Should donors and recipients be matched in liver transplantation?

Minimizing Risks of Liver Transplantation With Steatotic Donor Livers by Preferred Recipient Matching

BACKGROUND

Donor livers with ≥30% macrosteatosis (steatotic livers) represent a possible expansion to the donor pool, but are frequently discarded as they are associated with an increased risk of mortality and graft loss. We hypothesized that there are certain recipient phenotypes that would tolerate donor steatosis well, and are therefore best suited to receive these grafts.

METHODS

Using national registry data from the Scientific Registry of Transplant Recipients between 2006 and 2017, we compared 2048 liver transplant recipients of steatotic livers with 69 394 recipients of nonsteatotic (<30%) livers. We identified recipient factors that amplified the impact of donor steatosis on mortality and graft loss using interaction analysis, classifying recipients without these factors as preferred recipients. We compared mortality and graft loss with steatotic versus nonsteatotic livers in preferred and nonpreferred recipients using Cox regression.

RESULTS

Preferred recipients of steatotic livers were determined to be first-time recipients with a model for end-stage liver disease 15-34, without primary biliary cirrhosis, and not on life support before transplant. Preferred recipients had no increased mortality risk (hazard ratio [HR]: 0.921.041.16; P = 0.5) or graft loss (HR: 0.931.031.15; P = 0.5) with steatotic versus nonsteatotic livers. Conversely, nonpreferred recipients had a 41% increased mortality risk (HR: 1.171.411.70; P < 0.001) and 39% increased risk of graft loss (HR: 1.161.391.66; P < 0.001) with steatotic versus nonsteatotic livers.

CONCLUSIONS

The risks of liver transplantation with steatotic donor livers could be minimized by appropriate recipient matching.

Sent Liver Grafts Do Not Have a Detrimental Impact on Post-transplant Outcome

INTRODUCTION

"Sent livers" (SL) (interregional allocated organs) are considered extended donor criteria grafts. These grafts influence post-transplant outcome. In our donor allocation program, the number of allocated SLs is increasing. The aim of our study is to provide data supporting the possibility to enlarge the use of SLs through adequate donor-to-recipient matching.

METHODS

A retrospective analysis was carried out from our prospective-collected database during 2014.

RESULTS

Fifty-seven liver transplantations (LTs) were included: 22 SLs and 35 grafts procured by us (nSLs). Only donor risk index among donor characteristics showed a trend toward significant values (SL 1.901 vs nSL 1.726, P = .07). Among LT variables, the number of patients who received interleukin-2 inhibitor induction (SL 7 vs nSL 20, P < .05) and the presence of hepatocellular carcinoma (SL 50% vs nSL 34%, P < .05) reached statistical significance. One case of primary nonfunction occurred in the nSL group. No major retrieval injuries were observed. Retransplantation was performed in 6 cases (2 SLs and 4 nSLs). One patient in the SL group died after retransplantation. Graft survival rates at 1, 3, 6, and 12 months were 100%, 100%, 90%, 86% and 91%, 86%, 86%, 86% (P = .79) in SL and nSL groups, respectively.

DISCUSSION

SL performance did not differ from that of nSL. SLs were usually allocated to noncritical candidates, and nSLs were transplanted more frequently in decompensated recipients. Despite this peculiar donor-recipient match, grafts survival was similar in the 2 groups of patients.

Biomarkers to assess graft quality during conventional and machine preservation in liver transplantation

A global rising organ shortage necessitates the use of extended criteria donors (ECD) for liver transplantation (LT). However, poor preservation and extensive ischemic injury of ECD grafts have been recognized as important factors associated with primary non-function, early allograft dysfunction, and biliary complications after LT. In order to prevent for these ischemia-related complications, machine perfusion (MP) has gained interest as a technique to optimize preservation of grafts and to provide the opportunity to assess graft quality by screening for extensive ischemic injury. For this purpose, however, objective surrogate biomarkers are required which can be easily determined at time of graft preservation and the various techniques of MP. This review provides an overview and evaluation of biomarkers that have been investigated for the assessment of graft quality and viability testing during different types of MP. Moreover, studies regarding conventional graft preservation by static cold storage (SCS) were screened to identify biomarkers that correlated with either allograft dysfunction or biliary complications after LT and which could potentially be applied as predictive markers during MP. The pros and cons of the different biomaterials that are available for biomarker research during graft preservation are discussed, accompanied with suggestions for future research. Though many studies are currently still in the experimental setting or of low evidence level due to small cohort sizes, the biomarkers presented in this review provide a useful handle to monitor recovery of ECD grafts during clinical MP in the near future.

Using old liver grafts for liver transplantation: Where are the limits?

The scarcity of ideal liver grafts for orthotopic liver transplantation (OLT) has led transplant teams to investigate other sources of grafts in order to augment the donor liver pool. One way to get more liver grafts is to use marginal donors, a not well-defined group which includes mainly donors > 60 years, donors with hypernatremia or macrosteatosis > 30%, donors with hepatitis C virus or hepatitis B virus positive serologies, cold ischemia time > 12 h, non-heart-beating donors, and grafts from split-livers or living-related donations. Perhaps the most practical and frequent measure to increase the liver pool, and thus to reduce waiting list mortality, is to use older livers. In the past years the results of OLT with old livers have improved, mainly due to better selection and maintenance of donors, improvements in surgical techniques in donors and recipients, and intra- and post-OLT management. At the present time, sexagenarian livers are generally accepted, but there still exists some controversy regarding the use of septuagenarian and octogenarian liver grafts. The aim of this paper is to briefly review the aging process of the liver and reported experiences using old livers for OLT. Fundamentally, the series of septuagenarian and octogenarian livers will be addressed to see if there is a limit to using these aged grafts.

MELD-based graft allocation system fails to improve liver transplantation efficacy in a single-center intent-to-treat analysis

BACKGROUND

Since March 2007, priority access to liver transplantation in France has been given to patients with the highest MELD scores.

OBJECTIVE

To undertake an intent-to-treat comparison of center-based vs. MELD-based liver graft allocation.

METHODS

Retrospective cohort analysis (patients listed 6th March 2007 to 5th March 2009; MELD period) with a matched historical cohort (patients listed 6th March 2005 to 5th March 2007; pre-MELD period) in a single high-volume center. Analysis was on an intent-to-treat basis, i.e. starting on the day of wait listing.

RESULTS

Compared to pre-MELD, fewer patients with a MELD score less or equal to 14 (P=0.002), and more patients with a MELD greater or equal to 24 (P<0.05) were transplanted during the MELD period. For HCC candidates, median waiting time increased (121 vs. 54 days, P=0.01), transplantation rate halved (35% vs. 73.5%, P<0.001) and dropouts due to tumor progression increased (16% vs. 0%, P<0.001). Moreover, postoperative course did not change significantly except for infectious complications (35% vs. 24%, P=0.02); overall patient survival was 69.8 ± 3.1% vs. 76 ± 2.9% (P=0.29) and overall graft survival was 77.6 ± 3.4% vs. 82.8 ± 2.9% (P=0.29). Transplant failures were mainly due to deaths on the waiting list in the previous system, but to dropouts related to disease progression in the new system. Cirrhotic patient survival rate did not change (78.1 ± 4.4% vs. 73.5 ± 4.5%, P=0.42), while that of HCC patients decreased (65.3 ± 5.3% vs. 86.8 ± 4.4%, P=0.01). Post-transplant survival worsened significantly according to pre-transplant MELD score (P=0.009).

CONCLUSION

The MELD-based graft allocation system introduced discrimination against HCC patients, whose incidence has increased dramatically, and should be reevaluated.

The Eurotransplant donor risk index in liver transplantation: ET-DRI

Recently we validated the donor risk index (DRI) as conducted by Feng et al. for the Eurotransplant region. Although this scoring system is a valid tool for scoring donor liver quality, for allocation purposes a scoring system tailored for the Eurotransplant region may be more appropriate. Objective of our study was to investigate various donor and transplant risk factors and design a risk model for the Eurotransplant region. This study is a database analysis of all 5939 liver transplantations from deceased donors into adult recipients from the 1st of January 2003 until the 31st of December 2007 in Eurotransplant. Data were analyzed with Kaplan-Meier and Cox regression models. From 5723 patients follow-up data were available with a mean of 2.5 years. After multivariate analysis the DRI (p < 0.0001), latest lab GGT (p = 0.005) and rescue allocation (p = 0.007) remained significant. These factors were used to create the Eurotransplant Donor Risk Index (ET-DRI). Concordance-index calculation shows this ET-DRI to have high predictive value for outcome after liver transplantation. Therefore, we advise the use of this ET-DRI for risk indication and possibly for allocation purposes within the Eurotrans-plant region.

MELD and other predictors of survival after liver transplantation

BACKGROUND

This study examined how reliable is the pre-transplant model for end-stage liver disease (MELD) score in predicting post-transplantation survival and analyzed variables associated with patient survival.

METHODS

A cohort study was conducted. Receiver operating characteristic curve c-statistics were used to determine the ability of MELD score to predict mortality. The Kaplan-Meier (KM) method was used to analyze survival as a function of time regarding the MELD score and Child-Turcotte-Pugh (CTP) category. The Cox model was employed to assess the association between baseline risk factors and mortality.

RESULTS

Recipients and donors were mostly male, with a mean age of 51.6 and 38.5 yr, respectively (n = 436 transplants). The c-statistic values for three-month patient mortality were 0.60 and 0.61 for MELD score and CTP category, respectively. KM survival at three, six and 12 months were lower in those who had a MELD score > or =21 or were CTP category C. Multivariate analysis revealed that recipient age > or =65 yr, MELD > or = 21, CTP C category, bilirubin > or = 7 mg/dL, creatinine > or = 1.5 mg/dL, platelet transfusion, hepatocellular carcinoma, and non-white color donor skin were predictors of mortality.

CONCLUSIONS

Severe pre-transplant liver disease, age > or = 65, non-white skin donor, and hepatocellular carcinoma are associated with poor outcome.

Algorithm for Prioritization of Patients on the Waiting List for Liver Transplantation

Prioritization of patients on the waiting list (WL) for OLT is still a critical issue. Numerous models have been developed to predict mortality before and after OLT.

AIM

The aim of the study was to prospectively evaluate cirrhotics with and without hepatocellular carcinoma (HCC) undergoing orthotopic liver transplantation (OLT) severity of liver disease on the WL and at transplant, mortality on the WL and after OLT, and their correlations.

MATERIALS AND METHODS

An algorithm based on seven patient variables (MELD, CTP, UNOS, HCC, BMI, waiting time, age) was created by software dedicated to prioritize patients on the waiting list.

RESULTS

We evaluated 118 patients including 75 men and 43 women of age range 19 to 66 years, who underwent OLT from July 2004 to June 2006. Mean CTP and MELD at listing were 8.44 (range 6-12) and 13 (range 2-24), respectively. Overall mortality on the WL at 24 months was 13%, which was significantly higher among patients with MELD > 25 compared to patients with MELD 0 to 15 (P < .0001) or MELD 16 to 25 (P = .0007) at listing. Mean MELD at OLT was 15 (range 7-36), which was significantly lower in patients with than without HCC (MELD 12 vs 16; P = .0003). Six hundred-day patient survival was significantly lower among patients with MELD > 25 compared to patients with MELD < 25 at OLT (P = .017), whereas no difference in survival was observed between patients with and without HCC.

CONCLUSIONS

The sickest patients are characterized by high mortality both on the waiting list and after liver transplantation. Patients with HCC are transplanted in better condition compared to patients without HCC with the same survival.

The model for end-stage liver disease (MELD)

The Model for End-stage Liver Disease (MELD) was initially created to predict survival in patients with complications of portal hypertension undergoing elective placement of transjugular intrahepatic portosystemic shunts. The MELD which uses only objective variables was validated subsequently as an accurate predictor of survival among different populations of patients with advanced liver disease. The major use of the MELD score has been in allocation of organs for liver transplantation. However, the MELD score has also been shown to predict survival in patients with cirrhosis who have infections, variceal bleeding, as well as in patients with fulminant hepatic failure and alcoholic hepatitis. MELD may be used in selection of patients for surgery other than liver transplantation and in determining optimal treatment for patients with hepatocellular carcinoma who are not candidates for liver transplantation. Despite the many advantages of the MELD score, there are approximately 15%-20% of patients whose survival cannot be accurately predicted by the MELD score. It is possible that the addition of variables that are better determinants of liver and renal function may improve the predictive accuracy of the model. Efforts at further refinement and validation of the MELD score will continue.