Impact of the new MELD-based allocation system on waiting list and post-transplant survival - a cohort analysis using the French national CRISTAL database

Recipient age influences survival after liver transplant: Results of the French national cohort 2007-2017

BACKGROUND

In recent years, age at liver transplantation (LT) has markedly increased. In the context of organ shortage, we investigated the impact of recipient age on post-transplantation mortality.

METHODS

All adult patients who received a first LT between 2007 and 2017 were included in this cross-sectional study. Recipients' characteristics at the time of listing, donor and surgery data, post-operative complications and follow-up of vital status were retrieved from the national transplantation database. The impact of age on 5-year overall mortality post-LT was estimated using a flexible multivariable parametric model which was also used to estimate the association between age and 10-year net survival, accounting for expected age- and sex-related mortality.

RESULTS

Among the 7610 patients, 21.4% were aged 60-65 years, and 15.7% over 65. With increasing age, comorbidities increased but severity of liver disease decreased. Older recipient age was associated with decreased observed survival at 5 years after LT (p < .001), with a significant effect particularly during the first 2 years. The linear increase in the risk of death associated with age does not allow any definition of an age's threshold for LT (p = .832). Other covariates associated with an increased risk of 5-year death were dialysis and mechanical ventilation at transplant, transfusion during LT, hepatocellular carcinoma and donor age. Ten-year flexible net survival analysis confirmed these results.

CONCLUSION

Although there was a selection process for older recipients, increasing age at LT was associated with an increased risk of death, particularly in the first years after LT.

Modelling kidney outcomes based on MELD eras - impact of MELD score in renal endpoints after liver transplantation

Background

Acute kidney injury is a common complication in solid organ transplants, notably liver transplantation. The MELD is a score validated to predict mortality of cirrhotic patients, which is also used for organ allocation, however the influence of this allocation criteria on AKI incidence and mortality after liver transplantation is still uncertain.

Methods

This is a retrospective single center study of a cohort of patients submitted to liver transplant in a tertiary Brazilian hospital: Jan/2002 to Dec/2013, divided in two groups, before and after MELD implementation (pre-MELD and post MELD). We evaluate the differences in AKI based on KDIGO stages and mortality rates between the two groups.

Results

Eight hundred seventy-four patients were included, 408 in pre-MELD and 466 in the post MELD era. The proportion of patients that developed AKI was lower in the post MELD era (p 0.04), although renal replacement therapy requirement was more frequent in this group (p < 0.01). Overall mortality rate at 28, 90 and 365 days was respectively 7%, 11% and 15%. The 1-year mortality rate was lower in the post MELD era (20% vs. 11%, p < 0.01). AKI incidence was 50% lower in the post MELD era even when adjusted for clinically relevant covariates (p < 0.01).

Conclusion

Liver transplants performed in the post MELD era had a lower incidence of AKI, although there were more cases requiring dialysis. 1-year mortality was lower in the post MELD era, suggesting that patient care was improved during this period.

Liver transplantation for critically ill cirrhotic patients: Results from the French transplant registry

This study describes the population of cirrhotic patients who were transplanted from the ICU in France, identifying pre-transplant risk factors of post-transplant mortality and describing geographic variations in ICU transplant activity. Cirrhotic patients transplanted between 2008 and 2018 were included through the national transplant registry. The demographic, clinical and biological characteristics of the patients transplanted from the ICU were compared to cirrhotic patients who were transplanted from home or from the hospital. Risk factors of post-transplant one-year mortality were identified in uni- and multivariable analysis within the population transplanted from the ICU. Funnel plots were used to illustrate center-specific differences in ICU transplant activity. 1,047 cirrhotic patients were transplanted from the ICU during the study period. While the national rate of transplants performed from the ICU was 14.3% the absolute number and the rate of cirrhotic patients transplanted from the ICU varied significantly from one center to another, ranging from 6.6% to 22.8% (p < 0.05). Three recipient-associated independent risk factors one-year post-LT mortality were identified in the population transplanted from the ICU: age > 50 years (HR 1.65, 95%CI 1.16-2.36), p = 0.005), diabetes (HR 1.46, 95%CI 1.07-1.98, p = 0.02) and intubation (HR2.12, 95%CI 1.62-2.78), p < 0.001). Donor age was also independently associated with mortality (HR 1.01, 95%CI 1.01-1.02, p < 0.001). Funnel plots showed significant differences in the proportion of patients transplanted from the ICU and the distribution of risk factors across French transplant centers, especially the inclination to transplant intubated patients. This study underlines the increased post-transplant mortality among cirrhotic patients transplanted from the ICU. It identifies four clinically pertinent independent risk factors associated with post-transplant mortality in this specific sub-group of transplant candidates. Finally, it illustrates how diverse the landscape of liver transplantation for critically ill cirrhotic patients is across a single country, despite a unified allocation algorithm.

Impact of MELD 30-allocation policy on liver transplant outcomes in Italy

BACKGROUND & AIMS

In Italy, since August 2014, liver transplant (LT) candidates with model for end-stage liver disease (MELD) scores ≥30 receive national allocation priority. This multicenter cohort study aims to evaluate time on the waiting list, dropout rate, and graft survival before and after introducing the macro-area sharing policy.

METHODS

A total of 4,238 patients registered from 2010 to 2018 were enrolled and categorized into an ERA-1 Group (n = 2,013; before August 2014) and an ERA-2 Group (n = 2,225; during and after August 2014). A Cox proportional hazards model was used to estimate the hazard ratio (HR) of receiving a LT or death between the two eras. The Fine-Gray model was used to estimate the HR for dropout from the waiting list and graft loss, considering death as a competing risk event. A Fine-Gray model was also used to estimate risk factors of graft loss.

RESULTS

Patients with MELD ≥30 had a lower median time on the waiting list (4 vs.12 days, p <0.001) and a higher probability of being transplanted (HR 2.27; 95% CI 1.78-2.90; p = 0.001) in ERA-2 compared to ERA-1. The subgroup analysis on 3,515 LTs confirmed ERA-2 (odds ratio 0.56; 95% CI 0.46-0.68; p = 0.001) as a protective factor for better graft survival rate. The protective variables for lower dropouts on the waiting list were: ERA-2, high-volume centers, no competition centers, male recipients, and hepatocellular carcinoma. The protective variables for graft loss were high-volume center and ERA-2, while MELD ≥30 remained related to a higher risk of graft loss.

CONCLUSIONS

The national MELD ≥30 priority allocation was associated with improved patient outcomes, although MELD ≥30 was associated with a higher risk of graft loss. Transplant center volumes and competition among centers may have a role in recipient prioritization and outcomes.

CLINICAL TRIAL NUMBER

NCT04530240 LAY SUMMARY: Italy introduced a new policy in 2014 to give national allocation priority to patients with a model for end-stage liver disease (MELD) score ≥30 (i.e. very sick patients). This policy has led to more liver transplants, fewer dropouts, and shorter waiting times for patients with MELD ≥30. However, a higher risk of graft loss still burdens these cases. Transplant center volumes and competition among centers may have a role in recipient prioritization and outcomes.

A systematic review of auxiliary liver transplantation of small for size grafts in patients with chronic liver disease

Background & Aims

The shortage of liver grafts continues to worsen. Because the expanded use of small-for-size grafts (SFSGs) would substantially alleviate this shortage, we aimed to analyse the available knowledge on auxiliary liver transplantation (ALT) with SFSGs in patients with chronic liver disease (CLD) to identify opportunities to develop ALT with SFSGs in patients with CLD.

Methods

This is a systematic review on ALT using SFSGs in patients with CLD. The review was completed by updates obtained from the authors of the retained reports.

Results

Heterotopic ALT was performed in 26 cases between 1980 and 2017, none for SFGS stricto sensu, and auxiliary partial orthotopic liver transplantation (APOLT) in 27 cases (from 1999 to 2021), all for SFSG. In APOLT cases, partial native liver resection was performed in most of cases, whereas the second-stage remnant native liver hepatectomy was performed in 9 cases only. The median graft-to-body weight ratio was 0.55, requiring perioperative or intraoperative portal modulation in 16 cases. At least 1 complication occurred in 24 patients following the transplant procedure (morbidity rate, 89%). Four patients (4/27, 15%) died after the APOLT procedure. At the long term, 19 (70%) patients were alive and well at 13 months to 24 years (median, 4.5 years) including 18 with the APOLT graft in place and 1 following retransplantation.

Conclusions

Despite high postoperative morbidity, and highly reported technical variability, the APOLT technique is a promising technique to use SFSGs in patients with CLD, achieving satisfactory long-term results. The results need to be confirmed on a larger scale, and a standardised technique could lead to even better results.

Lay summary

At the cost of a high postoperative morbidity, the long-term results of APOLT for small-for-size grafts are good. Standardisation of the procedure and of portal modulation remain needed.

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Using a small-for-size graft is a risk factor of small-for-size syndrome.

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Auxiliary liver transplantation can be orthotopic or heterotopic.

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In auxiliary transplantation, the remnant native liver prevents small-for-size syndrome.

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Transplantation with a small-for-size graft requires individually tailored portal modulation.

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Auxiliary liver transplantation might substantially increase the number of available grafts.

Liver transplantation for patients with acute-on-chronic liver failure (ACLF) in Europe: Results of the ELITA/EF-CLIF collaborative study (ECLIS)

BACKGROUND & AIMS

Liver transplantation (LT) has been proposed as an effective salvage therapy even for the sickest patients with acute-on-chronic liver failure (ACLF). This large collaborative study was designed to assess the current clinical practice and outcomes of patients with ACLF who are wait-listed for LT in Europe.

METHODS

This was a retrospective study including 308 consecutive patients with ACLF, listed in 20 centres across 8 European countries, from January 2018 to June 2019.

RESULTS

A total of 2,677 patients received a LT: 1,216 (45.4%) for decompensated cirrhosis. Of these, 234 (19.2%) had ACLF at LT: 58 (4.8%) had ACLF-1, 78 (6.4%) had ACLF-2, and 98 (8.1%) had ACLF-3. Wide variations were observed amongst countries: France and Germany had high rates of ACLF-2/3 (27-41%); Italy, Switzerland, Poland and the Netherlands had medium rates (9-15%); and the United Kingdom and Spain had low rates (3-5%) (p <0.0001). The 1-year probability of survival after LT for patients with ACLF was 81% (95% CI 74-87). Pre-LT arterial lactate levels >4 mmol/L (hazard ratio [HR] 3.14; 95% CI 1.37-7.19), recent infection from multidrug resistant organisms (HR 3.67; 95% CI 1.63-8.28), and renal replacement therapy (HR 2.74; 95% CI 1.37-5.51) were independent predictors of post-LT mortality. During the same period, 74 patients with ACLF died on the waiting list. In an intention-to-treat analysis, 1-year survival of patients with ACLF on the LT waiting list was 73% for ACLF-1 or -2 and 50% for ACLF-3.

CONCLUSION

The results reveal wide variations in the listing of patients with ACLF in Europe despite favourable post-LT survival. Risk factors for mortality were identified, enabling a more precise prognostic assessment of patients with ACLF.

LAY SUMMARY

Acute-on-chronic liver failure (ACLF) is a severe clinical condition for which liver transplantation is an effective therapeutic option. This study has demonstrated that in Europe, referral and access to liver transplantation (LT) for patients with ACLF needs to be harmonised to avoid inequities. Post-LT survival for patients with ACLF was >80% after 1 year and some factors have been identified to help select patients with favourable outcomes.

The Role of Ex Situ Hypothermic Oxygenated Machine Perfusion and Cold Preservation Time in Extended Criteria Donation After Circulatory Death and Donation After Brain Death

Hypothermic oxygenated machine perfusion (HOPE) has the potential to counterbalance the detrimental consequences of cold and warm ischemia time (WIT) in both donation after brain death (DBD) and donation after circulatory death (DCD). Herein we investigated the protective effects of HOPE in extended criteria donor (ECD) DBD and overextended WIT DCD grafts. The present retrospective case series included 50 livers subjected to end-ischemic HOPE or dual DHOPE in 2 liver transplantation (LT) centers from January 2018 to December 2019. All DCD donors were subjected to normothermic regional perfusion before organ procurement. Results are expressed as median (interquartile range [IQR]). In the study period, 21 grafts were derived from overextended WIT DCD donors (total WIT 54 [IQR, 40-60] minutes and 75% classified as futile), whereas 29 were from ECD DBD. A total of 3 biliary complications and 1 case of ischemia-type biliary lesion were diagnosed. The rate of early allograft dysfunction (EAD) was 20%, and those patients had higher Comprehensive Complication Index scores. Through a changing point analysis, cold preservation time >9 hours was associated with prolonged hospital stays (P = 0.02), higher rates of EAD (P = 0.009), and worst post-LT complications (P = 0.02). Logistic regression analyses indicated a significant relationship between cold preservation time and EAD. No differences were shown in terms of the early post-LT results between LTs performed with DCD and DBD. Overall, our data are fully comparable with benchmark criteria in LT. In conclusion, the application of DHOPE obtained satisfactory and promising results using ECD-DBD and overextended DCD grafts. Our findings indicate the need to reduce cold preservation time also in the setting of DHOPE, particularly for grafts showing poor quality.

Frailty as a predictive factor for survival after liver transplantation, especially for patients with MELD≤15-a prospective study

Introduction

Frailty has been discussed as a predictor of morbidity and mortality for liver cirrhosis. The aim of our study is to evaluate the role of frailty in liver transplantation, particularly for patients with MELD scores < 15.

Methods

All patients listed for liver transplantation between September 2015 and November 2018 were prospectively included in the study. Frailty was assessed by Fried’s frailty classification. Pre-, intra-, and postoperative data were prospectively recorded. Univariate and multivariate regression analyses were performed. The ethical approval of the institutional board review was obtained for the study.

Results

There were 114 patients included in the study, and their median MELD score was 16. Of these, 86 patients were defined as frail (75.4%). A total of 62 patients (54.4%) underwent liver transplantation, 11 (17.7%) died postoperatively, and 24 patients (21.0%) died while on the waitlist. All postoperative mortality cases were frail, and only 3 patients (12.5%) were non-frail in the waitlist mortality group. There were 14 patients who had MELD scores of <15 (58.3%). The overall survival of non-frail patients was significantly better than that of frail patients. The multivariate regression analyses identified frailty criteria, including unintended weight loss and low hand grip strength, and platelet count and being married or living in a solid partnership were prognostic factors for survival in all patients.

Conclusion

The addition of frailty assessment can be beneficial for predicting mortality after liver transplantation, especially in patients with low MELD score. Frail patients on the waitlist have significant risk for mortality even with low MELD score.

Removing administrative boundaries using a gravity model for a national liver allocation system

Geographic disparities emerged as an increasing issue in organ allocation policies. Because of the sequential and discrete geographical models used for allocation scores, artificial regional boundaries may impede the access of candidates with the greatest medical urgency to vital organs. This article describes a continuous geographical allocation model that provides accurate organ access by introducing a multiplicative interaction between the patient's condition and the distance to the graft by using a gravity model. Patients with the most urgent need will thus have access to organs from farther away, while those in less urgent need may only have access to organs geographically closer. Compared to the previous French liver allocation scheme, the gravity model precluded transplantations for candidates with a Model for End-Stage Liver Disease (MELD) ≤ 14 for decompensated cirrhosis from 10.3% to 0.6%. Death and delisting while on the waiting list at 1 year also decreased from 30.1% to 22.4% for MELD ≥ 35. Waiting list (cumulative hazard ratio (CHR)  0.84 after adjustment) and posttransplant survival improved significantly (hazard ratio = 0.83 after adjustment). This new liver allocation system provides more equitable access to liver transplants and an efficient and safe alternative to administrative boundaries for geographical models in organ allocation.

Liver Transplantation with "Hors Tour" Allocated Versus Standard MELD Allocated Grafts: Single-Center Audit and Impact on the Liver Pool in France

BACKGROUND

The French transplant governing system defined "Rescue" (the so-called "Hors Tour") livers as those livers which were declined for the five top-listed patients. This study compares the outcomes following liver transplantation (LT) in patients who received a donor liver through a rescue allocation (RA) procedure or according to MELD score priority (standard allocation, SA) and evaluates the impact on the graft pool of a proactive policy to accept RA grafts.

METHODS

Data from all consecutive patients who underwent LT with SA or RA grafts from 2011 to 2015 were compared in terms of short- and long-term outcomes.

RESULTS

The 249 elective first LTs were performed with 64 (25.7%) RA and 185 (74.3%) SA grafts. RA grafts were obtained from older donors and were associated with a longer cold ischemia time. Recipients of RA livers were older and had lower MELD scores. The rates of delayed graft function, primary nonfunction, retransplantation, complications, and mortality were similar between the RA and SA groups. At 1 and 3 and 5 years, graft and patient survival rates were similar between the groups. These results were maintained after matching on recipient characteristics. Our proactive policy to accept RA grafts increased the liver pool for elective first transplantation by 25%.

CONCLUSIONS

RA livers can be safely transplanted into selected recipients and significantly expand the liver pool.