Donor risk index and MELD interactions in predicting long-term graft survival: a single-centre experience. Transplantation. 2009;87:1858-1863. [PMID: 19543065 DOI: 10.1097/tp.0b013e3181a75b37]

Guidelines for the Management of Adult Acute and Acute-on-Chronic Liver Failure in the ICU: Neurology, Peri-Transplant Medicine, Infectious Disease, and Gastroenterology Considerations

OBJECTIVES

To develop evidence-based recommendations for clinicians caring for adults with acute liver failure (ALF) or acute on chronic liver failure (ACLF) in the ICU.

DESIGN

The guideline panel comprised 27 members with expertise in aspects of care of the critically ill patient with liver failure or methodology. We adhered to the Society of Critical Care Medicine standard operating procedures manual and conflict-of-interest policy. Teleconferences and electronic-based discussion among the panel, as well as within subgroups, served as an integral part of the guideline development.

INTERVENTIONS

In part 2 of this guideline, the panel was divided into four subgroups: neurology, peri-transplant, infectious diseases, and gastrointestinal groups. We developed and selected Population, Intervention, Comparison, and Outcomes (PICO) questions according to importance to patients and practicing clinicians. For each PICO question, we conducted a systematic review and meta-analysis where applicable. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence to decision framework to facilitate recommendations formulation as strong or conditional. We followed strict criteria to formulate best practice statements.

MEASUREMENTS AND MAIN RESULTS

We report 28 recommendations (from 31 PICO questions) on the management ALF and ACLF in the ICU. Overall, five were strong recommendations, 21 were conditional recommendations, two were best-practice statements, and we were unable to issue a recommendation for five questions due to insufficient evidence.

CONCLUSIONS

Multidisciplinary, international experts formulated evidence-based recommendations for the management ALF and ACLF patients in the ICU, acknowledging that most recommendations were based on low quality and indirect evidence.

Machine Learning Prediction of Liver Allograft Utilization From Deceased Organ Donors Using the National Donor Management Goals Registry

Early prediction of whether a liver allograft will be utilized for transplantation may allow better resource deployment during donor management and improve organ allocation. The national donor management goals (DMG) registry contains critical care data collected during donor management. We developed a machine learning model to predict transplantation of a liver graft based on data from the DMG registry.

Methods

Several machine learning classifiers were trained to predict transplantation of a liver graft. We utilized 127 variables available in the DMG dataset. We included data from potential deceased organ donors between April 2012 and January 2019. The outcome was defined as liver recovery for transplantation in the operating room. The prediction was made based on data available 12-18 h after the time of authorization for transplantation. The data were randomly separated into training (60%), validation (20%), and test sets (20%). We compared the performance of our models to the Liver Discard Risk Index.

Results

Of 13 629 donors in the dataset, 9255 (68%) livers were recovered and transplanted, 1519 recovered but used for research or discarded, 2855 were not recovered. The optimized gradient boosting machine classifier achieved an area under the curve of the receiver operator characteristic of 0.84 on the test set, outperforming all other classifiers.

Conclusions

This model predicts successful liver recovery for transplantation in the operating room, using data available early during donor management. It performs favorably when compared to existing models. It may provide real-time decision support during organ donor management and transplant logistics.

Prognostic role of the Donor Risk Index, the Eurotransplant Donor Risk Index, and the Balance of Risk score on graft loss after liver transplantation

This study aimed to identify cutoff values for donor risk index (DRI), Eurotransplant (ET)-DRI, and balance of risk (BAR) scores that predict the risk of liver graft loss. MEDLINE and Web of Science databases were searched systematically and unrestrictedly. Graft loss odds ratios and 95% confidence intervals were assessed by meta-analyses using Mantel-Haenszel tests with a random-effects model. Cutoff values for predicting graft loss at 3 months, 1 year, and 3 years were analyzed for each of the scores. Measures of calibration and discrimination used in studies validating the DRI and the ET-DRI were summarized. DRI ≥ 1.4 (six studies, n = 35 580 patients) and ET-DRI ≥ 1.4 (four studies, n = 11 666 patients) were associated with the highest risk of graft loss at all time points. BAR > 18 was associated with the highest risk of 3-month and 1-year graft loss (n = 6499 patients). A DRI cutoff of 1.8 and an ET-DRI cutoff of 1.7 were estimated using a summary receiver operator characteristic curve, but the sensitivity and specificity of these cutoff values were low. A DRI and ET-DRI score ≥ 1.4 and a BAR score > 18 have a negative influence on graft survival, but these cutoff values are not well suited for predicting graft loss.

A preoperative nomogram predicts prognosis of patients with hepatocellular carcinoma after liver transplantation: a multicenter retrospective study

Background

Although criteria for liver transplantation, such as the Milan criteria and Hangzhou experiences, have become popular, criteria to guide adjuvant therapy for patients with hepatocellular carcinoma after liver transplantation are lacking.

Methods

We collected data from all consecutive patients from 2012 to 2019 at three liver transplantation centers in China retrospectively. Univariate and multivariate analyses were used to analyze preoperative parameters, such as demographic and clinical data. Using data obtained in our center, calibration curves and the concordance Harrell’s C-indices were used to establish the final model. The validation cohort comprised the patients from the other centers.

Results

Data from 233 patients were used to construct the nomogram. The validation cohort comprised 36 patients. Independent predictors of overall survival (OS) were identified as HbeAg positive (P = 0.044), blood-type compatibility unmatched (P = 0.034), liver transplantation criteria (P = 0.003), and high MELD score (P = 0.037). For the validation cohort, to predict OS, the C-index of the nomogram was 0.874. Based on the model, patients could be assigned into low-risk (≥ 50%), intermediate-risk (30–50%), and high-risk (≤ 30%) groups to guide adjuvant therapy after surgery and to facilitate personalized management.

Conclusions

The OS in patients with hepatocellular carcinoma after liver transplantation could be accurately predicted using the developed nomogram.

RISK FACTORS ASSOCIATED WITH HEPATIC ARTERY THROMBOSIS: ANALYSIS OF 1050 LIVER TRANSPLANTS

Background:

Hepatic artery thrombosis is an important cause of graft loss and ischemic biliary complications. The risk factors have been related to technical aspects of arterial anastomosis and non-surgical ones.

Aim:

To evaluate the risk factors for the development of hepatic artery thrombosis.

Methods:

The sample consisted of 1050 cases of liver transplant. A retrospective and cross-sectional study was carried out, and the variables studied in both donor and recipient.

Results:

Univariate analysis indicated that the variables related to hepatic artery thrombosis are: MELD (p=0.04) and warm time ischemia (p=0.005). In the multivariate analysis MELD=14.5 and warm ischemia time =35 min were independent risk factors for hepatic artery thrombosis. In the prevalence ratio test for analysis of the anastomosis as a variable, it was observed that patients with continuous suture had an increase in thrombosis when compared to interrupted suture.

Conclusions:

Prolonged warm ischemia time, calculated MELD and recipient age were independent risk factors for hepatic artery thrombosis after liver transplantation in adults. Transplanted patients with continuous suture had an increase in thrombosis when compared to interrupted suture. Re-transplantation due to hepatic artery thrombosis was associated with higher recipient mortality.

An international multicenter study of protocols for liver transplantation during a pandemic: A case for quadripartite equipoise

BACKGROUND & AIMS

The outbreak of COVID-19 has vastly increased the operational burden on healthcare systems worldwide. For patients with end-stage liver failure, liver transplantation is the only option. However, the strain on intensive care facilities caused by the pandemic is a major concern. There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources.

METHODS

We performed an international multicenter study of transplant centers to understand the evolution of policies for transplant prioritization in response to the pandemic in March 2020. To describe the ethical tension arising in this setting, we propose a novel ethical framework, the quadripartite equipoise (QE) score, that is applicable to liver transplantation in the context of limited national resources.

RESULTS

Seventeen large- and medium-sized liver transplant centers from 12 countries across 4 continents participated. Ten centers opted to limit transplant activity in response to the pandemic, favoring a "sickest-first" approach. Conversely, some larger centers opted to continue routine transplant activity in order to balance waiting list mortality. To model these and other ethical tensions, we computed a QE score using 4 factors - recipient outcome, donor/graft safety, waiting list mortality and healthcare resources - for 7 countries. The fluctuation of the QE score over time accurately reflects the dynamic changes in the ethical tensions surrounding transplant activity in a pandemic.

CONCLUSIONS

This four-dimensional model of quadripartite equipoise addresses the ethical tensions in the current pandemic. It serves as a universally applicable framework to guide regulation of transplant activity in response to the increasing burden on healthcare systems.

LAY SUMMARY

There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources during the COVID-19 pandemic. We describe a four-dimensional model of quadripartite equipoise that models these ethical tensions and can guide the regulation of transplant activity in response to the increasing burden on healthcare systems.

RELATIONSHIP BETWEEN DONOR QUALITY AND RECIPIENT GRAVITY IN LIVER TRANSPLANT

Background:

Tools such as MELD score and DRI are currently used to predict risks and benefits on liver allocation for transplantation.

Aim:

To evaluate the relation between donor quality and recipient severity on liver allocation.

Methods:

Liver transplants performed in 2017 and 2018 were evaluated. Data were collected from Paraná’s State Government Registry. DRI was evaluated in relation to recipient MELD score and position on waiting list.

Results:

It was observed relation between DRI and position on waiting list: higher risk organs were allocated to recipients with worse waiting list position. There was no relation between DRI and MELD score. Afrodescendents and elderly donor organs were allocated to lower MELD score and worse waiting list position recipients.

Conclusion:

There is no relation between DRI and MELD on liver allocation. However, DRI interferes with allocation decision based on recipients waiting list position. Donor race and age interfere on both recipient MELD score and waiting list position

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Multiplication product of Model for End-stage Liver Disease and Donor Risk Index as predictive models of survival after liver transplantation

BACKGROUND

Liver transplantation (LT) is the treatment of choice for most end-stage liver diseases. This treatment increases survival rates and improves quality of life. Because of the shortage of organ donors, as opposed to waiting patients, the need to optimize the matching of donors to recipients for maximum utility is crucial.

AIM

The aim of this study was to examine a predictive model based on the combination of donor and recipient risk factors using the liver Donor Risk Index (DRI) and recipient Model of End-stage Liver Disease (MELD) to predict patients' survival following LT.

PATIENTS AND METHODS

The charts of 289 adult primary LT patients, who had undergone transplantation in Israel between 2010 and 2015, were studied retrospectively using prospectively gathered data.

RESULTS

Two variables, DRI and MELD, were found to significantly affect post-transplant patient survival. DRI negatively affected survival in a continuous fashion, whereas MELD had a significantly negative effect only at MELD more than 30. Both female sex and the presence of hepatocellular carcinoma were associated with increased patient survival.

CONCLUSION

According to our findings, the model described here is a novel prediction tool for the success of orthotopic LT and can thus be considered in liver allocation.

Quantifying the Effect of Transplanting Older Donor Livers Into Younger Recipients: The Need for Donor-recipient Age Matching

BACKGROUND

Increasing recipient and donor age are independently associated with survival after liver transplantation (LT). Whether donor age differentially impacts post-LT outcomes based on recipient age is unknown.

METHODS

This was a retrospective cohort study using Organ Procurement and Transplantation Network data. All adult deceased-donor, single organ, primary LTs from 2002 to 2015 were included. Donor and recipient age were categorized as younger than 40 years, 40 to 59 years, and 60 years or older. Mixed-effects survival analysis evaluated the risk of graft failure and death according to the interaction of donor and recipient age categories.

RESULTS

Of 63 628 LTs, 6.6% were in recipients younger than 40 years, of which 51.4% used an age-matched donor younger than 40 years. There was a significant among-center variability unrelated to United Network for Organ Sharing region in the use of older organs in young recipients, ranging from 0% to 25% or greater (overall center median, 9.7%; interquartile range, 5.4-16.5%). There was a significant interaction between donor and recipient age (P < 0.05) such that the impact of older donor age was more pronounced in younger recipients. Transplanting livers from donors aged 40 to 59 years and 60 years or older was associated with worse graft survival in recipients younger than 40 years, but there was no difference based on donor age in recipients 60 years or older.

CONCLUSIONS

There is a differential impact of using older donors in younger recipients than that in older recipients. Given their longer expected post-LT survival and the ethical imperative to maximize utilization of the scarce resource of transplantable livers, efforts should be made to allocate the highest-quality organs to those most likely to derive lasting benefit.

Factors Associated with Survival of Patients With Severe Acute-On-Chronic Liver Failure Before and After Liver Transplantation

BACKGROUND & AIMS

Liver transplantation for patients with acute-on-chronic liver failure (ACLF) with 3 or more failing organs (ACLF-3) is controversial. We compared liver waitlist mortality or removal according to model for end-stage liver disease (MELD) score vs ACLF category. We also studied factors associated with reduced odds of survival for 1 year after liver transplantation in patients with ACLF-3.

METHODS

We analyzed data from the United Network for Organ Sharing (UNOS) from 2005 through 2016. We identified patients who were on the waitlist (100,594) and those who received liver transplants (50,552). Patients with ACLF were identified based on the European Association for the Study of the Liver-chronic liver failure criteria. Outcomes were evaluated with competing risks regression, Kaplan-Meier analysis, and Cox proportional hazards regression.

RESULTS

Patients with ACLF-3 were more likely to die or be removed from the waitlist, regardless of MELD-sodium (MELD-Na) score, compared with the other ACLF groups; the proportion was greatest for patients with an ACLF-3 score and MELD-Na score below 25 (43.8% at 28 days). Mechanical ventilation at liver transplantation (hazard ratio [HR] 1.49; 95% confidence interval [CI] 1.22-1.84), donor risk index above 1.7 (HR 1.22; 95% CI 1.09-1.35), and liver transplantation within 30 days of listing (HR 0.89; 95% CI 0.81-0.98) were independently associated with survival for 1 year after liver transplantation CONCLUSIONS: In an analysis of data from the UNOS registry, we found high mortality among patients with ACLF-3 on the liver transplant waitlist, even among those with lower MELD-Na scores. So, certain patients with ACLF-3 have poor outcomes regardless of MELD-Na score. Liver transplantation increases odds of survival for these patients, particularly if performed within 30 days of placement on the waitlist. Mechanical ventilation at liver transplantation and use of marginal organs were associated with increased risk of death.

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.

"Real-time" risk models of postoperative morbidity and mortality for liver transplants

AIM

A comprehensive description of morbidity and mortality risk factors for post liver transplant has not been available to date. In this study, we established real-time risk models of postoperative morbidities and mortality in liver transplant recipients using two Japanese nationwide databases.

METHODS

Data from two Japanese nationwide databases were combined and used for this study. We developed real-time prognostic models for morbidity and mortality from a derivation cohort (n = 1472) and validated the findings with an independent cohort (n = 395). Preoperative variables (C1), preoperative and intraoperative variables (C2), and all variables including postoperative morbidities within 30 days (C3) were analyzed to evaluate the independent risk factors for postoperative morbidity and mortality.

RESULTS

We established real-time risk models for morbidity and mortality. Areas under the curve (AUC) of C1 and C2 risk models for mortality were 0.74 (0.63-0.82) and 0.79 (0.69-0.86), respectively. Multivariate logistic analysis using C3 showed that hemoglobin <10 g/dL, operative time (hours), and five postoperative morbidities (prolonged ventilation >48 hours, coma >24 hours, renal dysfunction, postoperative systemic sepsis, and serum total bilirubin ≥10 mg/dL) represented independent risk factors for mortality (AUC = 0.87, 95% confidence interval [CI]: 0.78-0.93).

CONCLUSIONS

Real-time risk models of postoperative morbidities and mortality at various perioperative time points in liver transplant recipients were established. These novel approaches may improve postoperative outcomes of liver transplant recipients. Furthermore, these real-time risk models may be applicable to other surgical procedures.

High Center Volume Does Not Mitigate Risk Associated with Using High Donor Risk Organs in Liver Transplantation

BACKGROUND

High-risk donor allografts increase access to liver transplant, but potentially reduce patient and graft survival.

AIMS

It is unclear whether the risk associated with using marginal donor livers is mitigated by increasing center experience.

METHODS

The United Network for Organ Sharing registry was queried for adult first-time liver transplant recipients between 2/2002 and 12/2015. High donor risk was defined as donor risk index >1.9, and 1-year patient and graft survival were compared according to donor risk index in small and large centers. Multivariable Cox regression estimated the hazard ratio (HR) associated with using high-risk donor organs, according to a continuous measure of annual center volume.

RESULTS

The analysis included 51,770 patients. In 67 small and 67 large centers, high donor risk index predicted increased mortality (p = 0.001). In multivariable analysis, high-donor risk index allografts predicted greater mortality hazard at centers performing 20 liver transplants per year (HR 1.35; 95% CI 1.22, 1.49; p < 0.001) and, similarly, at centers performing 70 per year (HR 1.35; 95% CI 1.26, 1.43; p < 0.001). The interaction between high donor risk index and center volume was not statistically significant (p = 0.747), confirming that the risk associated with using marginal donor livers was comparable between smaller and larger centers. Results were consistent when examining graft loss.

CONCLUSION

At both small and large centers, high-risk donor allografts were associated with reduced patient and graft survival after liver transplant. Specific strategies to mitigate the risk of liver transplant involving high-risk donors are needed, in addition to accumulation of center expertise.

The donor risk index: A decade of experience

In 2006, derivation of the donor risk index (DRI) highlighted the importance of donor factors for successful liver transplantation. Over the last decade, the DRI has served as a useful metric of donor quality and has enhanced our understanding of donor factors and their impact upon recipients with hepatitis C virus, those with low Model for End-Stage Liver Disease (MELD) score, and individuals undergoing retransplantation. DRI has provided the transplant community with a common language for describing donor organ characteristics and has served as the foundation for several tools for organ risk assessment. It is a useful tool in assessing the interactions of donor factors with recipient factors and their impact on posttransplant outcomes. However, limitations of statistical modeling, choice of donor factors, exclusion of unaccounted donor and geographic factors, and the changing face of the liver transplant recipient have tempered its widespread use. In addition, the DRI was derived from data before the MELD era but is currently being applied to expand the donor pool while concurrently meeting the demands of a dynamic allocation system. A decade after its introduction, DRI remains relevant but may benefit from being updated to provide guidance in the use of extended criteria donors by accounting for the impact of geography and unmeasured donor characteristics. DRI could be better adapted for recipients with nonalcoholic fatty liver disease by examining and including recipient factors unique to this population. Liver Transplantation 23 1216-1225 2017 AASLD.

Factors Associated With Short- and Long-term Liver Graft Survival in the United Kingdom: Development of a UK Donor Liver Index

BACKGROUND

A measure of donor liver quality, the donor liver index, was developed and validated for the UK population of transplant recipients. Unlike previously proposed measures, this index is only based on variables that are available at the point of retrieval, and so does not include cold ischemic time.

METHODS

Indices of liver quality were based on data from the UK Transplant Registry on all 7929 liver transplants between January 2000 and December 2014.

RESULTS

The donor liver index (DLI) was based on factors shown to affect graft survival, which included donor age, sex, height, type (donor after brain death or circulatory death), bilirubin, smoking history, and whether the liver was split. A separate index (DLI1) looking at 1-year survival showed donor cardiac disease, black ethnicity, and steatosis to be additional risk factors. A strong association was found between DLI and whether or not a surgeon accepts an offered liver for transplant, with a marked fall in acceptance rates for livers with an index greater than 1.31. Since 2000, there has been a notable reduction in the quality of livers transplanted, coupled with variation between the 7 UK liver transplant centers in risk appetite.

CONCLUSIONS

The DLI is an index of liver quality which enables analysis of the changing trends in liver quality and center behavior. DLI1 enables identification of factors affecting shorter-term survival, and perhaps identifies a cohort of livers that may benefit from novel preservation technologies.

Comparison of Two Questionnaires on Informed Consent in "Marginal" Donor Liver

The necessity of liver donors has contributed to overcoming the traditional criteria and to propose new ones for the acceptance of livers for transplantation. For this reason expanded or extended criteria donation (ECD) or even overextended criteria for marginal or high-risk organ donors have been developed. Ethical, Legal and Psychological Aspects of Organ Transplantation (ELPAT) and European Liver and Intestine Transplant Association (ELITA) - European Liver Transplantation Registry (ELTR) coordinated the distribution of a previously reported questionnaire that was sent to 53 European liver transplant centers. Criteria were divided based on the response rate. Donor criteria such as steatosis and serum sodium >165 mmol/L, as well as recipient criteria such as previous history of cancer, were not considered contraindications to transplantation in more than 60% of cases. Criteria such as ICU (intensive care unit) stay, body mass index >30, serum bilirubin >3 mg/dL, and HIV infection or critical illness were not considered adequate for transplantation in 30% to 59% of cases. On the other hand, there was no agreement on other extended liver donor and recipient criteria, such as age up to 80 years, serum glutamic oxaloacetic transaminase >90 U/L, serum glutamic pyruvic transaminase >105 U/L, high-risk sex practices, drug users, patients older than 65 years, and patients younger than 65 years, respectively. Criteria such as serum sodium could not be considered ECD criteria. In conclusion, development of more studies and inclusion of more liver transplantation centers are required to confirm these data.

Liver transplant recipients with portal vein thrombosis receiving an organ from a high-risk donor are at an increased risk for graft loss due to hepatic artery thrombosis

We hypothesize that recipients with pretransplant portal vein thrombosis (PVT) receiving organs from high-risk donors (HRD) are at an increased risk of HAT. Data on all liver transplants in the United States from February 2002 to March 2015 were analyzed. Recipients were sorted into two groups: those with PVT and those without. HRDs were defined by donor risk index (DRI) >1.7. Multivariable logistic regression models were constructed to assess the independent risk factors for HAT with the resultant graft loss ≤90 days from transplantation. A total of 60 404 candidates underwent liver transplantation; of those recipients, 623 (1.0%) had HAT, of which 66.0% (n = 411) received organs from HRDs compared with 49.3% (n = 29 473) in recipients without HAT (P < 0.001); 2250 (3.7%) recipients had pretransplantation PVT and received organs from HRDs. On adjusted multivariable analysis, PVT with a HRD organ was the most significant independent risk factor (OR 3.56, 95% CI 2.52-5.02, P < 0.001) for the development of HAT. Candidates with pretransplant PVT who receive an organ from a HRD are at the highest risk for postoperative HAT independent of other measurable factors. Recipients with pretransplant PVT would benefit from careful donor selection and possibly anticoagulation perioperatively.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1(th) and the 5(th) day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Ventilator associated pneumonia following liver transplantation: Etiology, risk factors and outcome

AIM: To determine the incidence, etiology, risk factors and outcome of ventilator-associated pneumonia (VAP) in patients undergoing orthotopic liver transplantation (OLT).

METHODS: This retrospective study considered 242 patients undergoing deceased donor OLT. VAP was diagnosed according to clinical and microbiological criteria.

RESULTS: VAP occurred in 18 (7.4%) patients, with an incidence of 10 per 1000 d of mechanical ventilation (MV). Isolated bacterial etiologic agents were mainly Enterobacteriaceae (79%). Univariate logistic analysis showed that model for end-stage liver disease (MELD) score, pre-operative hospitalization, treatment with terlipressin, Child-Turcotte-Pugh score, days of MV and red cell transfusion were risk factors for VAP. Multivariate analysis, considering significant risk factors in univariate analysis, demonstrated that pneumonia was strongly associated with terlipressin usage, pre-operative hospitalization, days of MV and red cell transfusion. Mortality rate was 22% in the VAP group vs 4% in the group without VAP.

CONCLUSION: Our data suggest that VAP is an important cause of nosocomial infection during postoperative period in OLT patients. MELD score was a significant risk factor in univariate analysis. Multiple transfusions, treatment with terlipressin, preoperative hospitalization rather than called to the hospital while at home and days of MV constitute important risk factors for VAP development.

Eurotransplant donor-risk-index and recipient factors: influence on long-term outcome after liver transplantation - A large single-center experience

The organ shortage has led to increased use of marginal organs. The Eurotransplant Donor-Risk-Index (ET-DRI) was established to estimate outcome after Liver Transplantation (LT). Currently, data on impact of ET-DRI on long-term outcome for different indications and recipient conditions are missing. Retrospective, single-center analysis of long-term graft survival (GS) of 1767 adult primary LTs according to indication, labMELDcategory (1: ≤18; 2: >18-25; 3: >25-35; 4: >35), and ET-DRI. Mean ET-DRI in our cohort was 1.63 (±0.43). One-, 10, and 15-yr GS was 83.5%, 63.3%, and 54.8%. Long-term GS was significantly influenced by ET-DRI. Accordingly, four ET-DRI categories were defined and analyzed with respect to underlying disease. Significant impact of these categories was observed for: Alcohol, cholestatic/autoimmune diseases (CD/AIH), and HCV, but not for HCC, HBV, cryptogenic cirrhosis, and acute liver failure. labMELD categories showed no significant influence on graft, but on patient survival. Matching ET-DRI categories with labMELD revealed significant differences in long-term GS for labMELDcategories 1, 2, and 3, but not 4. In multivariate analysis, HCV combined with ET-DRI > 2 and labMELDcategory 3 combined with ET-DRI > 2 emerged as negative predictors. To achieve excellent long-term graft survival, higher risk organs (ET-DRI > 1.4) should be used restrictively for patients with CD/AIH or HCV. Organs with ET-DRI > 2 should be avoided in patients with a labMELD of >25-35.

Effects of Donor Age and Cold Ischemia on Liver Transplantation Outcomes According to the Severity of Recipient Status

BackgroundProlonged cold ischemic time (CIT) and increased donor age are well-known factors negatively influencing outcomes after liver transplantation (LT).

AIMS

The aim of this study was to evaluate whether the magnitude of their negative effects is related to recipient model for end-stage liver disease (MELD) score.

METHODS

This retrospective study was based on a cohort of 1402 LTs, divided into those performed in low-MELD (<10), moderate-MELD (10–20), and high-MELD (>20) recipients.

RESULTS

While neither donor age (p = 0.775) nor CIT (p = 0.561) was a significant risk factor for worse 5-year graft survival in low-MELD recipients, both were found to yield independent effects (p = 0.003 and p = 0.012, respectively) in moderate-MELD recipients, and only CIT (p = 0.004) in high-MELD recipients. However, increased donor age only triggered the negative effect of CIT in moderate-MELD recipients, which was limited to grafts recovered from donors aged ≥46 years (p = 0.019). Notably, utilization of grafts from donors aged ≥46 years with CIT ≥9 h in moderate-MELD recipients (p = 0.003) and those with CIT ≥9 h irrespective of donor age in high-MELD recipients (p = 0.031) was associated with particularly compromised outcomes.

CONCLUSIONS

In conclusion, the negative effects of prolonged CIT seem to be limited to patients with moderate MELD receiving organs procured from older donors and to high-MELD recipients, irrespective of donor age. Varying effects of donor age and CIT according to recipient MELD score should be considered during the allocation process in order to avoid high-risk matches.

Acute-on-chronic liver failure

Acute-on-chronic liver failure combines an acute deterioration in liver function in an individual with pre-existing chronic liver disease and hepatic and extrahepatic organ failures, and is associated with substantial short-term mortality. Common precipitants include bacterial and viral infections, alcoholic hepatitis, and surgery, but in more than 40% of patients, no precipitating event is identified. Systemic inflammation and susceptibility to infection are characteristic pathophysiological features. A new diagnostic score, the Chronic Liver Failure Consortium (CLIF-C) organ failure score, has been developed for classification and prognostic assessment of patients with acute-on-chronic liver failure. Disease can be reversed in many patients, and thus clinical management focuses upon the identification and treatment of the precipitant while providing multiorgan-supportive care that addresses the complex pattern of physiological disturbance in critically ill patients with liver disease. Liver transplantation is a highly effective intervention in some specific cases, but recipient identification, organ availability, timing of transplantation, and high resource use are barriers to more widespread application. Recognition of acute-on-chronic liver failure as a clinically and pathophysiologically distinct syndrome with defined diagnostic and prognostic criteria will help to encourage the development of new management pathways and interventions to address the unacceptably high mortality.

Age and equity in liver transplantation: An organ allocation model

A moral liver allocation policy must be fair. We considered a 2-step, 2-principle allocation system called "age mapping." Its first principle, equal opportunity, ensures that candidates of all ages have an equal chance of getting an organ. Its second principle, prudential lifespan equity, allocates younger donor grafts to younger candidates and older donors to older candidates in order to increase the likelihood that all recipients achieve a "full lifespan." Data from 2476 candidates and 1371 consecutive adult liver transplantations (from 1999 to 2012) were used to determine whether age mapping can reduce the gap in years of life lost (YLL) between younger and older recipients. A parametric Weibull prognostic model was developed to estimate total life expectancy after transplantation using survival of the general population matched by sex and age as a reference. Life expectancy from birth was calculated by adding age at transplant and total life expectancy after transplantation. In multivariate analysis, recipient age, hepatitis C virus status, Model for End-Stage Liver Disease score at transplant of >30, and donor age were significantly related to prognosis after surgery (P < 0.05). The mean (and standard deviation) number of years of life from birth, calculated from the current allocation model, for various age groups were: recipients 18-47 years (n = 340) = 65.2 (3.3); 48-55 years (n = 387) = 72.7 (2.1); 56-61 years (n = 372) = 74.7 (1.7) and for recipients >61 years (n = 272) = 77.4 (1.4). The total number of YLL equaled 523 years. Redistributing liver grafts, using an age mapping algorithm, reduces the lifespan gap between younger and older candidates by 33% (from 12.3% to 8.3%) and achieves a 14% overall reduction of YLL (73 years) compared to baseline liver distribution. In conclusion, deliberately incorporating age into an allocation algorithm promotes fairness and increases efficiency.

Factors Associated with Mortality and Graft Failure in Liver Transplants: A Hierarchical Approach

BACKGROUND

Liver transplantation has received increased attention in the medical field since the 1980s following the introduction of new immunosuppressants and improved surgical techniques. Currently, transplantation is the treatment of choice for patients with end-stage liver disease, and it has been expanded for other indications. Liver transplantation outcomes depend on donor factors, operating conditions, and the disease stage of the recipient. A retrospective cohort was studied to identify mortality and graft failure rates and their associated factors. All adult liver transplants performed in the state of São Paulo, Brazil, between 2006 and 2012 were studied.

METHODS AND FINDINGS

A hierarchical Poisson multiple regression model was used to analyze factors related to mortality and graft failure in liver transplants. A total of 2,666 patients, 18 years or older, (1,482 males; 1,184 females) were investigated. Outcome variables included mortality and graft failure rates, which were grouped into a single binary variable called negative outcome rate. Additionally, donor clinical, laboratory, intensive care, and organ characteristics and recipient clinical data were analyzed. The mortality rate was 16.2 per 100 person-years (py) (95% CI: 15.1-17.3), and the graft failure rate was 1.8 per 100 py (95% CI: 1.5-2.2). Thus, the negative outcome rate was 18.0 per 100 py (95% CI: 16.9-19.2). The best risk model demonstrated that recipient creatinine ≥ 2.11 mg/dl [RR = 1.80 (95% CI: 1.56-2.08)], total bilirubin ≥ 2.11 mg/dl [RR = 1.48 (95% CI: 1.27-1.72)], Na+ ≥ 141.01 mg/dl [RR = 1.70 (95% CI: 1.47-1.97)], RNI ≥ 2.71 [RR = 1.64 (95% CI: 1.41-1.90)], body surface ≥ 1.98 [RR = 0.81 (95% CI: 0.68-0.97)] and donor age ≥ 54 years [RR = 1.28 (95% CI: 1.11-1.48)], male gender [RR = 1.19(95% CI: 1.03-1.37)], dobutamine use [RR = 0.54 (95% CI: 0.36-0.82)] and intubation ≥ 6 days [RR = 1.16 (95% CI: 1.10-1.34)] affected the negative outcome rate.

CONCLUSIONS

The current study confirms that both donor and recipient characteristics must be considered in post-transplant outcomes and prognostic scores. Our data demonstrated that recipient characteristics have a greater impact on post-transplant outcomes than donor characteristics. This new concept makes liver transplant teams to rethink about the limits in a MELD allocation system, with many teams competing with each other. The results suggest that although we have some concerns about the donors features, the recipient factors were heaviest predictors for bad outcomes.

Model for End-Stage Liver Disease, Model for Liver Transplantation Survival and Donor Risk Index as predictive models of survival after liver transplantation in 1,006 patients

OBJECTIVES

Liver transplantation has not increased with the number of patients requiring this treatment, increasing deaths among those on the waiting list. Models predicting post-transplantation survival, including the Model for Liver Transplantation Survival and the Donor Risk Index, have been created. Our aim was to compare the performance of the Model for End-Stage Liver Disease, the Model for Liver Transplantation Survival and the Donor Risk Index as prognostic models for survival after liver transplantation.

METHOD

We retrospectively analyzed the data from 1,270 patients who received a liver transplant from a deceased donor in the state of São Paulo, Brazil, between July 2006 and July 2009. All data obtained from the Health Department of the State of São Paulo at the 15 registered transplant centers were analyzed. Patients younger than 13 years of age or with acute liver failure were excluded.

RESULTS

The majority of the recipients had Child-Pugh class B or C cirrhosis (63.5%). Among the 1,006 patients included, 274 (27%) died. Univariate survival analysis using a Cox proportional hazards model showed hazard ratios of 1.02 and 1.43 for the Model for End-Stage Liver Disease and the Model for Liver Transplantation Survival, respectively (p<0.001). The areas under the ROC curve for the Donor Risk Index were always less than 0.5, whereas those for the Model for End-Stage Liver Disease and the Model for Liver Transplantation Survival were significantly greater than 0.5 (p<0.001). The cutoff values for the Model for End-Stage Liver Disease (≥29.5; sensitivity: 39.1%; specificity: 75.4%) and the Model for Liver Transplantation Survival (≥1.9; sensitivity 63.9%, specificity 54.5%), which were calculated using data available before liver transplantation, were good predictors of survival after liver transplantation (p<0.001).

CONCLUSIONS

The Model for Liver Transplantation Survival displayed similar death prediction performance to that of the Model for End-Stage Liver Disease. A simpler model involving fewer variables, such as the Model for End-Stage Liver Disease, is preferred over a complex model involving more variables, such as the Model for Liver Transplantation Survival. The Donor Risk Index had no significance in post-transplantation survival in our patients.

Early markers of reperfusion injury after liver transplantation: association with primary dysfunction

BACKGROUND

In patients with end-stage liver disease, liver transplantation is the only available curative treatment. Although the outcome and quality of life in the patients have improved over the past decades, primary dys- or nonfunction (PDF/PNF) can occur. Early detection of PDF and PNF is crucial and could lead to individual therapies. This study was designed to identify early markers of reperfusion injury and PDF in liver biopsies taken during the first hour after reperfusion.

METHODS

Biopsies from donor livers were prospectively taken as a routine during the first hour after reperfusion. Recipient data, transaminases and outcome were routinely monitored. In total, 10 biopsy specimens taken from patients with 90-day mortality and PDF, and patients with long-term survival but without PDF were used for DNA microarrays. Markers that were significantly up- or down-regulated in the microarray were verified using quantitative real-time PCR.

RESULTS

Age, indications and labMELD score were similar in both groups. Peak-transaminases during the first week after transplantation were significantly different in the two groups. In total, 20 differentially regulated markers that correlated to PDF were identified using microarray analysis and verified with quantitative real-time PCR.

CONCLUSIONS

The markers identified in this study could predict PDF at a very early time point and might point to interventions that ameliorate reperfusion injury and thus prevent PDF. Identification of patients and organs at risk might lead to individualized therapies and could ultimately improve outcome.

The MELD score predicts the short-term and overall survival after liver transplantation in patients with primary sclerosing cholangitis or autoimmune liver diseases

PURPOSE

Liver transplantation (LT) is well established in patients with autoimmune liver disease. Despite excellent outcomes, organ scarcity demands careful patients' selection and timing of transplantation.

METHODS

This retrospective study analyzes data of 79 consecutive patients with primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH), and overlap syndrome, undergoing LT between 2001 and 2012. Overall survival (OS) and graft survival were assessed using Kaplan-Meier estimate. Multivariate survival analysis was performed to identify prognostic factors by using Cox regression model.

RESULTS

After 59.6-month median follow-up, the 5-year OS and graft survival were 75.3 and 68.8%, respectively. The 5-year survival rates for patients with PSC (n=57), AIH (n=17), and overlap syndrome (n=5) were 76.3, 76.0, and 60.0%. The 90-day mortality rate of 70.0% was significantly higher in patients with a labMELD score≥20 (n=10) compared to 26.1% in 69 patients with a labMELD<20 (p=0.009). A lab Model for End-Stage Liver Disease (MELD) score≥20 was an independent predictor of impaired OS (p=0.050, hazard ratio 2.5). The 5-year OS was 55.7% in patients with a labMELD score≥20 compared to 84.7% in patients with a labMELD score<20.

CONCLUSION

The recipients' MELD score is a predictor for the short-term outcome after LT in patients with autoimmune liver disease. Meticulous selection for transplant listing remains necessary to safe scarce donor organs.

Impact of deceased organ donor demographics and critical care end points on liver transplantation and graft survival rates

BACKGROUND

The criteria for organ acceptance remain inconsistent, which limits the ability to standardize critical care practices. We sought to examine predictors of liver graft use and survival to better guide the selection and management of potential organ donors.

STUDY DESIGN

A prospective observational study of all donors managed by the 8 organ procurement organizations in United Network for Organ Sharing Region 5 was conducted from July 2008 to March 2011. Critical care end points that reflect the normal hemodynamic, acid-base, respiratory, endocrine, and renal status of the donor were collected at 3 time points. Critical care and demographic data associated with liver transplantation and graft survival rates were first determined using univariate analyses, and then logistic regression was used to identify independent predictors of these two outcomes.

RESULTS

From 961 donors, 730 (76%) livers were transplanted and 694 (95%) were functioning after 74 ± 73 days of follow-up. After regression analysis, donor BMI (odds ratio [OR] = 0.94), male sex (OR = 1.89), glucose <150 mg/dL (OR = 1.97), lower dopamine dose (OR = 0.95), vasopressin use (OR = 1.95), and ejection fraction >50% (OR = 1.77) remained as independent predictors of liver use. Graft survival was associated with lower donor BMI (OR = 0.91) and sodium levels (OR = 0.95).

CONCLUSIONS

After controlling for donor age, sex, and BMI, both hemodynamic and endocrine critical care end points were associated with increased liver graft use. Both donor BMI and lower sodium levels during the course of donor management were independently predictive of improved graft survival. These results may help guide the management and selection of potential organ donors after neurologic determination of death.

Outcomes among older adult liver transplantation recipients in the model of end stage liver disease (MELD) era

BACKGROUND

Since 2002, the Model of End Stage Liver Disease (MELD) score has been the basis of the liver transplant (LT) allocation system. Among older adult LT recipients, short-term outcomes in the MELD era were comparable to the pre-MELD era, but long-term outcomes remain unclear.

MATERIAL AND METHODS

This is a retrospective cohort study using the UNOS data on patients age ≥ 50 years who underwent primary LT from February 27, 2002 until October 31, 2011.

RESULTS

A total of 35,686 recipients met inclusion criteria. The cohort was divided into 5-year interval age groups. Five-year over-all survival rates for ages 50-54, 55-59, 60-64, 65-69, and 70+ were 72.2%, 71.6%, 69.5%, 65.0%, and 57.5%, respectively. Five-year graft survival rates after adjusting for death as competing risk for ages 50-54, 55-59,60-64, 65-69 and 70+ were 85.8%, 87.3%, 89.6%, 89.1% and 88.9%, respectively. By Cox proportional hazard modeling, age ≥ 60, increasing MELD, donor age ≥ 60, hepatitis C, hepatocellular carcinoma (HCC), dialysis and impaired pre-transplant functional status (FS) were associated with increased 5-year mortality. Using Fine and Gray sub-proportional hazard modeling adjusted for death as competing risk, 5-year graft failure was associated with donor age ≥ 60, increasing MELD, hepatitis C, HCC, and impaired pre-transplant FS.

CONCLUSIONS

Among older LT recipients in the MELD era, long-term graft survival after adjusting for death as competing risk was improved with increasing age, while over-all survival was worse. Donor age, hepatitis C, and pre-transplant FS represent potentially modifiable risk factors that could influence long-term graft and patient survival.

A preliminary European Liver and Intestine Transplant Association-European Liver Transplant Registry study on informed recipient consent and extended criteria liver donation

The European Liver and Intestine Transplant Association (ELITA) and the European Liver Transplant Registry (ELTR) coordinated the distribution to European liver transplantation centers of an electronic questionnaire, developed by the first author, concerning the definition of extended criteria liver donation (ECD) and the implication for informed consent of transplant recipients. Completed questionnaires were received from 35 centers. All centers accepted ECD liver donors. The criteria for defining a liver donor as ECD were as follows: steatosis in 33 centers (94%); age up to 80 years in 15 centers (43%); serum sodium >165 mmol/L in 25 centers (71%); intensive care unit (ICU) stay with ventilation longer than 7 days in 17 centers (48%); aspartate aminotransferase (AST) >90 U/L, in 6 centers (17%); body mass index (BMI) >30 in 19 centers (54%); alanine aminotransferase (ALT) >105 U/L in 8 centers (23%); serum bilirubin >3 mg/dL in 15 centers (43%); and all criteria together in 2 centers (6%). Thirty-one centers informed the transplantation candidate of the ECD status of the donor, 20 (65%) when the patient registered for transplantation, 1 (3%) when an ECD liver became available, and 10 centers (32%) on both occasions. Thirteen centers required the liver transplantation candidate to sign a special consent form. Twenty centers informed the potential recipient of the donor's serology. Only 6 centers informed the potential recipient of any high-risk behavior of the donor.

Prediction of postoperative mortality in liver transplantation in the era of MELD-based liver allocation: a multivariate analysis

BACKGROUND AND AIMS

Liver transplantation is the only curative treatment for end-stage liver disease. While waiting list mortality can be predicted by the MELD-score, reliable scoring systems for the postoperative period do not exist. This study's objective was to identify risk factors that contribute to postoperative mortality.

METHODS

Between December 2006 and March 2011, 429 patients underwent liver transplantation in our department. Risk factors for postoperative mortality in 266 consecutive liver transplantations were identified using univariate and multivariate analyses. Patients who were <18 years, HU-listings, and split-, living related, combined or re-transplantations were excluded from the analysis. The correlation between number of risk factors and mortality was analyzed.

RESULTS

A labMELD ≥20, female sex, coronary heart disease, donor risk index >1.5 and donor Na+>145 mmol/L were identified to be independent predictive factors for postoperative mortality. With increasing number of these risk-factors, postoperative 90-day and 1-year mortality increased (0-1: 0 and 0%; 2: 2.9 and 17.4%; 3: 5.6 and 16.8%; 4: 22.2 and 33.3%; 5-6: 60.9 and 66.2%).

CONCLUSIONS

In this analysis, a simple score was derived that adequately identified patients at risk after liver transplantation. Opening a discussion on the inclusion of these parameters in the process of organ allocation may be a worthwhile venture.

Donor risk index predicts graft failure reliably but not post-transplant infections

BACKGROUND

The Donor Risk Index (DRI) is used to predict graft survival following liver transplantation, but has not been used to predict post-operative infections in graft recipients. We hypothesized that lower-quality grafts would result in more frequent infectious complications.

METHODS

Using a prospectively collected infection data set, we matched liver transplant recipients (and the respective allograft DRI scores) with their specific post-transplant infectious complications. All transplant recipients were organized by DRI score and divided into groups with low-DRI and high-DRI scores.

RESULTS

We identified 378 liver transplants, with 189 recipients each in the low-DRI and high-DRI groups. The mean DRI scores for the low- and high-DRI-score groups were 1.14±0.01 and 1.74±0.02, respectively (p<0.0001 for the difference). The mean Model for End-Stage Liver Disease (MELD) scores were 26.25±0.53 and 24.76±0.55, respectively (p=0.052), and the mean number of infectious complications per patient were 1.60±0.19 and 1.94±0.24, respectively (p=0.26). Logistic regression showed only length of hospital stay and a history of vascular disease as being associated independently with infection, with a trend toward significance for MELD score (p=0.13).

CONCLUSION

We conclude that although DRI score predicts graft-liver survival, infectious complications depend more heavily on recipient factors.

Ethical considerations surrounding survival benefit-based liver allocation

The disparity between the demand for and supply of donor livers has continued to grow over the last 2 decades, and this has placed greater weight on the need for efficient and effective liver allocation. Although the use of extended criteria donors has shown great potential, it remains unregulated. A survival benefit-based model was recently proposed to answer calls to increase efficiency and reduce futile transplants. However, it was previously determined that the current allocation system was not in need of modification and that instead geographic disparities should be addressed. In contrast, we believe that there is a significant need to replace the current allocation system and complement efforts to improve donor liver distribution. We illustrate this need first by identifying major ethical concerns shaping liver allocation and then by using these concerns to identify strengths and shortcomings of the Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease system and a survival benefit-based model. The latter model is a promising means of improving liver allocation: it incorporates a greater number of ethical principles, uses a sophisticated statistical model to increase efficiency and reduce waste, minimizes bias, and parallels developments in the allocation of other organs. However, it remains limited in its posttransplant predictive accuracy and may raise potential issues regarding informed consent. In addition, the proposed model fails to include quality-of-life concerns and prioritize younger patients. We feel that it is time to take the next steps toward better liver allocation not only through reductions in geographic disparities but also through the adoption of a model better equipped to balance the many ethical concerns shaping organ allocation. Thus, we support the development of a similar model with suggested amendments.

Liver-specific deceased donor risk indices

In order to assess the quality of the donor liver, procuring surgeons should accurately evaluate not only general donor risk indices, such as donor age, causes of brain death and cold ischemic time, but also consider the specific donor risk indices. In this review, we focus on liver-specific deceased donor risk indices, including liver steatosis, anti-hepatitis B core (HBc) positive or hepatitis C virus (HCV) positive donors, hypernatremia and anatomical variations. Liver steatosis is strongly associated with poor graft function after liver transplantation. Liver with more than 40-50% macrosteatosis should not be used. However, at present the quantity of fatty livers lack accepted standards. The computerized image analysis programs should be used to automate the determination of fat content in liver biopsy specimens. Liver grafts from anti-HBc positive donors can be safely used, preferentially in hepatitis B surface antigen (HBsAg) positive or anti-HBc/anti-HBs positive recipients. HCV positive allografts free from fibrosis or severe inflammation are a safe option for HCV positive recipients. The procurement team should consider liver biopsy to evaluate these HCV positive allografts. Donor serum sodium over 150 mm may predict a higher rate of graft primary non-functions. Recently, however, some investigators reported the sodium level likely has little clinical impact on post-transplant liver function. The incidence of hepatic artery variations has been reported to be approximately 30%. To avoid injuries, it is very important to know and identify these variations with precision at the time of organ procurement.

The Physiology of Brain Death and Organ Donor Management

Brain death is associated with complex physiologic changes that may impact the management of the potential organ donor. Medical management is critical to actualizing the individual or family’s intent to donate and maximizing the benefit of that intent. This interval of care in the PICU begins with brain death and consent to donation and culminates with surgical organ procurement. During this phase, risks for hemodynamic instability and compromise of end organ function are high. The brain dead organ donor is in a distinct and challenging pathophysiologic condition that culminates in multifactorial shock. The potential benefits of aggressive medical management of the organ donor may include increased number of donors providing transplantable organs and increased number of organs transplanted per donor. This may improve graft function, graft survival, and patient survival in those transplanted. In this chapter, pathophysiologic changes occurring after brain death are reviewed. General and organ specific donor management strategies and logistic considerations are discussed. There is a significant opportunity for enhancing donor multi-organ function and improving organ utilization with appropriate PICU management.

Prognostic limitations of the Eurotransplant-Donor Risk Index in liver transplantation

Background

Liver transplantation is the only life-saving therapeutic option for end-stage liver disease. Progressive donor organ shortage and declining donor organ quality justify the evaluation of the leverage of the Donor-Risk-Index, which was recently adjusted to the Eurotransplant community’s requirements (ET-DRI). We analysed the prognostic value of the ET-DRI for the prediction of outcome after liver transplantation in our center within the Eurotransplant community.

Results

291 consecutive adult liver transplants were analysed in a single centre study with ongoing data collection. Determination of the area under the receiver operating characteristic curve (AUROC) was performed to calculate the sensitivity, specificity, and overall correctness of the Eurotransplant-Donor-Risk-Index (ET-DRI) for the prediction of 3-month and 1-year mortality, as well as 3-month and 1-year graft survival. Cut-off values were determined with the best Youden-index. The ET-DRI is unable to predict 3-month mortality (AUROC: 0.477) and 3-month graft survival (AUROC: 0.524) with acceptable sensitivity, specificity and overall correctness (54% and 56.3%, respectively). Logistic regression confirmed this finding (p = 0.573 and p = 0.163, respectively). Determined cut-off values of the ET-DRI for these predictions had no significant influence on long-term patient and graft survival (p = 0.230 and p = 0.083, respectively; Kaplan-Meier analysis with Log-Rank test).

Conclusions

The ET-DRI should not be used for donor organ allocation policies without further evaluation, e.g. in combination with relevant recipient variables. Robust and objective prognostic scores for donor organ allocation purposes are desperately needed to balance equity and utility in donor organ allocation.

Donor-recipient matching: myths and realities

Liver transplant outcomes keep improving, with refinements of surgical technique, immunosuppression and post-transplant care. However, these excellent results and the limited number of organs available have led to an increasing number of potential recipients with end-stage liver disease worldwide. Deaths on waiting lists have led liver transplant teams maximize every organ offered and used in terms of pre and post-transplant benefit. Donor-recipient (D-R) matching could be defined as the technique to check D-R pairs adequately associated by the presence of the constituents of some patterns from donor and patient variables. D-R matching has been strongly analysed and policies in donor allocation have tried to maximize organ utilization whilst still protecting individual interests. However, D-R matching has been written through trial and error and the development of each new score has been followed by strong discrepancies and controversies. Current allocation systems are based on isolated or combined donor or recipient characteristics. This review intends to analyze current knowledge about D-R matching methods, focusing on three main categories: patient-based policies, donor-based policies and combined donor-recipient systems. All of them lay on three mainstays that support three different concepts of D-R matching: prioritarianism (favouring the worst-off), utilitarianism (maximising total benefit) and social benefit (cost-effectiveness). All of them, with their pros and cons, offer an exciting controversial topic to be discussed. All of them together define D-R matching today, turning into myth what we considered a reality in the past.

[Extended donor criteria defined by the German Medical Association : study on their usefulness as prognostic model for early outcome after liver transplantation]

INTRODUCTION

Expansion of the donor pool by the use of grafts with extended donor criteria reduces waiting list mortality with an increased risk for graft and patient survival after liver transplantation. The ability of the number of fulfilled extended donor criteria as currently defined by the German Medical Association (BÄK-Score) to predict early outcome is unclear.

PATIENTS

A total of 291 consecutive adult liver transplantations (01.01.2007-31.12.2010) in 257 adult recipients were analyzed.

METHODS

Primary study endpoints were 30 day mortality, 3 month mortality, 3 month patient and graft survival and the necessity of acute retransplantation within 30 days. For primary study endpoints a ROC curve analysis was performed to calculate sensitivity, specificity and overall model correctness of the BÄK score as a predictive model. Further methods included Kaplan-Meier estimates, log-rank tests, Cox regression analysis, logistic regression analysis and χ(2)-tests.

RESULTS

The number of extended donor criteria fulfilled had no statistically significant influence on the primary study endpoints (p > 0.05) or on patient survival (p > 0.05). ROC curve analysis revealed areas under the curve ≤ 0.561 for the prediction of primary study endpoints (overall model correctness < 58%, sensitivity < 52%).

CONCLUSIONS

The number of fulfilled extended donor criteria as currently defined by the German Medical Association is unable to predict early outcome after liver transplantation.

The Eurotransplant donor risk index in liver transplantation: ET-DRI

Recently we validated the donor risk index (DRI) as conducted by Feng et al. for the Eurotransplant region. Although this scoring system is a valid tool for scoring donor liver quality, for allocation purposes a scoring system tailored for the Eurotransplant region may be more appropriate. Objective of our study was to investigate various donor and transplant risk factors and design a risk model for the Eurotransplant region. This study is a database analysis of all 5939 liver transplantations from deceased donors into adult recipients from the 1st of January 2003 until the 31st of December 2007 in Eurotransplant. Data were analyzed with Kaplan-Meier and Cox regression models. From 5723 patients follow-up data were available with a mean of 2.5 years. After multivariate analysis the DRI (p < 0.0001), latest lab GGT (p = 0.005) and rescue allocation (p = 0.007) remained significant. These factors were used to create the Eurotransplant Donor Risk Index (ET-DRI). Concordance-index calculation shows this ET-DRI to have high predictive value for outcome after liver transplantation. Therefore, we advise the use of this ET-DRI for risk indication and possibly for allocation purposes within the Eurotrans-plant region.

Trends in liver transplantation 2011

This review will highlight some of the important recent trends in liver transplantation. When possible, we will compare and contrast these trends across various regions of the world, in an effort to improve global consensus and better recognition of emerging data.

Development of organ-specific donor risk indices

Because of the shortage of deceased donor organs, transplant centers accept organs from marginal deceased donors, including older donors. Organ-specific donor risk indices have been developed to predict graft survival with various combinations of donor and recipient characteristics. Here we review the kidney donor risk index (KDRI) and the liver donor risk index (LDRI) and compare and contrast their strengths, limitations, and potential uses. The KDRI has a potential role in developing new kidney allocation algorithms. The LDRI allows a greater appreciation of the importance of donor factors, particularly for hepatitis C virus-positive recipients; as the donor risk index increases, the rates of allograft and patient survival among these recipients decrease disproportionately. The use of livers with high donor risk indices is associated with increased hospital costs that are independent of recipient risk factors, and the transplantation of livers with high donor risk indices into patients with Model for End-Stage Liver Disease scores < 15 is associated with lower allograft survival; the use of the LDRI has limited this practice. Significant regional variations in donor quality, as measured by the LDRI, remain in the United States. We also review other potential indices for liver transplantation, including donor-recipient matching and the retransplant donor risk index. Although substantial progress has been made in developing donor risk indices to objectively assess donor variables that affect transplant outcomes, continued efforts are warranted to improve these indices to enhance organ allocation policies and optimize allograft survival.

Grade of deceased donor liver macrovesicular steatosis impacts graft and recipient outcomes more than the Donor Risk Index

BACKGROUND AND AIM

Donor liver steatosis can impact on liver allograft outcomes. The aim of the present study was to comprehensively report on the impact of type and grade of donor steatosis, as well as donor and recipient factors, including the reported Donor Risk Index (DRI), on liver allograft outcomes.

METHODS

A review of unit data for all adult liver transplant procedures from 2001 to 2007, as well as donor offers. Donor liver biopsies were regraded for steatosis by an experienced histopathologist.

RESULTS

Steatosis was detected in 184/255 (72%) of biopsies, of which 114 (62%) had microvesicular steatosis (MiS; 68 mild, 22 moderate, 24 severe) and 70 (38%) macrovesicular steatosis (MaS; 59 mild, 7 moderate, 4 severe). The majority (66/70, 94%) of biopsies with MaS also contained MiS. Allograft steatosis was associated with increasing donor body mass index (P = 0.000), plus donor male sex (P < 0.05). Primary non function (P = 0.002), early renal failure (P = 0.040), and requirement for retransplantation (P = 0.012) were associated only with severe MaS. Early biliary complications were associated with moderate MaS (P = 0.039). Only severe MaS was significantly associated with inferior allograft survival at 3 months (relative risk = 12.09 [8.75-19.05], P = 0.000) and 1 year (P = 0.000).

CONCLUSIONS

MiS is a common finding and frequently coexists with MaS on liver allograft biopsy, while isolated MaS is uncommon. Only the presence of moderate to severe MaS is associated with inferior early allograft outcomes. The impact of severe MaS on allograft survival appears greater than other donor factors, including the calculated DRI.

Balancing donor and recipient risk factors in liver transplantation: the value of D-MELD with particular reference to HCV recipients

Donor-recipient match is a matter of debate in liver transplantation. D-MELD (donor age × recipient biochemical model for end-stage liver disease [MELD]) and other factors were analyzed on a national Italian database recording 5946 liver transplants. Primary endpoint was to determine factors predictive of 3-year patient survival. D-MELD cutoff predictive of 5-year patient survival <50% (5yrsPS<50%) was investigated. A prognosis calculator was implemented (http://www.D-MELD.com). Differences among D-MELD deciles allowed their regrouping into three D-MELD classes (A < 338, B 338-1628, C >1628). At 3 years, the odds ratio (OR) for death was 2.03 (95% confidence interval [CI], 1.44-2.85) in D-MELD class C versus B. The OR was 0.40 (95% CI, 0.24-0.66) in class A versus class B. Other predictors were hepatitis C virus (HCV; OR = 1.42; 95% CI, 1.11-1.81), hepatitis B virus (HBV; OR = 0.69; 95% CI, 0.51-0.93), retransplant (OR = 1.82; 95% CI, 1.16-2.87) and low-volume center (OR = 1.48; 95% CI, 1.11-1.99). Cox regressions up to 90 months confirmed results. The hazard ratio was 1.97 (95% CI, 1.59-2.43) for D-MELD class C versus class B and 0.42 (95% CI, 0.29-0.60) for D-MELD class A versus class B. Recipient age, HCV, HBV and retransplant were also significant. The 5yrsPS<50% cutoff was identified only in HCV patients (D-MELD ≥ 1750). The innovative approach offered by D-MELD and covariates is helpful in predicting outcome after liver transplantation, especially in HCV recipients.