RESUMO
Liver transplantation is hampered by a severe shortage of donor organs. Normothermic machine perfusion (NMP) of donor livers allows dynamic preservation in addition to viability assessment before transplantation. Little is known about the injury and repair mechanisms induced during NMP. To investigate these mechanisms, we examined gene and protein expression changes in a cohort of discarded human livers, stratified by hepatocellular function, during NMP. Six human livers acquired through donation after circulatory death (DCD) underwent 12 h of NMP. Of the six livers, three met predefined criteria for adequate hepatocellular function. We applied transcriptomic profiling and protein analysis to evaluate temporal changes in gene expression during NMP between functional and nonfunctional livers. Principal component analysis segregated the two groups and distinguished the various perfusion time points. Transcriptomic analysis of biopsies from functional livers indicated robust activation of innate immunity after 3 h of NMP followed by enrichment of prorepair and prosurvival mechanisms. Nonfunctional livers demonstrated delayed and persistent enrichment of markers of innate immunity. Functional livers demonstrated effective induction of autophagy, a cellular repair and homeostasis pathway, in contrast to nonfunctional livers. In conclusion, NMP of discarded DCD human livers results in innate immune-mediated injury, while also activating autophagy, a presumed mechanism for support of cellular repair. More pronounced activation of autophagy was seen in livers that demonstrated adequate hepatocellular function.NEW & NOTEWORTHY We demonstrate that ischemia-reperfusion injury occurs in all livers during NMP, though there are notable differences in gene expression between functional and nonfunctional livers. We further demonstrate that activation of the liver's repair and homeostasis mechanisms through autophagy plays a vital role in the graft's response to injury and may impact liver function. These findings indicate that liver autophagy might be a key therapeutic target for rehabilitating the function of severely injured or untransplantable livers.
Assuntos
Autofagia/fisiologia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Fígado/patologia , Traumatismo por Reperfusão/patologia , Humanos , Transplante de Fígado/métodos , Doadores Vivos , PerfusãoRESUMO
BACKGROUND: Over 700 donor livers are discarded annually in the United States due to high risk of poor graft function. The objective of this study was to determine the impact of using normothermic machine perfusion to identify transplantable livers among those currently discarded. STUDY DESIGN: A series of 21 discarded human livers underwent viability assessment during normothermic machine perfusion. Cross-sectional analysis of the Scientific Registry of Transplant Recipients database and cost analysis was performed to extrapolate the case series to national experience. RESULTS: 21 discarded human livers were included in the perfusion cohort. 11 of 20 (55%) eligible grafts met viability criteria for transplantation. Grafts in the perfusion cohort had a similar donor risk index compared with discarded grafts (n = 1402) outside of New England in 2017 and 2018 (median [IQR]: 2.0 [1.5, 2.4] vs. 2.0 [1.7, 2.3], P = .40). 705 (IQR 677-741) livers were discarded annually in the United States since 2005, translating to the potential for 398 additional transplants nationally. The median cost to identify a transplantable graft with machine perfusion was $28,099 USD. CONCLUSIONS: Normothermic machine perfusion of discarded livers could identify a significant number of transplantable grafts, significantly improving access to liver transplantation.
Assuntos
Transplante de Fígado , Estudos Transversais , Humanos , Fígado , Preservação de Órgãos , PerfusãoRESUMO
Recent advances in machine perfusion technology have reinvigorated the field of liver transplantation with the possibilities of vastly improving the efficiency and safety of the life-saving procedure. With this improved preservation technology, transplant surgeons are now able to use previously untransplantable donor livers without significantly compromising patient outcomes. Early clinical studies demonstrate the ability to extend preservation times and assess a graft's potential viability using normothermic machine perfusion, in addition to restoring the energy supply in donor livers by supporting metabolism through circulation of vital nutrients and blood-based oxygen carriers. Future endeavors for surgeons and scientists should focus on improving criteria to assess viability, optimizing protocols for perfusion research, investigating mechanisms of poor graft viability, and targeting these mechanisms with novel therapies to improve graft function prior to transplantation. Long-term goals include extending preservation times on the scale of days to weeks, enabling long-distance organ sharing, and establishing regional organ perfusion centers to streamline the procurement, perfusion, and transplantation process.
Assuntos
Transplante de Fígado/tendências , Preservação de Órgãos/tendências , Perfusão/tendências , Doadores de Tecidos/provisão & distribuição , Animais , Difusão de Inovações , Sobrevivência de Enxerto , História do Século XX , História do Século XXI , Humanos , Transplante de Fígado/efeitos adversos , Transplante de Fígado/história , Preservação de Órgãos/efeitos adversos , Preservação de Órgãos/história , Perfusão/efeitos adversos , Perfusão/história , Complicações Pós-Operatórias/etiologia , Fatores de Risco , Doadores de Tecidos/história , Resultado do TratamentoRESUMO
PURPOSE OF REVIEW: The recent discovery of effective systemic treatments for melanoma has dramatically improved the prognosis for patients with advanced disease. As a result, the multidisciplinary management of melanoma has evolved significantly. In the past decades surgery was reserved for symptomatic palliation in patients with metastatic melanoma. Today surgical treatment of patients responding to systemic therapies has become an integral part of disease control. RECENT FINDINGS: Current efforts are focused on minimizing the morbidity of surgery (laparoscopic inguinal lymph node dissection, selective completion lymphadenectomy) as well as combining surgery with systemic therapy in novel ways (neoadjuvant targeted and/or immunotherapy, isolated limb infusion/perfusion with systemic immunotherapy). This review examines the use of surgery for advanced melanoma in the era predating modern systemic therapy as well as potential applications moving forward.
Assuntos
Excisão de Linfonodo/métodos , Metástase Linfática/diagnóstico , Melanoma/diagnóstico , Melanoma/cirurgia , Humanos , Metástase Linfática/patologia , Melanoma/patologia , Prognóstico , Biópsia de Linfonodo Sentinela , Resultado do TratamentoRESUMO
INTRODUCTION: Traditional treatment for the esophageal motility disorder, achalasia, ranges from endoscopic botulinum toxin (Botox) injections or balloon dilatation, to laparoscopic or open surgical myotomy. Recent advances in endoscopic therapy have led to peroral endoscopic myotomy (POEM) as a viable alternative to traditional techniques for myotomy. Uncertainty exists as to whether the procedure is feasible for patients who have already received prior endoscopic or surgical procedures for therapy, as these groups experience higher failure rates as well as intraoperative mucosal perforations and technical difficulty during Heller myotomy. We describe our first 40 patients who have undergone POEM and compare outcomes between patients who have or have not received previous treatment for achalasia. METHODS AND PROCEDURES: We evaluated our prospectively collected database of POEM procedures performed by two surgeons (JLP and JMM) at a single institution. Perioperative data was collected for operative and hospital outcomes. Patients completed pre- and postoperative GERD-Health-Related Quality of Life Questionnaires (GERD-HRQL) and SF-12 surveys for symptom scoring. RESULTS: Forty patients received a POEM procedure between 2011 and 2013. Of these, 40% (n = 16) had had at least one prior endoscopic or surgical procedure. Nine had prior Botox injections, 7 had balloon dilations, 3 had both Botox and dilations, and 3 received prior laparoscopic Heller myotomy (two with Dor fundoplication). Mean operative time was 102 min for patients with prior procedures (Prior Tx) and 118 min for patients without any prior procedure (No Tx) (p = 0.07). Intraoperative complication rates for the Prior Tx group were 12.5 versus 16.7% for the No Tx group. Mean follow-up was 10 months. Both groups independently demonstrated clinical improvement in both the GERD-HRQL and SF-12 scores following POEM. There were no statistical differences between the two groups for GERD-HRQL reflux and dysphagia subset scores, or SF-12 mental component summary. CONCLUSION: We found favorable outcomes following POEM in patients who have had prior endoscopic or surgical treatments for achalasia, as well as for patients without prior intervention. There were no significant differences between these two groups with regards to operative times, GERD-HRQL scores, and mental component SF-12 scores. One complication requiring intervention occurred in a patient that had received multiple prior Botox injections and balloon dilatations. POEM appears to be a viable alternative for treatment of achalasia compared to traditional techniques, however, long-term data are needed to establish the durability of this technique and to determine whether symptoms will recur necessitating re-intervention.
Assuntos
Transtornos da Motilidade Esofágica/cirurgia , Fundoplicatura/métodos , Complicações Intraoperatórias/prevenção & controle , Cirurgia Endoscópica por Orifício Natural/métodos , Complicações Pós-Operatórias/prevenção & controle , Idoso , Feminino , Humanos , Incidência , Complicações Intraoperatórias/epidemiologia , Masculino , Boca , Complicações Pós-Operatórias/epidemiologia , Inquéritos e Questionários , Estados Unidos/epidemiologiaAssuntos
Transplante de Fígado , Humanos , Metabolismo dos Lipídeos , Fígado , Doadores Vivos , PerfusãoRESUMO
BACKGROUND: In past decade, the treatment of gastric adenocarcinoma has evolved as a result of the publication of two seminal randomized controlled trials. We aimed to examine treatment trends for resectable gastric cancer (stage I-III) using the National Cancer Data Base (NCDB). Our hypothesis was that the use of chemotherapy and chemoradiotherapy in addition to surgery for the treatment of gastric adenocarcinoma has increased from 2000 to 2009. METHODS: Patients diagnosed with stage I-III gastric adenocarcinoma between 2000 and 2009 were selected from the NCDB Hospital Comparison Benchmark Reports. Attention was paid to the initial treatment regimen and data on hospital setting were collected and analyzed. The Cochran-Armitage test for trend was used to assess changes in treatment over time. RESULTS: A total of 50,778 patients with stage I-III gastric adenocarcinoma were included in the analysis. Between 2000 and 2009, the use of surgery alone decreased significantly across all three stages at both teaching hospitals and community hospitals (p < 0.0001 for all cases). In the same period, the use of chemotherapy in addition to surgery increased significantly across all three stages and at both hospital settings (p < 0.0001 for all cases). Surgery plus chemoradiotherapy increased for stage I-III disease at community hospitals (p < 0.05 for all) but only increased significantly for stage II disease at teaching hospitals (p < 0.01). Incidentally, nonsurgical treatment increased across all three stages at both hospital settings (p < 0.001 for all cases). CONCLUSIONS: Data from the NCDB from 2000 to 2009 demonstrate that there has been an increasing use of chemotherapy in addition to surgery for resectable gastric cancer.
Assuntos
Adenocarcinoma/cirurgia , Carcinoma de Células em Anel de Sinete/cirurgia , Gastrectomia/tendências , Hospitais Comunitários/tendências , Hospitais de Ensino/tendências , Neoplasias Gástricas/cirurgia , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células em Anel de Sinete/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Neoplasias Gástricas/patologiaRESUMO
Sacrococcygeal teratoma is the most common type of extragonadal germ cell tumor in infants and young children. Sacrococcygeal teratomas can uncommonly present in an intra-abdominal fashion, with minimal clinical findings. Dermatologic lesions overlying the vertebrae or buttocks are often associated with sacrococcygeal teratoma and may be the only clue to their presence. Here, we report a case of an intra-abdominal sacrococcygeal teratoma presenting with an anatomically separate buttock hemangioma.
Assuntos
Hemangioma/diagnóstico , Hemangioma/cirurgia , Neoplasias Pélvicas/diagnóstico , Neoplasias Pélvicas/cirurgia , Teratoma/diagnóstico , Teratoma/cirurgia , Nádegas , Diagnóstico Diferencial , Feminino , Hemangioma/complicações , Humanos , Lactente , Imageamento por Ressonância Magnética/métodos , Neoplasias Pélvicas/complicações , Região Sacrococcígea/diagnóstico por imagem , Região Sacrococcígea/patologia , Teratoma/complicações , UltrassonografiaRESUMO
Access to lifesaving liver transplantation is limited by a severe organ shortage. One factor contributing to the shortage is the high rate of discard in livers with histologic steatosis. Livers with <30% macrosteatosis are generally considered safe for transplant. However, histologic assessment of steatosis by a pathologist remains subjective and is often limited by image quality. Here, we address this bottleneck by creating an automated digital algorithm for calculating histologic steatosis using only images of liver biopsy histology obtained with a smartphone. Methods: Multiple images of frozen section liver histology slides were captured using a smartphone camera via the optical lens of a simple light microscope. Biopsy samples from 80 patients undergoing liver transplantation were included. An automated digital algorithm was designed to capture and count steatotic droplets in liver tissue while discounting areas of vascular lumen, white space, and processing artifacts. Pathologists of varying experience provided steatosis scores, and results were compared with the algorithm's assessment. Interobserver agreement between pathologists was also assessed. Results: Interobserver agreement between all pathologists was very low but increased with specialist training in liver pathology. A significant linear relationship was found between steatosis estimates of the algorithm compared with expert liver pathologists, though the latter had consistently higher estimates. Conclusions: This study demonstrates proof of the concept that smartphone-captured images can be used in conjunction with a digital algorithm to measure steatosis. Integration of this technology into the transplant workflow may significantly improve organ utilization rates.
RESUMO
Access to liver transplantation is limited by a significant organ shortage. The recent introduction of machine perfusion technology allows surgeons to monitor and assess ex situ liver function prior to transplantation. However, many donated organs are of inadequate quality for transplant, though opportunities exist to rehabilitate organ function with adjunct therapeutics during normothermic machine perfusion. In this preclinical study, we targeted the apoptosis pathway as a potential method of improving hepatocellular function. Treatment of discarded human livers during normothermic perfusion with an irreversible pan-caspase inhibitor, emricasan, resulted in significant mitigation of innate immune and pro-inflammatory responses at both the transcriptional and protein level. This was evidenced by significantly decreased circulating levels of the pro-inflammatory cytokines, interleukin-6, interleukin-8, and interferon-gamma, compared to control livers. Compared to emricasan-treated livers, untreated livers demonstrated transcriptional changes notable for enrichment in pathways involved in innate immunity, leukocyte migration, and cytokine-mediated signaling. Targeting of unregulated apoptosis may represent a viable therapeutic intervention for immunomodulation during machine perfusion.
Assuntos
Transplante de Fígado , Preservação de Órgãos , Caspases/metabolismo , Humanos , Imunidade Inata , Fígado/metabolismo , Transplante de Fígado/métodos , Preservação de Órgãos/métodos , Perfusão/métodosRESUMO
The limited preservation duration of organs has contributed to the shortage of organs for transplantation. Recently, a tripling of the storage duration was achieved with supercooling, which relies on temperatures between -4 and -6 °C. However, to achieve deeper metabolic stasis, lower temperatures are required. Inspired by freeze-tolerant animals, we entered high-subzero temperatures (-10 to -15 °C) using ice nucleators to control ice and cryoprotective agents (CPAs) to maintain an unfrozen liquid fraction. We present this approach, termed partial freezing, by testing gradual (un)loading and different CPAs, holding temperatures, and storage durations. Results indicate that propylene glycol outperforms glycerol and injury is largely influenced by storage temperatures. Subsequently, we demonstrate that machine perfusion enhancements improve the recovery of livers after freezing. Ultimately, livers that were partially frozen for 5-fold longer showed favorable outcomes as compared to viable controls, although frozen livers had lower cumulative bile and higher liver enzymes.
Assuntos
Crioprotetores , Gelo , Animais , Criopreservação/métodos , Crioprotetores/farmacologia , Congelamento , Fígado , Perfusão/métodos , RatosRESUMO
Low-cost non-invasive diagnostic tools for staging the progression of non-alcoholic chronic liver failure from fatty liver disease to steatohepatitis are unavailable. Here, we describe the development and performance of a portable single-sided magnetic-resonance sensor for grading liver steatosis and fibrosis using diffusion-weighted multicomponent T2 relaxometry. In a diet-induced mouse model of non-alcoholic fatty liver disease, the sensor achieved overall accuracies of 92% (Cohen's kappa, κ = 0.89) and 86% (κ = 0.78) in the ex vivo grading of steatosis and fibrosis, respectively. Localization of the measurements in living mice through frequency-dependent spatial encoding led to an overall accuracy of 87% (κ = 0.81) for the grading of steatosis. In human liver samples, the sensor graded steatosis with an overall accuracy of 93% (κ = 0.88). The use of T2 relaxometry as a sensitive measure in fully automated low-cost magnetic-resonance devices at the point of care would alleviate the accessibility and cost limits of magnetic-resonance imaging for diagnosing liver disease and assessing liver health before liver transplantation.
Assuntos
Fibrose/patologia , Cirrose Hepática/patologia , Fígado/patologia , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Animais , Humanos , Transplante de Fígado/instrumentação , Camundongos , Camundongos Endogâmicos C57BL , Aplicativos Móveis , Hepatopatia Gordurosa não Alcoólica/patologia , Sistemas Automatizados de Assistência Junto ao LeitoRESUMO
Ischemia reperfusion injury (IRI) is a critical problem in liver transplantation that can lead to life-threatening complications and substantially limit the utilization of livers for transplantation. However, because there are no early diagnostics available, fulminant injury may only become evident post-transplant. Mitochondria play a central role in IRI and are an ideal diagnostic target. During ischemia, changes in the mitochondrial redox state form the first link in the chain of events that lead to IRI. In this study we used resonance Raman spectroscopy to provide a rapid, non-invasive, and label-free diagnostic for quantification of the hepatic mitochondrial redox status. We show this diagnostic can be used to significantly distinguish transplantable versus non-transplantable ischemically injured rat livers during oxygenated machine perfusion and demonstrate spatial differences in the response of mitochondrial redox to ischemia reperfusion. This novel diagnostic may be used in the future to predict the viability of human livers for transplantation and as a tool to better understand the mechanisms of hepatic IRI.
Assuntos
Fígado/lesões , Mitocôndrias Hepáticas/metabolismo , Perfusão/efeitos adversos , Traumatismo por Reperfusão/diagnóstico , Animais , Ciências Biocomportamentais , Diagnóstico Precoce , Humanos , Fígado/metabolismo , Oxirredução , Perfusão/instrumentação , Ratos , Traumatismo por Reperfusão/metabolismo , Análise Espectral RamanRESUMO
Background: A major limitation in expanding the use of donation after circulatory death (DCD) livers in transplantation is the increased risk of graft failure secondary to ischemic cholangiopathy. Warm ischemia causes thrombosis and injury to the peribiliary vascular plexus (PVP), which is supplied by branches of the hepatic artery, causing higher rates of biliary complications in DCD allografts. Aims/Objectives: We aimed to recondition discarded DCD livers with tissue plasminogen activator (tPA) while on normothermic machine perfusion (NMP) to improve PVP blood flow and reduce biliary injury. Methods: Five discarded DCD human livers underwent 12 h of NMP. Plasminogen was circulated in the base perfusate prior to initiation of perfusion and 1 mg/kg of tPA was administered through the hepatic artery at T = 0.5 h. Two livers were split prior to perfusion (S1, S2), with tPA administered in one lobe, while the other served as a control. The remaining three whole livers (W1-W3) were compared to seven DCD control liver perfusions (C1-C7) with similar hepatocellular and biliary viability criteria. D-dimer levels were measured at T = 1 h to verify efficacy of tPA. Lactate, total bile production, bile pH, and difference in biliary injury scores before and after perfusion were compared between tPA and non-tPA groups using unpaired, Mann-Whitney tests. Results: Average weight-adjusted D-dimer levels were higher in tPA livers in the split and whole-liver model, verifying drug function. There were no differences in perfusion hepatic artery resistance, portal vein resistance, and arterial lactate between tPA livers and non-tPA livers in both the split and whole-liver model. However, when comparing biliary injury between hepatocellular and biliary non-viable whole livers, tPA livers had significantly lower PVP injury scores (0.67 vs. 2.0) and mural stroma (MS) injury scores (1.3 vs. 2.7). Conclusion: This study demonstrates that administration of tPA into DCD livers during NMP can reduce PVP and MS injury. Further studies are necessary to assess the effect of tPA administration on long term biliary complications.
RESUMO
There is a significant organ shortage in the field of liver transplantation, partly due to a high discard rate of steatotic livers from donors. These organs are known to function poorly if transplanted but make up a significant portion of the available pool of donated livers. This study demonstrates the ability to improve the function of steatotic rat livers using a combination of ex situ machine perfusion and a "defatting" drug cocktail. After 6 hours of perfusion, defatted livers demonstrated lower perfusate lactate levels and improved bile quality as demonstrated by higher bile bicarbonate and lower bile lactate. Furthermore, defatting was associated with decreased gene expression of pro-inflammatory cytokines and increased expression of enzymes involved in mitochondrial fatty acid oxidation. Rehabilitation of marginal or discarded steatotic livers using machine perfusion and tailored drug therapy can significantly increase the supply of donor livers for transplantation.
Assuntos
Fígado Gorduroso/terapia , Fígado/fisiopatologia , Preservação de Órgãos/instrumentação , Animais , Bicarbonatos/análise , Citocinas/genética , Modelos Animais de Doenças , Fígado Gorduroso/genética , Fígado Gorduroso/fisiopatologia , Regulação da Expressão Gênica , Ácido Láctico/análise , Fígado/química , Transplante de Fígado , Masculino , Preservação de Órgãos/métodos , Perfusão , Ratos , Doadores de TecidosRESUMO
Access to liver transplantation continues to be hindered by the severe organ shortage. Extended-criteria donor livers could be used to expand the donor pool but are prone to ischemia-reperfusion injury (IRI) and post-transplant graft dysfunction. Ex situ machine perfusion may be used as a platform to rehabilitate discarded or extended-criteria livers prior to transplantation, though there is a lack of data guiding the utilization of different perfusion modalities and therapeutics. Since amino acid derivatives involved in inflammatory and antioxidant pathways are critical in IRI, we analyzed differences in amino acid metabolism in seven discarded non-steatotic human livers during normothermic- (NMP) and subnormothermic-machine perfusion (SNMP) using data from untargeted metabolomic profiling. We found notable differences in tryptophan, histamine, and glutathione metabolism. Greater tryptophan metabolism via the kynurenine pathway during NMP was indicated by significantly higher kynurenine and kynurenate tissue concentrations compared to pre-perfusion levels. Livers undergoing SNMP demonstrated impaired glutathione synthesis indicated by depletion of reduced and oxidized glutathione tissue concentrations. Notably, ATP and energy charge ratios were greater in livers during SNMP compared to NMP. Given these findings, several targeted therapeutic interventions are proposed to mitigate IRI during liver machine perfusion and optimize marginal liver grafts during SNMP and NMP.
RESUMO
Ex-vivo liver perfusion (EVLP) is an ideal platform to study liver disease, therapeutic interventions, and pharmacokinetic properties of drugs without any patient risk. Rat livers are an ideal model for EVLP due to less organ quality variability, ease of hepatectomy, well-defined molecular pathways, and relatively low costs compared to large animal or human perfusions. However, the major limitation with rat liver normothermic machine perfusion (NMP) is maintaining physiologic liver function on an ex-vivo machine perfusion system. To address this need, our research demonstrates 24-hour EVLP in rats under normothermic conditions. Early (6 hour) perfusate transaminase levels and oxygen consumption of the liver graft are shown to be good markers of perfusion success and correlate with viable 24-hour post-perfusion histology. Finally, we address overcoming challenges in long-term rat liver perfusions such as rising intrahepatic pressures and contamination, and offer future directions necessary to build upon our work.
RESUMO
There continues to be a significant shortage of donor livers for transplantation. One impediment is the discard rate of fatty, or steatotic, livers because of their poor post-transplant function. Steatotic livers are prone to significant ischemia-reperfusion injury (IRI) and data regarding how best to improve the quality of steatotic livers is lacking. Herein, we use normothermic (37°C) machine perfusion in combination with metabolic and lipidomic profiling to elucidate deficiencies in metabolic pathways in steatotic livers, and to inform strategies for improving their function. During perfusion, energy cofactors increased in steatotic livers to a similar extent as non-steatotic livers, but there were significant deficits in anti-oxidant capacity, efficient energy utilization, and lipid metabolism. Steatotic livers appeared to oxidize fatty acids at a higher rate but favored ketone body production rather than energy regeneration via the tricyclic acid cycle. As a result, lactate clearance was slower and transaminase levels were higher in steatotic livers. Lipidomic profiling revealed ω-3 polyunsaturated fatty acids increased in non-steatotic livers to a greater extent than in steatotic livers. The novel use of metabolic and lipidomic profiling during ex situ normothermic machine perfusion has the potential to guide the resuscitation and rehabilitation of steatotic livers for transplantation.
Assuntos
Fígado Gorduroso/metabolismo , Lipidômica , Metabolômica , Perfusão , Ressuscitação , Temperatura , Trifosfato de Adenosina/biossíntese , Ácidos e Sais Biliares/metabolismo , Ácidos Graxos/metabolismo , Fígado Gorduroso/patologia , Fígado Gorduroso/fisiopatologia , Glucose/metabolismo , Hemodinâmica , Humanos , Fígado/patologia , Fígado/fisiopatologia , Testes de Função Hepática , Oxirredução , Estresse Oxidativo , Resistência VascularRESUMO
Ex situ machine perfusion is a promising technology to help improve organ viability prior to transplantation. However, preclinical studies using discarded human livers to evaluate therapeutic interventions and optimize perfusion conditions are limited by significant graft heterogeneity. In order to improve the efficacy and reproducibility of future studies, a split-liver perfusion model was developed to allow simultaneous perfusion of left and right lobes, allowing one lobe to serve as a control for the other. Eleven discarded livers were surgically split, and both lobes perfused simultaneously on separate perfusion devices for 3 h at subnormothermic temperatures. Lobar perfusion parameters were also compared with whole livers undergoing perfusion. Similar to whole-liver perfusions, each lobe in the split-liver model exhibited a progressive decrease in arterial resistance and lactate levels throughout perfusion, which were not significantly different between right and left lobes. Split liver lobes also demonstrated comparable energy charge ratios. Ex situ split-liver perfusion is a novel experimental model that allows each graft to act as its own control. This model is particularly well suited for preclinical studies by avoiding the need for large numbers of enrolled livers necessary due to the heterogenous nature of discarded human liver research.
RESUMO
Cellular rejection of liver transplant allografts remains a concern despite immunosuppressant use. Existing transplant biomarkers are often not sensitive enough to detect acute or chronic rejection at an early enough stage to allow successful clinical intervention. We herein developed a cell-based sensor that can potentially be used for monitoring local events following liver transplantation. Utilizing a machine perfusion system as a platform to engraft the cells into a donor liver, we effectively established the biocompatibility of the biosensor cells and confirmed efficient delivery of cells distributed throughout the organ. This work proves an innovative concept of integrating synthetic reporter cells ex vivo into organs as a transplant-within-a-transplant during functional organ preservation with a vision to use cell biosensors as a broad way to monitor and treat tissue transplants.