Donor factors predicting recipient survival after liver retransplantation: the retransplant donor risk index

Has the risk of liver re-transplantation improved over the two decades?

BACKGROUND

Despite advancements in liver transplantation (LT) over the past two decades, liver re-transplantation (re-LT) presents challenges. This study aimed to assess improvements in re-LT outcomes and contributing factors.

METHODS

Data from the United Network for Organ Sharing database (2002-2021) were analyzed, with recipients categorized into four-year intervals. Trends in re-LT characteristics and postoperative outcomes were evaluated.

RESULTS

Of 128,462 LT patients, 7254 received re-LT. Graft survival (GS) for re-LT improved (91.3%, 82.1%, and 70.8% at 30 days, 1 year, and 3 years post-LT from 2018 to 2021). However, hazard ratios (HRs) for GS remained elevated compared to marginal donors including donors after circulatory death (DCD), although the difference in HRs decreased in long-term GS. Changes in re-LT causes included a reduction in hepatitis C recurrence and an increase in graft failure post-primary LT involving DCD. Trends identified included recent decreased cold ischemic time (CIT) and increased distance from donor hospital in re-LT group. Meanwhile, DCD cohort exhibited less significant increase in distance and more marked decrease in CIT. The shortest CIT was recorded in urgent re-LT group. The highest Model for End-Stage Liver Disease score was observed in urgent re-LT group, while the lowest was recorded in DCD group. Analysis revealed shorter time interval between previous LT and re-listing, leading to worse outcomes, and varying primary graft failure causes influencing overall survival post-re-LT.

DISCUSSION

While short-term re-LT outcomes improved, challenges persist compared to DCD. Further enhancements are required, with ongoing research focusing on optimizing risk stratification models and allocation systems for better LT outcomes.

The Evolution of Redo Liver Transplantation Over 35 Years: Analysis of 654 Consecutive Adult Liver Retransplants at a Single Center

OBJECTIVE

To examine liver retransplantation (ReLT) over 35 years at a single center.

BACKGROUND

Despite the durability of liver transplantation (LT), graft failure affects up to 40% of LT recipients.

METHODS

All adult ReLTs from 1984 to 2021 were analyzed. Comparisons were made between ReLTs in the pre versus post-model for end-stage liver disease (MELD) eras and between ReLTs and primary-LTs in the modern era. Multivariate analysis was used for prognostic modeling.

RESULTS

Six hundred fifty-four ReLTs were performed in 590 recipients. There were 372 pre-MELD ReLTs and 282 post-MELD ReLTs. Of the ReLT recipients, 89% had one previous LT, whereas 11% had ≥2. Primary nonfunction was the most common indication in the pre-MELD era (33%) versus recurrent disease (24%) in the post-MELD era. Post-MELD ReLT recipients were older (53 vs 48, P = 0.001), had higher MELD scores (35 vs 31, P = 0.01), and had more comorbidities. However, post-MELD ReLT patients had superior 1, 5, and 10-year survival compared with pre-MELD ReLT (75%, 60%, and 43% vs 53%, 43%, and 35%, respectively, P < 0.001) and lower in-hospital mortality and rejection rates. Notably, in the post-MELD era, the MELD score did not affect survival. We identified the following risk factors for early mortality (≤12 months after ReLT): coronary artery disease, obesity, ventilatory support, older recipient age, and longer pre-ReLT hospital stay.

CONCLUSIONS

This represents the largest single-center ReLT report to date. Despite the increased acuity and complexity of ReLT patients, post-MELD era outcomes have improved. With careful patient selection, these results support the efficacy and survival benefit of ReLT in an acuity-based allocation environment.

Modern Outcomes After Liver Retransplantation: A Single-center Experience

BACKGROUND

The need for liver retransplantation (reLT) has increased proportionally with greater numbers of liver transplants (LTs) performed, use of marginal donors, degree of recipient preoperative liver dysfunction, and longer survival after LT. However, outcomes following reLT have been historically regarded as poor.

METHODS

To evaluate reLT in modern recipients, we retrospectively examined our single-center experience. Analysis included 1268 patients undergoing single LT and 68 patients undergoing reLT from January 2008 to December 2021.

RESULTS

Pre-LT mechanical ventilation, body mass index at LT, donor-recipient ABO incompatibility, early acute rejection, and length of hospitalization were associated with increased risk of needing reLT following index transplant. Overall and graft survival outcomes in the reLT cohort were equivalent to those after single LT. Mortality after reLT was associated with Kidney Donor Profile Index, national organ sharing at reLT, and LT donor death by anoxia and blood urea nitrogen levels. Survival after reLT was independent of the interval between initial LT and reLT, intraoperative packed red blood cell use, cold ischemia time, and preoperative mechanical ventilation, all previously linked to worse outcomes.

CONCLUSIONS

These data suggest that reLT is currently a safer option for patients with liver graft failure, with comparable outcomes to primary LT.

Factors affecting survival after liver retransplantation: a systematic review and meta-analysis

Background

Liver retransplantation (reLT) has historically had inferior survival relative to primary liver transplant (LT). To improve outcomes after reLT, researchers have identified factors predicting overall (OS) and/or graft survival (GS) after reLT. This systematic review and random effects meta-analysis sought to summarize this literature to elucidate the strongest independent predictors of post-reLT.

Methods

A systematic review was conducted to identify manuscripts reporting factors affecting survival in multivariable Cox proportional hazards analyses. Papers with overlapping cohorts were excluded.

Results

All 25 included studies were retrospective, and 15 (60%) were single-center studies. Patients on pre-transplant ventilation (HR, 3.11; 95% CI, 1.56-6.20; p = 0.001) and with high serum creatinine (HR, 1.46; 95% CI, 1.15-1.87; p = 0.002) had the highest mortality risk after reLT. Recipient age, Model for End-Stage Liver Disease score, donor age, and cold ischemia time >12 h also conferred a significant risk of post-reLT death (all p < 0.05). Factors affecting GS included donor age and retransplant interval (the time between LT and reLT; both p < 0.05). OS is significantly higher when the retransplant interval is ≤7 days relative to 8-30 days (p = 0.04).

Conclusions

The meta-analysis was complicated by papers utilizing non-standardized cut-off values to group variables, which made between-study comparisons difficult. However, it did identify 7 variables that significantly impact survival after reLT, which could stimulate future research into improving post-reLT outcomes.

The Liver Retransplantation Risk Score: a prognostic model for survival after adult liver retransplantation

High‐risk combinations of recipient and graft characteristics are poorly defined for liver retransplantation (reLT) in the current era. We aimed to develop a risk model for survival after reLT using data from the European Liver Transplantation Registry, followed by internal and external validation. From 2006 to 2016, 85 067 liver transplants were recorded, including 5581 reLTs (6.6%). The final model included seven predictors of graft survival: recipient age, model for end‐stage liver disease score, indication for reLT, recipient hospitalization, time between primary liver transplantation and reLT, donor age, and cold ischemia time. By assigning points to each variable in proportion to their hazard ratio, a simplified risk score was created ranging 0–10. Low‐risk (0–3), medium‐risk (4–5), and high‐risk (6–10) groups were identified with significantly different 5‐year survival rates ranging 56.9% (95% CI 52.8–60.7%), 46.3% (95% CI 41.1–51.4%), and 32.1% (95% CI 23.5–41.0%), respectively (P < 0.001). External validation showed that the expected survival rates were closely aligned with the observed mortality probabilities. The Retransplantation Risk Score identifies high‐risk combinations of recipient‐ and graft‐related factors prognostic for long‐term graft survival after reLT. This tool may serve as a guidance for clinical decision‐making on liver acceptance for reLT.

Results of Early Liver Retransplantation

BACKGROUND

Liver retransplantation can be classified as urgent (when performed in the first week after the transplantation) or elective, which may be considered as early (first month post-transplantation) or late (after the first month). The time in which retransplantation takes place is determined by the cause that makes it necessary. The goal of this study is to analyze the causes and results of early retransplantation in our center.

METHODS

A retrospective analysis of liver retransplantations performed within the first month after the original transplantation in our center between 2007 and 2017 was carried out. The variables analyzed were demographic, causes of the first transplant and retransplantation, and the complications and mortality resulting from the latter.

RESULTS

A total of 698 liver transplants were performed, including 67 patients who required retransplantation (8.9%). Among these, 37 were late elective retransplantations and 30 were early retransplantations. Regarding the latter, the causes that led to the first transplant were hepatocellular carcinoma (46.7%) and noncholestatic cirrhosis (30%). On the other hand, the main precipitants of the retransplantation were hepatic artery thrombosis (60%) and primary graft failure (13.3%). The reoperation rate was 16.7%, and the perioperative mortality rate was 16.7%. The 1-, 2-, and 5-year survival rates were 83.3%, 76.7% and 59.9%, respectively.

CONCLUSION

Despite the high perioperative morbidity of liver retransplantation, its results in terms of survival are similar to those of the global series of liver 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.

Age and liver transplantation

The average age of liver transplant donors and recipients has increased over the years. Independent of the cause of liver disease, older candidates have more comorbidities, higher waitlist mortality and higher post-transplant mortality than younger patients. However, transplant benefit may be similar in older and younger recipients, provided older recipients are carefully selected. The cohort of elderly patients transplanted decades ago is also increasingly raising issues concerning long-term exposure to immunosuppression and aging of the transplanted liver. Excellent results can be achieved with elderly donors and there is virtually no upper age limit for donors after brain death liver transplantation. The issue is how to optimise selection, procurement and matching to ensure good results with elderly donors. The impact of old donor age is more pronounced in younger recipients and patients with a high model for end-stage liver disease score. Age matching between the donor and the recipient should be incorporated into allocation policies with a multistep approach. However, age matching may vary depending on the objectives of different allocation policies. In addition, age matching must be revisited in the era of direct-acting antivirals. More restrictive limits have been adopted in donation after circulatory death. Perfusion machines which are currently under investigation may help expand these limits. In living donor liver transplantation, donor age limit is essentially guided by morbidity related to procurement. In this review we summarise changing trends in recipient and donor age. We discuss the implications of older age donors and recipients. We also consider different options for age matching in liver transplantation that could improve outcomes.

Potential value and limitations of different clinical scoring systems in the assessment of short- and long-term outcome following orthotopic liver transplantation

BACKGROUND

In an attempt to further improve liver allograft utilization and outcome in orthotopic liver transplantation (OLT), a variety of clinical scoring systems have been developed. Here we aimed to comparatively investigate the association of the Balance-of-Risk (BAR), Survival-Outcomes-Following-Liver-Transplant (SOFT), Preallocation-Survival-Outcomes-Following-Liver-Transplant (pSOFT), Donor-Risk-Index (DRI), and the Eurotransplant-Donor-Risk-Index (ET-DRI) scores with short- and long-term outcome following OLT.

METHODS

We included 338 consecutive patients, who underwent OLT in our institution between May 2010 and November 2017. For each prognostic model, the optimal cutoff values were determined with the help of the Youden-index and their diagnostic accuracy for 90-day post OLT-mortality and major postoperative complications was measured by the area under the receiver operating characteristic curve (AUROC). Patient- and graft survival were analyzed using the Kaplan-Meier method and the log-rank test. Morbidity was assessed using the Clavien-Dindo classification and the Comprehensive-Complication-Index.

RESULTS

BAR, SOFT, and pSOFT performed well above the conventional AUROC-threshold of 0.70 with good prediction of early mortality. Only BAR showed AUC>0.70 for both mortality and major morbidity. With the cutoffs of 14, 31, and 22 respectively for BAR, SOFT, and pSOFT, subgroup analysis showed significant differences (p<0.001) in morbidity and mortality, length of intensive care- and hospital-stay and early allograft dysfunction rates. Five-years patient survival was inferior in the high BAR, pSOFT, and SOFT groups.

CONCLUSIONS

Out of all scores tested, the BAR-score had the best value in predicting both 90-day morbidity and mortality after OLT showing the highest AUCs. The pSOFT and SOFT scores demonstrated an acceptable accuracy in predicting 90-day morbidity and mortality. The used BAR, SOFT, and pSOFT cutoffs allowed the identification of patients at risk in terms of five-year patient survival. The DRI and ET-DRI scores have failed to predict recipient outcomes in the present setting.

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.

Liver Retransplantation: How Much Is Too Much?

Hepatic retransplantation has been surgically challenging since the beginning of liver transplant. Outcomes have improved over time, but patient survival with retransplant continues to be significantly worse than that of primary transplant. Many studies have focused on factors to predict outcomes. Models have been developed to help predict risk, but the decision for retransplant must be a multidisciplinary transplant team decision. The question of "when is too much?" can be guided by recipient and donor factors but is an ethical decision that must be made by the liver transplant team.

Extended-criteria donors in liver transplantation Part II: reviewing the impact of extended-criteria donors on the complications and outcomes of liver transplantation

Extended-criteria donors (ECDs) have an impact on early allograft dysfunction (EAD), biliary complications, relapse of hepatitis C virus (HCV), and survivals. Early allograft dysfunction was frequently seen in grafts with moderate and severe steatosis. Donors after cardiac death (DCD) have been associated with higher rates of graft failure and biliary complications compared to donors after brain death. Extended warm ischemia, reperfusion injury and endothelial activation trigger a cascade, leading to microvascular thrombosis, resulting in biliary necrosis, cholangitis, and graft failure. The risk of HCV recurrence increased by donor age, and associated with using moderately and severely steatotic grafts. With the administration of protease inhibitors sustained virological response was achieved in majority of the patients. Donor risk index and EC donor scores (DS) are reported to be useful, to assess the outcome. The 1-year survival rates were 87% and 40% respectively, for donors with a DS of 0 and 3. Graft survival was excellent up to a DS of 2, however a DS >2 should be avoided in higher-risk recipients. The 1, 3 and 5-year survival of DCD recipients was comparable to optimal donors. However ECDs had minor survival means of 85%, 78.6%, and 72.3%. The graft survival of split liver transplantation (SLT) was comparable to that of whole liver orthotopic liver transplantation. SLT was not regarded as an ECD factor in the MELD era any more. Full-right-full-left split liver transplantation has a significant advantage to extend the high quality donor pool. Hypothermic oxygenated machine perfusion can be applied clinically in DCD liver grafts. Feasibility and safety were confirmed. Reperfusion injury was also rare in machine perfused DCD livers.

Extended criteria donors in liver transplantation Part I: reviewing the impact of determining factors

The definition and factors of extended criteria donors have already been set; however, details of the various opinions still differ in many respects. In this review, we summarize the impact of these factors and their clinical relevance. Elderly livers must not be allocated for hepatitis C virus (HCV) positives, or patients with acute liver failure. In cases of markedly increased serum transaminases, donor hemodynamics is an essential consideration. A prolonged hypotension of the donor does not always lead to an increase in post-transplantation graft loss if post-OLT care is proper. Hypernatremia of less than 160 mEq/L is not an absolute contraindication to accept a liver graft per se. The presence of steatosis is an independent and determinant risk factor for the outcome. The gold standard of the diagnosis is the biopsy. This is recommended in all doubtful cases. The use of HCV+ grafts for HCV+ recipients is comparable in outcome. The leading risk factor for HCV recurrence is the actual RNA positivity of the donor. The presence of a proper anti-HBs level seems to protect from de novo HBV infection. A favourable outcome can be expected if a donation after cardiac death liver is transplanted in a favourable condition, meaning, a warm ischemia time < 30 minutes, cold ischemia time < 8-10 hours, and donor age 50-60 years. The pathway of organ quality assessment is to obtain the most relevant information (e.g. biopsy), consider the co-existing donor risk factors and the reserve capacity of the recipient, and avoid further technical issues.

Optimizing repeat liver transplant graft utility through strategic matching of donor and recipient characteristics

Repeat liver transplantation (LT) is controversial because of inferior outcomes versus primary LT. A minimum 1-year expected post-re-LT survival of 50% has been proposed. We aimed to identify combinations of Model for End-Stage Liver Disease (MELD), donor risk index (DRI), and recipient characteristics achieving this graft survival threshold. We identified re-LT recipients listed in the United States from March 2002 to January 2010 with > 90 days between primary LT and listing for re-LT. Using Cox regression, we estimated the expected probability of 1-year graft survival and identified combinations of MELD, DRI, and recipient characteristics attaining >50% expected 1-year graft survival. Re-LT recipients (n = 1418) had a median MELD of 26 and median age of 52 years. Expected 1-year graft survival exceeded 50% regardless of MELD or DRI in Caucasian recipients who were not infected with hepatitis C virus (HCV) of all ages and Caucasian HCV-infected recipients <50 years old. As age increased in HCV-infected Caucasian and non-HCV-infected African American recipients, lower MELD scores or lower DRI grafts were needed to attain the graft survival threshold. As MELD scores increased in HCV-infected African American recipients, lower-DRI livers were required to achieve the graft survival threshold. Use of high-DRI livers (>1.44) in HCV-infected recipients with a MELD score > 26 at re-LT failed to achieve the graft survival threshold with recipient age ≥ 60 years (any race), as well as at age ≥ 50 years for Caucasians and at age < 50 years for African Americans. Strategic donor selection can achieve >50% expected 1-year graft survival even in high-risk re-LT recipients (HCV infected, older age, African American race, high MELD scores). Low-risk transplant recipients (age < 50 years, non-HCV-infected) can achieve the survival threshold with varying DRI and MELD scores.

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.

Outcomes of adult liver re-transplant patients in the model for end-stage liver disease era: is it time to reconsider its indications?

OBJECTIVE

To better understand the outcomes and utility of liver re-transplantation in non-hepatitis C patients, we sought to identify predictors that impact post-transplant patient and graft survival comparing primary liver transplant patients to those receiving subsequent allografts.

METHODS

We conducted a retrospective cohort analysis using the United Network for Organ Sharing database from February 2002 through December 2012, including non-hepatitis C infected adults (18 yr and older) who underwent primary and repeat liver transplantation. Patient and graft survival were compared between the two groups using the Kaplan-Meier estimator. Cox proportional hazards models were constructed to evaluate variables associated with both patient and graft survival.

RESULTS

We identified 33 176 primary transplant recipients and 2710 re-transplants. Re-transplantation patients were more likely to be on dialysis prior to transplant (18% vs. 10%), hospitalized (26% vs. 16%), in the intensive care unit (ICU) (34% vs. 13%), on a ventilator (17% vs. 3%), and had higher model for end-stage liver disease (MELD) score (27 vs. 21). Re-transplants also received livers with a lower donor risk index (DRI) (1.57 vs. 1.64). We estimated an adjusted hazard ratio (HR) of 1.7 for patient survival (95% CI: 1.56-1.84) and 1.61 (95% CI: 1.5-1.73) for graft survival.

CONCLUSIONS

Liver re-transplantation in non-hepatitis C patients, although life saving, has significantly inferior patient and graft survival compared to primary liver transplantation. Higher quality grafts are used inefficiently in a sicker patient population, suggesting that a more optimal strategy may include restricting their use to patients who obtain a longer term benefit.

Hepatic retransplant: what have we learned?

Hepatic retransplant accounts for 5% to 15% of liver transplants in most series and is associated with significantly increased hospital costs and inferior patient survival when compared with primary liver transplant. Early retransplants are usually due to primary graft nonfunction or vascular thrombosis, whereas later retransplants are most commonly necessitated by chronic rejection or recurrent primary liver disease. Hepatic retransplant remains the sole option for survival in many patients facing allograft failure after liver transplant. With improved techniques to match retransplant candidates with appropriate donor grafts, it is hoped that the outcomes of retransplant will continue to improve in future.

Decision making in liver transplantation--limited application of the liver donor risk index

The liver donor risk index (LDRI), originally developed in 2006 by Feng et al. and since modified, is a method of evaluating liver grafts from deceased donors through the determination of the relative risk of graft failure after transplantation. Online and paper surveys about attitudes and practices regarding decision making in liver transplantation and the role of the LDRI were sent to liver transplant physicians. One hundred forty-seven of 401 eligible respondents (37%) returned partial or complete surveys. The majority of the respondents were male (116/134 or 87%) and practiced in academic medical centers (128/138 or 93%). Transplant coordinators initially contacted the candidate with an offer in 81% of the programs. Eighty-eight of 143 respondents (62%) reported that they were very familiar with the LDRI, but the vast majority (114/137 or 83%) rarely or never discussed the concept of the LDRI with their patients. A majority of the respondents (96/132 or 73%) believed that the LDRI does not adequately describe a liver's relative risk of graft failure and that there are factors making the LDRI potentially misleading (122/138 or 88%). Nevertheless, 60 of 130 respondents (46%) believed that the LDRI would increase/improve shared decision making. The LDRI has not been widely adopted because of concerns that (1) it does not accurately reflect posttransplant survival, (2) it excludes relevant donor and recipient factors, and (3) it is too complicated for candidates to grasp. There is a need to improve it or to develop other decision-making tools to help promote shared decision making. There is also great diversity in how liver offers are made to ambulatory candidates and in how transplant programs address a candidate's refusal. Research is needed to determine evidence-based best practice.

Retransplantation using living-donor right-liver grafts

BACKGROUND

This study reviews the outcomes of retransplantation using living-donor right-liver grafts.

METHODS

A retrospective study of liver retransplants performed between 1996 and 2013 was conducted. The retransplants were divided into the DD group (with deceased donors) and the LD group (with living donors). Survival outcomes were analyzed.

RESULTS

The DD group contained 23 patients and 27 retransplants using whole-liver grafts and the LD group contained 11 patients and 11 retransplants using right-liver grafts. Vascular and biliary complications were the main indications for retransplantation in both groups. The LD group had significantly younger donors, lighter grafts, shorter cold ischemia and longer operations. The two groups were comparable in age, preoperative liver function, warm ischemia, blood loss, transfusion, intensive care unit stay, hospital stay, hospital mortality, complication and graft loss. The 1-year, 3-year and 5-year patient survival rates were 78.3%, 73.7% and 63.8%, respectively, in the DD group. The LD group had the corresponding rates all at 90.9% (P = 0.246). The 1-year, 3-year and 5-year graft survival rates were 74.1%, 65.8% and 61.5%, respectively, in the DD group. The LD group had the corresponding rates all at 90.9% (P = 0.132).

CONCLUSION

Excellent long-term survival after retransplantation using living-donor right-liver grafts can be achieved.

The difficulty in defining extended donor criteria for liver grafts: the Eurotransplant experience

Donor criteria for liver grafts have been expanded because of organ shortage. Currently, no exact definitions for extended donor grafts have been established. The aim of this study was to analyze the impact of donor-specific risk factors, independent of recipient characteristics. In collaboration with Eurotransplant and European Liver Transplant Register, solely donor-specific parameters were correlated with 1-year survival following liver transplantation. Analyses of 4701 donors between 2000 and 2005 resulted in the development of a nomogram to estimate graft survival for available grafts. Predictions by nomogram were compared to those by Donor Risk Index (DRI). In the multivariate analysis, cold ischemic time (CIT), highest sodium, cause of donor death, γ-glutamyl transferase (γ-GT), and donor sex (female) were statistically significant factors for 3 months; CIT, γ-GT, and cause of donor death for 12-month survival. The median DRI of this study population was 1.45 (Q1: 1.17; Q3: 1.67). The agreement between the nomogram and DRI was weak (kappa = 0.23). Several donor-specific risk factors were identified for early survival after liver transplantation. The provided nomogram will support quick organ quality assessment. Nevertheless, this study showed the difficulties of determining an exact definition of extended criteria donors.

Donation after cardio-circulatory death liver transplantation

The renewed interest in donation after cardio-circulatory death (DCD) started in the 1990s following the limited success of the transplant community to expand the donation after brain-death (DBD) organ supply and following the request of potential DCD families. Since then, DCD organ procurement and transplantation activities have rapidly expanded, particularly for non-vital organs, like kidneys. In liver transplantation (LT), DCD donors are a valuable organ source that helps to decrease the mortality rate on the waiting lists and to increase the availability of organs for transplantation despite a higher risk of early graft dysfunction, more frequent vascular and ischemia-type biliary lesions, higher rates of re-listing and re-transplantation and lower graft survival, which are obviously due to the inevitable warm ischemia occurring during the declaration of death and organ retrieval process. Experimental strategies intervening in both donors and recipients at different phases of the transplantation process have focused on the attenuation of ischemia-reperfusion injury and already gained encouraging results, and some of them have found their way from pre-clinical success into clinical reality. The future of DCD-LT is promising. Concerted efforts should concentrate on the identification of suitable donors (probably Maastricht category III DCD donors), better donor and recipient matching (high risk donors to low risk recipients), use of advanced organ preservation techniques (oxygenated hypothermic machine perfusion, normothermic machine perfusion, venous systemic oxygen persufflation), and pharmacological modulation (probably a multi-factorial biologic modulation strategy) so that DCD liver allografts could be safely utilized and attain equivalent results as DBD-LT.

Liver transplantation in the setting of chronic HCV

Recurrent HCV disease is the most common cause of graft loss and patient mortality in HCV-infected liver transplant (LT) recipients. Risk factors for more severe recurrence that are potentially modifiable are older donor age, prolonged cold ischaemia time, prior treated acute rejection, CMV hepatitis, IL28B donor genotype, and post-LT insulin resistance. The most effective means of preventing HCV recurrence is eradicating HCV prior to LT. Select wait-list candidates with compensated or mildly decompensated disease can be considered for antiviral treatment with peginterferon, ribavirin (and protease inhibitor if genotype 1). For the majority of LT patients, HCV treatment must be delayed until post-transplant. Treatment is generally undertaken if histologic severity reaches grade 3 or 4 necroinflammation or stage ≥2 fibrosis, or if cholestatic hepatitis. Achievement of sustained viral response (SVR) post-LT is associated with stabilization of fibrosis and improved graft survival. SVR is attained in ~30% of patients treated with peginterferon and ribavirin. Poor tolerability of therapy is a limitation. Combination therapy with telaprevir or boceprevir added to peginterferon and ribavirin is anticipated to increase efficacy but with higher rates of adverse effects and challenges in managing drug-drug interactions between the protease inhibitors and calcineurin inhibitors/sirolimus.

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.

Liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompensation. The use of poor quality organs, particularly from older donors, has a highly negative impact on the severity of recurrence and patient/graft survival. Although immunosuppressive regimens have a considerable impact on the outcome, the optimal regimen after liver transplantation for HCV-infected patients remains unclear. Disease progression monitoring with protocol biopsy and new noninvasive methods is essential for predicting patient/graft outcome and starting antiviral treatment with the appropriate timing. Antiviral treatment with pegylated interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. Living-donor liver transplantation is now widely accepted as an established treatment for HCV cirrhosis and the results are equivalent to those of deceased donor liver transplantation.

In vitro systems for the study of hepatitis C virus infection

The study of a virus is made possible by the availability of culture systems in which the viral lifecycle can be realized. Such systems support robust virus entry, replication, assembly, and secretion of nascent virions. Furthermore, culture models provide a platform in which therapeutic interventions can be devised or monitored. Hepatitis C virus (HCV) has a restricted tropism to human and chimpanzees; thus investigations of HCV biology have been hindered for many years due to a lack of small animal models. Nevertheless, significant efforts have been directed at developing cell culture models to elucidate the viral lifecycle in vitro. HCV primarily infects liver parenchymal cells commonly known as hepatocytes. The liver is a highly specialized and complex organ and the development of in vitro systems that reflects this complexity has proven difficult. Consequently, host cell receptor molecules that potentiate HCV infection were identified over a decade after the virus was discovered. A summary of the various HCV in vitro culture models, their advantages, and disadvantages are described.

Effect of centre volume and high donor risk index on liver allograft survival

BACKGROUND

A growth in the utilization of high-risk allografts is reflective of a critical national shortage and the increasing waiting list mortality. Using risk-adjusted models, the aim of the present study was to determine whether a volume-outcome relationship existed among liver transplants at high risk for allograft failure.

METHODS

From 2002 to 2008, the Scientific Registry of Transplant Recipients (SRTR) database for all adult deceased donor liver transplants (n = 31 587) was queried. Transplant centres (n = 102) were categorized by volume into tertiles: low (LVC; 31 cases/year), medium (MVC: 64 cases/year) and high (HVC: 102 cases/year). Donor risk comparison groups were stratified by quartiles of the Donor Risk Index (DRI) spectrum: low risk (DRI ≤ 1.63), moderate risk (1.64 > DRI > 1.90), high risk (1.91 > DRI > 2.26) and very high risk (DRI ≥ 2.27).

RESULTS

HVC more frequently used higher-risk livers (median DRI: LVC: 1.82, MVC: 1.90, HVC: 1.97; P < 0.0001) and achieved better risk adjusted allograft survival outcomes compared with LVC (HR: 0.90, 95%CI: 0.85-0.95). For high and very high risk groups, transplantation at a HVC did contribute to improved graft survival [high risk: hazard ratio (HR): 0.85, 95% confidence interval (CI): 0.76-0.96; Very High Risk: HR: 0.88, 95%CI: 0.78-0.99].

CONCLUSION

While DRI remains an important aspect of allograft survival prediction models, liver transplantation at a HVC appears to result in improved allograft survival with high and very high risk DRI organs compared with LVC.

Honoring the contract with our patients: outcome after repeated re-transplantation of the liver

The aim of this study was to describe the outcome after repeated orthotopic liver re-transplantations (re-OLT) in a population of adults and children, and to determine whether such repeated re-transplantations are an effective treatment or should be considered futile. In a consecutive series of 867 patients, 628 adults and 239 children, who underwent OLT at the University Medical Center Groningen, 23 patients (2.7%), 10 adults and 13 children, underwent more than two re-transplantations of the liver between March 1979 and October 2008. All 23 patients had a second re-transplantation, and seven of them received a third transplant. The overall actuarial patient survival at 1, 5, and 10 yr after primary OLT was 96%, 87%, and 71%, respectively. The overall actuarial patient survival after the second re-OLT was 78%, 73%, and 67%, respectively. Sixteen patients (70%) survived long term. However, for the 23 repeated re-transplantation patients, 76 grafts were used. In a simulation calculation, it was shown that honoring the initial commitment to the 23 patients ultimately led to more surviving patients and less death than if treatment of the original patients was stopped after the first re-transplantation and the remaining grafts were allocated to other primary graft recipients.

Retransplantation in patients with hepatitis C recurrence after liver transplantation

Hepatitis C virus (HCV) infection recurs universally after liver transplantation (LT) and fibrosis progression is accelerated in the graft. Retransplantation (RT) is the only therapeutic option to achieve long-term survival in patients with decompensated cirrhosis after LT. Patient and graft survival rates after RT are inferior to those after primary LT. It is generally accepted that severe hepatitis C recurrence (cholestatic hepatitis) and forms with rapid fibrosis progression have a poor survival after RT. However, it is not clear whether rapid fibrosis progression in the first graft will be followed by the same rate of fibrosis progression in the second graft. The use of prognostic scores as screening tools has shown an improvement in survival in HCV-infected patients after RT, reaching similar survival rates as those obtained in non HCV-infected patients. Moreover, these scores can identify candidates with a high risk of mortality in whom the use of a new organ would be unreasonable. Prevention of severe hepatitis C recurrence could be the first step to avoid RT. Thus, antiviral treatment on the waiting list (if possible) and early identification and treatment of patients with severe hepatitis C recurrence may be a good strategy to avoid RT. In addition, active management of factors which can accelerate fibrosis progression (donor age, post-transplant diabetes, high dose of corticosteroids) might reduce the incidence of severe forms of hepatitis C recurrence.

Impact of donor cause of death on transplant outcomes: UNOS registry analysis

Donor cause of death (DCOD) has been described to influence allograft survival. Whether this effect is independent of other donor characteristics and whether it is similar across different solid organ allografts is not known. The aim of our study was to determine the impact of DCOD on organ utilization and on transplantation outcomes-graft rejection, function, and survival. The registry data were provided by the United Network for Organ Sharing/Organ Procurement and Transplantation Network. Stroke, head trauma, and anoxia were the cause of brain death in 97% of the more than 86,000 donors whose data were recorded between 1989 and 2008. In univariate analysis, stroke DCOD was associated with worse graft survival across all organs. After adjustment in a multivariable analysis, modest differences persisted in survival of heart, kidney, and liver allografts. DCOD also appeared to affect the incidence of allograft rejection. Anoxia DCOD was associated with significantly less rejection relative to donor death caused by head trauma and stroke. In summary, this multi-institutional study confirms that DCOD is a modest predictor of survival and rejection of solid organ allografts of different types.

Advanced recipient age (>60 years) alone should not be a contraindication to liver retransplantation

Advanced age has been shown to be a risk factor for survival in primary liver transplantation. We sought to determine the independent influence of recipient age on retransplantation survival. The UNOS dataset was analyzed for adult, nonstatus 1, liver retransplantations since February 27, 2002. The univariate effect of age on 90-day and 1-year survival was analyzed. Multivariate survival models were used to determine 90-day, 1-year, and overall survival. Recipient age, donor age, model for end-stage liver disease (MELD) score, and hepatitis C status were used to construct multivariable survival models. Some 2141 liver retransplantations were analyzed. Overall, increasing recipient age was independently predictive of increasing mortality after liver retransplantation. In recipients between 18 and 60, there remained a direct relationship between age and mortality. However, in recipients aged over 60, increasing age was not independently associated with 90-day mortality (P = 0.88) and 1-year mortality (P = 0.74), despite adjusting for donor age, MELD score, and viral hepatitis status, suggesting that their original liver condition, their co-morbidities or perioperative condition plays an important role in retransplantation survival. Increasing recipient age up to 60, adversely affects liver retransplantation survival. After 60, there are no additional risks. Advanced age alone should not be an exclusionary factor when considering liver retransplantation; only the overall ability of the patient to tolerate a major surgery should be the determining factor.

Transplant center volume and outcomes after liver retransplantation

Liver retransplantation surgery has a high rate of allograft failure due to patient comorbidities and technical demands of the procedure. Success of liver retransplantation could depend on surgeon experience and processes of care that relate to center volume. We performed a retrospective cohort study of adult liver retransplantation procedures performed from January 1, 1996 through December 31, 2005 using registry data from the Organ Procurement Transplantation Network. The primary outcome was 1-year allograft failure. Liver transplant centers were categorized as small, intermediate or high volume by dividing overall liver transplants into three tertiles of approximately equal size. Mean annual volume of overall liver transplants was <50 for low-volume centers, 50-88 for intermediate-volume centers and >88 for high-volume centers. The primary analysis consisted of 3977 liver retransplantation patients. The unadjusted risk of 1-year allograft failure was 37.8%. In multivariable logistic regression, the risk of 1-year allograft failure was not significantly different between low- (reference), intermediate- (OR 0.86, CI 0.72-1.03, p = 0.11) and high-volume centers (OR 0.88, CI 0.74-1.04, p = 0.14). Results were similar when the analysis was limited to retransplantation performed >160 days after initial transplantation. Center volume is an imprecise surrogate measure for 1-year outcomes after liver retransplantation.

Gender-incompatible liver transplantation is not a risk factor for patient survival

BACKGROUND/AIMS

Clinical data may be suggestive for differences in patient survival in gender-incompatible orthotopic liver transplantation (OLT), but findings are inconsistent and are putatively linked to circulating hormones. We therefore investigated patient survival as well as metabolism of steroids to identify possible causes of improved graft survival in gender-mismatched OLT.

METHODS

We examined our single-centre database of 1355 recipients of first liver transplants for overall patient survival by non-parametric and parametric analysis of multivariance taking the age of recipient and donor, ischaemia time, underlying liver disease and the time period of transplantation into account. Furthermore, the metabolism of androgens in gender-incompatible OLT was studied in cultures of primary human hepatocytes obtained from male and female patients.

RESULTS

Unlike previous studies we were unable to determine overall significant differences in patient survival in gender-incompatible OLT, even though a statistically significant improved patient survival was observed when male donor livers were transplanted into female recipients in univariant analysis (P=0.047). However, when the overall patient management was taken into account no difference in survival was determined in multivariant analysis. Importantly, the metabolism of testosterone did not differ between male and female hepatocyte cultures, except for the production of 6-alpha-hydroxy-testosterone (P<0.001).

CONCLUSIONS

Taken collectively, clinical observations may tend to suggest a slightly improved patient survival in gender-incompatible OLT but this cannot be explained on the bases of androgen metabolism. Overall, we view gender-incompatible liver transplantation not to be a confounder in patient survival after OLT.

Hepatitis C and liver transplantation: enhancing outcomes and should patients be retransplanted

Hepatitis C (HCV)-related end-stage liver disease is the most common indication for liver transplantation. Safe expansion of the donor pool with improved rates of deceased donation and more widespread use of living and extended criteria donation are likely to decrease wait list mortality. In addition, improved antiviral treatments and a better understanding of the delicate balance between under- and over-immunosuppression in this population are needed. Finally, when recurrent advanced fibrosis occurs, the criteria for patient selection for retransplantation remain widely debated. This article reviews the literature on these topics and the work being done in each area to maximize outcomes in patients receiving transplants for HCV-related cirrhosis.

Liver transplantation: an update 2008

PURPOSE OF REVIEW

Expansion of the donor pool for liver transplantation is a priority. Management of hepatitis C and hepatocellular carcinoma has focused on decreasing recurrence rates after transplantation.

RECENT FINDINGS

Expansion of the pool of donors has focused on live donor liver transplantation and extended criteria donor grafts. The results of live donor liver transplantation are equivalent to those of deceased donor liver transplantation. The use of extended criteria donor grafts has increased significantly. The results are associated with decreased graft survival with the use of grafts that have multiple factors considered as extended criteria for transplantation, particularly in high-risk individuals such as critically ill recipients. Judicious matching of extended criteria donors with recipients is essential to reduce waiting list mortality without reducing posttransplantation survival. The role of pretransplant ablation therapy for hepatocellular carcinoma is evolving to reduce tumor progression and dropout on the list as well as to influence posttransplant recurrence rates. Antiviral and immunosuppressive strategies in reducing the severity of hepatitis C virus recurrence are discussed as is retransplantation for the disease.

SUMMARY

Expansion of the donor pool with the use of extended criteria donors and live donor liver transplantation is a major challenge. Transplantation for hepatocellular carcinoma and hepatitis C virus relapse are major areas of research.