liver transplantation. Based on UK national data, the new UK DCD Risk Score involves the following seven clinically relevant risk factors: donor age, donor body mass index, functional donor warm ischaemia, cold storage, recipient age, recipient laboratory model for end-stage liver disease, and retransplantation. Three risk classes were defined: low risk (0-5 points), high risk (6-10 points), and futile (>10 points). This new model stratified best in terms of graft survival compared to other available models. Futile combinations (>10 points) achieved an only very limited 1- and 5-year graft survival of 37% and less than 20%, respectively. In contrast, an excellent graft survival has been shown in low-risk combinations (≤5 points). The new model is easy to calculate at the time of liver acceptance. It may help to decide which risk combination will benefit from additional graft treatment, or which DCD liver should be declined for a certain recipient.


Assuntos
Doença Hepática Terminal , Rejeição de Enxerto , Sobrevivência de Enxerto/fisiologia , Transplante de Fígado , Pontuação de Propensão , Medição de Risco/métodos , Transplantes/normas , Adulto , Isquemia Fria , Morte , Doença Hepática Terminal/patologia , Doença Hepática Terminal/fisiopatologia , Doença Hepática Terminal/cirurgia , Feminino , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/prevenção & controle , Humanos , Fígado/patologia , Fígado/fisiopatologia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Transplante de Fígado/estatística & dados numéricos , Masculino , Futilidade Médica , Fatores de Risco , Doadores de Tecidos/classificação , Doadores de Tecidos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/métodos , Obtenção de Tecidos e Órgãos/normas , Isquemia Quente
17.
Liver Transpl ; 24(3): 352-362, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28885771

RESUMO

Advanced donor age has been identified as a risk factor when combined with donor warm ischemia time (WIT), eg, in donation after circulatory death (DCD). In several countries, DCD livers older than 60 years are not considered suitable due to concerns related to poor graft function and development of ischemic cholangiopathy. In this study, we evaluate outcomes after DCD liver transplantation using grafts from donors older than 60 years. We analyzed outcomes after DCD liver transplantation (n = 315), comparing donors > 60 years (n = 93) and donors ≤ 60 years (n = 222) from our center between 2005 and 2015. End points included graft function and complications and patient and graft survival. Multivariate risk analysis was performed to define further key factors that predicted inferior outcome. Donor age at the cutoff 60 years failed to stratify patient and graft survival. The rate of vascular, biliary, and overall complications was comparably low in both cohorts, and the median comprehensive complication index was 42.7 points, independent from the donor age. Second, donor body mass index (BMI) above a threshold of 25 kg/m2 significantly impacted on graft and patient survival at any donor age, whereas donor WIT and cold ischemia times were not predictive for graft loss. In conclusion, older DCD donors can be successfully used for liver transplantation with good longterm outcomes when further risk factors are limited. Additional risk is transmitted by an increased donor BMI regardless of donor age. Liver Transplantation 24 352-362 2018 AASLD.


Assuntos
Seleção do Doador , Transplante de Fígado , Doadores de Tecidos , Fatores Etários , Idoso , Índice de Massa Corporal , Inglaterra , Feminino , Sobrevivência de Enxerto , Humanos , Estimativa de Kaplan-Meier , Transplante de Fígado/efeitos adversos , Transplante de Fígado/mortalidade , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Complicações Pós-Operatórias/etiologia , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
18.
Liver Transpl ; 24(12): 1699-1715, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30058119

RESUMO

Hypothermic oxygenated perfusion (HOPE) and normothermic perfusion are seen as distinct techniques of ex situ machine perfusion of the liver. We aimed to demonstrate the feasibility of combining both techniques and whether it would improve functional parameters of donor livers into transplant standards. Ten discarded human donor livers had either 6 hours of normothermic perfusion (n = 5) or 2 hours of HOPE followed by 4 hours of normothermic perfusion (n = 5). Liver function was assessed according to our viability criteria; markers of tissue injury and hepatic metabolic activity were compared between groups. Donor characteristics were comparable. During the hypothermic perfusion phase, livers down-regulated mitochondrial respiration (oxygen uptake, P = 0.04; partial pressure of carbon dioxide perfusate, P = 0.04) and increased adenosine triphosphate levels 1.8-fold. Following normothermic perfusion, those organs achieved lower tissue expression of markers of oxidative injury (4-hydroxynonenal, P = 0.008; CD14 expression, P = 0.008) and inflammation (CD11b, P = 0.02; vascular cell adhesion molecule 1, P = 0.05) compared with livers that had normothermic perfusion alone. All livers in the combined group achieved viability criteria, whereas 40% (2/5) in the normothermic group failed (P = 0.22). In conclusion, this study suggests that a combined protocol of hypothermic oxygenated and normothermic perfusions might attenuate oxidative stress, tissue inflammation, and improve metabolic recovery of the highest-risk donor livers compared with normothermic perfusion alone.


Assuntos
Seleção do Doador/normas , Transplante de Fígado/métodos , Preservação de Órgãos/métodos , Perfusão/métodos , Aloenxertos/metabolismo , Aloenxertos/cirurgia , Biomarcadores/análise , Biomarcadores/metabolismo , Isquemia Fria/instrumentação , Isquemia Fria/métodos , Estudos de Viabilidade , Humanos , Fígado/metabolismo , Fígado/cirurgia , Testes de Função Hepática , Transplante de Fígado/normas , Preservação de Órgãos/instrumentação , Estresse Oxidativo , Perfusão/instrumentação , Isquemia Quente/instrumentação , Isquemia Quente/métodos
19.
Liver Transpl ; 24(10): 1453-1469, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30359490

RESUMO

Increased use of high-risk allografts is critical to meet the demand for liver transplantation. We aimed to identify criteria predicting viability of organs, currently declined for clinical transplantation, using functional assessment during normothermic machine perfusion (NMP). Twelve discarded human livers were subjected to NMP following static cold storage. Livers were perfused with a packed red cell-based fluid at 37°C for 6 hours. Multilevel statistical models for repeated measures were employed to investigate the trend of perfusate blood gas profiles and vascular flow characteristics over time and the effect of lactate-clearing (LC) and non-lactate-clearing (non-LC) ability of the livers. The relationship of lactate clearance capability with bile production and histological and molecular findings were also examined. After 2 hours of perfusion, median lactate concentrations were 3.0 and 14.6 mmol/L in the LC and non-LC groups, respectively. LC livers produced more bile and maintained a stable perfusate pH and vascular flow >150 and 500 mL/minute through the hepatic artery and portal vein, respectively. Histology revealed discrepancies between subjectively discarded livers compared with objective findings. There were minimal morphological changes in the LC group, whereas non-LC livers often showed hepatocellular injury and reduced glycogen deposition. Adenosine triphosphate levels in the LC group increased compared with the non-LC livers. We propose composite viability criteria consisting of lactate clearance, pH maintenance, bile production, vascular flow patterns, and liver macroscopic appearance. These have been tested successfully in clinical transplantation. In conclusion, NMP allows an objective assessment of liver function that may reduce the risk and permit use of currently unused high-risk livers.


Assuntos
Transplante de Fígado/efeitos adversos , Preservação de Órgãos/normas , Traumatismo por Reperfusão/diagnóstico , Sobrevivência de Tecidos , Coleta de Tecidos e Órgãos/efeitos adversos , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Preservação de Órgãos/métodos , Perfusão/métodos , Perfusão/normas , Prognóstico , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/prevenção & controle
20.
Liver Transpl ; 24(10): 1437-1452, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30040176

RESUMO

Ischemia/reperfusion injury (IRI) is the main cause of complications following liver transplantation. Reactive oxygen species (ROS) were thought to be the main regulators of IRI. However, recent studies demonstrate that ROS activate the cytoprotective mechanism of autophagy promoting cell survival. Liver IRI initially damages the liver endothelial cells (LEC), but whether ROS-autophagy promotes cell survival in LEC during IRI is not known. Primary human LEC were isolated from human liver tissue and exposed to an in vitro model of IRI to assess the role of autophagy in LEC. The role of autophagy during liver IRI in vivo was assessed using a murine model of partial liver IRI. During IRI, ROS specifically activate autophagy-related protein (ATG) 7 promoting autophagic flux and the formation of LC3B-positive puncta around mitochondria in primary human LEC. Inhibition of ROS reduces autophagic flux in LEC during IRI inducing necrosis. In addition, small interfering RNA knockdown of ATG7 sensitized LEC to necrosis during IRI. In vivo murine livers in uninjured liver lobes demonstrate autophagy within LEC that is reduced following IRI with concomitant reduction in autophagic flux and increased cell death. In conclusion, these findings demonstrate that during liver IRI ROS-dependent autophagy promotes the survival of LEC, and therapeutic targeting of this signaling pathway may reduce liver IRI following transplantation.


Assuntos
Células Endoteliais/fisiologia , Transplante de Fígado/efeitos adversos , Mitofagia/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/patologia , Animais , Autofagia/fisiologia , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/metabolismo , Sobrevivência Celular , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Humanos , Fígado/citologia , Fígado/cirurgia , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Cultura Primária de Células , RNA Interferente Pequeno/metabolismo , Traumatismo por Reperfusão/etiologia , Transdução de Sinais/fisiologia
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