Rescue allocation for liver transplantation within Eurotransplant: the Heidelberg experience

The impact of perceived donor liver quality on post-transplant outcome

BACKGROUND

We analysed the impact of perceived liver donor quality on transplant recipient outcomes.

METHODS

this prospective cohort study included all deceased liver donors during 2008-2018 in the Swiss Transplant Cohort Study. Perceived low-quality liver donors were defined when refused for ≥5 top listed recipients or for all recipients in at least one centre before being transplanted. The effect of liver donor quality on relisting or recipient death at 1 week and 1 year after transplantation was analysed using Kaplan-Meier and Cox proportional hazard models. A 1:3 matching was also performed using a recipient score.

RESULTS

Of 973 liver donors, 187 (19.2%) had perceived poor-quality. Males, obesity, donation after circulatory death and alanine aminotransferase values were significantly associated with perceived poor-quality, with no significant effect of the perceived quality on re-listing or death within the first week and first year post-transplant [(aHR) = 1.45, 95% CI: (0.6, 3.5), P = 0.41 and aHR = 1.52 (95% CI 0.98-2.35), P = 0.06], adjusting by recipient age and gender, obesity, diabetes, prior liver transplantation and model for end-stage liver disease (MELD) score. At 1 year, prior liver transplantation and higher MELD score associated with higher risk of re-listing or death.

CONCLUSION

Comparable post-transplant outcomes with different perceived quality liver donors stresses the need to improve donor selection in liver transplantation.

Early- and long-term outcomes of liver transplantation with rescue allocation grafts

In France, liver grafts which have been refused by at least five centers are proposed as rescue allocation (RA). The aim of this study is to clarify the feasibility and safety of RA grafts in liver transplantation (LT). Short- and long-term outcomes of patients who received RA grafts (RA group) were compared with those of patients who received standard allocation (SA) grafts (SA group). From a total of 1635 patients, 102 patients received RA grafts. Before matching, the RA group was characterized primarily by less severe liver disease, but the quality of graft was worse. After matching recipients' characteristics of 102 patients who used RA grafts with 306 patients who used SA grafts, recipients' characteristics were well balanced (1:3 matching). Although the rate of primary dysfunction was significantly higher in the RA group, there is no significant difference in the occurrence of major complications, length of hospitalization, and mortality between two groups. Graft survival (GS) and overall survival (OS) in the RA group were not significantly different from the SA group (GS; HR = 1.03 P = .89, OS; HR = 1.03 P = .90). In the French allocation system, the feasibility and safety of RA grafts might be comparable to SA grafts for carefully selected patients.

The Graz Liver Allocation Strategy-Impact of Extended Criteria Grafts on Outcome Considering Immunological Aspects

Background: Transplant centers are forced to use livers of extended criteria donors for transplantation due to a dramatic organ shortage. The outcome effect of extended donor criteria (EDCs) remains unclear. Thus, this study was designed to assess the impact of EDCs on outcome including immunological aspects after liver transplantation (LT).

Patients and Methods: Between November 2016 and March 2018, 49 patients (85.7% male) with a mean age of 57 ± 11 years underwent LT. The impact of EDCs on outcome after LT was assessed retrospectively using both MedOcs and ENIS (Eurotransplant Network Information System).

Results: About 80% of grafts derived from extended criteria donors. Alanine aminotransferase/aspartate aminotransferase (AST/ALT) levels elevated more than three times above normal values in organ donors was the only significant risk factor for primary dysfunction (PDF) and primary non-function (PNF)/Re-LT and early non-anastomotic biliary strictures (NAS). Balance of risk (BAR) score did not differ between EDC and non-EDC recipients. PDF (14.3% of all patients) and PNF (6.1% of all patients) occurred in 23.1% of EDC-graft recipients and in 10.0% of non-EDC-graft recipients (RR 2.31, p = 0.663). The 90-day mortality was 3.6%. There was no difference of early non-anastomotic biliary tract complications and biopsy proven rejections (BPR). There was no correlation of PDF/PNF with BPR and NAS, respectively; however, 66.7% of the patients with BPR also developed early NAS (p < 0.001).

Conclusion: With the Graz liver allocation strategy, excellent survival can be achieved selecting livers with no more than 2 not outcome-relevant EDCs for patients with MELD >20. Further, BPR is associated with biliary complications.

Should we use liver grafts repeatedly refused by other transplant teams?

Background & Aims

In France, liver grafts that have been refused at least 5 times can be “rescued” and allocated to a centre which chooses a recipient from its own waiting list, outside the patient-based allocation framework. We explored whether these “rescued” grafts were associated with worse graft/patient survival, as well as assessing their effect on survival benefit.

Methods

Among 7,895 candidates, 5,218 were transplanted between 2009 and 2014 (336 centre-allocated). We compared recipient/graft survival between patient allocation and centre allocation, considering a selection bias and the distribution of centre-allocation recipients among the transplant teams. We used a propensity score approach and a weighted Cox model using the inverse probability of treatment weighting method. We also explored the survival benefit associated with centre-allocation grafts.

Results

There was a significantly higher risk of graft loss/death in the centre allocation group compared to the patient allocation group (hazard ratio 1.13; 95% CI 1.05–1.22). However, this difference was no longer significant for teams that performed more than 7% of the centre-allocation transplantations. Moreover, receiving a centre-allocation graft, compared to remaining on the waiting list and possibly later receiving a patient-allocation graft, did not convey a poorer survival benefit (hazard ratio 0.80; 95% CI 0.60–1.08).

Conclusions

In centres which transplanted most of the centre-allocation grafts, using grafts repeatedly refused for top-listed candidates was not detrimental. Given the organ shortage, our findings should encourage policy makers to restrict centre-allocation grafts to targeted centres.

Lay summary

“Centre allocation” (CA) made it possible to save 6 out of 100 available liver grafts that had been refused at least 5 times for use in the top-listed candidates on the national waiting list. In this series, the largest on this topic, we showed that, in centres which transplanted most of the CA grafts, using grafts repeatedly refused for top-listed candidates did not appear to be detrimental. In the context of organ shortage, our results, which could be of interest for any country using this CA strategy, should encourage policy makers to reassess some aspects of graft allocation by restricting CA grafts to targeted centres, fostering the “best” matching between grafts and candidates on the waiting list.

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Centre allocation (CA) made it possible to save 6 out of 100 liver grafts.

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13% higher graft loss/death for CA patients.

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In transplant centres performing most CA transplants, survival was not impacted.

Use of Organs for Heart Transplantation after Rescue Allocation: Comparison of Outcome with Regular Allocated High Urgent Recipients

BACKGROUND

 The number of patients waiting for heart transplantation (HTx) is exceeding the number of actual transplants. Subsequently, waiting times are increasing. One possible solution may be an increased acceptance of organs after rescue allocation. These organs had been rejected by at least three consecutive transplant centers due to medical reasons.

METHODS

 Between October 2010 and July 2019, a total of 139 patients underwent HTx in our department. Seventy (50.4%) of the 139 patients were transplanted with high urgency (HU) status and regular allocation (HU group); the remaining received organs without HU listing after rescue allocation (elective group, n = 69).

RESULTS

 Donor parameters were comparable between the groups. Thirty-day mortality was comparable between HU patients (11.4%) and rescue allocation (12.1%). Primary graft dysfunction with extracorporeal life support occurred in 26.9% of the elective group with rescue allocated organs, which was not inferior to the regular allocated organs (HU group: 35.7%). No significant differences were observed regarding the incidence of common perioperative complications as well as morbidity and mortality during 1-year follow-up.

CONCLUSIONS

 Our data support the use of hearts after rescue allocation for elective transplantation of patients without HU status. We could show that patients with rescue allocated organs showed no significant disadvantages in the early perioperative morbidity and mortality as well at 1-year follow-up.

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.

Recipient Selection for Optimal Utilization of Discarded Grafts in Liver Transplantation

BACKGROUND

In France, liver grafts that have been refused by at least 5 teams are considered for rescue allocation (RA), with the choice of the recipient being at the team's discretion. Although this system permits the use of otherwise discarded grafts in a context of organ shortage, outcomes and potential benefits need to be assessed.

METHODS

Between 2011 and 2015, outcomes of RA grafts (n = 33) were compared with SA grafts (n = 321) at a single French center.

RESULTS

Liver grafts in the RA group were older (63 ± 17 years vs 54 ± 18 years, P = 0.007) and had a higher DRI (1.86 ± 0.45 vs 1.61 ± 0.47, P = 0.010). Recipients in this group had a lower Model for End-Stage Liver Disease score (14 ± 5 vs 22 ± 10, P < 0.001) and had mostly hepatocellular carcinoma (67.0% vs 40.4%, P = 0.010). The balance of risk score was significantly lower in the RA group (5.5 ± 2.9 vs 9.2 ± 5.5, P < 0.001). There were higher rates of early and delayed hepatic artery thrombosis (15.2% vs 3.1%, P = 0.001) and retransplantation (18.2% vs 4.7%, P = 0.002) in the RA group. Patient survival was not different between groups, but graft survival was impaired (95% vs 82% at 1 year and 94% vs 74% at 3 years, P = 0.001).

CONCLUSION

Our results show that discarded liver grafts can be used provided that there is a strict recipient selection process, although hepatic artery thrombosis and retransplantation are more frequent. This strategy enables utilization of otherwise discarded grafts in the context of organ shortage.

Donor information based prediction of early allograft dysfunction and outcome in liver transplantation

BACKGROUND & AIMS

Poor initial graft function was recently newly defined as early allograft dysfunction (EAD) [Olthoff KM, Kulik L, Samstein B, et al. Validation of a current definition of early allograft dysfunction in liver transplant recipients and analysis of risk factors. Liver Transpl 2010; 16: 943]. Aim of this analysis was to evaluate predictive donor information for development of EAD.

METHODS

Six hundred and seventy-eight consecutive adult patients (mean age 51.6 years; 60.3% men) who received a primary liver transplantation (LT) (09/2003-12/2011) were included. Standard donor data were correlated with EAD and outcome by univariable/multivariable logistic regression and Cox proportional hazards to identify prognostic donor factors after adjustment for recipient confounders. Estimates of relevant factors were utilized for construction of a new continuous risk index to develop EAD.

RESULTS

38.7% patients developed EAD. 30-day survival of grafts with and without EAD was 59.8% and 89.7% (P < 0.0001). 30-day survival of patients with and without EAD was 68.5% and 93.1% (P < 0.0001) respectively. Donor body mass index (P = 0.0112), gGT (P = 0.0471), macrosteatosis (P = 0.0006) and cold ischaemia time (CIT) (P = 0.0031) were predictors of EAD. Internal cross validation showed a high predictive value (c-index = 0.622).

CONCLUSIONS

Early allograft dysfunction correlates with early results of LT and can be predicted by donor data only. The newly introduced risk index potentially optimizes individual decisions to accept/decline high risk organs. Outcome of these organs might be improved by shortening CIT.

Donor selection criteria for liver transplantation in Argentina: are current standards too rigorous?

Organ shortage is the major limitation for the growth of deceased donor liver transplant worldwide. One strategy to ameliorate this problem is to maximize the liver utilization rate. To assess predictors of liver utilization in Argentina. The national database was used to analyze transplant activity in 2010. Donor, recipient, and transplant variables were evaluated as predictors of graft utilization of number of rejected donor offers before grafting and with the occurrence of primary nonfunction (PNF) or early post-transplant mortality (EM). Of the 582 deceased donors, 293 (50.3%) were recovered for liver transplant. Variables associated with the nonrecovery of the liver were age ≥46 years, umbilical perimeter ≥92 cm, organ procurement outside Gran Buenos Aires, AST ≥42 U/l and ALT ≥29 U/l. The median number of rejected offers before grafting was 4, and in 71 patients (25%), there were ≥13. The only independent predictor for the occurrence of PNF (3.4%) or EM (5.2%) was the recipient's emergency status. During 2010 in Argentina, the liver was recovered in only half of donors. The low incidence of PNF and EM and the characteristics of the nonrecovered liver donors suggest that organ acceptance criteria should be less rigorous.

Liver Transplantation for Hepatocellular Carcinoma beyond Milan Criteria: Multidisciplinary Approach to Improve Outcome

The implementation of the Milan criteria (MC) in 1996 has dramatically improved prognosis after liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). Liver transplantation has, thereby, become the standard therapy for patients with "early-stage" HCC on liver cirrhosis. The MC were consequently adopted by United Network of Organ Sharing (UNOS) and Eurotransplant for prioritization of patients with HCC. Recent advancements in the knowledge about tumor biology, radiographic imaging techniques, locoregional interventional treatments, and immunosuppressive medications have raised a critical discussion, if the MC might be too restrictive and unjustified keeping away many patients from potentially curative LT. Numerous transplant groups have, therefore, increasingly focussed on a stepwise expansion of selection criteria, mainly based on tumor macromorphology, such as size and number of HCC nodules. Against the background of a dramatic shortage of donor organs, however, simple expansion of tumor macromorphology may not be appropriate to create a safe extended criteria system. In contrast, rather the implementation of reliable prognostic parameters of tumor biology into selection process prior to LT is mandatory. Furthermore, a multidisciplinary approach of pre-, peri-, and posttransplant modulating of the tumor and/or the patient has to be established for improving prognosis in this special subset of patients.

HTK-N, a modified HTK solution, decreases preservation injury in a model of microsteatotic rat liver transplantation

BACKGROUND

Ischemia/reperfusion injury is an obstacle especially in steatotic livers, including those with steatosis induced by acute toxic stress. Recently, a modified histidine-tryptophan-ketoglutarate (HTK) solution, HTK-N, has been developed. This solution contains N-acetylhistidine, amino acids, and iron chelators. This study was designed to test the effects of HTK-N on preservation injury to rat livers after acute toxic injury.

METHODS

Microvesicular steatosis was induced by a single dose of ethanol (8 g/kg BW). Livers were harvested and stored at 4 °C for 8 h with HTK or HTK-N before transplantation. Tissue and blood samples were taken at 1, 8, and 24 h after reperfusion to compare serum liver enzymes (aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase), standard histology, and immunohistochemistry for myeloperoxidase (MPO), caspase-3, and inducible nitric oxide synthase. Survival was compared after 1 week. For statistics, Analysis of Variance and t test were used.

RESULTS

HTK-N improved survival from 12.5% in HTK to 87.5% (p < 0.05). Furthermore, liver enzymes were decreased to 2-75% of HTK values (p < 0.05). Necrosis and leukocyte infiltration and MPO, caspase-3, and iNOS expression after transplantation were decreased (p < 0.05).

CONCLUSIONS

This study demonstrates that HTK-N protects liver grafts with microvesicular steatosis caused by acute toxic injury from cold ischemic injury better than standard HTK most likely via inhibition of hypoxic injury and oxidative stress and amelioration of the inflammatory reaction occurring upon reperfusion.

The European experience

This mini-review on European experiences with tackling the problem of organ shortage for transplantation was based on a literature review of predominantly European publications dealing with the issue of organ donation from deceased donors. The authors tried to identify the most significant factors that have demonstrated to impact on donation rates from deceased donors and subsequent transplant successes. These factors include legislative measures (national laws and European Directives), optimization of the donation process, use of expanded criteria donors, innovative preservation and surgical techniques, organizational efforts, and improved allocation algorithms.

"Rescue allocation offers" in liver transplantation: is there any reason to reject "unwanted" organs?

To increase the number of transplanted organs, the Eurotransplant foundation uses a so-called "rescue-organ-allocation" procedure for organs that had been rejected by at least three consecutive transplant centers for medical reasons. The transplant center that finally accepts such an organ can then freely choose a patient from its own waiting list, without being bound to regular allocation criteria. Almost 30% of deceased donor livers are now allocated through this process in the Eurotransplant region. We report our results of 38 "rescue-allocation" livers (RA livers) transplanted at our institution (2003-2007), compared to a group of 115 regularly allocated organs within the same period. From our data, RA livers have the same results as regularly allocated livers. Type and frequency of postoperative morbidity did not differ between both groups, though the analysis of subgroups showed a tendency toward reduced survival of RA livers in patients with viral hepatitis. Interestingly, the Donor Risk Index (DRI) showed no difference between RA livers and regularly allocated livers. Although preliminary due to small numbers, we conclude that RA livers can be safely transplanted without increased mortality or morbidity. However, no donor specific criteria which would justify rejecting a RA liver were found. This highly challenges the applicability of the RA procedure in its current form.