Declining liver utilization for transplantation in the United States and the impact of donation after cardiac death

Incidence and Impact of Acute Kidney Injury after Liver Transplantation: A Meta-Analysis

BACKGROUND

The study's aim was to summarize the incidence and impacts of post-liver transplant (LTx) acute kidney injury (AKI) on outcomes after LTx.

METHODS

A literature search was performed using the MEDLINE, EMBASE and Cochrane Databases from inception until December 2018 to identify studies assessing the incidence of AKI (using a standard AKI definition) in adult patients undergoing LTx. Effect estimates from the individual studies were derived and consolidated utilizing random-effect, the generic inverse variance approach of DerSimonian and Laird. The protocol for this systematic review is registered with PROSPERO (no. CRD42018100664).

RESULTS

Thirty-eight cohort studies, with a total of 13,422 LTx patients, were enrolled. Overall, the pooled estimated incidence rates of post-LTx AKI and severe AKI requiring renal replacement therapy (RRT) were 40.7% (95% CI: 35.4%⁻46.2%) and 7.7% (95% CI: 5.1%⁻11.4%), respectively. Meta-regression showed that the year of study did not significantly affect the incidence of post-LTx AKI (p = 0.81). The pooled estimated in-hospital or 30-day mortality, and 1-year mortality rates of patients with post-LTx AKI were 16.5% (95% CI: 10.8%⁻24.3%) and 31.1% (95% CI: 22.4%⁻41.5%), respectively. Post-LTx AKI and severe AKI requiring RRT were associated with significantly higher mortality with pooled ORs of 2.96 (95% CI: 2.32⁻3.77) and 8.15 (95%CI: 4.52⁻14.69), respectively. Compared to those without post-LTx AKI, recipients with post-LTx AKI had significantly increased risk of liver graft failure and chronic kidney disease with pooled ORs of 3.76 (95% CI: 1.56⁻9.03) and 2.35 (95% CI: 1.53⁻3.61), respectively.

CONCLUSION

The overall estimated incidence rates of post-LTx AKI and severe AKI requiring RRT are 40.8% and 7.0%, respectively. There are significant associations of post-LTx AKI with increased mortality and graft failure after transplantation. Furthermore, the incidence of post-LTx AKI has remained stable over the ten years of the study.

Study protocol for a multicenter randomized controlled trial to compare the efficacy of end-ischemic dual hypothermic oxygenated machine perfusion with static cold storage in preventing non-anastomotic biliary strictures after transplantation of liver grafts donated after circulatory death: DHOPE-DCD trial

BACKGROUND

The major concern in liver transplantation of grafts from donation after circulatory death (DCD) donors remains the high incidence of non-anastomotic biliary strictures (NAS). Machine perfusion has been proposed as an alternative strategy for organ preservation which reduces ischemia-reperfusion injury (IRI). Experimental studies have shown that dual hypothermic oxygenated machine perfusion (DHOPE) is associated with less IRI, improved hepatocellular function, and better preserved mitochondrial and endothelial function compared to conventional static cold storage (SCS). Moreover, DHOPE was safely applied with promising results in a recently performed phase-1 study. The aim of the current study is to determine the efficacy of DHOPE in reducing the incidence of NAS after DCD liver transplantation.

METHODS

This is an international multicenter randomized controlled trial. Adult patients (≥18 yrs. old) undergoing transplantation of a DCD donor liver (Maastricht category III) will be randomized between the intervention and control group. In the intervention group, livers will be subjected to two hours of end-ischemic DHOPE after SCS and before implantation. In the control group, livers will be subjected to care as usual with conventional SCS only. Primary outcome is the incidence of symptomatic NAS diagnosed by a blinded adjudication committee. In all patients, magnetic resonance cholangiography will be obtained at six months after transplantation.

DISCUSSION

DHOPE is associated with reduced IRI of the bile ducts. Whether reduced IRI of the bile ducts leads to lower incidence of NAS after DCD liver transplantation can only be examined in a randomized controlled trial.

TRIAL REGISTRATION

The trial was registered in Clinicaltrials.gov in September 2015 with the identifier NCT02584283 .

Prevalence of Steatosis Hepatis in the Eurotransplant Region: Impact on Graft Acceptance Rates

Due to the shortage of liver allografts and the rising prevalence of fatty liver disease in the general population, steatotic liver grafts are considered for transplantation. This condition is an important risk factor for the outcome after transplantation. We here analyze the characteristics of the donor pool offered to the Charité – Universitätsmedizin Berlin from 2010 to 2016 with respect to liver allograft nonacceptance and steatosis hepatis. Of the 2653 organs offered to our center, 19.9% (n=527) were accepted for transplantation, 58.8% (n=1561) were allocated to other centers, and 21.3% (n = 565) were eventually discarded from transplantation. In parallel to an increase of the incidence of steatosis hepatis in the donor pool from 20% in 2010 to 30% in 2016, the acceptance rates for steatotic organs increased in our center from 22.3% to 51.5% in 2016 (p < 0.001), with the majority (86.9%; p > 0.001) having less than 30% macrovesicular steatosis hepatis. However, by 2016, the number of canceled transplantations due to higher grades of steatosis hepatis had significantly increased from 14.7% (n = 15) to 63.6% (42; p < 0.001). The rising prevalence of steatosis hepatis in the donor pool has led to higher acceptance rates of steatotic allografts. Nonetheless, steatosis hepatis remains a predominant phenomenon in discarded organs necessitating future concepts such as organ reconditioning to increase graft utilization.

Normothermic Ex-vivo Liver Perfusion and the Clinical Implications for Liver Transplantation

Despite significant improvements in outcomes after liver transplantation, many patients continue to die on the waiting list, while awaiting an available organ for transplantation. Organ shortage is not only due to an inadequate number of available organs, but also the inability to adequately assess and evaluate these organs prior to transplantation. Over the last few decades, ex-vivo perfusion of the liver has emerged as a useful technique for both improved organ preservation and assessment of organs prior to transplantation. Large animal studies have shown the superiority of ex-vivo perfusion over cold static storage. However, these studies have not, necessarily, been translatable to human livers. Small animal studies have been essential in understanding and improving this technology. Similarly, these results have yet to be translated into clinical use. A few Phase 1 clinical trials have shown promise and confirmed the viability of this technology. However, more robust studies are needed before ex-vivo liver perfusion can be widely accepted as the new clinical standard of organ preservation. Here, we aimed to review all relevant large and small animal research, as well as human liver studies on normothermic ex-vivo perfusion, and to identify areas of deficiency and opportunities for future research endeavors.

Influence of gut microbiota on the development and progression of nonalcoholic steatohepatitis

INTRODUCTION

Nonalcoholic steatohepatitis (NASH) is characterized by the presence of steatosis, inflammation, and ballooning degeneration of hepatocytes, with or without fibrosis. The prevalence of NASH has increased with the obesity epidemic, but its etiology is multifactorial. The current studies suggest the role of gut microbiota in the development and progression of NASH. The aim is to review the studies that investigate the relationship between gut microbiota and NASH. These review also discusses the pathophysiological mechanisms and the influence of diet on the gut-liver axis.

RESULT

The available literature has proposed mechanisms for an association between gut microbiota and NASH, such as: modification energy homeostasis, lipopolysaccharides (LPS)-endotoxemia, increased endogenous production of ethanol, and alteration in the metabolism of bile acid and choline. There is evidence to suggest that NASH patients have a higher prevalence of bacterial overgrowth in the small intestine and changes in the composition of the gut microbiota. However, there is still a controversy regarding the microbiome profile in this population. The abundance of Bacteroidetes phylum may be increased, decreased, or unaltered in NASH patients. There is an increase in the Escherichia and Bacteroides genus. There is depletion of certain taxa, such as Prevotella and Faecalibacterium.

CONCLUSION

Although few studies have evaluated the composition of the gut microbiota in patients with NASH, it is observed that these individuals have a distinct gut microbiota, compared to the control groups, which explains, at least in part, the genesis and progression of the disease through multiple mechanisms. Modulation of the gut microbiota through diet control offers new challenges for future studies.

Application of Perfusate With Human-Derived Oxygen Carrier Solution Under Subnormothermic Machine Perfusion for Donation After Cardiac Death Liver Grafts in Pigs

Oxygenation is necessary for aerobic metabolism, which maintains adenosine triphosphate within the graft organ. In recent years, some studies have demonstrated that subnormothermic machine perfusion (SNMP) with hemoglobin-based oxygen carriers has the potential to improve oxygen metabolism.

OBJECTIVE

The aim of this study was to evaluate the effectiveness of perfusate with human-derived hemoglobin vesicles (HbV) under SNMP in a pig model of donation after cardiac death.

MATERIALS AND METHODS

In this study, pig livers were procured with a warm ischemic time of 60 minutes and were preserved in 3 groups for 240 minutes. The preservation conditions were as follows: 4°C cold storage (Group 1); SNMP with University of Wisconsin perfusate alone (Group 2); and SNMP (21°C) with University of Wisconsin solution and HbV (hemoglobin, 0.6 mg/dL) perfusate (Group 3). All livers were perfused for 120 minutes using pig autologous blood machine perfusion (reperfusion phase). We investigated the aspartate transaminase level and hemodynamics (portal vein resistance and oxygen consumption) in the preservation and reperfusion phases. A histologic study (hematoxylin-eosin staining) was performed after 240 minutes of preservation.

RESULTS

The portal vein resistance of Group 3 was not increased in comparison with Group 2. During preservation, the oxygen consumption of Group 3 was higher than that of Group 2. However, the level of aspartate transaminase did not differ between Groups 2 and 3.

CONCLUSION

The present study revealed that perfusate with HbV increased the oxygen consumption of the donor liver during SNMP.

Normothermic Machine Preservation of the Liver: State of the Art

Purpose of Review

This review aims to introduce the concept of normothermic machine perfusion (NMP) and its role in liver transplantation. By discussing results from recent clinical studies and highlighting the potential opportunities provided by this technology, we aim to provide a greater insight into NMP and the role it can play to enhance liver transplantation.

Recent Findings

NMP has recently been shown to be both safe and feasible in liver transplantation and has also demonstrated its superiority to traditional cold storage in terms of early biochemical liver function. Through the ability to perform a viability assessment during preservation and extend preservation times, it is likely that an increase in organ utilisation will follow. NMP may facilitate the enhanced preservation with improved outcomes from donors after cardiac death and steatotic livers. Furthermore, it provides the exciting potential for liver-directed therapeutic interventions.

Summary

Evidence to date suggests that NMP facilitates the enhanced preservation of liver grafts with improved early post-transplant outcomes. The key role for this technology is to increase the number and quality of liver grafts available for transplantation and to reduce waiting list deaths.

The case for normothermic machine perfusion in liver transplantation

In recent years, there has been growing interest in normothermic machine perfusion (NMP) as a preservation method in liver transplantation. In most countries, because of a donor organ shortage, an unacceptable number of patients die while awaiting transplantation. In an attempt to increase the number of donor organs available, transplant teams are implanting a greater number of high-risk livers, including those from donation after circulatory death, older donors, and donors with steatosis. NMP maintains the liver ex vivo on a circuit by providing oxygen and nutrition at 37°C. This permits extended preservation times, the ability to perform liver viability assessment, and the potential for liver-directed therapeutic interventions during preservation. It is hoped that this technology may facilitate the enhanced preservation of marginal livers with improved posttransplant outcomes by reducing ischemia/reperfusion injury. Clinical trials have demonstrated its short-term superiority over cold storage in terms of early biochemical liver function, and it is anticipated that it may result in increased organ utilization, helping to reduce the number of wait-list deaths. However, further studies are required to demonstrate longer-term efficacy and the impact on biliary complications as well as further knowledge to exploit and maximize the potential of this exciting new technology. Liver Transplantation 24 269-275 2018 AASLD.

Liver Transplant for Unusually Large Polycystic Liver Disease: Challenges and Pitfalls

Patients with polycystic liver disease are described in the literature as both recipient and donor for liver transplant. Due to well-preserved liver function, it is often difficult for these patients to receive an organ. Livers of these patients are often large and heavier than a normal organ. We describe two cases who had exceedingly large livers, weighing 14 and 19 kg. To the best of our knowledge and search, these are some of the heaviest explanted livers, and one of the patients incidentally received a liver from a donor with ADPKD. The aim of this report is to discuss the challenges and pitfalls of evaluating and listing, technical aspect of the transplant, possibility of transplanting a liver from a donor with a genetic cystic disease to a cystic disease recipient, and the related literature with some highlights on the facts from UNOS/OPTN data.

Liver biopsy in assessment of extended criteria donors

The safety and liver utilization with prerecovery liver biopsy (PLB) in extended criteria liver donors are unclear. We conducted a retrospective cohort study in 1323 brain death donors (PLB = 496) from 3 organ procurement organizations (OPOs). Outcomes were complications, preempted liver recovery (PLR), and liver transplantation (LT). Additional analyses included liver-only and propensity score-matched multiorgan donor subgroups. PLB donors were older (57 versus 53 years; P < 0.001). Hepatitis C antibody positivity (14.3% versus 9.6%, P = 0.01) and liver-only donors (42.6% versus 17.5%; P < 0.001) were more prevalent. The PLB cohort had fewer complications (31.9% versus 42.3%; P < 0.001). In the PLB cohort, PLR was significantly higher (odds ratio [OR], 3.45; 95% confidence interval [CI], 2.42-4.92) and LT lower (OR, 0.69; 95% CI, 0.52-0.91). In liver-only and propensity score-matched multiorgan donor subgroups, PLR was significantly higher (OR, 1.76; 95% CI, 1.06-2.94 and OR, 2.29; 95% CI, 1.37-3.82, respectively) without a decrease in LT (OR, 0.71; 95% CI, 0.43-1.18 and OR, 0.91; 95% CI, 0.63-1.33, respectively) in PLB subgroups. In conclusion, in extended criteria liver donors, PLB is safe and decreases futile liver recovery without decreasing LT. Increased use of PLB, especially in liver-only donors, is likely to save costs to OPOs and transplant centers and improve efficiencies in organ allocation. Liver Transplantation 24 182-191 2018 AASLD.

The Implications of the Shift Toward Donation After Circulatory Death in Australia

BACKGROUND

In recent years, an increasing number of donor livers are being declined for transplantation in Australia. The aim of this study was to evaluate the impact of donation after cardiac death and other factors associated with organ quality on liver utilization rates in Australia.

METHODS

Data on organ donors who donated at least 1 organ between 2005 and 2014 were obtained from the Australia and New Zealand organ donation registry. Temporal changes in donor characteristics were assessed and a logistical regression analysis was performed to evaluate their association with liver nonuse.

RESULTS

The number of organ donors increased from 175 in 2005 to 344 in 2014, with overall 19% being donation after cardiac death donors (P < 0.001). The percentage of livers deemed unsuitable for transplantation increased from 24% in 2005 to 41% in 2014 (P < 0.001). Donation after cardiac death was identified as the most important risk factor for nonuse with an odds ratio of 25.88 (95% confidence interval, 18.84-35.56), P < 0.001) followed by donor age, obesity, and diabetes.

DISCUSSION

This study shows that livers donated after circulatory death are an underused resource in Australia. Better use of these currently available organs would be a highly cost-effective way of reducing waiting list mortality in liver transplantation.

Cold storage or normothermic perfusion for liver transplantation: probable application and indications

PURPOSE OF REVIEW

Preservation of the liver via normothermic machine perfusion (NMP) is rapidly becoming an area of great academic and clinical interest. This review focuses on the benefits and limitations of NMP and where the role for static cold storage may lie.

RECENT FINDINGS

Clinical studies have recently been published reporting the use of NMP in liver preservation for transplantation. They have described the technology to be well tolerated and feasible with potentially improved posttransplant outcomes. NMP facilitates extended preservation times as well as the potential to increase organ utilization through viability assessment and regeneration. However, this technology is considerably more costly than cold storage and carries significant logistical challenges. Cold storage remains the gold standard preservation for standard criteria livers with good long-term patient and graft survival.

SUMMARY

NMP is an exciting new technological advancement in liver preservation, which is likely to have a positive impact in liver transplantation. However, randomized controlled trials are required to justify its inclusion into standard practice and provide evidence to support its efficacy.

Clinical outcomes of donation after circulatory death liver transplantation in primary sclerosing cholangitis

BACKGROUND & AIM

Primary sclerosing cholangitis (PSC) is a progressive fibro-inflammatory cholangiopathy for which liver transplantation is the only life-extending intervention. These patients may benefit from accepting liver donation after circulatory death (DCD), however their subsequent outcome is unknown. The aim of this study was to determine the clinical impact of using DCD liver grafts in patients specifically undergoing transplantation for PSC.

METHODS

Clinical outcomes were prospectively evaluated in PSC patients undergoing transplantation from 2006 to 2016 stratified by donor type (DCD, n=35 vs. donation after brainstem death [DBD], n=108).

RESULTS

In liver transplantation for PSC; operating time, days requiring critical care support, total ventilator days, incidence of acute kidney injury, need for renal replacement therapy (RRT) or total days requiring RRT were not significantly different between DCD vs. DBD recipients. Although the incidence of ischaemic-type biliary lesions was greater in the DCD group (incidence rate [IR]: 4.4 vs. 0 cases/100-patient-years; p<0.001) there was no increased risk of post-transplant biliary strictures overall (hazard ratio [HR]: 1.20, 0.58-2.46; p=0.624), or in sub-analysis specific to anastomotic strictures or recurrent PSC, between donor types. Graft loss and mortality rates were not significantly different following transplantation with DCD vs. DBD livers (IR: 3.6 vs. 3.1 cases/100-patient-years, p=0.34; and 3.9 vs. 4.7, p=0.6; respectively). DCD liver transplantation in PSC did not impart a heightened risk of graft loss (HR: 1.69, 0.58-4.95, p=0.341) or patient mortality (0.75, 0.25-2.21, p=0.598).

CONCLUSION

Transplantation with DCD (vs. DBD) livers in PSC patients does not impact graft loss or patient survival. In an era of organ shortage, DCD grafts represent a viable therapeutic option for liver transplantation in PSC patients. Lay summary: This study examines the impact of liver transplantation in primary sclerosing cholangitis (PSC) with organs donated after circulatory death (DCD), compared to donation after brainstem death (DBD). We show that in appropriately selected patients, the outcomes for DCD transplantation mirror those using DBD livers, with no significant differences in complication rate, patient survival or transplanted liver survival. In an era of organ shortage and increasing wait-list times, DCD livers represent a potential treatment option for transplantation in PSC.

Trends in Characteristics of Patients Listed for Liver Transplantation Will Lead to Higher Rates of Waitlist Removal Due to Clinical Deterioration

BACKGROUND

Changes in the epidemiology of end-stage liver disease may lead to increased risk of dropout from the liver transplant waitlist. Anticipating the future of liver transplant waitlist characteristics is vital when considering organ allocation policy.

METHODS

We performed a discrete event simulation to forecast patient characteristics and rate of waitlist dropout. Estimates were simulated from 2015 to 2025. The model was informed by data from the Organ Procurement and Transplant Network, 2003 to 2014. National data are estimated along with forecasts for 2 regions.

RESULTS

Nonalcoholic steatohepatitis will increase from 18% of waitlist additions to 22% by 2025. Hepatitis C will fall from 30% to 21%. Listings over age 60 years will increase from 36% to 48%. The hazard of dropout will increase from 41% to 46% nationally. Wait times for transplant for patients listed with a Model for End-Stage Liver Disease (MELD) between 22 and 27 will double. Region 5, which transplants at relatively higher MELD scores, will experience an increase from 53% to 64% waitlist dropout. Region 11, which transplants at lower MELD scores, will have an increase in waitlist dropout from 30% to 44%.

CONCLUSIONS

The liver transplant waitlist size will remain static over the next decade due to patient dropout. Liver transplant candidates will be older, more likely to have nonalcoholic steatohepatitis and will wait for transplantation longer even when listed at a competitive MELD score. There will continue to be significant heterogeneity among transplant regions where some patients will be more likely to drop out of the waitlist than receive a transplant.

Effect of organ donation after circulatory determination of death on number of organ transplants from donors with neurologic determination of death

BACKGROUND

To increase the available pool of organ donors, Ontario introduced donation after circulatory determination of death (DCD) in 2006. Other jurisdictions have reported a decrease in donations involving neurologic determination of death (NDD) after implementation of DCD, with a drop in organ yield and quality. In this study, we examined the effect of DCD on overall transplant activity in Ontario.

METHODS

We examined deceased donor and organ transplant activity during 3 distinct 4-year eras: pre-DCD (2002/03 to 2005/06), early DCD (2006/07 to 2009/10) and recent DCD (2010/11 to 2013/14). We compared these donor groups by categorical characteristics.

RESULTS

Donation increased by 57%, from 578 donors in the pre-DCD era to 905 donors in the recent DCD era, with a 21% proportion (190/905) of DCD donors in the recent DCD era. However, overall NDD donation also increased. The mean length of hospital stay before declaration for NDD was 2.7 days versus 6.0 days before withdrawal of life support and subsequent asystole in cases of DCD. The average organ yield was 3.73 with NDD donation versus 2.58 with DCD (p < 0.001). Apart from hearts, all organs from DCD donors were successfully transplanted. From the pre-DCD era to the recent DCD era, transplant activity in each era increased for all solid-organ recipients, including heart (from 158 to 216), kidney (from 821 to 1321), liver (from 477 to 657) and lung (from 160 to 305).

INTERPRETATION

Implementation of DCD in Ontario led to increased transplant activity for all solid-organ recipients. There was no evidence that the use of DCD was pre-empting potential NDD donation. In contrast to groups receiving other organs, heart transplant candidates have not yet benefited from DCD.

Organ Procurement Organization Survey of Practices and Beliefs Regarding Prerecovery Percutaneous Liver Biopsy in Donation After Neurologic Determination of Death

BACKGROUND

Prerecovery liver biopsy (PLB) allows histological evaluation of the organ before procurement. The opinions and what factors might influence PLB use within Organ Procurement Organizations (OPOs) are unknown.

METHODS

A survey instrument was distributed by the Association of OPOs to the clinical directors of all 58 OPOs. Descriptive statistics were calculated. Results were also stratified based on OPO characteristics.

RESULTS

Forty-nine (84.5%) of 58 OPOs responded to the survey; 40 (81.6%) of 49 currently perform PLB. This did not vary based on land mass, population, livers discarded, transplanted, donor age, or recipient MELD scores. Donor age, obesity, alcohol abuse, hepatitis serology, liver only donor, imaging results, and transplant center request were the most common indications for PLB in over 80% of OPOs. The median rate of performance is 5% to 10% of donors. Most use interventional radiologists to perform and the donor hospital pathologist/s to interpret PLB. Most OPOs believe PLBs are safe, reliable, useful, and performed often enough. Most say they did not believe they are easy to obtain. Beliefs were mixed regarding accuracy. The topics likely to influence PLB use were utility and accuracy of PLB, and availability of staff to perform PLB. OPOs that perform PLB more often were more likely to have favorable opinions of safety and pathologist availability, and more influenced by safety, reliability, availability, and a national consensus on the use of PLB.

CONCLUSIONS

Considerable variability exists in the use of PLB. Additional information on the utility, accuracy, and safety of PLB are needed to optimize its use.

Trends in brain-dead organ donor characteristics: a 13-year analysis

BACKGROUND

Driven by disease trends, such as obesity and metabolic syndrome, that are increasingly prevalent in the general population, we aimed to evaluate the comorbidities and attributes of the brain-dead organ donor population over time in a longitudinal study.

METHODS

We compared overall health and baseline attributes of organ donors between 2000-2005 and 2006-2012 using our prospective transplant database. Descriptive and comparative analyses of the 2 historical cohorts were performed.

RESULTS

A total of 1040 brain-dead organ donors were included in our analysis: 496 from the 2000-2005 period and 544 from the 2006-2012 period. Our analysis revealed that donors from the recent (2006-2012) period were more likely to have increased body mass index (26.4 ± 6.0 v. 25.0 ± 4.8, p = 0.003), smoking history (57.0% v. 27.2%, p < 0.001), coronary artery disease (14.3% v. 3.2%, p = 0.015) and dyslipidemia (19.1% v. 4.2%, p < 0.001), but less likely to have concurrent infection (1.1% v. 7.9%, p < 0.001) than those from the earlier period.

CONCLUSION

Our data suggest that the characteristics and comorbidities of brain-dead organ donors have somewhat deteriorated over the last decade. Further studies are needed to evaluate the impact of these health attributes on donated organ utilization and outcomes.

NAFLD and liver transplantation: Current burden and expected challenges

Because of global epidemics of obesity and type 2 diabetes, the prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing both in Europe and the United States, becoming one of the most frequent causes of chronic liver disease and predictably, one of the leading causes of liver transplantation both for end-stage liver disease and hepatocellular carcinoma. For most transplant teams around the world this will raise many challenges in terms of pre- and post-transplant management. Here we review the multifaceted impact of NAFLD on liver transplantation and will discuss: (1) NAFLD as a frequent cause of cryptogenic cirrhosis, end-stage chronic liver disease, and hepatocellular carcinoma; (2) prevalence of NAFLD as an indication for liver transplantation both in Europe and the United States; (3) the impact of NAFLD on the donor pool; (4) the access of NAFLD patients to liver transplantation and their management on the waiting list in regard to metabolic, renal and vascular comorbidities; (5) the prevalence and consequences of post-transplant metabolic syndrome, recurrent and de novo NAFLD; (6) the alternative management and therapeutic options to improve the long-term outcomes with particular emphasis on the correction and control of metabolic comorbidities.

Machine Perfusion of Porcine Livers with Oxygen-Carrying Solution Results in Reprogramming of Dynamic Inflammation Networks

Background:Ex vivo machine perfusion (MP) can better preserve organs for transplantation. We have recently reported on the first application of an MP protocol in which liver allografts were fully oxygenated, under dual pressures and subnormothermic conditions, with a new hemoglobin-based oxygen carrier (HBOC) solution specifically developed for ex vivo utilization. In those studies, MP improved organ function post-operatively and reduced inflammation in porcine livers. Herein, we sought to refine our knowledge regarding the impact of MP by defining dynamic networks of inflammation in both tissue and perfusate.

Methods: Porcine liver allografts were preserved either with MP (n = 6) or with cold static preservation (CSP; n = 6), then transplanted orthotopically after 9 h of preservation. Fourteen inflammatory mediators were measured in both tissue and perfusate during liver preservation at multiple time points, and analyzed using Dynamic Bayesian Network (DyBN) inference to define feedback interactions, as well as Dynamic Network Analysis (DyNA) to define the time-dependent development of inflammation networks.

Results: Network analyses of tissue and perfusate suggested an NLRP3 inflammasome-regulated response in both treatment groups, driven by the pro-inflammatory cytokine interleukin (IL)-18 and the anti-inflammatory mediator IL-1 receptor antagonist (IL-1RA). Both DyBN and DyNA suggested a reduced role of IL-18 and increased role of IL-1RA with MP, along with increased liver damage with CSP. DyNA also suggested divergent progression of responses over the 9 h preservation time, with CSP leading to a stable pattern of IL-18-induced liver damage and MP leading to a resolution of the pro-inflammatory response. These results were consistent with prior clinical, biochemical, and histological findings after liver transplantation.

Conclusion: Our results suggest that analysis of dynamic inflammation networks in the setting of liver preservation may identify novel diagnostic and therapeutic modalities.

The Current State of Liver Transplantation in the United States: Perspective From American Society of Transplant Surgeons (ASTS) Scientific Studies Committee and Endorsed by ASTS Council

This article is a review of the salient points and a future prospective based on the 2014 Organ Procurement and Transplantation Network (OPTN)/Scientific Registry of Transplant Recipients (SRTR) liver donation and transplantation data report recently published by the American Journal of Transplantation. Emphasis of our commentary and interpretation is placed on data relating to waitlist dynamics, organ utilization rates, the impact of recent advances in the treatment of hepatitis C, and the increases in end-stage renal disease among liver transplant candidates. Finally, we share our vision on potential areas of innovation that are likely to significantly improve the field of liver transplantation in the near future.

Donations After Circulatory Death in Liver Transplant

The supply of liver grafts for treatment of end-stage liver disease continues to fall short of ongoing demands. Currently, most liver transplants originate from donations after brain death. Enhanced utilization of the present resources is prudent to address the needs of the population. Donation after circulatory or cardiac death is a mechanism whereby the availability of organs can be expanded. Donations after circulatory death pose unique challenges given their exposure to warm ischemia. Technical principles of donations after circulatory death procurement and pertinent studies investigating patient outcomes, graft outcomes, and complications are highlighted in this review. We also review associated risk factors to suggest potential avenues to achieve improved outcomes and reduced complications. Future considerations and alternative techniques of organ preservation are discussed, which may suggest novel strategies to enhance preservation and donor expansion through the use of marginal donors. Ultimately, without effective measures to bolster organ supply, donations after circulatory death should remain a consideration; however, an understanding of inherent risks and limitations is necessary.

Normothermic machine perfusion reduces bile duct injury and improves biliary epithelial function in rat donor livers

Bile duct injury may occur during liver procurement and transplantation, especially in livers from donation after circulatory death (DCD) donors. Normothermic machine perfusion (NMP) has been shown to reduce hepatic injury compared to static cold storage (SCS). However, it is unknown whether NMP provides better preservation of bile ducts. The aim of this study was to determine the impact of NMP on bile duct preservation in both DCD and non-DCD livers. DCD and non-DCD livers obtained from Lewis rats were preserved for 3 hours using either SCS or NMP, followed by 2 hours ex vivo reperfusion. Biomarkers of bile duct injury (gamma-glutamyltransferase and lactate dehydrogenase in bile) were lower in NMP-preserved livers compared to SCS-preserved livers. Biliary bicarbonate concentration, reflecting biliary epithelial function, was 2-fold higher in NMP-preserved livers (P < 0.01). In parallel with this, the pH of the bile was significantly higher in NMP-preserved livers (7.63 ± 0.02 and 7.74 ± 0.05 for non-DCD and DCD livers, respectively) compared with SCS-preserved livers (7.46 ± 0.02 and 7.49 ± 0.04 for non-DCD and DCD livers, respectively). Scanning and transmission electron microscopy of donor extrahepatic bile ducts demonstrated significantly decreased injury of the biliary epithelium of NMP-preserved donor livers (including the loss of lateral interdigitations and mitochondrial injury). Differences between NMP and SCS were most prominent in DCD livers. Compared to conventional SCS, NMP provides superior preservation of bile duct epithelial cell function and morphology, especially in DCD donor livers. By reducing biliary injury, NMP could have an important impact on the utilization of DCD livers and outcome after transplantation. Liver Transplantation 22 994-1005 2016 AASLD.

An ultrasonic caliper device for measuring acoustic nonlinearity

In medical and industrial ultrasound, it is often necessary to measure the acoustic properties of a material. A specific medical application requires measurements of sound speed, attenuation, and nonlinearity to characterize livers being evaluated for transplantation. For this application, a transmission-mode caliper device is proposed in which both transmit and receive transducers are directly coupled to a test sample, the propagation distance is measured with an indicator gage, and receive waveforms are recorded for analysis. In this configuration, accurate measurements of nonlinearity present particular challenges: diffraction effects can be considerable while nonlinear distortions over short distances typically remain small. To enable simple estimates of the nonlinearity coefficient from a quasi-linear approximation to the lossless Burgers' equation, the calipers utilize a large transmitter and plane waves are measured at distances of 15-50 mm. Waves at 667 kHz and pressures between 0.1 and 1 MPa were generated and measured in water at different distances; the nonlinearity coefficient of water was estimated from these measurements with a variability of approximately 10%. Ongoing efforts seek to test caliper performance in other media and improve accuracy via additional transducer calibrations.

Lipidomics comparing DCD and DBD liver allografts uncovers lysophospholipids elevated in recipients undergoing early allograft dysfunction

Finding specific biomarkers of liver damage in clinical evaluations could increase the pool of available organs for transplantation. Lipids are key regulators in cell necrosis and hence this study hypothesised that lipid levels could be altered in organs suffering severe ischemia. Matched pre- and post-transplant biopsies from donation after circulatory death (DCD, n = 36, mean warm ischemia time = 2 min) and donation after brain death (DBD, n = 76, warm ischemia time = none) were collected. Lipidomic discovery and multivariate analysis (MVA) were applied. Afterwards, univariate analysis and clinical associations were conducted for selected lipids differentiating between these two groups. MVA grouped DCD vs. DBD (p = 6.20 × 10(-12)) and 12 phospholipids were selected for intact lipid measurements. Two lysophosphatidylcholines, LysoPC (16:0) and LysoPC (18:0), showed higher levels in DCD at pre-transplantation (q < 0.01). Lysophosphatidylcholines were associated with aspartate aminotransferase (AST) 14-day post-transplantation (q < 0.05) and were more abundant in recipients undergoing early allograft dysfunction (EAD) (p < 0.05). A receiver-operating characteristics (ROC) curve combining both lipid levels predicted EAD with 82% accuracy. These findings suggest that LysoPC (16:0) and LysoPC (18:0) might have a role in signalling liver tissue damage due to warm ischemia before transplantation.

Predicting Liver Transplant Capacity Using Discrete Event Simulation

The number of liver transplants (LTs) performed in the US increased until 2006 but has since declined despite an ongoing increase in demand. This decline may be due in part to decreased donor liver quality and increasing discard of poor-quality livers. We constructed a discrete event simulation (DES) model informed by current donor characteristics to predict future LT trends through the year 2030. The data source for our model is the United Network for Organ Sharing database, which contains patient-level information on all organ transplants performed in the US. Previous analysis showed that liver discard is increasing and that discarded organs are more often from donors who are older, are obese, have diabetes, and donated after cardiac death. Given that the prevalence of these factors is increasing, the DES model quantifies the reduction in the number of LTs performed through 2030. In addition, the model estimatesthe total number of future donors needed to maintain the current volume of LTs and the effect of a hypothetical scenario of improved reperfusion technology.We also forecast the number of patients on the waiting list and compare this with the estimated number of LTs to illustrate the impact that decreased LTs will have on patients needing transplants. By altering assumptions about the future donor pool, this model can be used to develop policy interventions to prevent a further decline in this lifesaving therapy. To our knowledge, there are no similar predictive models of future LT use based on epidemiological trends.

Declining liver graft quality threatens the future of liver transplantation in the United States

National liver transplantation (LT) volume has declined since 2006, in part because of worsening donor organ quality. Trends that degrade organ quality are expected to continue over the next 2 decades. We used the United Network for Organ Sharing (UNOS) database to inform a 20-year discrete event simulation estimating LT volume from 2010 to 2030. Data to inform the model were obtained from deceased organ donors between 2000 and 2009. If donor liver utilization practices remain constant, utilization will fall from 78% to 44% by 2030, resulting in 2230 fewer LTs. If transplant centers increase their risk tolerance for marginal grafts, utilization would decrease to 48%. The institution of "opt-out" organ donation policies to increase the donor pool would still result in 1380 to 1866 fewer transplants. Ex vivo perfusion techniques that increase the use of marginal donor livers may stabilize LT volume. Otherwise, the number of LTs in the United States will decrease substantially over the next 15 years. In conclusion, the transplant community will need to accept inferior grafts and potentially worse posttransplant outcomes and/or develop new strategies for increasing organ donation and utilization in order to maintain the number of LTs at the current level.

Normothermic perfusion machine in liver transplant with cardiac death donor grafts

The increasing difference between the number of patients in waiting lists for liver transplantation and the number of available donors has generated a great interest in the use of non-ideal organs, like grafts obtained from cardiac death donors (DCD). However, the extreme sensibility to ischemia of these livers results in a low utilization rate and a high percentage of post-transplant complications and re-transplantation. Normothermic perfusion machines (NMP) emerged as an alternative that tries to maintain the viability of the organ and even to improve its function. This review focuses on current results of DCD liver transplantation and on the role that NMP may have in this field.

Functional Implications of Biochemical and Molecular Characteristics of Donation After Circulatory Death Livers

Supplemental digital content is available in the text.

In aggregate, livers donated after circulatory death (DCD) provide lower rates of graft and patient survival compared to brain dead donors (DBD). A method to identify DCD livers likely to perform well would lead to better decision-making regarding which livers to use and which to discard and is an important unmet clinical need. We hypothesized that the ischemic time between extubation and cold perfusion in the donor leads to immediate and unique biochemical and molecular changes that could be used to predict subsequent function.

Donation after cardiac death liver transplantation: Graft quality evaluation based on pretransplant liver biopsy

Donation after cardiac death (DCD) liver grafts are associated with inferior clinical outcomes and high discard rates because of poor graft quality. We investigated the predictive value of DCD liver biopsy for the pretransplant graft quality evaluation. DCD liver transplants that took place between October 2010 and April 2014 were included (n = 127). Histological features of graft biopsy samples were analyzed to assess risk factors for graft survival. Macrovesicular steatosis ≥ 20% [hazard ratio (HR) = 2.973; P = 0.045] and sinusoidal neutrophilic infiltrate (HR = 6.969; P = 0.005) were confirmed as independent risk factors for graft survival; hepatocellular swelling, vacuolation, and necrosis failed to show prognostic value. Additionally, a donor serum total bilirubin level ≥ 34.2 μmol/L was also associated with a lower probability of graft survival. Our analysis indicates that macrovesicular steatosis ≥ 20% and sinusoidal neutrophilic infiltrate are novel and useful histological markers for DCD liver grafts with unacceptable quality. This finding can be used by transplant surgeons to improve DCD liver acceptance protocols.

Clinical outcomes and quality of life in recipients of livers donated after cardiac death

Donation after cardiac death (DCD) has expanded in the last decade in the US; however, DCD liver utilization has flattened in recent years due to poor outcomes. We examined clinical and quality of life (QOL) outcomes of DCD recipients by conducting a retrospective and cross-sectional review of patients from 2003 to 2010. We compared clinical outcomes of DCD recipients (n = 60) to those of donation after brain death (DBD) liver recipients (n = 669) during the same time period. DCD recipients had significantly lower rates of 5-year graft survival (P < 0.001) and a trend toward lower rates of 5-year patient survival (P = 0.064) when compared to the DBD cohort. In order to examine QOL outcomes in our cohorts, we administered the Short Form Liver Disease Quality of Life questionnaire to 30 DCD and 60 DBD recipients. The DCD recipients reported lower generic and liver-specific QOL. We further stratified the DCD cohort by the presence of ischemic cholangiopathy (IC). Patients with IC reported lower QOL when compared to DBD recipients and those DCD recipients without IC (P < 0.05). While the results are consistent with clinical experience, this is the first report of QOL in DCD recipients using standardized measures. These data can be used to guide future comparative effectiveness studies.

Nonalcoholic steatohepatitis is the second leading etiology of liver disease among adults awaiting liver transplantation in the United States

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) has been predicted to become the leading indication for liver transplantation (LT) in the United States. However, few studies have evaluated changes in the etiology of liver diseases among patients awaiting LT, and none have focused on the effects of NASH on liver transplant waitlists in the United States.

METHODS

We collected data from the United Network for Organ Sharing and Organ Procurement and Transplantation Network registry from 2004 through 2013, on liver transplant waitlist registrants with hepatitis C virus (HCV) infection, NASH, alcoholic liver disease (ALD), or a combination of HCV infection and ALD. We compared differences in survival within 90 days of registration (90-day survival) and probability of LT among patients with different diseases using Kaplan-Meier and multivariate logistic regression models.

RESULTS

Between 2004 and 2013, new waitlist registrants with NASH increased by 170% (from 804 to 2174), with ALD increased by 45% (from 1400 to 2024), and with HCV increased by 14% (from 2887 to 3291); registrants with HCV and ALD decreased by 9% (from 880 to 803). In 2013, NASH became the second-leading disease among liver transplant waitlist registrants, after HCV. Patients with ALD had a significantly higher mean Model for End-Stage Liver Disease score at time of waitlist registration than other registrants. However, after multivariate adjustment, patients with ALD were less likely to die within 90 days when compared with patients with NASH (odds ratio [OR] = 0.77; 95% confidence interval [CI]: 0.67-0.89; P < .001); patients with HCV infection or HCV and ALD had similar odds for 90-day survival compared with NASH patients. Compared with patients with NASH, patients with HCV (OR = 1.45; 95% CI: 1.35-1.55; P < .001), ALD (OR = 1.15; 95% CI: 1.06-1.24; P < .001), or HCV and ALD (OR = 1.29; 95% CI: 1.18-1.42; P < .001) had higher odds for 90-day survival.

CONCLUSIONS

Based on data from US adult LT databases, since 2004 the number of adults with NASH awaiting LTs has almost tripled. However, patients with NASH are less likely to undergo LT and less likely to survive for 90 days on the waitlist than patients with HCV, ALD, or HCV and ALD.

Thrombolytic protocol minimizes ischemic-type biliary complications in liver transplantation from donation after circulatory death donors

Liver transplantation (LT) with donation after circulatory death (DCD) donors has been associated with a high rate of ischemic-type biliary strictures (ITBSs) and inferior graft survival. To investigate the impact of an intraoperative tissue plasminogen activator (tPA) on outcomes following DCD LT, we conducted a retrospective analysis of DCD LT at the Toronto General Hospital (TGH) and the Ochsner Medical Center (OMC). Between 2009 and 2013, 85 DCD LTs were performed with an intraoperative tPA injection (n = 30 at TGH, n = 55 at OMC), and they were compared with 33 DCD LTs without a tPA. Donor and recipient characteristics were similar in the 2 groups. There was no significant difference in the intraoperative packed red blood cell transfusion requirement (3.2 ± 3.4 versus 3.1 ± 2.3 U, P = 0.74). Overall, biliary strictures occurred less commonly in the tPA-treated group (16.5% versus 33.3%, P = 0.07) with a much lower rate of diffuse intrahepatic strictures (3.5% versus 21.2%, P = 0.005). After 1 and 3 years, the tPA group versus the non-tPA group had superior patient survival (97.6% versus 87.0% and 92.7% versus 79.7%, P = 0.016) and graft survival (96.4% versus 69.7% and 90.2% versus 63.6%, P < 0.001). In conclusion, a tPA injection into the hepatic artery during DCD LT reduces ITBSs and improves graft and patient survival without increasing the risk for bleeding.

Liver preservation with machine perfusion and a newly developed cell-free oxygen carrier solution under subnormothermic conditions

We describe a new preservation modality combining machine perfusion (MP) at subnormothermic conditions(21 °C) with a new hemoglobin-based oxygen carrier (HBOC) solution. MP (n=6) was compared to cold static preservation (CSP; n=6) in porcine orthotopic liver transplants after 9 h of cold ischemia and 5-day follow-up. Recipients' peripheral blood, serial liver biopsies, preservation solutions and bile specimens were collected before, during and after liver preservation. Clinical laboratorial and histological analyses were performed in addition to mitochondrial functional assays, transcriptomic, metabolomic and inflammatory inflammatory mediator analyses. Compared with CSP, MP animals had: (1) significantly higher survival (100%vs. 33%; p<0.05); (2) superior graft function (p<0.05);(3) eight times higher hepatic O2 delivery than O2 consumption (0.78 mL O2/g/h vs. 0.096 mL O2/g/h) during MP; and (4) significantly greater bile production (MP=378.5 ± 179.7; CS=151.6 ± 116.85). MP downregulated interferon (IFN)-α and IFN-γ in liver tissue. MP allografts cleared lactate, produced urea, sustained gluconeogenesis and produced hydrophilic bile after reperfusion. Enhanced oxygenation under subnormothermic conditions triggers regenerative and cell protective responses resulting in improved allograft function. MP at 21 °C with the HBOC solution significantly improves liver preservation compared to CSP.

Hypothermic machine preservation facilitates successful transplantation of "orphan" extended criteria donor livers

Hypothermic machine preservation (HMP) remains investigational in clinical liver transplantation. It is widely used to preserve kidneys for transplantation with improved results over static cold storage (SCS). At our center, we have used HMP in 31 adults receiving extended criteria donor (ECD) livers declined by the originating United Network for Organ Sharing region ("orphan livers"). These cases were compared to ECD SCS cases in a matched cohort study design. Livers were matched for donor age, recipient age, cold ischemic time, donor risk index and Model for End-Stage Liver Disease (MELD) score. HMP was performed for 3-7 h at 4-8 °C using our previously published protocol. Early allograft dysfunction rates were 19% in the HMP group versus 30% in the control group (p = 0.384). One-year patient survival was 84% in the HMP group versus 80% in the SCS group (p = NS). Post hoc analysis revealed significantly less biliary complications in the HMP group versus the SCS group (4 vs. 13, p = 0.016). Mean hospital stay was significantly shorter in the HMP group (13.64 ± 10.9 vs. 20.14 ± 11.12 days in the SCS group, p = 0.001). HMP provided safe and reliable preservation in orphan livers transplanted at our center.

Criteria for viability assessment of discarded human donor livers during ex vivo normothermic machine perfusion

Although normothermic machine perfusion of donor livers may allow assessment of graft viability prior to transplantation, there are currently no data on what would be a good parameter of graft viability. To determine whether bile production is a suitable biomarker that can be used to discriminate viable from non-viable livers we have studied functional performance as well as biochemical and histological evidence of hepatobiliary injury during ex vivo normothermic machine perfusion of human donor livers. After a median duration of cold storage of 6.5 h, twelve extended criteria human donor livers that were declined for transplantation were ex vivo perfused for 6 h at 37 °C with an oxygenated solution based on red blood cells and plasma, using pressure controlled pulsatile perfusion of the hepatic artery and continuous portal perfusion. During perfusion, two patterns of bile flow were identified: (1) steadily increasing bile production, resulting in a cumulative output of ≥ 30 g after 6 h (high bile output group), and (2) a cumulative bile production <20 g in 6 h (low bile output group). Concentrations of transaminases and potassium in the perfusion fluid were significantly higher in the low bile output group, compared to the high bile output group. Biliary concentrations of bilirubin and bicarbonate were respectively 4 times and 2 times higher in the high bile output group. Livers in the low bile output group displayed more signs of hepatic necrosis and venous congestion, compared to the high bile output group. In conclusion, bile production could be an easily assessable biomarker of hepatic viability during ex vivo machine perfusion of human donor livers. It could potentially be used to identify extended criteria livers that are suitable for transplantation. These ex vivo findings need to be confirmed in a transplant experiment or a clinical trial.

Obesity and the liver: nonalcoholic fatty liver disease

The increasing prevalence of nonalcoholic fatty liver disease (NAFLD) parallels the rise of obesity and its complications. NAFLD is a common cause of cirrhosis and a leading indication for liver transplant. Genetic susceptibility, dietary composition, and exercise habits influence the development of NAFLD, and insulin resistance results in widespread metabolic perturbations with a net effect of triglyceride accumulation in the liver. Some patients will develop hepatocyte cellular injury and fibrosis of the liver, which can progress to cirrhosis and require liver transplant. Treatments targeting the pathophysiological mechanisms of NAFLD exist, but carry some potential risk and are not universally effective. Weight loss and lifestyle changes remain the most effective and safest approach, but sustainable change is difficult for most patients to achieve. Future work will continue to focus on developing effective and safe interventions to prevent the development of advanced liver disease, whereas efforts in the public health domain continue to combat obesity.

"Resuscitation" of marginal liver allografts for transplantation with machine perfusion technology

As the rate of medically suitable donors remains relatively static worldwide, clinicians have looked to novel methods to meet the ever-growing demand of the liver transplant waiting lists worldwide. Accordingly, the transplant community has explored many strategies to offset this deficit. Advances in technology that target the ex vivo "preservation" period may help increase the donor pool by augmenting the utilization and improving the outcomes of marginal livers. Novel ex vivo techniques such as hypothermic, normothermic, and subnormothermic machine perfusion may be useful to "resuscitate" marginal organs by reducing ischemia/reperfusion injury. Moreover, other preservation techniques such as oxygen persufflation are explored as they may also have a role in improving function of "marginal" liver allografts. Currently, marginal livers are frequently discarded or can relegate the patient to early allograft dysfunction and primary non-function. Bench to bedside advances are rapidly emerging and hold promise for expanding liver transplantation access and improving outcomes.

Pilot test of a patient decision aid about liver transplant organ quality

Prior studies have shown that patients are reluctant to accept donor-specific risks, and transplant professionals lack an effective and time-efficient means of obtaining informed consent. We designed and pilot-tested a Web-based patient decision aid (DA) on organ quality. The DA was administered to 53 liver transplant candidates (median Model for End-Stage Liver Disease score = 14, range = 7-26), and they took a mean of 15 minutes to complete it. Questions about knowledge and attitudes were asked before and after the DA. Subjects' knowledge improved, with 53% and 60% correctly answering questions about hepatitis B virus and human immunodeficiency virus transmission before the DA and 94% and 100%, respectively, correctly answering them afterward (P < 0.001). The accuracy of mortality prediction also improved from a mean 3-month mortality estimate of 22% before the DA to 12% afterward (P < 0.001). After the DA, subjects felt that it was more likely that they might be offered a less-than-perfect liver (P = 0.001), and they were more likely to consider accepting such a liver (P < 0.001). In conclusion, implementing a Web-based patient DA is feasible and improves knowledge among liver transplant candidates. The use of this tool may decrease candidates' reluctance to accept extended criteria organs.

Improving outcomes in DCDD liver transplantation: there can only be strength in numbers

In the United States, liver transplantation using donation after circulatory determination of death (DCDD) donors is challenged by persistently inferior graft survival compared with donation after neurological death (DND), along with declining rates of liver transplantation relative to the total number of DCDD donors. Advances in adult-to-adult living donor liver transplantation graft survival temporally related to the Adult-to-Adult Living Donor Liver Transplantation Cohort Study consortium suggest that a similarly focused collaborative effort may serve to stimulate evolution within DCDD liver transplantation. Without a multi-center consortium to support innovative trials, the current state of DCDD liver transplantation is unlikely to progress.