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

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.

The impact of major extended donor criteria on graft failure and patient mortality after liver transplantation

INTRODUCTION

Numerous extended donor criteria (EDC) have been identified in liver transplantation (LT), but different EDC have different impacts on graft and patient survival. This study aimed to identify major EDC (maEDC) that were best able to predict the outcome after LT and to examine the plausibility of an allocation algorithm based on these criteria.

METHODS

All consecutive LTs between 12/2006 and 03/2014 were included (n = 611). We analyzed the following EDC: donor age > 65 years, body mass index > 30, malignancy and drug abuse history, intensive care unit stay/ventilation > 7 days, aminotransferases > 3 times normal, serum bilirubin > 3 mg/dL, serum Na⁺ > 165 mmol/L, positive hepatitis serology, biopsy-proven macrovesicular steatosis (BPS) > 40%, and cold ischemia time (CIT) > 14 h. We analyzed hazard risk ratios of graft failure for each EDC and evaluated primary non-function (PNF). In addition, we analyzed 30-day, 90-day, 1-year, and 3-year graft survival. We established low- and high-risk graft (maEDC 0 vs. ≥ 1) and recipient (labMELD < 20 vs. ≥ 20) groups and compared the post-LT outcomes between these groups.

RESULTS

BPS > 40%, donor age > 65 years, and CIT > 14 h (all p < 0.05) were independent predictors of graft failure and patient mortality and increased PNF, 30-day, 90-day, 1-year, and 3-year graft failure rates. Three-year graft and patient survival decreased in recipients of ≥ 1 maEDC grafts (all p < 0.05) and LT of high-risk grafts into high-risk recipients yielded worse outcomes compared with other groups.

CONCLUSION

Donor age > 65 years, BPS > 40%, and CIT > 14 h are major EDC that decrease short and 3-year graft survival, and 3-year patient survival. An allocation algorithm based on maEDC and labMELD is therefore plausible.

Influence of Donor Obesity on Long-Term Liver Transplantation Outcomes

OBJECTIVE

To analyze liver transplantation outcomes according to the body mass index (BMI) of donors.

MATERIAL AND METHODS

A retrospective descriptive study was conducted in patients transplanted at our center between January 2006 and December 2014, comparing outcomes between grafts from obese (body mass index [BMI] ≥30) and nonobese (BMI ≤30) donors. We analyzed the reasons for transplantation, the morbidity-mortality related variables, and survival after a minimum follow-up of 24 months. A multivariate logistic model was constructed to predict the mortality. Survival was analyzed with the Kaplan-Meier method, and survival curves were compared using the log-rank test.

RESULTS

The study included 50 obese and 175 nonobese donors. A significant difference between the groups was found in the pre-extraction intensive care unit (ICU) stay of the donors (P = .006) but not in the post-transplantation complications or survival of the respective recipients (P > .05). In the multivariate analysis, mortality was significantly associated with the presence of the hepatitis C virus (HCV) (P = .001) in the recipient and with the age of the donor (P = .043), finding the risk of death to be 2.87-fold higher in patients with HCV versus without HCV (95% confidence interval [1.641-5.043]) and 1.7% higher with every additional year of donor age (odds ratio 1.017, 95% confidence interval [1-1.034]).

CONCLUSIONS

A significantly longer pre-extraction ICU stay was observed in obese (BMI ≥30) versus nonobese (BMI <30) donors, but no significant between-group difference was found in the post-transplant complications or survival of the respective recipients. The mortality risk was higher in HCV-positive recipients and in those receiving grafts from older donors.

Grade of donor liver microvesicular steatosis does not affect the postoperative outcome after liver transplantation

BACKGROUND

The potential effect of graft steatosis on the postoperative liver function is discussed controversially. The present study aimed to evaluate the effect of the donor liver microvesicular steatosis on the postoperative outcome after liver transplantation.

METHODS

Ninety-four patients undergoing liver transplantation at the University Hospital Aachen were included in this study. The patient cohort was divided into three groups according to the grade of microvesicular steatosis (MiS): MiS <30% (n=27), MiS 30%-60% (n=41) and MiS >60% (n=26). The outcomes after liver transplantation were evaluated, including the 30-day and 1-year patient and graft survival rates and the incidences of early allograft dysfunction (EAD) and primary nonfunction (PNF).

RESULTS

The incidences of EAD and PNF did not differ significantly between the groups. We observed 5 cases of PNF, one occurred in the MiS <30% group and 4 in the MiS 30%-60% group. The 30-day and 1-year graft survivals did not differ significantly between groups. The 30-day patient survival rates were 100% in all groups. The 1-year patient survival rates were 94.4% in the MiS <30% group, 87.9% in the MiS 30%-60% group and 90.9% in the MiS >60% group.

CONCLUSION

Microvesicular steatosis of donor livers has no negative effect on the postoperative outcome after liver transplantation.

The new liver allocation score for transplantation is validated and improved transplant survival benefit in Germany but not in the United Kingdom

Prognostic models for the prediction of 90-day mortality after transplantation with pretransplant donor and recipient variables are needed to calculate transplant benefit. Transplants in adult recipients in Germany (Hannover, n = 770; Kiel, n = 234) and the United Kingdom (Birmingham, n = 829) were used for prognostic model design and validation in separate training and validation cohorts. The survival benefit of transplantation was estimated by subtracting the observed posttransplant 90-day mortality from the expected 90-day mortality without transplantation determined by the Model for End-Stage Liver Disease (MELD) score. A prognostic model called the liver allocation score (LivAS) was derived using a randomized sample from Hannover using pretransplant donor and recipient variables. This model could be validated in the German training and validation cohorts (area under the receiver operating characteristic curve [AUROC] > 0.70) but not in the English cohort (AUROC, 0.58). Although 90-day mortality rates after transplantation were 13.7% in Hannover, 12.1% in Kiel, and 8.3% in Birmingham, the calculated 90-day survival benefits of transplantation were 6.8% in Hannover, 7.8% in Kiel, and 2.8% in Birmingham. Deployment of the LivAS for limiting allocation to donor and recipient combinations with likely 90-day survival as indicated by pretransplant LivAS values below the cutoff value would have increased the survival benefit to 12.9% in the German cohorts, whereas this would have decreased the benefit in England to 1.3%. The English and German cohorts revealed significant differences in 21 of 28 pretransplant variables. In conclusion, the LivAS could be validated in Germany and may improve German allocation policies leading to greater survival benefits, whereas validation failed in England due to profound differences in the selection criteria for liver transplantation. This study suggests the need for national prognostic models. Even though the German centers had higher rates of 90-day mortality, estimated survival benefits were greater. Liver Transplantation 22 743-756 2016 AASLD.

Bypass during Liver Transplantation: Anachronism or Revival? Liver Transplantation Using a Combined Venovenous/Portal Venous Bypass-Experiences with 163 Liver Transplants in a Newly Established Liver Transplantation Program

Introduction. The venovenous/portal venous (VVP) bypass technique has generally become obsolete in liver transplantation (LT) today. We evaluated our experience with 163 consecutive LTs that used a VVP bypass. Patients and Methods. The liver transplant program was started in our center in 2010. LTs were performed using an extracorporal bypass device. Results. Mean operative time was 269 minutes and warm ischemic time 43 minutes. The median number of transfusion of packed cells and plasma was 7 and 14. There was no intraoperative death, and the 30-day mortality was 3%. Severe bypass-induced complications did not occur. Discussion. The introduction of a new LT program requires maximum safety measures for all of the parties involved. Both surgical and anaesthesiological management (reperfusion) can be controlled very reliably using a VVP bypass device. Particularly when using marginal grafts, this approach helps to minimise both surgical and anaesthesiological complications in terms of less volume overload, less use of vasopressive drugs, less myocardial injury, and better peripheral blood circulation. Conclusion. Based on our experiences while establishing a new liver transplantation program, we advocate the reappraisal of the extracorporeal VVP bypass.

Value and limitations of the BAR-score for donor allocation in liver transplantation

PURPOSE

The MELD-score was shown to be able to predict 90-day mortality in most patients with end-stage liver disease prior to liver transplantation and is used as a widely accepted measure for transplantation urgency. Prognostic ability of the BAR-score to predict 90-day post-transplant mortality by detection of unfavourable pretransplant combinations of donor and recipient factors may help to better balance urgency versus utility.

METHODS

Two German cohorts (Hannover, n=453; Kiel, n=234) were retrospectively analyzed using ROC-curve analysis, goodness-of-model-fit tests, summary measures and risk-adjusted multivariate binary regression. Included were all consecutive liver transplants performed in adult recipients (minimum age 18 years). Excluded were all combined transplants and living-related organ donor transplants.

RESULTS

Risk-adjusted multivariate regression revealed that the BAR-score is an independent risk factor for 90-day mortality after transplantation in both cohorts from Hannover and Kiel combined (p<0.001, OR=1.017, 95% CI:1.031-1.113). The area under the ROC-curve (AUROC) for the prediction of 90-day mortality using the BAR-score was 0.662 (95% CI 0.624-0.699, power>95%). Measures for association between observed 90-day mortality and the predicted probabilities in the combined cohort were concordant in 63.5% with low summary measures (Somers' D test 0.32, Goodman-Kruskal Gamma test 0.34 and Kendall's Tau a test 0.07).

CONCLUSIONS

The BAR-score performed below accepted thresholds for potentially useful clinical prognostic models. Prognostic models with better predictive ability with AUROCs>0.700, concordance>70% and larger summary measures are required for the prediction of 90-day post-transplant mortality to enable donor organ allocation with reliable weighing of urgency versus utility.

Outcome stagnation of liver transplantation for primary sclerosing cholangitis in the Model for End-Stage Liver Disease era

PURPOSE

Survival after liver transplantation (LTX) has decreased in Germany since the implementation of Model for end-stage liver disease (MELD)-based liver allocation. Primary sclerosing cholangitis (PSC) is known for its otherwise excellent outcome after LTX. The influence of MELD-based liver allocation and subsequent allocation policy alterations on the outcome of LTX for PSC is analyzed.

METHODS

This is a retrospective observational study including 126 consecutive patients treated with LTX for PSC between January 1, 1999 and August 31, 2012. The PSC cohort was further compared to all other indications for LTX in the study period (n=1420) with a mean follow-up of 7.9 years (SD 3.2). Multivariate risk-adjusted analyses were performed. Alterations of allocation policy have been taken into account systematically.

RESULTS

Transplant recipients suffering from PSC are significantly younger (p<0.001), can be discharged earlier (p=0.018), and have lower 3-month mortality than patients with other indications (p=0.044). The observed time on the waiting list is significantly longer for patients with PSC (p<0.001), and there is a trend toward lower match MELD points in the PSC cohort (p=0.052). No improvement in means of short-term mortality could be shown in relation to alterations of allocation policy within the MELD era (p=0.375). Survival rates of the pre-MELD era did not differ significantly from those of the MELD era (p=0.097) in multivariate risk-adjusted analysis. Patients in the MELD era suffered pre-transplant significantly more frequently from dominant bile duct stenosis (p=0.071, p=0.059, p=0.048, respectively; chi2).

CONCLUSIONS

Progress is stagnating in LTX for PSC. Current liver allocation for PSC patients should be reconsidered.

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

Background

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

Results

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

Conclusions

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