Experience using extended criteria donors in first 100 cases of deceased donor liver transplantation in Japan

Development of a risk score model for 1‐year graft loss after adult deceased donor liver transplantation in Japan based on a 20‐year nationwide cohort

Aim

Using nationwide data collected over the past 20 years, we aimed to investigate deceased donor liver transplantation (DDLT) outcomes to develop a unique risk model that can be used to establish a standard for organ acceptance in Japan.

Methods

Data were collected for 449 recipients aged ≥18 years who underwent DDLT between 1999 and 2019. Least absolute shrinkage and selection operator (LASSO) regression analysis was utilized to develop an original risk score model for 1‐year graft loss (termed the Japan Risk Index [JRI]). We developed risk indices according to recipient, donor, and surgery components (termed JRI‐R, D, and S, respectively). The JRI was validated via a 5‐fold cross‐validation. We also compared DDLT outcomes and risk indices among Era1 (−2011), Era2 (−2015), and Era3 (−2019).

Results

The 1‐year graft survival rate was 89.5% and improved significantly, reaching 84.7%, 87.6%, and 93.9% in Era1, Era2, and Era3, respectively. The JRI was calculated as JRI‐R (re‐transplantation, Model for End‐Stage Liver Disease score, medical condition in intensive care unit) × JRI‐D (age, catecholamine index, maximum sodium, maximum total bilirubin) × JRI‐S (total ischemic time) × 0.84. The risk model achieved a mean C‐statistic value of 0.81 in the validation analysis. The risk index was significantly lower in Era3 than in Era2.

Conclusion

Changes in the risk index over time indicated that avoiding risks contributed to the improved outcomes in Era3. The JRI is unique to adult DDLT in Japan and may be useful as a reference for organ acceptance in the future.

The Suitability of Potential Organ Donors Using Real Case-Scenarios; Do we Need to Create a "Donor Board" Process for Donors Perceived as Unlikely Suitable?

Introduction: Despite availability of selection criteria, different interpretations can lead to variability in the appreciation of donor eligibility with possible viable organs missed. Our primary objective was to test the perception of feasibility of potential organ donors through the survey of a small sample of external evaluators.

Methods: Clinical scenarios summarizing 66 potential donors managed in the first year of our Organ Recovery Center were sent to four critical care physicians to evaluate the feasibility of the potential donors and the probability of organ procurement.

Results: Potential donors procuring at least one organ were identified in 55 of the 66 cases (83%). Unanimity was reached in 38 cases, encompassing 35 out of the 55 converted and 3 of the non-converted donors. The overall agreement was moderate (kappa = 0.60, 95% CI: 0.37–0.82). For the organs finally procured for transplantation, organ donation was predicted for the majority of the cases, but high discrepancy was present with the final outcome of organs not procured (particularly liver and kidney).

Conclusion: The assessment of a potential donor is a complex dynamic process. In order to increase organ availability, standardized electronically clinical data, as well a “donor board” structure of decision might inform future systems.

Liver transplantation in Japan

As of December 31, 2014, 7937 liver transplants (7673 living donor transplants and 264 deceased donor liver transplantations [DDLTs; 261 from heart-beating donors and 3 from non-heart-beating donors]) have been performed in 67 institutions in Japan. The revised Organ Transplant Law in Japan came into effect in July 2010, which allows organ procurement from brain-dead individuals, including children, with family consent if the patient had not previously refused organ donation. However, the number of deceased donor organ donations has not increased as anticipated. The rate of deceased organ donations per million population (pmp) has remained at less than 1. To maximize the viability of the limited numbers of donated organs, a system has been adopted that includes the partnership of well-trained transplant consultant doctors and local doctors. For compensating for the decreased opportunity of on-site training, an educational system regarding quality organ procurement for transplant surgeons has also been established. Furthermore, experts in the field of liver transplantation are currently discussing adoption of the Model for End-Stage Liver Disease score for allocation, promoting split-liver transplantation, arranging in-house coordinators, and improving the frequency of proposing the option to donate organs to the families. To overcome the shortage of donors during efforts to promote organ donation, living donor liver transplantation (LDLT) has been developed in Japan. Continuous efforts to increase DDLT in addition to the successful experience of LDLT will increase the benefits of liver transplantation for more patients. Liver Transplantation 22 1401-1407 2016 AASLD.

Low-volume deceased donor liver transplantation alongside a strong living donor liver transplantation service

BACKGROUND

At our center, living donor liver transplantation (LDLT) is the main workload supported by a strong, mature service. Deceased donor liver transplantation (DDLT) is performed but in small volume. This study aimed to review the results of a low-volume DDLT service alongside a strong LDLT service.

METHODS

Consecutive DDLTs for adults performed from 1991 to 2009 were reviewed. The 1st to the 50th DDLTs were categorized as Era I cases, and the rest were Era II cases. The outcomes of the DDLTs were analyzed and compared with those achieved overseas.

RESULTS

Eras I and II consisted of 59 and 183 DDLTs, respectively. All donors were brain-dead and heart-beating with a median age of 49 years (range 7-76 years). Among the 242 DDLTS, 30.2 % were on a high-urgency basis and 15.3 % were for hepatocellular carcinoma. The patients had a median model for end-stage liver disease score of 21 (range 6-40), and most (67.8 %) were hepatitis B virus carriers. Before transplantation, 16.1 % of the patients were in the intensive care unit and 30.2 % were in the hospital. The hospital mortality rate dropped from 13.6 % (8/59) during Era I to 3.8 % (7/183) during Era II (p = 0.012). For Era I, the 1-, 3-, and 5-year survival rates were 84.7, 79.7, and 76.3 %, respectively, which improved to 92.9, 89.0 and 87.2 % for Era II (p = 0.026).

CONCLUSIONS

The recipient survival of this series compares favorably with contemporary series. It is shown that a low-volume DDLT service alongside a strong LDLT service can have excellent results.

Comparing outcomes of donation after cardiac death versus donation after brain death in liver transplant recipients with hepatitis C: a systematic review and meta-analysis

BACKGROUND

Liver transplantation (LT) using organs donated after cardiac death (DCD) is increasing due, in large part, to a shortage of organs. The outcome of using DCD organs in recipients with hepatits C virus (HCV) infection remains unclear due to the limited experience and number of publications addressing this issue.

OBJECTIVE

To evaluate the clinical outcomes of DCD versus donation after brain death (DBD) in HCV-positive patients undergoing LT.

METHODS

Studies comparing DCD versus DBD LT in HCV-positive patients were identified based on systematic searches of seven electronic databases and multiple sources of gray literature.

RESULTS

The search identified 58 citations, including three studies, with 324 patients meeting eligibility criteria. The use of DCD livers was associated with a significantly higher risk of primary nonfunction (RR 5.49 [95% CI 1.53 to 19.64]; P=0.009; I2=0%), while not associated with a significantly different patient survival (RR 0.89 [95% CI 0.37 to 2.11]; P=0.79; I2=51%), graft survival (RR 0.40 [95% CI 0.14 to 1.11]; P=0.08; I2=34%), rate of recurrence of severe HCV infection (RR 2.74 [95% CI 0.36 to 20.92]; P=0.33; I2=84%), retransplantation or liver disease-related death (RR 1.79 [95% CI 0.66 to 4.84]; P=0.25; I2=44%), and biliary complications.

CONCLUSIONS

While the literature and quality of studies assessing DCD versus DBD grafts are limited, there was significantly more primary nonfunction and a trend toward decreased graft survival, but no significant difference in biliary complications or recipient mortality rates between DCD and DBD LT in patients with HCV infection. There is insufficient literature on the topic to draw any definitive conclusions.

Regulation of molecular pathways in ischemia-reperfusion injury after liver transplantation

BACKGROUND

Ischemia-reperfusion (I/R) injury is a multifactorial phenomenon that occurs during the transplant event and frequently compromises early graft function after liver transplantation (LT). Current comprehension of molecular mechanisms and regulation processes of I/R injury lacks clarity. MicroRNA (miRNA) regulation results critical in several biological processes.

METHODS

This study evaluated gene expression and miRNA expression profiles using microarrays in 34 graft biopsies collected at preimplantation (L1) and at 90 min postreperfusion (L2) from consecutives deceased-donor LT recipients. miRNA profiles were first analyzed. Data integration analysis (gene expression/miRNA expression) aimed to identify potential target genes for each identified miRNA from the L1/L2 differential gene expression profile.

RESULTS

Pairwise comparison analyses identified 40 miRNAs and 3168 significantly differentially expressed genes at postreperfusion time compared with preimplantation time. Pathway analysis of miRNAs associated these profiles with antiapoptosis, inhibition of cellular proliferation, and proinflammatory processes. Target analysis identified an miRNA-associated molecular profile of 2172 genes involved in cellular growth and proliferation modulation by cell cycle regulation, cell death and survival, and proinflammatory and anti-inflammatory processes. miRNA-independent genes involved proinflammatory molecules.

CONCLUSION

We identified a miRNA profile involved in posttranscriptional regulatory mechanisms in I/R injury post-LT. A better understanding of these molecular processes involved in I/R may contribute to develop new strategies to minimize graft injury.