Early allograft dysfunction after liver transplantation: a definition and predictors of outcome. National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database

OXIDATIVE study: A pilot prospective observational cohort study protocol examining the influence of peri-reperfusion hyperoxemia and immune dysregulation on early allograft dysfunction after orthotopic liver transplantation

Early allograft dysfunction (EAD) is a functional hepatic insufficiency within a week of orthotopic liver transplantation (OLT) and is associated with morbidity and mortality. The etiology of EAD is multifactorial and largely driven by ischemia reperfusion injury (IRI), a phenomenon characterized by oxygen scarcity followed by paradoxical oxidative stress and inflammation. With the expanded use of marginal allografts more susceptible to IRI, the incidence of EAD may be increasing. This necessitates an in-depth understanding of the innate molecular mechanisms underlying EAD and interventions to mitigate its impact. Our central hypothesis is peri-reperfusion hyperoxemia and immune dysregulation exacerbate IRI and increase the risk of EAD. We will perform a pilot prospective single-center observational cohort study of 40 patients. The aims are to determine (1) the association between peri-reperfusion hyperoxemia and EAD and (2) whether peri-reperfusion perturbed cytokine, protein, and hypoxia inducible factor-1 alpha (HIF-1α) levels correlate with EAD after OLT. Inclusion criteria include age ≥ 18 years, liver failure, and donation after brain or circulatory death. Exclusion criteria include living donor donation, repeat OLT within a week of transplantation, multiple organ transplantation, and pregnancy. Partial pressure of arterial oxygen (PaO2) as the study measure allows for the examination of oxygen exposure within the confines of existing variability in anesthesiologist-administered fraction of inspired oxygen (FiO2) and the inclusion of patients with intrapulmonary shunting. The Olthoff et al. definition of EAD is the primary outcome. Secondary outcomes include postoperative acute kidney injury, pulmonary and biliary complications, surgical wound dehiscence and infection, and mortality. The goal of this study protocol is to identify EAD contributors that could be targeted to attenuate its impact and improve OLT outcomes. If validated, peri-reperfusion hyperoxemia and immune perturbations could be targeted via FiO2 titration to a goal PaO2 and/or administration of an immunomodulatory agent by the anesthesiologist intraoperatively.

Intraoperative Anesthetic Strategies to Mitigate Early Allograft Dysfunction After Orthotopic Liver Transplantation: A Narrative Review

Orthotopic liver transplantation (OLT) is the most effective treatment for patients with end-stage liver disease (ESLD). Hepatic insufficiency within a week of OLT, termed early allograft dysfunction (EAD), occurs in 20% to 25% of deceased donor OLT recipients and is associated with morbidity and mortality. Primary nonfunction (PNF), the most severe form of EAD, leads to death or retransplantation within 7 days. The etiology of EAD is multifactorial, including donor, recipient, and surgery-related factors, and largely driven by ischemia-reperfusion injury (IRI). IRI is an immunologic phenomenon characterized by dysregulation of cellular oxygen homeostasis and innate immune defenses in the allograft after temporary cessation (ischemia) and later restoration (reperfusion) of oxygen-rich blood flow. The rising global demand for OLT may lead to the use of marginal allografts, which are more susceptible to IRI, and thus lead to an increased incidence of EAD. It is thus imperative the anesthesiologist is knowledgeable about EAD, namely its pathophysiology and intraoperative strategies to mitigate its impact. Intraoperative strategies can be classified by 3 phases, specifically donor allograft procurement, storage, and recipient reperfusion. During procurement, the anesthesiologist can use pharmacologic preconditioning with volatile anesthetics, consider preharvest hyperoxemia, and attenuate the use of norepinephrine as able. The anesthesiologist can advocate for normothermic regional perfusion (NRP) and machine perfusion during allograft storage at their institution. During recipient reperfusion, the anesthesiologist can optimize oxygen exposure, consider adjunct anesthetics with antioxidant-like properties, and administer supplemental magnesium. Unfortunately, there is either mixed, little, or no data to support the routine use of many free radical scavengers. Given the sparse, limited, or at times conflicting evidence supporting some of these strategies, there are ample opportunities for more research to find intraoperative anesthetic strategies to mitigate the impact of EAD and improve postoperative outcomes in OLT recipients.

L-GrAFT7 has High Accuracy in Predicting Early Allograft Failure after Liver Transplantation: A Multicenter Cohort Study in China

Background and Aims

Increasing utilization of extended criteria donor leads to an increasing rate of early allograft failure after liver transplantation. However, consensus of definition of early allograft failure is lacking.

Methods

A retrospective, multicenter study was performed to validate the Liver Graft Assessment Following Transplantation (L-GrAFT) risk model in a Chinese cohort of 942 adult patients undergoing primary liver transplantation at three Chinese centers. L-GrAFT (L-GrAFT7 and L-GrAFT10) was compared with existing models: the Early Allograft Failure Simplified Estimation (EASE) score, the model of early allograft function (MEAF), and the Early Allograft Dysfunction (EAD) model. Univariate and multivariate logistic regression were used to find risk factors of L-GrAFT high-risk group.

Results

L-GrAFT7 had an area under the curve of 0.85 in predicting 90-day graft survival, significantly superior to MEAF [area under the curve (AUC=0.78, p=0.044)] and EAD (AUC=0.78, p=0.006), while there was no statistical significance between the predicting abilities of L-GrAFT7 and EASE (AUC=0.84, p>0.05). Furthermore, L-GrAFT7 maintains good predicting ability in the subgroup of high-donor risk index (DRI) cases (AUC=0.83 vs. MEAF, p=0.007 vs. EAD, p=0.014) and recipients of donors after cardiac death (AUC=0.92 vs. EAD, p<0.001). Through multivariate analysis, pretransplant bilirubin level, units of packed red blood cells, and the DRI score were selected as independent risk factors of a L-GrAFT7 high-risk group.

Conclusions

The accuracy of L-GrAFT7 in predicting early allograft failure was validated in a Chinese multicenter cohort, indicating that it has the potential to become an accurate endpoint of clinical practice and transitional study of machine perfusion.

Early allograft dysfunction after living donor liver transplantation-current concepts and future directions

Early allograft dysfunction (EAD) after liver transplantation is a significant clinical problem that negatively impacts graft and patient outcomes. The rising incidence of EAD and what it means concerning living donor liver transplantation (LDLT) is an area of great interest. However, EAD after LDLT is a complex research topic yet to be reviewed comprehensively. Most of the literature on EAD is based on experience in deceased donor liver transplantation, and limited information is available in the context of LDLT. Thus, in this review, we present an overview of EAD after LDLT and have attempted to present balanced points of view on all its aspects, such as definitions, pathogenesis, risk factors, predictive markers, and management. The review aims to broadly overview the nature and extent of ongoing research evidence on this complex topic and inform practice in the field by identifying key concepts and knowledge gaps and highlighting areas that require further inquiry.

End-ischemic hypothermic oxygenated perfusion for extended criteria donors in liver transplantation: a multicenter, randomized controlled trial-HOPExt

BACKGROUND

Given the scarce donor supply, an increasing number of so-called marginal or extended criteria donor (ECD) organs are used for liver transplantation. These ECD liver grafts are however known to be associated with a higher rate of early allograft dysfunction and primary non-function because of a greater vulnerability to ischemia-reperfusion injury. The end-ischemic hypothermic oxygenated machine perfusion (HOPE) technique may improve outcomes of liver transplantation with ECD grafts by decreasing reperfusion injury.

METHODS

HOPExt trial is a comparative open-label, multicenter, national, prospective, randomized, controlled study, in two parallel groups, using static cold storage, the gold standard procedure, as control. The trial will enroll adult patients on the transplant waiting list for liver failure or liver cirrhosis and/or liver malignancy requiring liver transplantation and receiving an ECD liver graft from a brain-dead donor. In the experimental group, ECD liver grafts will first undergo a classical static cold (4 °C) storage followed by a hypothermic oxygenated perfusion (HOPE) for a period of 1 to 4 h. The control group will consist of the classic static cold storage which is the gold standard procedure in liver transplantation. The primary objective of this trial is to study the efficacy of HOPE used before transplantation of ECD liver grafts from brain-dead donors in reducing postoperative early allograft dysfunction within the first 7 postoperative days compared to simple cold static storage.

DISCUSSION

We present in this protocol all study procedures in regard to the achievement of the HOPExt trial, to prevent biased analysis of trial outcomes and improve the transparency of the trial results. Enrollment of patients in the HOPExt trial has started on September 10, 2019, and is ongoing.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03929523. Registered on April 29, 2019, before the start of inclusion.

Biomarkers and predictive models of early allograft dysfunction in liver transplantation - A systematic review of the literature, meta-analysis, and expert panel recommendations

BACKGROUND

Prompt identification of early allograft dysfunction (EAD) is critical to reduce morbidity and mortality in liver transplant (LT) recipients.

OBJECTIVES

Evaluate the evidence supporting biomarkers that can provide diagnostic and predictive value for EAD.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach was derived from an international expert panel. Studies that investigated biomarkers or models for predicting EAD in adult LT recipients were included for in-depth evaluation and meta-analysis. Olthoff's criteria were used as the standard reference for the diagnostic accuracy evaluation.

PROSPERO ID

CRD42021293838 RESULTS: Ten studies were included for the systematic review. Lactate, lactate clearance, uric acid, Factor V, HMGB-1, CRP to ALB ratio, phosphocholine, total cholesterol, and metabolomic predictive model were identified as potential early EAD predictive biomarkers. The sensitivity ranged between .39 and .92, while the specificity ranged from .63 to .90. Elevated lactate level was most indicative of EAD after adult LT (pooled diagnostic odds ratio of 7.15 (95%CI: 2.38-21.46)). The quality of evidence (QOE) for lactate as indicator was moderate according to the GRADE approach, whereas the QOE for other biomarkers was very low to low likely as consequence of study design characteristics such as single study, small sample size, and large ranges of sensitivity or specificity.

CONCLUSIONS

Lactate is an early indicator to predict EAD after LT (Quality of Evidence: Moderate | Grade of Recommendation: Strong). Further multicenter studies and the use of machine perfusion setting should be implemented for validation.

Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit

Prolonged treatment of organ donors in the intensive care unit (ICU) may be associated with complications influencing the outcome after heart transplantation (HTx). We therefore aim to explore the potential impact of the donor length of stay (LOS) in the ICU on outcomes in our cohort. We included all patients undergoing HTx in our center between September 2010 and April 2022 (n = 241). Recipients were divided around the median into three groups regarding their donor LOS in the ICU: 0 to 3 days (≤50th percentile, n = 92), 4 to 7 days (50th–75th percentile, n = 80), and ≥8 days (≥75th percentile, n = 69). Donor LOS in the ICU ranged between 0 and 155 days (median 4, IQR 3–8 days). No association between the LOS in the ICU and survival after HTx was observed (AUC for overall survival 0.514). Neither the Kaplan–Meier survival analysis up to 5 years after HTx (Log-Rank p = 0.789) nor group comparisons showed significant differences. Baseline recipient characteristics were comparable between the groups, while the donor baselines differed in some parameters, such as less cardiopulmonary resuscitation prior to HTx in those with a prolonged LOS. However, regarding the recipients’ peri- and postoperative parameters, the groups did not differ in all of the assessed parameters. Thus, in this retrospective analysis, although the donors differed in baseline parameters, the donor LOS in the ICU was not associated with altered recipient survival or outcome after HTx.

The Edge of Unknown: Postoperative Critical Care in Liver Transplantation

Perioperative care of patients undergoing liver transplantation (LT) is very complex. Metabolic derangements, hypothermia, coagulopathy and thromboses, severe infections, and graft dysfunction can affect outcomes. In this manuscript, we discuss several perioperative problems that can be encountered in LT recipients. The authors present the most up-to-date information regarding predicting and treating hemodynamic instability, coagulation monitoring and management, postoperative ventilation strategies and early extubation, management of infections, and ESLD-related pulmonary complications. In addition, early post-transplant allograft dysfunction will be discussed.

Liver Graft Hypothermic Static and Oxygenated Perfusion (HOPE) Strategies: A Mitochondrial Crossroads

Marginal liver grafts, such as steatotic livers and those from cardiac death donors, are highly vulnerable to ischemia–reperfusion injury that occurs in the complex route of the graft from “harvest to revascularization”. Recently, several preservation methods have been developed to preserve liver grafts based on hypothermic static preservation and hypothermic oxygenated perfusion (HOPE) strategies, either combined or alone. However, their effects on mitochondrial functions and their relevance have not yet been fully investigated, especially if different preservation solutions/effluents are used. Ischemic liver graft damage is caused by oxygen deprivation conditions during cold storage that provoke alterations in mitochondrial integrity and function and energy metabolism breakdown. This review deals with the relevance of mitochondrial machinery in cold static preservation and how the mitochondrial respiration function through the accumulation of succinate at the end of cold ischemia is modulated by different preservation solutions such as IGL-2, HTK, and UW (gold-standard reference). IGL-2 increases mitochondrial integrity and function (ALDH2) when compared to UW and HTK. This mitochondrial protection by IGL-2 also extends to protective HOPE strategies when used as an effluent instead of Belzer MP. The transient oxygenation in HOPE sustains the mitochondrial machinery at basal levels and prevents, in part, the accumulation of energy metabolites such as succinate in contrast to those that occur in cold static preservation conditions. Additionally, several additives for combating oxygen deprivation and graft energy metabolism breakdown during hypothermic static preservation such as oxygen carriers, ozone, AMPK inducers, and mitochondrial UCP2 inhibitors, and whether they are or not to be combined with HOPE, are presented and discussed. Finally, we affirm that IGL-2 solution is suitable for protecting graft mitochondrial machinery and simplifying the complex logistics in clinical transplantation where traditional (static preservation) and innovative (HOPE) strategies may be combined. New mitochondrial markers are presented and discussed. The final goal is to take advantage of marginal livers to increase the pool of suitable organs and thereby shorten patient waiting lists at transplantation clinics.

Primary Nonfunction and Early Allograft Dysfunction after Liver Transplantation

BACKGROUND

Despite continuous progress in the field of liver transplantation, considerable proportion of patients still suffer from the postoperative graft dysfunction. Clinically, it presents as early allograft dysfunction (EAD), and its more severe form defined as primary nonfunction (PNF). Posttransplant liver dysfunction translates into significantly worse treatment outcomes.

SUMMARY

Both entities are multifactorial, with donor (graft), recipient, and procedure-related factors playing the key roles. Ischemia-reperfusion injury is a major driver of their development. So far, various noninvasive (pharmacological) and invasive strategies have been tested to mitigate its negative effects. This article pre-sents the current approach to diagnosis, prediction, and management of EAD and PNF.

KEY MESSAGES

Different pharmacological interventions may be considered to improve graft function after liver transplantation. Machine perfusion seems to be the most effective method at the moment.

Hepatoprotective and therapeutic effects of resveratrol: A focus on anti-inflammatory and anti- oxidative activities

Being the most essential organ in the body, the liver performs critical functions. Hepatic disorders, such as alcoholic liver disease, hepatic steatosis, liver fibrosis, non-alcoholic fatty liver disease, hepatocellular carcinoma and hepatic failure, have an impact on the biochemical and physiological functions of the body. The main representative of the flavonoid subgroup of flavones, Resveratrol (RES), exhibits suitable pharmacological activities for treating various liver diseases, such as fatty hepatitis, liver steatosis, liver cancer and liver fibrosis. According to various studies, grapes and red wine are good sources of RES. RES has various health properties; it is anti-inflammatory, anti-apoptotic, anti-oxidative and hepatoprotective against several hepatic diseases and hepatoxicity. Therefore, we performed a thorough research and created a summary of the distinct targets of RES in various stages of liver diseases. We concluded that RES inhibited liver inflammation essentially by causing a significant decrease in the expression of various pro-inflammatory cytokines like TNF-α, IL-1α, IL-1β, and IL-6. It also inhibits the transcription factor nuclear NF-κB that brings about the inflammatory cascade. RES also inhibits the PI3K/Akt/mTOR pathway to induce apoptosis. Additionally, it reduces oxidative stress in hepatic tissue by markedly reducing MDA and NO contents, and significantly increasing the levels of CAT, SOD and reduced GSH, in addition to AST and ALT, against toxic chemicals like CC14, As2O3 and TTA. Due to its anti-oxidant, anti-inflammatory and anti-fibrotic properties, RES reduces liver injury markers. RES is safe natural antioxidant that provides pharmacological rectification of the hepatoxicity of toxic chemicals.

Prediction of Graft Survival Post-liver Transplantation by L-GrAFT Risk Score Model, EASE Score, MEAF Scoring, and EAD

Background: Early allograft dysfunction (EAD) is correlated with poor patient or graft survival in liver transplantation. However, the power of distinct definitions of EAD in prediction of graft survival is unclear. Methods: This retrospective, single-center study reviewed data of 677 recipients undergoing orthotopic liver transplant between July 2015 and June 2020. The following EAD definitions were compared: liver graft assessment following transplantation (L-GrAFT) risk score model, early allograft failure simplified estimation score (EASE), model for early allograft function (MEAF) scoring, and Olthoff criteria. Risk factors for L-GrAFT₇ high risk group were evaluated with univariate and multivariable logistic regression analysis. Results: L-GrAFT₇ had a satisfied C-statistic of 0.87 in predicting a 3-month graft survival which significantly outperformed MEAF (C-statistic = 0.78, P = 0.01) and EAD (C-statistic = 0.75, P < 0.001), respectively. L-GrAFT₁₀, EASE was similar to L-GrAFT₇, and they had no statistical significance in predicting survival. Laboratory model for end-stage liver disease score and cold ischemia time are risk factors of L-GrAFT₇ high-risk group. Conclusion: L-GrAFT₇ risk score is capable for better predicting the 3-month graft survival than the MEAF and EAD in a Chinese cohort, which might standardize assessment of early graft function and serve as a surrogate endpoint in clinical trial.

The Need to Update Endpoints and Outcome Analysis in the Rapidly Changing Field of Liver Transplantation

Liver transplantation (LT) survival rates have continued to improve over the last decades, mostly due to the reduction of mortality early after transplantation. The advancement is facilitating a liberalization of access to LT, with more patients with higher risk profiles being added to the waiting list. At the same time, the persisting organ shortage fosters strategies to rescue organs of high-risk donors. This is facilitated by novel technologies such as machine perfusion. Owing to these developments, reconsideration of the current and emerging endpoints for the assessment of the efficacy of existing and new therapies is warranted. While conventional early endpoints in LT have focused on the damage induced to the parenchyma, the fate of the bile duct and the recurrence of the underlying disease have a stronger impact on the long-term outcome. In light of this evolving landscape, we here attempt to reflect on the appropriateness of the currently used endpoints in the field of LT trials.

Ischaemia-free liver transplantation in humans: a first-in-human trial

Background Ischaemia-reperfusion injury is considered an inevitable component of organ transplantation, compromising organ quality and outcomes. Although several treatments have been proposed, none has avoided graft ischaemia and its detrimental consequences. Methods Ischaemia-free liver transplantation (IFLT) comprises surgical techniques enabling continuous oxygenated blood supply to the liver of brain-dead donor during procurement, preservation, and implantation using normothermic machine perfusion technology. In this non-randomised study, 38 donor livers were transplanted using IFLT and compared to 130 conventional liver transplants (CLT). Findings Two recipients (5•3%) in the IFLT group experienced early allograft dysfunction, compared to 50•0% in patients receiving conventional transplants (absolute risk difference, 44•8%; 95% confidence interval, 33•6-55•9%). Recipients of IFLT had significantly reduced median (IQR) peak aspartate aminotransferase levels within the first week compared to CLT recipients (365, 238-697 vs 1445, 791-3244 U/L, p<0•001); likewise, median total bilirubin levels on day 7 were significantly lower (2•34, 1•39-4•09 mg/dL) in the IFLT group than in the CLT group (5•10, 1•90-11•65 mg/dL) (p<0•001). Moreover, IFLT recipients had a shorter median intensive care unit stay (1•48, 0•75-2•00 vs 1•81, 1•00-4•58 days, p=0•006). Both one-month recipient (97•4% vs 90•8%, p=0•302) and graft survival (97.4% vs 90•0%, p=0•195) were better for IFLT than CLT, albeit differences were not statistically significant. Subgroup analysis showed that the extended criteria donor livers transplanted using the IFLT technique yielded faster post-transplant recovery than did the standard criteria donor livers transplanted using the conventional approach. Interpretation IFLT provides a novel approach that may improve outcomes, and allow the successful utilisation of extended criteria livers. Funding This study was funded by National Natural Science Foundation of China, Guangdong Provincial Key Laboratory Construction Projection on Organ Donation and Transplant Immunology, and Guangdong Provincial international Cooperation Base of Science and Technology. Panel: Research in context.

Combination of arterial lactate levels and Cv-aCO2/Da-vO2 ratio to predict early allograft dysfunction after liver transplantation

PURPOSE

We examined the ability of the P(v-a)CO2/Da-vO2 ratio combined with elevated lactate levels to predict early allograft dysfunction (EAD).

MATERIALS AND METHODS

Patients were classified into four groups according to lactate levels and P(v-a)CO2/Da-vO2 ratio: Group 1; lactate >2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio >1.0; Group 2; lactate >2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio <1.0; group 3; lactate<2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio >1.0; group 4; lactate<2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio <1.0. We defined EAD according to Olthoff criteria.

RESULTS

One-hundred and fifty patients were included. EAD occurred in 41 patients (27.3%), and was associated with worse graft survival at 1 year (92% vs. 73%; P = ,003) as well as a higher re-transplantation rate (4,6% vs. 17,1%; P = ,019). The multivariate analysis revealed that P(v-a)CO2/Da-vO2 ratio at T6 [OR 7.05(CI95% 2.77-19.01, P<.001)] was an independent predictor for EAD. Belonging to group 1 at 6 h was associated with worse clinical outcomes but no association was found with 1-year graft survival or 1-year patient survival.

CONCLUSIONS

In this single center, prospective, observational study in patients who received an OLT, we found that elevated lactate levels combined with a high Cv-aCO2/Da-vO2 after 6 h was associated with the development of EAD and worse clinical outcomes in the early postoperative period.

Organ Procurement From Poisoned Patients: A 14-Year Survey in 2 Academic Centers

OBJECTIVES

Organ transplant from poisoned donors is an issue that has received much attention, especially over the past decade. Unfortunately, there are still opponents to this issue who emphasize that toxins and drugs affect the body's organs and do not consider organs from poisoned donors appropriate for transplantation.

MATERIALS AND METHODS

Cases of brain death due to poisoning were collected from 2 academic centers in Tehran, Iran during a period from 2006 to 2020. Donor information and recipient condition at 1 month and 12 months after transplant and the subsequent transplant success rates were investigated.

RESULTS

From 102 poisoned donors, most were 30 to 40 years old (33.4%) and most were men (55.9%). The most common causes of poisoning among donors were opioids (28.4%). Six candidate donors had been referred with cardiorespiratory arrest; these patients had organs that were in suitable condition, and transplant was successful. Acute kidney injury was seen in 30 donors, with emergency dialysis performed in 23 cases. For 51% of donors, cardiopulmonary resuscitation was performed. The most donated organs were the liver (81.4%), left kidney (81.4%), and right kidney (80.4%). Survival rate of recipients at 1 month and 12 months was 92.5% and 91.4%, respectively. Graft rejection rate at 1 month and 12 months after transplant was 0.7% and 2.21%, respectively.

CONCLUSIONS

Organ donation from poisoning-related brain deaths is one of the best sources of organ supply for people in need. If the organ is in optimal condition before transplant, there are no exclusions for use of the graft.

Early Allograft Dysfunction and Complications in DCD Liver Transplantation: Expert Consensus Statements From the International Liver Transplantation Society

Livers for transplantation from donation after circulatory death donors are relatively more prone to early and ongoing alterations in graft function that might ultimately lead to graft loss and even patient death. In consideration of this fact, this working group of the International Liver Transplantation Society has performed a critical evaluation of the medical literature to create a set of statements regarding the assessment of early allograft function/dysfunction and complications arising in the setting of donation after circulatory death liver transplantation.

Using Rotational Thromboelastometry to Identify Early Allograft Dysfunction after Living Donor Liver Transplantation

Background: Diagnostic tests for early allograft dysfunction (EAD) after living donor liver transplantation (LDLT) vary widely. We aimed to evaluate the predictive value of rotational thromboelastometry (ROTEM)-derived parameters in EAD. Materials and Methods: A total of 121 patients were reviewed. The definition of EAD proposed by Olthoff et al. included the presence of any of the following at postoperative day 7: bilirubin level ≥ 10 mg/dL, INR ≥ 1.6, or serum AST or ALT levels > 2000 IU/L. All patients underwent ROTEM assay, which consisted of an extrinsically activated thromboelastometric test (EXTEM) before and 24 h after LDLT. Results: The 1-year/2-year OS were 68.%8/64.5% and 94.4%/90.8% for the EAD and non-EAD groups, respectively (p = 0.001). Two independent risks were identified for EAD, the postoperative clotting time (CT, p = 0.026) and time to maximum clot firmness (maximum clot firmness (MCF)-t, p = 0.009) on the EXTEM. CT yielded a specificity of 82.0% and negative predictive value of 83.0%, and MCF-t displayed a specificity of 76.4% and negative predictive value of 81.9% in diagnosing EAD. The use of the 24 h post-LDLT ROTEM increased the effectiveness of predicting overall survival (OS) compared to using the Olthoff’s EAD criteria alone (p < 0.001). Conclusion: We conclude that CT and MCF on EXTEM were independent predictors of EAD. The 24 h post-LDLT ROTEM can be used with conventional laboratory tests to diagnose EAD. It increases the effectiveness of predicting OS.

Early Allograft Dysfunction After Liver Transplantation With Donation After Circulatory Death and Brain Death Grafts: Does the Donor Type Matter?

Background.

Early allograft dysfunction (EAD) after liver transplantation has been associated with long-term reduced graft and patient survival.

Methods.

In this single-center cohort study, we aimed to compare incidence, risk factors, and outcomes in liver transplant recipients who developed EAD. Patients who received donation after circulatory death (DCD) or donation after brain death (DBD) grafts between January 2007 and December 2017 were included. EAD was defined as bilirubin of ≥10 mg/dL (171 μmol/L) or an international normalized ratio of ≥1.6 on postoperative day 7 or transaminases >2000 U\L in the first-week posttransplantation as previously described.

Results.

In our cohort of 1068 patients, incidence of EAD was 44%. EAD occurred more frequently in the DCD versus DBD group (71% versus 41%, P < 0.01). Overall, recipients who developed EAD showed a significantly lower graft and patient survival at 1, 3, and 5 y after transplantation (all P < 0.05). This was also the case for recipients of DBD grafts. However, for recipients of DCD grafts, patient and graft survival were not affected by the presence of EAD. For recipients of DBD grafts, donor age, body mass index (BMI) and gender, recipient BMI and model for end-stage liver disease score and warm and cold ischemia time were associated with EAD. For DCD recipients, donor BMI and cold ischemia time were associated with EAD.

Conclusions.

In our cohort study, EAD resulted in reduced long-term patient and graft survival only for DBD recipients but not for DCD recipients. Predictive markers for EAD were dependent on the donor type.

Prediction model for early graft failure after liver transplantation using aspartate aminotransferase, total bilirubin and coagulation factor

This study was designed to build models predicting early graft failure after liver transplantation. Cox regression model for predicting early graft failure after liver transplantation using post-transplantation aspartate aminotransferase, total bilirubin, and international normalized ratio of prothrombin time was constructed based on data from both living donor (n = 1153) and deceased donor (n = 359) liver transplantation performed during 2004 to 2018. The model was compared with Model for Early Allograft Function Scoring (MEAF) and early allograft dysfunction (EAD) with their C-index and time-dependent area-under-curve (AUC). The C-index of the model for living donor (0.73, CI = 0.67–0.79) was significantly higher compared to those of both MEAF (0.69, P = 0.03) and EAD (0.66, P = 0.001) while C-index for deceased donor (0.74, CI = 0.65–0.83) was only significantly higher compared to C-index of EAD. (0.66, P = 0.002) Time-dependent AUC at 2 weeks of living donor (0.96, CI = 0.91–1.00) and deceased donor (0.98, CI = 0.96–1.00) were significantly higher compared to those of EAD. (both 0.83, P < 0.001 for living donor and deceased donor) Time-dependent AUC at 4 weeks of living donor (0.93, CI = 0.86–0.99) was significantly higher compared to those of both MEAF (0.87, P = 0.02) and EAD. (0.84, P = 0.02) Time-dependent AUC at 4 weeks of deceased donor (0.94, CI = 0.89–1.00) was significantly higher compared to both MEAF (0.82, P = 0.02) and EAD. (0.81, P < 0.001). The prediction model for early graft failure after liver transplantation showed high predictability and validity with higher predictability compared to traditional models for both living donor and deceased donor liver transplantation.

Multicenter validation of the liver graft assessment following transplantation (L-GrAFT) score for assessment of early allograft dysfunction

BACKGROUND & AIMS

Early allograft dysfunction (EAD) following liver transplantation (LT) negatively impacts graft and patient outcomes. Previously we reported that the liver graft assessment following transplantation (L-GrAFT₇) risk score was superior to binary EAD or the model for early allograft function (MEAF) score for estimating 3-month graft failure-free survival in a single-center derivation cohort. Herein, we sought to externally validate L-GrAFT₇, and compare its prognostic performance to EAD and MEAF.

METHODS

Accuracies of L-GrAFT₇, EAD, and MEAF were compared in a 3-center US validation cohort (n = 3,201), and a Consortium for Organ Preservation in Europe (COPE) normothermic machine perfusion (NMP) trial cohort (n = 222); characteristics were compared to assess generalizability.

RESULTS

Compared to the derivation cohort, patients in the validation and NMP trial cohort had lower recipient median MELD scores; were less likely to require pretransplant hospitalization, renal replacement therapy or mechanical ventilation; and had superior 1-year overall (90% and 95% vs. 84%) and graft failure-free (88% and 93% vs. 81%) survival, with a lower incidence of 3-month graft failure (7.4% and 4.0% vs. 11.1%; p <0.001 for all comparisons). Despite significant differences in cohort characteristics, L-GrAFT₇ maintained an excellent validation AUROC of 0.78, significantly superior to binary EAD (AUROC 0.68, p = 0.001) and MEAF scores (AUROC 0.72, p <0.001). In post hoc analysis of the COPE NMP trial, the highest tertile of L-GrAFT₇ was significantly associated with time to liver allograft (hazard ratio [HR] 2.17, p = 0.016), Clavien ≥IIIB (HR 2.60, p = 0.034) and ≥IVa (HR 4.99, p = 0.011) complications; post-LT length of hospitalization (p = 0.002); and renal replacement therapy (odds ratio 3.62, p = 0.016).

CONCLUSIONS

We have validated the L-GrAFT₇ risk score as a generalizable, highly accurate, individualized risk assessment of 3-month liver allograft failure that is superior to existing scores. L-GrAFT₇ may standardize grading of early hepatic allograft function and serve as a clinical endpoint in translational studies (www.lgraft.com).

LAY SUMMARY

Early allograft dysfunction negatively affects outcomes following liver transplantation. In independent multicenter US and European cohorts totaling 3,423 patients undergoing liver transplantation, the liver graft assessment following transplantation (L-GrAFT) risk score is validated as a superior measure of early allograft function that accurately discriminates 3-month graft failure-free survival and post-liver transplantation complications.

The Role of Resveratrol in Liver Disease: A Comprehensive Review from In Vitro to Clinical Trials

Many studies have shown that resveratrol has a lot of therapeutic effects on liver disorders. Its administration can significantly increase the survival rate after liver transplantation, reduce fat deposition and ischemia-induced necrosis and apoptosis in Wistar rats. Resveratrol can provide Liver protection against chemical, cholestatic, and alcohol-mediated damage. It can improve glucose metabolism and lipid profile, reduce liver fibrosis, and steatosis. Additionally, it is capable of altering the fatty acid composition of the liver cells. Resveratrol may be a potential treatment option for the management of non-alcoholic fatty liver disease (NAFLD) due to its anti-inflammatory, antioxidant, and calorie-restricting effects. There are also studies that have evaluated the effect of resveratrol on lipid and liver enzyme profiles among patients with metabolic syndrome (MetS) and related disorders. Based on the extent of liver disease worldwide and the need to find new treatment possibilities, this review critically examines current in vitro and in vivo preclinical studies and human clinical studies related to liver protection.

Development and Validation of a Comprehensive Model to Estimate Early Allograft Failure Among Patients Requiring Early Liver Retransplant

Question

Can the individual risk estimation for early allograft failure (EAF) be improved in view of liver retransplant?

Findings

In this multicenter cohort study investigating the association between donor-recipient factors and EAF, a novel Early Allograft Failure Simplified Estimation (EASE) score was developed. The score includes Model for End-stage Liver Disease score, transfused packed red blood cells, and hepatic vessel early thrombosis as well as transaminases, platelet, and bilirubin kinetics as variables on day 10 after transplant. The EASE score outperformed previous model scores, estimating EAF risk with 87% accuracy on day 90 after transplant; EASE was developed on a multicenter Italian database (1609 recipients) and validated on an external UK database (538 recipients).

Meaning

In this study, the EASE score rated the EAF risk (0%-100%) and identified cases at unsustainable risk to be listed for retransplant.

Importance

Expansion of donor acceptance criteria for liver transplant increased the risk for early allograft failure (EAF), and although EAF prediction is pivotal to optimize transplant outcomes, there is no consensus on specific EAF indicators or timing to evaluate EAF. Recently, the Liver Graft Assessment Following Transplantation (L-GrAFT) algorithm, based on aspartate transaminase, bilirubin, platelet, and international normalized ratio kinetics, was developed from a single-center database gathered from 2002 to 2015.

Objective

To develop and validate a simplified comprehensive model estimating at day 10 after liver transplant the EAF risk at day 90 (the Early Allograft Failure Simplified Estimation [EASE] score) and, secondarily, to identify early those patients with unsustainable EAF risk who are suitable for retransplant.

Design, Setting, and Participants

This multicenter cohort study was designed to develop a score capturing a continuum from normal graft function to nonfunction after transplant. Both parenchymal and vascular factors, which provide an indication to list for retransplant, were included among the EAF determinants. The L-GrAFT kinetic approach was adopted and modified with fewer data entries and novel variables. The population included 1609 patients in Italy for the derivation set and 538 patients in the UK for the validation set; all were patients who underwent transplant in 2016 and 2017.

Main Outcomes and Measures

Early allograft failure was defined as graft failure (codified by retransplant or death) for any reason within 90 days after transplant.

Results

At day 90 after transplant, the incidence of EAF was 110 of 1609 patients (6.8%) in the derivation set and 41 of 538 patients (7.6%) in the external validation set. Median (interquartile range) ages were 57 (51-62) years in the derivation data set and 56 (49-62) years in the validation data set. The EASE score was developed through 17 entries derived from 8 variables, including the Model for End-stage Liver Disease score, blood transfusion, early thrombosis of hepatic vessels, and kinetic parameters of transaminases, platelet count, and bilirubin. Donor parameters (age, donation after cardiac death, and machine perfusion) were not associated with EAF risk. Results were adjusted for transplant center volume. In receiver operating characteristic curve analyses, the EASE score outperformed L-GrAFT, Model for Early Allograft Function, Early Allograft Dysfunction, Eurotransplant Donor Risk Index, donor age × Model for End-stage Liver Disease, and Donor Risk Index scores, estimating day 90 EAF in 87% (95% CI, 83%-91%) of cases in both the derivation data set and the internal validation data set. Patients could be stratified in 5 classes, with those in the highest class exhibiting unsustainable EAF risk.

Conclusions and Relevance

This study found that the developed EASE score reliably estimated EAF risk. Knowledge of contributing factors may help clinicians to mitigate risk factors and guide them through the challenging clinical decision to allocate patients to early liver retransplant. The EASE score may be used in translational research across transplant centers.

A nomogram for prediction of early allograft dysfunction in living donor liver transplantation

Liver transplantation is the treatment of choice for end-stage liver diseases. However, early allograft dysfunction (EAD) is frequently encountered and associated with graft loss or mortality after transplantation. This study aimed to establish a predictive model of EAD after living donor liver transplantation. A total of 77 liver transplants were recruited to the study. Multivariate analysis was utilized to identify significant risk factors for EAD. A nomogram was constructed according to the contributions of the risk factors. The predictive values were determined by discrimination and calibration methods. A cohort of 30 patients was recruited to validate this predictive model. Four independent risk factors, including donor age, intraoperative blood loss, preoperative alanine aminotransferase (ALT), and reperfusion total bilirubin, were identified and used to build the nomogram. The c-statistics of the primary cohort and the validation group were 0.846 and 0.767, respectively. The calibration curves for the probability of EAD presented an acceptable agreement between the prediction by the nomogram and the actual incidence. In conclusion, the study developed a new nomogram for predicting the risk of EAD following living donor liver transplantation. This model may help clinicians to determine individual risk of EAD following living donor liver transplantation.

A simple scoring model for predicting early graft failure and postoperative mortality after liver transplantation

INTRODUCTION AND OBJECTIVES

Graft failure and postoperative mortality are the most serious complications after liver transplantation. The aim of this study is to establish a prognostic scoring system to predict graft and patient survival based on serum transaminases levels that are routinely used during the postoperative period in human cadaveric liver transplants.

PATIENTS AND METHODS

Postoperative graft failure and patient mortality after liver transplant were analyzed from a consecutive series of 1299 patients undergoing cadaveric liver transplantation. This was correlated with serum liver function tests and the rate of reduction in transaminase levels over the first postoperative week. A cut-off transaminase level correlating with graft and patient survival was calculated and incorporated into a scoring system.

RESULTS

Aspartate-aminotransferase (AST) on postoperative day one showed significant correlation with early graft failure for levels above 723U/dl and early postoperative mortality for levels above 750U/dl. AST reduction rate (day 1 to 3) greater than 1.8 correlated with reduced graft failure and greater than 2 with mortality. Alanine-aminotransferase (ALT) reduction in the first 48h post transplantation also correlated with outcomes.

CONCLUSION

A scoring system with these three variables allowed us to classify our patients into three groups of risk for early graft failure and mortality.

The Role of Ischemia/Reperfusion Injury in Early Hepatic Allograft Dysfunction

Liver transplantation (LT) is the only available curative treatment for patients with end-stage liver disease. Early allograft dysfunction (EAD) is a life-threatening complication of LT and is thought to be mediated in large part through ischemia/reperfusion injury (IRI). However, the underlying mechanisms linking IRI and EAD after LT are poorly understood. Most previous studies focused on the clinical features of EAD, but basic research on the underlying mechanisms is insufficient, due, in part, to a lack of suitable animal models of EAD. There is still no consensus on definition of EAD, which hampers comparative analysis of data from different LT centers. IRI is considered as an important risk factor of EAD, which can induce both damage and adaptive responses in liver grafts. IRI and EAD are closely linked and share several common pathways. However, the underlying mechanisms remain largely unclear. Therapeutic interventions against EAD through the amelioration of IRI is a promising strategy, but most approaches are still in preclinical stages. To further study the mechanisms of EAD and promote collaborations between LT centers, optimized animal models and unified definitions of EAD are urgently needed. Because IRI and EAD are closely linked, more attention should be paid to the underlying mechanisms and the fundamental relationship between them. Ischemia/reperfusion-induced adaptive responses may play a crucial role in the prevention of EAD, and more preclinical studies and clinical trials are urgently needed to address the current limitation of available therapeutic interventions.

Early Allograft Dysfunction Following Liver Transplant: Impact of Obesity, Diabetes, and Red Blood Cell Transfusion

PURPOSE

We examined the role of obesity and intraoperative red blood cell (RBC) and platelet transfusion in early allograft dysfunction (EAD) following liver transplantation (LT).

METHODS

This is a retrospective analysis of 239 adult deceased-donor LT recipients over a 10-year period. EAD was defined by Olthoff's criteria. Data collection included donor (D) and recipient (R) age, body mass index (BMI) ≥ 35 kg/m², diabetes mellitus, allograft macrosteatosis, and intraoperative (RBC) and platelet administration. We employed logistic regression to evaluate associations of these factors with EAD. Results are presented as odds ratios (OR) and 95% confidence intervals (CI) with corresponding P values. A P ≤ .05 was considered statistically significant.

RESULTS

EAD occurred in 85 recipients (36%). Macrosteatosis data were available for 199 donors. In the multivariate analyses, BMI-D ≥ 35 kg/m² increased the odds of developing EAD by 156% in the entire cohort (OR 2.56, 95% CI 1.09-6.01) and by 187% in recipients with macrosteatosis data (n = 199, OR 2.87, 95% CI 1.15-7.15). Each unit of RBCs increased the odds for EAD by 8% (OR 1.08, 95% CI 1.02-1.14) and, for the subgroup of 238 recipients with macrosteatosis data, by 9% (OR 1.09, 95% CI 1.02-1.16).

CONCLUSION

We found a significant independent association of donor obesity and intraoperative RBC transfusion with EAD but no such association for platelet administration, MELD score, age, recipient obesity, and diabetes.

Anticholestatic Effect of Bardoxolone Methyl on Hepatic Ischemia-reperfusion Injury in Rats

Supplemental Digital Content is available in the text.

Background.

Cholestasis is a sign of hepatic ischemia-reperfusion injury (IRI), which is caused by the dysfunction of hepatocyte membrane transporters (HMTs). As transcriptional regulation of HMTs during oxidative stress is mediated by nuclear factor erythroid 2-related factor 2, we hypothesized that bardoxolone methyl (BARD), a nuclear factor erythroid 2-related factor 2 activator, can mitigate cholestasis associated with hepatic IRI.

Methods.

BARD (2 mg/kg) or the vehicle was intravenously administered into rats immediately before sham surgery, 60 min of ischemia (IR60), or 90 min of ischemia (IR90); tissue and blood samples were collected after 24 h to determine the effect on key surrogate markers of bile metabolism and expression of HMT genes (Mrp (multidrug resistance-associated protein) 2, bile salt export pump, Mrp3, sodium-taurocholate cotransporter, and organic anion-transporting polypeptide 1).

Results.

Significantly decreased serum bile acids were detected upon BARD administration in the IR60 group but not in the IR90 group. Hepatic tissue analyses revealed that BARD administration increased mRNA levels of Mrp2 and Mrp3 in the IR60 group, and it decreased those of bile salt export pump in the IR90 group. Protein levels of multidrug resistance–associated protein 2, multidrug resistance–associated protein 3, and sodium-taurocholate cotransporter were higher in the IR90 group relative to those in the sham or IR60 groups, wherein the difference was notable only when BARD was administered. Immunohistochemical and morphometric analyses showed that the area of expression for multidrug resistance–associated protein 2 and for sodium-taurocholate cotransporter was larger in the viable tissues than in the necrotic area, and the area for multidrug resistance–associated protein 3 was smaller; these differences were notable upon BARD administration.

Conclusions.

BARD may have the potential to change HMT regulation to mitigate cholestasis in hepatic IRI.

Study design of the DAS-OLT trial: a randomized controlled trial to evaluate the impact of dexmedetomidine on early allograft dysfunction following liver transplantation

Background

Perioperative ischemia/reperfusion (I/R) injury during liver transplantation is strongly associated with early allograft dysfunction (EAD), graft loss, and mortality. Hepatic I/R injury also causes remote damage to other organs including the renal and pulmonary systems. Dexmedetomidine (DEX), a selective α2-adrenoceptor agonist which is used as an adjuvant to general anesthesia, has been shown in preclinical studies to provide organ protection by ameliorating the effects of I/R injury in a range of tissues (including the liver). However, prospective clinical evidence of any potential benefits in improving outcomes in liver transplantation is lacking. This study aimed to verify the hypothesis that the application of dexmedetomidine during the perioperative period of liver transplantation can reduce the incidence of EAD and primary graft non-function (PNF). At the same time, the effects of dexmedetomidine application on perioperative renal function and lung function were studied.

Methods

This is a prospective, single-center, randomized, parallel-group study. Two hundred participants (18–65 years) scheduled to undergo liver transplantation under general anesthesia will be included in this study. For participants in the treatment group, a loading dose of DEX will be given after induction of anesthesia (1 μg/kg over 10 min) followed by a continuous infusion (0.5 μg/kg /h) until the end of surgery. For participants in the placebo group, an equal volume loading dose of 0.9% saline will be given after the induction of anesthesia followed by an equal volume continuous infusion until the end of surgery. All other supplements, e.g., opioids, sedatives, and muscle relaxant, will be identical in both arms and administered according to routine clinical practice.

Discussion

The present trial will examine whether DEX confers organoprotective effects in the liver, in terms of reducing the incidence of EAD and PNF in orthotopic liver transplantation recipients.

Trial registration

ClinicalTrials.gov NCT03770130. Registered on 10 December 2018. https://clinicaltrials.gov/ct2/show/NCT03770130

First Preliminary Experience with Preservation of Liver Grafts from Extended-Criteria Donors by Normothermic Machine Perfusion in Asia

BACKGROUND Normothermic machine perfusion (NMP) can provide access to evaluate and resuscitate high-risk donor livers before transplantation. The purpose of this study was to determine the efficacy of NMP in preservation and assessment of extended-criteria donor (ECD) livers in China. CASE REPORT From September 2018 to March 2019, 4 liver grafts from 3 transplant center defined as ECD were subjected to NMP, and then were transplanted successfully. During perfusion, perfusion parameters such as vascular flow, glucose level, lactate clearance, and bile production/composition were recorded to assess graft viability. All recipients were followed up 6 months after transplantation. CONCLUSIONS NMP provides a potential tool for preservation and assessment of ECD livers in China.

Hyperoside Attenuates Hepatic Ischemia-Reperfusion Injury by Suppressing Oxidative Stress and Inhibiting Apoptosis in Rats

PURPOSE

Hepatic ischemia-reperfusion (IR) injury is a serious complication of many clinical conditions, which may lead to liver or multiple organ failure. Hyperoside, a flavonoid compound, has been reported to protect against myocardial and cerebral injury induced by IR. This study aimed to investigate the protective effects of hyperoside on hepatic IR injury in rats.

METHODS

Using the 70% hepatic IR injury model, we divided 32 male Wistar rats into 4 groups (n = 8): sham-operated, IR+saline (saline/p.o.), IR+vehicle (carboxy methyl cellulose/p.o.), and IR+hyperoside (50 mg/kg/d/p.o.). At 24 hours after reperfusion, blood and liver tissue were collected. The effects of hyperoside on hepatic IR injury were assessed through tests of serum transaminase, hepatic histopathology, and measurement of markers of oxidative stress and apoptosis.

RESULTS

Pretreatment with hyperoside protected the liver from IR injury by a reduction in serum aspartate aminotransferase/alanine aminotransferase levels and a decrease in the severity of histologic changes. Hyperoside treatment also decreased the activity of malondialdehyde, increased the activities of superoxide dismutase and glutathione peroxidase, up-regulated the expression of heme oxygenase 1 and NAD(P)H:quinone oxidoreductase 1, and reduced the apoptotic index after IR injury. A decrease in the expression of caspase-3 and an increase in the ratio of B cell lymphoma 2 to B cell lymphoma 2-associated X also were observed.

CONCLUSION

Hyperoside has a protective effect on hepatic IR injury in rats, which may be due to its antioxidant and antiapoptotic properties.

Risk factors, surgical complications and graft survival in liver transplant recipients with early allograft dysfunction

BACKGROUND

Early allograft dysfunction (EAD) is a severe complication after liver transplantation. The associated risk factors and complications have re-gained recent interest. This study investigated risk factors, survival and complications associated with EAD in a large liver transplant center in Latin America.

METHODS

Retrospective, unicenter, cohort, based on data from adult patients undergoing first deceased-donor liver transplant from January 2009 to December 2013. EAD was defined by one or more of the following: (i) bilirubin ≥10 mg/dL on postoperative day 7; (ii) international normalized ratio ≥1.6 on postoperative day 7, and (iii) alanine aminotransferase or aspartate aminotransferase >2000 IU/L within the first seven days after transplant.

RESULTS

A total of 602 patients were included; of these 34.2% developed EAD. Donor risk factors were male (P = 0.007), age between 50 and 59 years (P = 0.034), overweight (P = 0.028) or grade I obesity (P = 0.012), sodium >157 mmol/L (P = 0.002) and grade IV ischemia/reperfusion injury (P = 0.002). Cold ischemia time ≥10 h (P = 0.008) and warm ischemia time ≥40 min (P = 0.013) were the surgical factors. Male (P <0.001) was the only recipient protective factor. Compared with the non-EAD group, patients with EAD were submitted to more reoperations (24.3% vs. 13.4%, P = 0.001) and had higher graft loss rates (37.9% vs. 21.2%, P <0.001), with similar patient survival rates (P = 0.238).

CONCLUSIONS

EAD risk factors are related to donor, surgical procedure and recipient. Donor risk factors for EAD were male, age between 50 and 59 years, donor overweight or grade I obesity, sodium >157 mmol/L and grade IV ischemia/reperfusion injury. Cold ischemia time ≥10 h and warm ischemia time ≥40 min were the surgical risk factors. Male was the only recipient protective factor. Patients with EAD had higher reoperations and graft loss rates.

Evaluation of Early Allograft Function Using the Liver Graft Assessment Following Transplantation Risk Score Model

Importance

Early allograft dysfunction (EAD) following a liver transplant (LT) unequivocally portends adverse graft and patient outcomes, but a widely accepted classification or grading system is lacking.

Objective

To develop a model for individualized risk estimation of graft failure after LT and then compare the model's prognostic performance with the existing binary EAD definition (bilirubin level of ≥10 mg/dL on postoperative day 7, international normalized ratio of ≥1.6 on postoperative day 7, or aspartate aminotransferase or alanine aminotransferase level of >2000 U/L within the first 7 days) and the Model for Early Allograft Function (MEAF) score.

Design, Setting, and Participants

This retrospective single-center analysis used a transplant database to identify all adult patients who underwent a primary LT and had data on 10 days of post-LT laboratory variables at the Dumont-UCLA Transplant Center of the David Geffen School of Medicine at UCLA between February 1, 2002, and June 30, 2015. Data collection took place from January 4, 2016, to June 30, 2016. Data analysis was conducted from July 1, 2016, to August 30, 2017.

Main Outcomes and Measures

Three-month graft failure-free survival.

Results

Of 2021 patients who underwent primary LT over the study period, 2008 (99.4%) had available perioperative data and were included in the analysis. The median (interquartile range [IQR]) age of recipients was 56 (49-62) years, and 1294 recipients (64.4%) were men. Overall survival and graft-failure-free survival rates were 83% and 81% at year 1, 74% and 71% at year 3, and 69% and 65% at year 5, with an 11.1% (222 recipients) incidence of 3-month graft failure or death. Multivariate factors associated with 3-month graft failure-free survival included post-LT aspartate aminotransferase level, international normalized ratio, bilirubin level, and platelet count, measures of which were used to calculate the Liver Graft Assessment Following Transplantation (L-GrAFT) risk score. The L-GrAFT model had an excellent C statistic of 0.85, with a significantly superior discrimination of 3-month graft failure-free survival compared with the existing EAD definition (C statistic, 0.68; P < .001) and the MEAF score (C statistic, 0.70; P < .001). Compared with patients with lower L-GrAFT risk, LT recipients in the highest 10th percentile of L-GrAFT scores had higher Model for End-Stage Liver Disease scores (median [IQR], 34 [26-40] vs 31 [25-38]; P = .005); greater need for pretransplant hospitalization (56.8% vs 44.8%; P = .003), renal replacement therapy (42.9% vs 30.5%; P < .001), mechanical ventilation (35.8% vs 18.1%; P < .001), and vasopressors (22.9% vs 11.0%; P < .001); longer cold ischemia times (median [IQR], 436 [311-539] vs 401 [302-506] minutes; P = .04); greater intraoperative blood transfusions (median [IQR], 17 [10-26] vs 10 [6-17] units of packed red blood cells; P < .001); and older donors (median [IQR] age, 47 [28-56] vs 41 [25-52] years; P < .001).

Conclusions and Relevance

The L-GrAFT risk score allows a highly accurate, individualized risk estimation of 3-month graft failure following LT that is more accurate than existing EAD and MEAF scores. Multicenter validation may allow for the adoption of the L-GrAFT as a tool for evaluating the need for a retransplant, for establishing standardized grading of early allograft function across transplant centers, and as a highly accurate clinical end point in translational studies aiming to mitigate ischemia or reperfusion injury by modulating donor quality and recipient factors.

Hepatic flow is an intraoperative predictor of early allograft dysfunction in whole-graft deceased donor liver transplantation: An observational cohort study

BACKGROUND

Early allograft dysfunction (EAD) after liver transplantation (LT) is an important cause of morbidity and mortality. To ensure adequate graft function, a critical hepatocellular mass is required in addition to an appropriate blood supply. We hypothesized that intraoperative measurement of portal venous and hepatic arterial flow may serve as a predictor in the diagnosis of EAD.

AIM

To study whether hepatic flow is an independent predictor of EAD following LT.

METHODS

This is an observational cohort study in a single institution. Hepatic arterial blood flow and portal venous blood flow were measured intraoperatively by transit flow. EAD was defined using the Olthoff criteria. Univariate and multivariate analyses were used to determine the intraoperative predictors of EAD. Survival analysis and prognostic factor analysis were performed using the Kaplan-Meier and Cox regression models.

RESULTS

A total of 195 liver transplant procedures were performed between January 2008 and December 2014 in 188 patients. A total of 54 (27.7%) patients developed EAD. The median follow-up was 39 mo. Portal venous flow, hepatic arterial flow (HAF) and total hepatic arterial flow were associated with EAD in both the univariate and multivariate analyses. HAF is an independent prognostic factor for 30-d patient mortality.

CONCLUSION

Intraoperative measurement of blood flow after reperfusion appears to be a predictor of EAD; Moreover, HAF should be considered a predictor of 30-d patient mortality.

Identifying the Superior Reperfusion Technique in Liver Transplantation: A Network Meta-Analysis

Objective

To investigate the clinical effects of different reperfusion techniques in liver transplantation based on network meta-analysis.

Method

Literature retrieval was conducted in globally recognized databases, namely, MEDLINE, EMBASE, and Cochrane Central, to address relative randomized controlled trials (RCTs) investigating the clinical effects of respective reperfusion techniques in liver transplantation. Short- and long-term parametric data, including ICU stay, dysfunction rate (DFR), biliary complications (BC), 1-year graft survival (GS), and patient survival (PS), were quantitatively pooled and estimated based on the Bayesian theorem. The P values of surface under the cumulative ranking (SUCRA) probabilities regarding each parameter were calculated and ranked by various techniques. The Grades of Recommendations Assessment, Development and Evaluation (GRADE) criteria were utilized for the recommendations of evidence from pairwise direct comparisons.

Results

Seven RCTs containing 6 different techniques were finally included for network meta-analysis. The results indicated that retrograde vena cava (RVC) reperfusion possessed the highest possibility of revealing the best clinical effects on DFR (SUCRA, P = 0.93), ICU stay (SUCRA, P = 0.76), and GS (SUCRA, P = 0.44), while portal-arterial reperfusion (simultaneous initialize) seemed to exhibit the most benefits in reducing BC (SUCRA, P = 0.67) and enhancing PS rate (SUCRA, P = 0.48). Moreover, sensitivity analysis with the inconsistency approach clarified the reliability of the main results, and the evidence of the most direct comparisons was ranked low or very low.

Conclusions

Current evidence demonstrated that RVC and portal-arterial reperfusion (simultaneously initialized) revealed superior clinical effects, compared to other interventions. Investigation of these 2 techniques should be a future research direction, and more high-quality RCTs are expected.

Neutrophil-to-lymphocyte ratio is a predictor of early graft dysfunction following living donor liver transplantation

BACKGROUND & AIMS

Early allograft dysfunction (EAD) is predictive of poor graft and patient survival following living donor liver transplantation (LDLT). Considering the impact of the inflammatory response on graft injury extent following LDLT, we investigated the association between neutrophil-to-lymphocyte ratio (NLR) and EAD, 1-year graft failure, and mortality following LDLT, and compared it to C-reactive protein (CRP), procalcitonin, platelet-to-lymphocyte ratio and the Glasgow prognostic score.

METHODS

A total of 1960 consecutive adult LDLT recipients (1531/429 as development/validation cohort) were retrospectively evaluated. Cut-offs were derived using the area under the receiver operating characteristic curve (AUROC), and multivariable regression and Cox proportional hazard analyses were performed.

RESULTS

The risk of EAD increased proportionally with increasing NLR, and the NLR AUROC was 0.73, similar to CRP and procalcitonin and higher than the rest. NLR ≥ 2.85 (best cut-off) showed a significantly higher EAD occurrence (20.5% vs 5.8%, P < 0.001), higher 1-year graft failure (8.2% vs 4.9%, log-rank P = 0.009) and higher 1-year mortality (7% vs 4.5%, log-rank P = 0.039). NLR ≥ 2.85 was an independent predictor of EAD (odds ratio, 1.89 [1.26-2.84], P = 0.002) after multivariable adjustment, whereas CRP and procalcitonin were not. Increasing NLR was independently associated with higher 1-year graft failure and mortality (both P < 0.001). Consistent results in the validation cohort strengthened the prognostic value of NLR.

CONCLUSIONS

Preoperative NLR ≥ 2.85 predicted higher risk of EAD, 1-year graft failure and 1-year mortality following LDLT, and NLR was superior to other parameters, suggesting that preoperative NLR may be a practical index for predicting graft function following LDLT.

Donor Risk Index Has an Impact in Intraoperative Measure of Hepatic Artery Flow and in Clearance of Indocyanine Green: An Observational Cohort Study

BACKGROUND

The increase in indications for liver transplantation has led to acceptance of donors with expanded criteria. The donor risk index (DRI) was validated with the aim of being a predictive model of graft survival based on donor characteristics. Intraoperative arterial hepatic flow and indocyanine green clearance (plasma clearance rate of indocyanine green [ICG-PDR]) are easily measurable variables in the intraoperative period that may be influenced by graft quality. Our aim was to analyze the influence of DRI on intraoperative liver hemodynamic alterations and on intraoperative dynamic liver function testing (ICG-PDR).

METHODS

This investigation was an observational study of a single-center cohort (n = 228) with prospective data collection and retrospective data analysis. Measurement of intraoperative flow was made with a VeriQ flowmeter based on measurement of transit time (MFTT). The ICG-PDR was obtained from all patients with a LiMON monitor (Pulsion Medical Systems AG, Munich, Germany). DRI was calculated using a previously validated formula. Normally distributed variables were compared using Student's t test. Otherwise, the Mann-Whitney U test or Kruskal-Wallis test was applied, depending on whether there were 2 or more comparable groups. The qualitative variables and risk measurements were analyzed using the chi-square test. P < .05 was considered statistically significant.

RESULTS

DRI score (mean ± SD) was 1.58 ± 0.31. The group with DRI >1.7 (poor quality) had an intraoperative arterial flow of 234.2 ± 121.35 mL/min compared with the group having DRI < 1.7 (high quality), with an intraoperative arterial flow of 287.24 ± 156.84 mL/min (P = .02). The group with DRI >1.70 had an ICG-PDR of 14.75 ± 6.52%/min at 60 minutes after reperfusion compared to the group with DRI <1.70, with an ICG-PDR of 16.68 ± 6.47%/min at 60 minutes after reperfusion (P = .09).

CONCLUSION

Poor quality grafts have greater susceptibility to ischemia-reperfusion damage. Decreased intraoperative hepatic arterial flow may represent an increase in intrahepatic resistance early in the intraoperative period.

The Macrophage Activation Marker Soluble CD163 is Associated With Early Allograft Dysfunction After Liver Transplantation

BACKGROUND/OBJECTIVES

Soluble CD163 (sCD163), a macrophage activation marker, is upregulated in conditions of macrophage proliferation and activation. Elevated sCD163 levels have been associated with liver disease severity and progression. During liver transplantation, the implanted liver is exposed to ischaemia and reperfusion injury, resulting in an acute inflammatory response and macrophage activation. The relationship between sCD163 levels during liver transplantation and the development of early allograft dysfunction (EAD) has not been investigated.

METHODS

We included 27 cirrhosis patients (age 55 [range 32-72] years, 23 men) on the waiting list for liver transplantation. Alcohol consumption and viral hepatitis were the most frequent causes for cirrhosis. Patients were characterised by standard biochemical analysis and based on clinical disease severity scores. Information about donor, graft and course of the liver transplantation was recorded. sCD163 levels were measured at the time of liver transplantation before surgery, 2 h after reperfusion, and then at 24 h after transplantation.

RESULTS

We observed above-normal sCD163 levels at baseline (5.9 mg/L [4.7-8.8]). Two hours after reperfusion, sCD163 levels increased significantly from baseline (8.4 mg/L [7.4-10.9]; P < 0.01). Twenty-four hours after transplantation, sCD163 levels were significantly reduced compared with baseline (3.7 mg/L [2.9-5.5]; P < 0.01). However, in patients with EAD (n = 16), sCD163 levels were increased compared with patients without EAD (4.1 [3.2-7.4] vs. 3.1 [2.8-3.8] mg/L; P = 0.03).

CONCLUSIONS

We observed elevated sCD163 levels in patients with EAD after liver transplantation, confirming macrophage activation to play a role in EAD. Thus, sCD163 may be used as an early marker for EAD after liver transplantation, but larger studies are warranted to validate these findings.

Early graft dysfunction after liver transplant: Comparison of different diagnostic criteria in a single-center prospective cohort

OBJECTIVE

Comparison of different diagnostic criteria for early liver allograft dysfunction (EAD) and their capability to predict mortality.

DESIGN

Single-center, prospective, cohort study.

SETTINGS

ICU in a Regional Hospital with a liver transplant program since 1997.

PATIENTS

253 consecutive patients admitted to our ICU immediately after liver transplantation between 2009 and 2015.

VARIABLES OF INTEREST

Differences in the incidence of EAD and its relation with ICU, Hospital and 2-year mortality depending on the definition applied using as comparator the UNOS (United Network for Organ Sharing) primary non-function criterion.

RESULTS

The incidence of early liver allograft dysfunction according to UNOS was 13.8%, to Makowka 6.3%, to Ardite 10.7%, to Nanashima 20.6%, to Dhillon 30.8% and to MEAF 13.4%. Kappa test did not show a good correlation among these criteria. EAD was related with ICU mortality for all diagnostic criteria except Dhillon but only UNOS, Makowka and MEAF were associated with 2-year mortality. Hospital mortality was poorly predicted by all criteria except for the MEAF score.

CONCLUSION

We found a poor agreement between different criteria analyzed for the diagnosis of EAD. In our population, the MEAF score showed the best relationship with short- and long-term mortality.

Predictive Value of Indocyanine Green Plasma Disappearance Rate on Liver Function and Complications After Liver Transplantation

BACKGROUND The aim of this study was to investigate the correlation between indocyanine green plasma disappearance rate (ICG-PDR) and allograft function as well as postoperative complications after liver transplantation. MATERIAL AND METHODS In this prospective study, 115 cases of adult liver transplantation performed from 1 June 2016 to 1 December 2016 were enrolled. These 115 patients were divided into a group of PDR <18%/min (50 cases) and a group of PDR ≥18%/min (65 cases). The rates of liver recovery, postoperative complications, and survival were compared between these 2 groups. RESULTS Among the total of 115 patients, 111 patients recovered well and were discharged, whereas 4 patients died during the first month after the operation. Between the 2 groups, significant differences were observed in terms of the model for end-stage liver disease (MELD) score, intraoperative bleeding volume, and the level of hemoglobin (Hb), pre-albumin (PA) and total bilirubin (TB) the first week after the operation. Overall, the incidence of hepatic arterial complications and pneumonia was much higher in the PDR<18%/min group (P<0.05). CONCLUSIONS The early postoperative value of ICG-PDR was closely related to graft function and could act as a good predictor for the incidence of postoperative arterial complications.

Heme oxygenase-1 regulates sirtuin-1-autophagy pathway in liver transplantation: From mouse to human

Liver ischemia-reperfusion injury (IRI) represents a major risk factor of early graft dysfunction and a key obstacle to expanding the donor pool in orthotopic liver transplantation (OLT). Although graft autophagy is essential for resistance against hepatic IRI, its significance in clinical OLT remains unknown. Despite recent data identifying heme oxygenase-1 (HO-1) as a putative autophagy inducer, its role in OLT and interactions with sirtuin-1 (SIRT1), a key autophagy regulator, have not been studied. We aimed to examine HO-1-mediated autophagy induction in human OLT and in a murine OLT model with extended (20 hours) cold storage, as well as to analyze the requirement for SIRT1 in autophagy regulation by HO-1. Fifty-one hepatic biopsy specimens from OLT patients were collected under an institutional review board protocol 2 hours after portal reperfusion, followed by Western blot analyses. High HO-1 levels correlated with well-preserved hepatocellular function and enhanced SIRT1/LC3B expression. In mice, HO-1 overexpression by genetically modified HO-1 macrophage therapy was accompanied by decreased OLT damage and increased SIRT1/LC3B expression, whereas adjunctive inhibition of SIRT1 signaling diminished HO-1-mediated hepatoprotection and autophagy induction. Our translational study confirms the clinical relevance of HO-1 cytoprotection and identifies SIRT1-mediated autophagy pathway as a new essential regulator of HO-1 function in IR-stressed OLT.

Development and Validation of a Nomogram for Predicting Incidence of Early Allograft Dysfunction Following Liver Transplantation

OBJECTIVE

Early allograft dysfunction (EAD) is frequent complication post-liver transplantation and is closely related to recipient's mortality and morbidity. We sought to develop a nomogram for predicting incidence of EAD.

METHODS

Based on multivariate analysis of donor, recipient, and operation data of 199 liver transplants from deceased donors between 2013 and 2015, we identified 5 significant risk factors for EAD to build a nomogram. The model was subjected to prospective validation with a cohort of 42 patients who was recruited between January and June 2016. The predictive accuracy and discriminative ability were measured by area under the receiver operating characteristic curve (AUC). The agreement between nomogram prediction and actual observation was showed by the calibration curve.

RESULTS

Incidence rate of EAD in the training set and validation cohort were 55.91% (104/199) and 54.76% (23/42), respectively. In the training set, according to the results of univariable and multivariable analysis, 5 independent risk factors including donor gender, donor serum gamma-glutamyl transpeptidase level, donor serum urea level, donor comorbidities (respiratory, cardiac, and renal dysfunction), and recipient Model for End-stage Liver Disease score were identified and assembled into the nomogram. The AUC of internal validation using bootstrap resampling and prospective validation using the external cohort of 42 patients was 0.74 and 0.60, respectively. The calibration curves for probability of EAD showed acceptable agreement between nomogram prediction and actual observation. According to the score table, the probability of EAD was under 30% when the total point tally was under 72. But when the total was up to 139, the risk of EAD increased to 60%.

CONCLUSION

We've established and validated a nomogram that can provide individual prediction of EAD for liver transplant recipients. The practical prognostic model may help clinicians to qualify the liver graft accurately, making a more reasonable allocation of organs.

Effect of early allograft dysfunction on outcomes following liver transplantation

Early allograft dysfunction (EAD) following liver transplantation (LT) remains a challenge for patients and clinicians. We retrospectively analyzed the effect of pre-defined EAD on outcomes in a 10-year cohort of deceased-donor LT recipients with clearly defined exclusion criteria. EAD was defined by at least one of the following: AST or ALT >2000 IU/L within first-week post-LT, total bilirubin ≥10 mg/dL, and/or INR ≥1.6 on post-operative day 7. Ten patients developed primary graft failure and were analyzed separately. EAD occurred in 86 (36%) recipients in a final cohort of 239 patients. In univariate and multivariate analyses, EAD was significantly associated with mechanical ventilation ≥2 days or death on days 0, 1, PACU/SICU stay >2 days or death on days 0-2 and renal failure (RF) at time of hospital discharge (all P<.05). EAD was also significantly associated with higher one-year graft loss in both uni- and multivariate Cox hazard analyses (P=.0203 and .0248, respectively). There was no difference in patient mortality between groups in either of the Cox proportional hazard models. In conclusion, we observed significant effects of EAD on short-term post-LT outcomes and lower graft survival.

In vivo therapeutic potential of Inula racemosa in hepatic ischemia-reperfusion injury following orthotopic liver transplantation in male albino rats

Hepatic ischemia-reperfusion (I/R) injury mainly occurs following hepatic resection and liver transplantation and cause severe liver damage, organ injuries, and dysfunction. Pro-inflammatory cytokines that promote injury are released when kupffer cell activates after getting induced by I/R. Repercussions of oxidative stress and cardiac function against isoproterenol based myocardial infarction are caused by flavonol glycosides which are found in high concentrations in Inula racemosa (Ir).The root was deemed to have analgesic and anti-inflammatory effects, and no report has been published about the liver-protective activity against hepatic I/R. Therefore, the present study was aimed to understand the therapeutic impact of Ir in hepatic I/R injury. Male albino, Wistar strain rats were used and were grouped into four total phenolic content, free radical scavenging activity and serum enzymes were determined. Histopathological and immunohistochemical analysis were also carried out. Inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin (IL-6) and protein expression of p53, bax, and bcl-2 were determined. The administration of extracts of Ir significantly increased total phenolic and free radical scavenging activity. Altered cellular morphology, cytokines and aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were returned to near normal level. IL-6 and TNF-α levels were reduced more than 25% following treatment. Also, the protein expression of p53, bax, and bcl-2 were also returned to near normal level. Taking all these data together, it is suggested that the extracts of Ir may be a potential therapeutic agent for providing several beneficial effects in hepatic I/R injury.

A new index predicts early allograft dysfunction following living donor liver transplantation: A propensity score analysis

OBJECTIVE/AIM

The aim of this study was to identify a new index to predict early allograft dysfunction following living donor liver transplantation.

METHODS

The study enrolled 260 adult living donor liver transplantation recipients. Postoperative laboratory variables were assessed for their association with the prevalence of early allograft dysfunction using the inverse probability of treatment weighting and propensity-score matching (n=93 pairs) analysis.

RESULTS

Forty-seven recipients (18.1%) developed early allograft dysfunction. In multivariable analysis, the alanine aminotransferase and gamma-glutamyl transpeptidase levels on postoperative day 1 were independent predictors of early allograft dysfunction. The alanine aminotransferase to gamma-glutamyl transpeptidase ratio (AGR) was developed. All cases were divided into two groups (Group 1 [AGR≥8.47, n=103] and Group 2 [AGR<8.47, n=157]). AGR≥8.47 (OR 10.345, 95%CI 4.502-23.772, p<0.001), hepatorenal syndrome (OR 3.016, 95%CI 1.119-8.125, p=0.029), and graft to recipient weight ratio <0.8% (OR 2.155, 95%CI 1.004-4.624, p=0.049) were independent risk factors for early allograft dysfunction. The prevalence of early allograft dysfunction was higher in group 1 (after adjusting for inverse probability of treatment weighting [n=39; 37.9% vs n=8; 5.1%] and propensity-score matching [n=33; 35.5% vs n=2; 2.2%]) than that in group 2 (p<0.001).

CONCLUSIONS

The postoperative AGR is a practical index for predicting early allograft dysfunction after living donor liver transplantation.