Survival of recipients of livers from donation after circulatory death who are relisted and undergo retransplant for graft failure

Modern-Day Practice of DCD Liver Transplantation: Controversies, Innovations, and Future Directions

PURPOSE OF REVIEW

Over the past decade, donation after circulatory death (DCD) liver transplantation has expanded in the United States due to improved surgical experience and perioperative management. Despite these advances, there remains a reluctance towards broader utilization of DCD liver allografts due to lack of standardized donation process, concern for inferior graft survival, and risk of ischemic cholangiopathy associated with temporary lack of oxygenated perfusion during withdrawal of life-supporting treatment during procurement.

RECENT FINDINGS

New perfusion technologies offer potential therapeutic options to mitigate biliary complications and expand utilization of marginal DCD grafts. As these modalities enter routine clinical practice, DCD utilization will continue to increase, and liver allocation policies in turn will evolve to reflect this growing practice. This review describes recent progress in DCD LT, current challenges with utilization of DCD liver allografts, and how novel technologies and policies could impact the future of the field.

Incidence and risk factors of primary non-function after liver transplantation using grafts from uncontrolled donors after circulatory death

BACKGROUND

Graft primary non-function (PNF) is the most severe complication after orthotopic liver transplantation (OLT) and is frequently associated with livers from uncontrolled circulatory death (uDCD).

METHODS

We reviewed retrospectively the incidence, risk factors, and outcome of patients showing PNF after receiving uDCD liver grafts. The series comprises 75 OLT performed during 11 years.

RESULTS

The incidence of PNF using uDCD livers was 8%. We compared patients who developed PNF (n = 6) vs. patients without PNF (n = 69). Mean pump flow of donors during normothermic regional perfusion (NRP) was significantly lower in PNF (p = .032). Day 1 post-OLT levels of transaminases and the incidence of renal complications and postoperative mortality were also significantly higher in the PNF group, but 5-year patient survival was similar in both groups (66.7% in PNF and 68.5% in non-PNF). All PNF patients underwent re-OLT, and 2 died. PNF incidence has decreased in the last 5-years. Binary logistic regression analysis confirmed final ALT value >4 times the normal value as risk factor for PNF, and median donor pump flow >3700 ml/min as protective effect.

CONCLUSIONS

Adequate donor pump flow during NRP was a protective.

Excellent Contemporary Graft Survival for Adult Liver Retransplantation: An Australian and New Zealand Registry Analysis From 1986 to 2017

Background.

Liver retransplantation is technically challenging, and historical outcomes are significantly worse than for first transplantations. This study aimed to assess graft and patient survival in all Australian and New Zealand liver transplantation units.

Methods.

A retrospective cohort analysis was performed using data from the Australia and New Zealand Liver Transplant Registry. Graft and patient survival were analyzed according to era. Cox regression was used to determine recipient, donor, or intraoperative variables associated with outcomes.

Results.

Between 1986 and 2017, Australia and New Zealand performed 4514 adult liver transplants, 302 (6.7%) of which were retransplantations (278 with 2, 22 with 3, 2 with 4). The main causes of graft failure were hepatic artery or portal vein thrombosis (29%), disease recurrence (21%), and graft nonfunction (15%). Patients retransplanted after 2000 had a graft survival of 85% at 1 year, 75% at 5 years, and 64% at 10 years. Patient survival was 89%, 81%, and 74%, respectively. This was higher than retransplantations before 2000 (P < 0.001). Univariate analysis found that increased recipient age (P = 0.001), recipient weight (P = 0.019), and donor age (P = 0.011) were associated with decreased graft survival prior to 2000; however, only increased patient weight was significant after 2000 (P = 0.041). Multivariate analysis found only increased recipient weight (P = 0.042) and donor age (P = 0.025) was significant prior to 2000. There was no difference in survival for second and third retransplants or comparing time to retransplant.

Conclusions.

Australia and New Zealand have excellent survival following liver retransplantation. These contemporary results should be utilized for transplant waitlist methods.

Uncontrolled deceased cardiac donation: An unutilized source for organ transplantation in the United States

The practice of uncontrolled donation after cardiac death (uDCD) has been met with tepid interest within the United States transplant community. Hesitancy stems largely from fears of eroding public trust due to complex ethical issues involving consent. Beyond ethical concerns, uDCD creates unique logistic challenges to obtain and to preserve organs within a short time frame. This mandates that organ recovery centers be able to rapidly mobilize, and that traditional cold preservation techniques may be inadequate. Proof of effective uDCD organ recovery comes from several European nations, and the frequency of its use is increasing due to early promising results. These scarce resources provide life-saving organs to desperate transplant candidates who otherwise experience high morbidity and mortality on a transplant waitlist. The objective of this review will be to provide an overview of the European experience with uDCD and discuss the unique ethical and logistic challenges associated with its implementation in the United States. Given existing models for it successful use, uDCD remains a poorly utilized source of donors in the United States at this time.

Marked Decrease in Urgent Listing for Liver Transplantation Over Time: Evolution of Characteristics and Outcomes of Status-1 Liver Transplantation

BACKGROUND

Approximately 5% of liver transplants annually are performed urgently with "status-1" designation. This study aims to determine if the demand, characteristics, and outcome for status-1 liver transplantation has changed over time.

METHODS

We used the Scientific Registry of Transplant Patients (2003-2015) to characterize 2352 adult patients who underwent 2408 status-1 liver transplants and compared them between Era1 (2003-6/2009) and Era2 (7/2009-2015).

RESULTS

Overall, there were fewer liver transplants performed with the status-1 designation in Era2 than Era1 (1099 vs 1309). Although the number of urgent liver transplants was relatively constant with successive years, the proportion transplanted with status-1 designation decreased markedly over time. Era2 patients were older (43.2 years vs 41.7 years, P = 0.01) and less likely be ABO-incompatible (1.1% vs 2.4%, P = 0.01) or retransplant (77 vs 124, P = 0.03). In terms of disease etiology, the largest group was "acute liver failure (ALF), nonspecified" (43.4%). There was no difference in proportion with drug-induced liver injury (DILI), but the subset of herbal/dietary supplements increased in Era2 (1.3% vs 0.46%, P = 0.04). Survival was increased in Era2 in the overall cohort and for patients with autoimmune disease (P < 0.05), despite longer waiting times for this etiology (186 days vs 149 days). DILI or nonspecified ALF had shorter waiting times, and 90% were transplanted within 7 days.

CONCLUSIONS

Liver transplantation for the most urgent indications (status-1) is decreasing while survival remains excellent. Fewer incidences of ALF are classified as indeterminate, mostly as a result of increasing awareness of autoimmune hepatitis and DILI as causes of the syndrome.

Attitudes and barriers to the use of donation after cardiac death livers: Comparison of a United States transplant center survey to the united network for organ sharing data

Transplantation of liver grafts from donation after cardiac death (DCD) is limited. To identify barriers of DCD liver utilization, all active US liver transplant centers (n = 138) were surveyed, and the responses were compared with the United Network for Organ Sharing (UNOS) data. In total, 74 (54%) centers responded, and diversity in attitudes was observed, with many not using organ and/or recipient prognostic variables defined in prior studies and UNOS data analysis. Most centers (74%) believed lack of a system allowing a timely retransplant is a barrier to utilization. UNOS data demonstrated worse 1- and 5-year patient survival (PS) and graft survival (GS) in DCD (PS, 86% and 64%; GS, 82% and 59%, respectively) versus donation after brain death (DBD) recipients (PS, 90% and 71%; GS, 88% and 69%, respectively). Donor alanine aminotransferase (ALT), recipient Model for End-Stage Liver Disease (MELD), and cold ischemia time (CIT) significantly impacted DCD outcomes to a greater extent than DBD outcomes. At 3 years, relisting and retransplant rates were 7.9% and 4.6% higher in DCD recipients. To optimize outcome, our data support the use of DCD liver grafts with CIT <6-8 hours in patients with MELD ≤ 20. In conclusion, standardization of donor and recipient criteria, defining the impact of ischemic cholangiopathy, addressing donor hospital policies, and developing a strategy for timely retransplant may help to expand the use of these organs. Liver Transplantation 23 1372-1383 2017 AASLD.

Waitlist Outcomes for Patients Relisted Following Failed Donation After Cardiac Death Liver Transplant: Implications for Awarding Model for End-Stage Liver Disease Exception Scores

Understanding of outcomes for patients relisted for ischemic cholangiopathy following a donation after cardiac death (DCD) liver transplant (LT) will help standardization of a Model for End-Stage Liver Disease exception scheme for retransplantation. Early relisting (E-RL) for DCD graft failure caused by primary nonfunction (PNF) or hepatic artery thrombosis (HAT) was defined as relisting ≤14 days after DCD LT, and late relisting (L-RL) due to biliary complications was defined as relisting 14 days to 3 years after DCD LT. Of 3908 DCD LTs performed nationally between 2002 and 2016, 540 (13.8%) patients were relisted within 3 years of transplant (168 [4.3%] in the E-RL group, 372 [9.5%] in the L-RL group). The E-RL and L-RL groups had waitlist mortality rates of 15.4% and 10.5%, respectively, at 3 mo and 16.1% and 14.3%, respectively, at 1 year. Waitlist mortality in the L-RL group was higher than mortality and delisted rates for patients with exception points for both hepatocellular carcinoma (HCC) and hepatopulmonary syndrome (HPS) at 3- to 12-mo time points (p < 0.001). Waitlist outcomes differed in patients with early DCD graft failure caused by PNF or HAT compared with those with late DCD graft failure attributed to biliary complications. In L-RL, higher rates of waitlist mortality were noted compared with patients listed with exception points for HCC or HPS.

The Optimal Timing of Hepatitis C Therapy in Transplant Eligible Patients With Child B and C Cirrhosis: A Cost-Effectiveness Analysis

BACKGROUND

Ledipasvir (LDV)/sofosbuvir (SOF) has demonstrated high efficacy, safety, and tolerability in hepatitis C virus (HCV)-infected patients. There is limited data, however, regarding the optimal timing of therapy in the context of possible liver transplantation (LT).

METHODS

We compared the cost-effectiveness of 12 weeks of HCV therapy before or after LT or nontreatment using a decision analytical microsimulation state-transition model for a simulated cohort of 10 000 patients with HCV Genotype 1 or 4 with Child B or C cirrhosis. All model parameters regarding the efficacy of therapy, adverse events and the effect of therapy on changes in model for end-stage liver disease (MELD) scores were derived from the SOLAR-1 and 2 trials. The simulations were repeated with 10 000 samples from the parameter distributions. The primary outcome was cost (2014 US dollars) per quality adjusted life year.

RESULTS

Treatment before LT yielded more quality-adjusted life year for less money than treatment after LT or nontreatment. Treatment before LT was cost-effective in 100% of samples at a willingness-to-pay threshold of US $100 000 in the base-case and when the analysis was restricted to Child B alone, Child C, or MELD > 15. Treatment before transplant was not cost-effective when MELD was 6-10. In sensitivity analyses, the MELD after which treatment before transplant was cost-effective was 13 and the maximum cost of LDV/SOF therapy at which treatment before LT is cost-effective is US $177 381.

CONCLUSIONS

From a societal perspective, HCV therapy using LDV/SOF with ribavirin before LT is the most cost-effective strategy for patients with decompensated cirrhosis and MELD score greater than 13.

Precision monitoring of immunotherapies in solid organ and hematopoietic stem cell transplantation

Pharmacological immunotherapies are a key component of post-transplant therapy in solid-organ and hematopoietic stem cell transplantation. In current clinical practice, immunotherapies largely follow a one-size fits all approach, leaving a large portion of transplant recipients either over- or under-immunosuppressed, and consequently at risk of infections or immune-mediated complications. Our goal here is to review recent and rapid advances in precision and genomic medicine approaches to monitoring of post-transplant immunotherapies. We will discuss recent advances in precision measurements of pharmacological immunosuppression, measurements of the plasma and gut microbiome, strategies to monitor for allograft injury and post-transplant malignancies via circulating cell-free DNA, and comprehensive measurements of the B and T cell immune cell repertoire.

Liver Retransplantation: How Much Is Too Much?

Hepatic retransplantation has been surgically challenging since the beginning of liver transplant. Outcomes have improved over time, but patient survival with retransplant continues to be significantly worse than that of primary transplant. Many studies have focused on factors to predict outcomes. Models have been developed to help predict risk, but the decision for retransplant must be a multidisciplinary transplant team decision. The question of "when is too much?" can be guided by recipient and donor factors but is an ethical decision that must be made by the liver transplant team.

Outcomes for primary kidney transplantation from donation after Citizens' death in China: a single center experience of 367 cases

BACKGROUND

The cases of donation after brain death followed by circulatory death (DBCD) and donation after cardiac death (DCD) have been increased year by year in China. Further research is needed to understand in the outcomes and risk factors of delayed graft function (DGF) in order to minimize the risk of DGF and ameliorate its potential impact on long-term outcomes. This study was to explore the differences in outcomes between DBCD and DCD transplant and the main risk factors for DGF in DBCD.

METHODS

Retrospective analysis of the clinical data of 367donations after citizens' death kidney transplant procedures (donors and recipients) between July 2012 and August 2015 at our center.

RESULTS

During the study period, the donation success rate was 25.3%. 164 cases of DBCD and 35 cases of DCD had been implemented and 367 kidneys were transplanted. The incidence of DGF in DBCD group were significantly lower than that of DCD group (12.0% vs. 27.0%, p = 0.002). The 1-year percent freedom from acute rejection (AR) was significantly higher in DBCD group compared with it of DCD group (94% vs. 82%, p = 0.036). Multivariate logistic regression analysis of the kidney transplants revealed that the high risk factors for DGF after renal transplantation in DBCD were history of hypertension (Odds Ratio [OR] = 5.88, 95% CI: 1.90 to 18.2, p = 0.002), low blood pressure (BP < 80 mmHg) (OR = 4.86, 95% CI: 1.58 to 14.9, p = 0.006) and serum creatinine of donor (OR = 1.09, 95% CI: 1.03 to 1.16, p = 0.003) before donation.

CONCLUSIONS

The outcomes of DBCD could be better than DCD in DGF and AR. The main risk factors for DGF in DBCD kidney transplants are donors with a history of hypertension, low blood pressure, and serum creatinine of donor before donation.

Liver transplant center variability in accepting organ offers and its impact on patient survival

BACKGROUND & AIMS

Despite an allocation system designed to give deceased-donor livers to the sickest patients, many transplantable livers are declined by U.S. transplant centers. It is unknown whether centers vary in their propensities to decline organs for the highest priority patients, and how these decisions directly impact patient outcomes.

METHODS

We analyzed Organ Procurement and Transplantation Network (OPTN) data from 5/1/07-6/17/13, and included all adult liver-alone waitlist candidates offered an organ that was ultimately transplanted. We evaluated acceptance rates of liver offers for the highest ranked patients and their subsequent waitlist mortality.

RESULTS

Of the 23,740 unique organ offers, 8882 (37.4%) were accepted for the first-ranked patient. Despite adjusting for organ quality and recipient severity of illness, transplant centers within and across geographic regions varied strikingly (p<0.001) in the percentage of organ offers they accepted for the highest priority patients. Among all patients ranked first on waitlists, the adjusted center-specific organ acceptance rates ranged from 15.7% to 58.1%. In multivariable models, there was a 27% increased odds of waitlist mortality for every 5% absolute decrease in a center's adjusted organ offer acceptance rate (adjusted OR: 1.27, 95% CI: 1.20-1.32). However, the absolute difference in median 5-year adjusted graft survival was 4% between livers accepted for the first-ranked patient, compared to those declined and transplanted at a lower position.

CONCLUSION

There is marked variability in center practices regarding accepting livers allocated to the highest priority patients. Center-level decisions to decline organs substantially increased patients' odds of dying on the waitlist without a transplant.

Donor preoperative oxygen delivery and post-extubation hypoxia impact donation after circulatory death hypoxic cholangiopathy

AIM: To evaluate donation after circulatory death (DCD) orthotopic liver transplant outcomes [hypoxic cholangiopathy (HC) and patient/graft survival] and donor risk-conditions.

METHODS: From 2003-2013, 45 DCD donor transplants were performed. Predonation physiologic data from UNOS DonorNet included preoperative systolic and diastolic blood pressure, heart rate, pH, SpO₂, PaO₂, FiO₂, and hemoglobin. Mean arterial blood pressure was computed from the systolic and diastolic blood pressures. Donor preoperative arterial O₂ content was computed as [hemoglobin (gm/dL) × 1.37 (mL O₂/gm) × SpO₂%) + (0.003 × PaO₂)]. The amount of preoperative donor red blood cell transfusions given and vasopressor use during the intensive care unit stay were documented. Donors who were transfused ≥ 1 unit of red-cells or received ≥ 2 vasopressors in the preoperative period were categorized as the red-cell/multi-pressor group. Following withdrawal of life support, donor ischemia time was computed as the number-of-minutes from onset of diastolic blood pressure < 60 mmHg until aortic cross clamping. Donor hypoxemia time was the number-of-minutes from onset of pulse oximetry < 80% until clamping. Donor hypoxia score was (ischemia time + hypoxemia time) ÷ donor preoperative hemoglobin.

RESULTS: The 1, 3, and 5 year graft and patient survival rates were 83%, 77%, 60%; and 92%, 84%, and 72%, respectively. HC occurred in 49% with 16% requiring retransplant. HC occurred in donors with increased age (33.0 ± 10.6 years vs 25.6 ± 8.4 years, P = 0.014), less preoperative multiple vasopressors or red-cell transfusion (9.5% vs 54.6%, P = 0.002), lower preoperative hemoglobin (10.7 ± 2.2 gm/dL vs 12.3 ± 2.1 gm/dL, P = 0.017), lower preoperative arterial oxygen content (14.8 ± 2.8 mL O₂/100 mL blood vs 16.8 ± 3.3 mL O₂/100 mL blood, P = 0.049), greater hypoxia score >2.0 (69.6% vs 25.0%, P = 0.006), and increased preoperative mean arterial pressure (92.7 ± 16.2 mmHg vs 83.8 ± 18.5 mmHg, P = 0.10). HC was independently associated with age, multi-pressor/red-cell transfusion status, arterial oxygen content, hypoxia score, and mean arterial pressure (r² = 0.6197). The transplantation rate was greater for the later period with more liberal donor selection [era 2 (7.1/year)], compared to our early experience [era 1 (2.5/year)]. HC occurred in 63.0% during era 2 and in 29.4% during era 1 (P = 0.03). Era 2 donors had longer times for extubation-to-asystole (14.4 ± 4.7 m vs 9.3 ± 4.5 m, P = 0.001), ischemia (13.9 ± 5.9 m vs 9.7 ± 5.6 m, P = 0.03), and hypoxemia (16.0 ± 5.1 m vs 11.1 ± 6.7 m, P = 0.013) and a higher hypoxia score > 2.0 rate (73.1% vs 28.6%, P = 0.006).

CONCLUSION: Easily measured donor indices, including a hypoxia score, provide an objective measure of DCD liver transplantation risk for recipient HC. Donor selection criteria influence HC rates.

Increasing the Number of Organ Transplants in the United States by Optimizing Donor Authorization Rates

While recent policies have focused on allocating organs to patients most in need and lessening geographic disparities, the only mechanism to increase the actual number of transplants is to maximize the potential organ supply. We conducted a retrospective cohort study using OPTN data on all "eligible deaths" from 1/1/08 to 11/1/13 to evaluate variability in donor service area (DSA)-level donor authorization rates, and to quantify the potential gains associated with increasing authorization rates. Despite adjustments for donor demographics (age, race/ethnicity, cause of death) and geographic factors (rural/urban status of donor hospital, statewide participation in deceased-donor registries) among 52 571 eligible deaths, there was significant variability (p < 0.001) in donor authorization rates across the 58 DSAs. Overall DSA-level adjusted authorization rates ranged from 63.5% to 89.5% (median: 72.7%). An additional 773-1623 eligible deaths could have been authorized, yielding 2679-5710 total organs, if the DSAs with authorization rates below the median and 75th percentile, respectively, implemented interventions to perform at the level of the corresponding reference DSA. Opportunities exist within the current organ acquisition framework to markedly improve DSA-level donor authorization rates. Such initiatives would mitigate waitlist mortality while increasing the number of transplants.

Use of model for end-stage liver disease exceptions for donation after cardiac death graft recipients relisted for liver transplantation

Donation after cardiac death (DCD) liver transplantation is associated with increased biliary complications and graft failure. Yet for unclear reasons, DCD recipients relisted for transplantation have lower wait-list mortality than other retransplant candidates. We used Organ Procurement and Transplantation Network and United Network for Organ Sharing data from 2002 to 2011 to evaluate all DCD recipients relisted for transplantation to evaluate the impact of the utilization of Model for End-Stage Liver Disease (MELD) exception points on wait-list outcomes. Of 262 DCD recipients relisted for liver transplantation >2 weeks after initial transplantation, 82 (31.3%) applied for a nonstandardized MELD exception, and 68 (82.9%) had ≥1 exception approved. Of the relisted DCD recipients, 187 (71.4%) underwent retransplantation; among those with an approved MELD exception, 85.2% underwent retransplantation versus 57.1% of those with an exception denied and 69.4% of those not applying for an exception (P=0.02). In contrast, those receiving MELD exception points were significantly less likely to be removed from the wait list for death or clinical deterioration in comparison with those not applying for an exception (7.1% versus 19.4%, P=0.02). In multivariate models, patients with an approved exception were 3.3 times more likely to undergo retransplantation than those not applying for an exception. Standardized criteria for exception points among DCD recipients should be established to ensure uniform access to retransplantation.