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

Protocol for an international multicenter, prospective, observational, non-competitive, study to validate and optimise prediction models of 90-day and 1-year allograft failure after liver transplantation: The global IMPROVEMENT Study

More liver transplants (LT) are performed worldwide thanks to extended criteria donors (ECD). This is paralleled by a supposed increased risk of allograft failure (AF) at 90 and 365 days. This study has been designed to portray the LT practice worldwide and investigate models of AF prediction and the impact of risk mitigation strategies for further improving graft and patient outcomes. This is a multicenter, international, non-competitive, observational two segment study on consecutive LTs over two periods (2017-2019 and 2022-2024). A steering committee of LT experts defined the study protocol. The prospective segment will enroll 750 patients from 15 high-volume LT centers (50 per center), and the retrospective segment will enrol 4200 patients from 56 LT centers (75 per center). To provide a snapshot of the LT activity globally and to develop new algorithms for the timely prediction of AF at 90 and 365 days post-LT. The study also aims (1) to validate the existing predictive models and (2) to investigate the best time for re-transplantation, paying attention to the differences in AF and Ischemic cholangiopathy according to the donor types and mitigation strategies implemented in the various settings. Since the adoption of machine perfusion has increased in different proportions worldwide, models will be adjusted according to this parameter. Finally, retrospective and prospective data will be available for further stratifications and modelling according to the degree of decompensation at transplant, gender match, postoperative complications and their management. This protocol was approved by Fondazione Policlinico Universitario Agostino Gemelli IRCCS Ethics Committee (study ID: 4571) and the Institutional Review Board of the University of California, Los Angeles. The provisional study protocol was submitted to the main scientific international societies in the transplant field. Results will be published in international peer-reviewed journals and presented at congresses.

Indications and Outcomes with Liver Retransplantation in 2025

Five to 10% of the annual liver transplants in the United States are performed in prior liver recipients with 70% occurring within 1 year of transplantation. Fortunately, the incidence of primary non-function (PNF) has significantly decreased from 8% in the 1980's to < 2%, but PNF and hepatic artery thromboses remain the leading reasons for early emergency retransplantation. Other indications for early retransplantation include severe biliary or vascular complications and refractory rejection. Fortunately, the need for late retransplantation (> 1 year) has also declined due to improved immunosuppression, earlier detection of recurrent disease, and use of oral antiviral agents for recurrent hepatitis C. Patient survival with retransplantation is consistently lower than with primary liver transplantation. Risk factors for poor outcomes with retransplantation include a higher MELD score, ICU status, renal failure, and use of marginal allografts. Therefore, most centers use younger, whole deceased brain-dead donor organs whenever possible. However, increased use of machine perfused livers has expanded the donor pool for these more complex and technically challenging cases. Retransplant recipients have a higher rate of early technical, infectious, and cardiovascular complications compared to primary LT recipients. Going forward, LT recipients with recurrent steatotic and alcoholic liver disease will likely pose ethical, medical, and surgical challenges to the transplant community.

A single center analysis of long-term outcomes and survival related risk factors in liver retransplantation

Background

Liver retransplant is the only option to save a patient with liver graft failure. However, it is controversial due to its poor survival outcome compared to primary transplantation. Insufficient deceased organ donation in Taiwan leads to high waitlist mortality. Hence, living-donor grafts offer a valuable alternative for retransplantation. This study aims to analyze the single center's outcome in living donor liver retransplantation (re-LDLT) and deceased donor liver retransplantation (re-DDLT) as well as the survival related confounding risk factors.

Methods

This is a single center retrospective study including 32 adults who underwent liver retransplantation (re-LT) from June 2002 to April 2020. The cohort was divided into a re-LDLT and a re-DDLT group and survival outcomes were analyzed. Patient outcomes over different periods, the effect of timing on survival, and multivariate analysis for risk factors were also demonstrated.

Results

Of the 32 retransplantations, the re-LDLT group (n=11) received grafts from younger donors (31.3 vs. 43.75 years, P=0.016), with lower graft weights (688 vs. 1,457.2 g, P<0.001) and shorter cold ischemia time (CIT) (45 vs. 313 min, P<0.001). The 5-year survival was significantly better in the re-LDLT group than in the re-DDLT group (100% vs. 70.8%, P=0.02). This difference was adjusted when only retransplantation after 2010 was analyzed. Further analysis showed that the timing of retransplantation (early vs. late) did not affect patient survival. Multivariate analysis revealed that prolonged warm ischemia time (WIT) and intraoperative blood transfusion were related to poor long-term survival.

Conclusions

Retransplantation with living donor graft demonstrated good long-term outcomes with acceptable complications to both recipient and donor. It may serve as a choice in areas lacking deceased donors. The timing of retransplantation did not affect the long-term survival. Further effort should be made to reduce WIT and massive blood transfusion as they contributed to poor survival after retransplantation.

The BAR Score Predicts and Stratifies Outcomes Following Liver Retransplantation: Insights From a Retrospective Cohort Study

Liver retransplantation (reLT) yields poorer outcomes than primary liver transplantation, necessitating careful patient selection to avoid futile reLT. We conducted a retrospective analysis to assess reLT outcomes and identify associated risk factors. All adult patients who underwent a first reLT at the Medical University of Innsbruck from 2000 to 2021 (N = 111) were included. Graft- and patient survival were assessed via Kaplan-Meier plots and log-rank tests. Uni- and multivariate analyses were performed to identify independent predictors of graft loss. Five-year graft- and patient survival rates were 64.9% and 67.6%, respectively. The balance of risk (BAR) score was found to correlate with and be predictive of graft loss and patient death. The BAR score also predicted sepsis (AUC 0.676) and major complications (AUC 0.720). Multivariate Cox regression analysis identified sepsis [HR 5.179 (95% CI 2.575-10.417), p < 0.001] as the most significant independent risk factor for graft loss. At a cutoff of 18 points, the 5 year graft survival rate fell below 50%. The BAR score, a simple and easy to use score available at the time of organ acceptance, predicts and stratifies clinically relevant outcomes following reLT and may aid in clinical decision-making.

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.

Management of Established Small-for-size Syndrome in Post Living Donor Liver Transplantation: Medical, Radiological, and Surgical Interventions: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) following living donor liver transplantation is a complication that can lead to devastating outcomes such as prolonged poor graft function and possibly graft loss. Because of the concern about the syndrome, some transplants of mismatched grafts may not be performed. Portal hyperperfusion of a small graft and hyperdynamic splanchnic circulation are recognized as main pathogenic factors for the syndrome. Management of established SFSS is guided by the severity of the presentation with the initial focus on pharmacological therapy to modulate portal flow and provide supportive care to the patient with the goal of facilitating graft regeneration and recovery. When medical management fails or condition progresses with impending dysfunction or even liver failure, interventional radiology (IR) and/or surgical interventions to reduce portal overperfusion should be considered. Although most patients have good outcomes with medical, IR, and/or surgical management that allow graft regeneration, the risk of graft loss increases dramatically in the setting of bilirubin >10 mg/dL and INR>1.6 on postoperative day 7 or isolated bilirubin >20 mg/dL on postoperative day 14. Retransplantation should be considered based on the overall clinical situation and the above postoperative laboratory parameters. The following recommendations focus on medical and IR/surgical management of SFSS as well as considerations and timing of retransplantation when other therapies fail.

Liver retransplantation: Timing is equally important

BACKGROUND AND AIM

To evaluate the effect of transplantation interval on patient and graft survival in liver retransplantation (reLT) using meta-analytical techniques.

METHODS

Literature search was undertaken until January 2022 to identify comparative studies evaluating patient survival rates, graft survival rates, and the interval time. Pooled hazard ratio (HR) or risk ratio (RR) and 95% confidence intervals (95% CI) were calculated with either the fixed or random effect model.

RESULTS

The 12 articles were included in this meta-analysis. The late reLT survival rate is better than the early reLT in the 30 days group, and there is no statistical significance in other time groups. The patient survival was significantly higher in late reLT than early reLT at 1 and 5 years (respectively: RR, 0.81 [95% CI, 0.73-0.89]; RR, 0.64 [95% CI, 0.46-0.88]). The graft survival was significantly higher in late reLT than early reLT at 1 year (RR, 0.75 [95% CI, 0.63-0.89]). The risk of death after reLT in early group was 1.43 times higher than that in late group (HR, 1.43 [95% CI, 1.21-1.71]).

CONCLUSIONS

Late reLT had significantly better survival rates than early reLT, and the transplantation interval was more reasonable to divide the early or late groups by 30 days.

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.

Allograft liver failure awaiting liver transplantation in Japan

BACKGROUND

Following liver transplantation (LT), allograft liver failure can be developed by various causes and requires re-LT. Hence, this study aimed to clarify the characteristics and prognostic factors of patients with allograft liver failure awaiting deceased donor LT (DDLT) in Japan.

METHODS

Of the 2686 DDLT candidates in Japan between 2007 and 2016, 192 adult patients listed for re-LT were retrospectively enrolled in this study. Factors associated with waitlist mortality were assessed using the Cox proportional hazards model. The transplant-free survival probabilities were evaluated using the Kaplan-Meier analysis and log-rank test.

RESULTS

The median period from the previous LT to listing for re-LT was 1548 days (range, 4-8449 days). Primary sclerosing cholangitis (PSC), which was a primary indication, showed a higher listing probability for re-LT as compared with other primary etiologies. Recurrent liver disease was a leading cause of allograft failure and was more frequently observed in the primary indication of hepatitis C virus (HCV) infection and PSC in contrast with other etiologies. Multivariate analysis identified the following independent risk factors associated with waitlist mortality: age, Child-Turcotte-Pugh (CTP) score, mode for end-stage liver disease (MELD) score, alanine aminotransferase (ALT), and causes of allograft failure.

CONCLUSIONS

Recurrent HCV and PSC were major causes of allograft liver failure in Japan. In addition to CTP and MELD scores, either serum ALT levels or causes of allograft failure should be considered as graft liver allocation measures.

Abdominal normothermic regional perfusion in controlled donation after circulatory determination of death liver transplantation: Outcomes and risk factors for graft loss

Postmortem normothermic regional perfusion (NRP) is a rising preservation strategy in controlled donation after circulatory determination of death (cDCD). Herein, we present results for cDCD liver transplants performed in Spain 2012-2019, with outcomes evaluated through December 31, 2020. Results were analyzed retrospectively and according to recovery technique (abdominal NRP [A-NRP] or standard rapid recovery [SRR]). During the study period, 545 cDCD liver transplants were performed with A-NRP and 258 with SRR. Median donor age was 59 years (interquartile range 49-67 years). Adjusted risk estimates were improved with A-NRP for overall biliary complications (OR 0.300, 95% CI 0.197-0.459, p < .001), ischemic type biliary lesions (OR 0.112, 95% CI 0.042-0.299, p < .001), graft loss (HR 0.371, 95% CI 0.267-0.516, p < .001), and patient death (HR 0.540, 95% CI 0.373-0.781, p = .001). Cold ischemia time (HR 1.004, 95% CI 1.001-1.007, p = .021) and re-transplantation indication (HR 9.552, 95% CI 3.519-25.930, p < .001) were significant independent predictors for graft loss among cDCD livers with A-NRP. While use of A-NRP helps overcome traditional limitations in cDCD liver transplantation, opportunity for improvement remains for cases with prolonged cold ischemia and/or technically complex recipients, indicating a potential role for complimentary ex situ perfusion preservation techniques.