Metabolic Considerations in Direct Procurement and Perfusion Protocols with DCD Heart Transplantation

Heart transplantation with donation after circulatory death (DCD) provides excellent patient outcomes and increases donor heart availability. However, unlike conventional grafts obtained through donation after brain death, DCD cardiac grafts are not only exposed to warm, unprotected ischemia, but also to a potentially damaging pre-ischemic phase after withdrawal of life-sustaining therapy (WLST). In this review, we aim to bring together knowledge about changes in cardiac energy metabolism and its regulation that occur in DCD donors during WLST, circulatory arrest, and following the onset of warm ischemia. Acute metabolic, hemodynamic, and biochemical changes in the DCD donor expose hearts to high circulating catecholamines, hypoxia, and warm ischemia, all of which can negatively impact the heart. Further metabolic changes and cellular damage occur with reperfusion. The altered energy substrate availability prior to organ procurement likely plays an important role in graft quality and post-ischemic cardiac recovery. These aspects should, therefore, be considered in clinical protocols, as well as in pre-clinical DCD models. Notably, interventions prior to graft procurement are limited for ethical reasons in DCD donors; thus, it is important to understand these mechanisms to optimize conditions during initial reperfusion in concert with graft evaluation and re-evaluation for the purpose of tailoring and adjusting therapies and ensuring optimal graft quality for transplantation.

Development and Validation of a Risk Score Predicting Death Without Transplant in Adult Heart Transplant Candidates

Importance

The US heart allocation system prioritizes medically urgent candidates with a high risk of dying without transplant. The current therapy-based 6-status system is susceptible to manipulation and has limited rank ordering ability.

Objective

To develop and validate a candidate risk score that incorporates current clinical, laboratory, and hemodynamic data.

Design, Setting, and Participants

A registry-based observational study of adult heart transplant candidates (aged ≥18 years) from the US heart allocation system listed between January 1, 2019, and December 31, 2022, split by center into training (70%) and test (30%) datasets. Adult candidates were listed between January 1, 2019, and December 31, 2022.

Main Outcomes and Measures

A US candidate risk score (US-CRS) model was developed by adding a predefined set of predictors to the current French Candidate Risk Score (French-CRS) model. Sensitivity analyses were performed, which included intra-aortic balloon pumps (IABP) and percutaneous ventricular assist devices (VAD) in the definition of short-term mechanical circulatory support (MCS) for the US-CRS. Performance of the US-CRS model, French-CRS model, and 6-status model in the test dataset was evaluated by time-dependent area under the receiver operating characteristic curve (AUC) for death without transplant within 6 weeks and overall survival concordance (c-index) with integrated AUC.

Results

A total of 16 905 adult heart transplant candidates were listed (mean [SD] age, 53 [13] years; 73% male; 58% White); 796 patients (4.7%) died without a transplant. The final US-CRS contained time-varying short-term MCS (ventricular assist-extracorporeal membrane oxygenation or temporary surgical VAD), the log of bilirubin, estimated glomerular filtration rate, the log of B-type natriuretic peptide, albumin, sodium, and durable left ventricular assist device. In the test dataset, the AUC for death within 6 weeks of listing for the US-CRS model was 0.79 (95% CI, 0.75-0.83), for the French-CRS model was 0.72 (95% CI, 0.67-0.76), and 6-status model was 0.68 (95% CI, 0.62-0.73). Overall c-index for the US-CRS model was 0.76 (95% CI, 0.73-0.80), for the French-CRS model was 0.69 (95% CI, 0.65-0.73), and 6-status model was 0.67 (95% CI, 0.63-0.71). Classifying IABP and percutaneous VAD as short-term MCS reduced the effect size by 54%.

Conclusions and Relevance

In this registry-based study of US heart transplant candidates, a continuous multivariable allocation score outperformed the 6-status system in rank ordering heart transplant candidates by medical urgency and may be useful for the medical urgency component of heart allocation.

Outcomes of Heart Transplantation Using a Temperature-controlled Hypothermic Storage System

BACKGROUND

The SherpaPak Cardiac Transport System is a novel technology that provides stable, optimal hypothermic control during organ transport. The objectives of this study were to describe our experience using the SherpaPak system and to compare outcomes after heart transplantation after using SherpaPak versus the conventional static cold storage method (non-SherpaPak).

METHODS

From 2018 to June 2021, 62 SherpaPak and 186 non-SherpaPak patients underwent primary heart transplantation at Stanford University with follow-up through May 2022. The primary end point was all-cause mortality, and secondary end points were postoperative complications. Optimal variable ratio matching, cox proportional hazards regression model, and Kaplan-Meier survival analyses were performed.

RESULTS

Before matching, the SherpaPak versus non-SherpaPak patients were older and received organs with significantly longer total allograft ischemic time. After matching, SherpaPak patients required fewer units of blood product for perioperative transfusion compared with non-SherpaPak patients but otherwise had similar postoperative outcomes such as hospital length of stay, primary graft dysfunction, inotrope score, mechanical circulatory support use, cerebral vascular accident, myocardial infarction, respiratory failure, new renal failure requiring dialysis, postoperative bleeding or tamponade requiring reoperation, infection, and survival.

CONCLUSIONS

In conclusion, this is one of the first retrospective comparison studies that evaluated the outcomes of heart transplantation using organs preserved and transported via the SherpaPak system. Given the excellent outcomes, despite prolonged total allograft ischemic time, it may be reasonable to adopt the SherpaPak system to accept organs from a remote location to further expand the donor pool.

Impact of donor kidney biopsy on kidney yield and posttransplant outcomes

Procurement biopsy is performed to determine kidney quality, but evidence supporting such association is poor. We investigated the impact of glomerulosclerosis percentage (GS%) on kidney yield and patient outcomes. Information on deceased kidney donors from July 1, 2017, to June 30, 2019, was collected. Association between GS% and kidney yield (number of kidneys procured per donor) and posttransplant graft and patient outcomes were studied. Maximal GS% and minimal GS% were calculated to determine the relationship between GS% and kidney yield; minimal GS% only for correlation with posttransplant outcomes. Multinomial logistic regression and Cox models with least absolute shrinkage and selection operator were used to analyze the association of GS% with kidney yield and posttransplant outcomes, respectively. The kidney yield was 1.63 when maximal GS% and minimal GS% were <5%, but was 0.88 when both GS% were >20%. The hazard ratio for graft failure 1 year after transplant was 1.05 when minimal GS% was 16% to 20%, but was 1.3 for GS% of >20%. The hazard ratio for mortality increased from 1 to 1.2 when minimal GS% reached >20%. In summary, higher GS% was associated with lower kidney yield and inferior posttransplant outcomes. Incorporation of GS% into Scientific Registry of Transplant Recipients models may reassure organ procurement organizations and transplant centers pursuing kidneys with relatively high GS% levels, thereby reducing kidney discard rates.

Outcomes of living liver donors are worse than those of matched healthy controls

BACKGROUND & AIMS

Donor death is the most serious complication of living liver donation but is reported rarely. We investigated the actual mortality of living liver donors (LLDs) compared with matched control groups based on analysis of the Korean National Health Insurance Services (NHIS) database.

METHODS

This cohort study included 12,372 LLDs who donated a liver graft between 2002 and 2018, and were registered in the Korean Network for Organ Sharing. They were compared to 3 matched control groups selected from the Korean NHIS and comprising a total of 123,710 individuals: healthy population (Group I); general population without comorbidities (Group II); and general population with comorbidities (Group III).

RESULTS

In this population, 78.5% of living liver donors were 20-39 years old, and 64.7% of all donors were male. Eighty-nine donors (0.7%) in the LLD group died (68 males and 21 females), a mortality rate (/1,000 person-years) of 0.91 (0.74-1.12). Mortality rate ratio and the adjusted hazard ratio of the LLD group was 2.03 (1.61-2.55) and 1.71 (1.31-2.25) compared to Control Group I, 0.75 (0.60-0.93) and 0.63 (0.49-0.82) compared to Control Group II, and 0.58 (0.46-0.71) and 0.49 (0.39-0.60) compared to Control Group III. LLD group, depression, and lower income were risk factors for adjusted mortality. The incidence of liver failure, depression, cancer, diabetes, hypertension, brain infarction, brain hemorrhage, and end-stage renal disease in the LLD group was significantly higher than in Control Group I.

CONCLUSIONS

Outcomes of the LLD group were worse than those of the matched healthy control group despite the small number of deaths and medical morbidities in this group. LLDs should receive careful medical attention for an extended period after donation.

LAY SUMMARY

The incidence of mortality, liver failure, depression, cancer, diabetes, hypertension, brain infarction, brain hemorrhage, and end-stage renal disease in the living liver donor group was significantly higher than in the matched healthy group. Careful donor evaluation and selection processes can improve donor safety and enable safe living donor liver transplantation.

Optimal Sequencing of Deceased Donor and Live Donor Kidney Transplant Among Pediatric Patients With Kidney Failure

IMPORTANCE

In the US, live donor (LD) kidney transplant rates have decreased in pediatric recipients. Pediatric patients with kidney failure will likely need more than 1 kidney transplant during their lifetime, but the optimal sequence of transplant (ie, deceased donor [DD] followed by LD or vice versa) is not known.

OBJECTIVE

To determine whether pediatric recipients should first receive a DD allograft followed by an LD allograft (DD-LD sequence) or an LD allograft followed by a DD allograft (LD-DD sequence).

DESIGN, SETTING, AND PARTICIPANTS

This decision analytical model examined US pediatric patients with kidney failure included in the US Renal Data System 2019 Report who were waiting for a kidney transplant, received a transplant, or experienced graft failure.

INTERVENTIONS

Kidney transplant sequences of LD-DD vs DD-LD.

MAIN OUTCOMES AND MEASURES

Difference in projected life-years between the 2 sequence options.

RESULTS

Among patients included in the analysis, the LD-DD sequence provided more net life-years in those 5 years of age (1.82 [95% CI, 0.87-2.77]) and 20 years of age (2.23 [95% CI, 1.31-3.15]) compared with the DD-LD sequence. The net outcomes in patients 10 years of age (0.36 [95% CI, -0.51 to 1.23] additional life-years) and 15 years of age (0.64 [95% CI, -0.15 to 1.39] additional life-years) were not significantly different. However, for those aged 10 years, an LD-DD sequence was favored if eligibility for a second transplant was low (2.09 [95% CI, 1.20-2.98] additional life-years) or if the LD was no longer available (2.32 [95% CI, 1.52-3.12] additional life-years). For those aged 15 years, the LD-DD sequence was favored if the eligibility for a second transplant was low (1.84 [95% CI, 0.96-2.72] additional life-years) or if the LD was no longer available (2.49 [95% CI, 1.77-3.27] additional life-years). Access to multiple DD transplants did not compensate for missing the LD opportunity.

CONCLUSIONS AND RELEVANCE

These findings suggest that the decreased use of LD kidney transplants in pediatric recipients during the past 2 decades should be scrutinized. Given the uncertainty of future recipient eligibility for retransplant and future availability of an LD transplant, the LD-DD sequence is likely the better option. This strategy of an LD transplant first would not only benefit pediatric recipients but allow DD kidneys to be used by others who do not have an LD option.

EASL-CLIF criteria outperform NACSELD criteria for diagnosis and prognostication in ACLF

BACKGROUND & AIMS

There is no consensus on the best definition for acute-on-chronic liver failure (ACLF). In this study, we compared the prevalence and 30-day all-cause and transplant-free mortality of patients with ACLF identified by European Association for the Study of the Liver-Chronic Liver Failure Consortium (EASL-CLIF) and North American Consortium for the Study of End-stage Liver Disease (NACSELD) criteria.

METHODS

We performed this comparative analysis using the United Network for Organ Sharing (UNOS) data from January 11, 2016 to August 31, 2020.

RESULTS

A total of 10,198 (21%) adult patients had EASL-CLIF ACLF grade 1-3, but of these only 15.3% had ACLF by NACSELD. Of the 2,562 with EASL-CLIF ACLF grade 3, only 48.8% had NACSELD-ACLF, 16.8% had no organ failure (OF) and 34.4% had 1 OF. The 30-day all-cause mortality was 1.5%, 7.7%, 13.3% and 25.8% for EASL-CLIF grade 0-3, respectively, and it was 15.4% and 28.1% in those without and with NACSELD-ACLF. When EASL-CLIF grade 3 patients were stratified by NACSELD OF, the mortality ranged from 18.6% with no OF to 41.0% with 4 OFs. The 30-day transplant-free mortality in those with no OF by NACSELD was 2.7%, but when the same group is stratified by EASL-CLIF grades 0-3, the mortality rates were 1.5%, 10.5%, 43.5% and 86%, respectively; the mortality rates ranged from 3.0% to 75.7% in those with 1 OF by NACSELD.

CONCLUSIONS

There is a clear discordance in the prevalence and 30-day mortality rates of patients with ACLF identified by the EASL-CLIF and NACSELD criteria. EASL-CLIF criteria have a better sensitivity to detect ACLF and have a better prognostic capability.

LAY SUMMARY

There is no consensus on the definition of acute-on-chronic liver failure. European (EASL-CLIF) and North American (NACSELD) consortia have each proposed a commonly used definition. In this study, we compared the prevalence and short-term (30-day) mortality based on these definitions. Using a very large data set, we observed that there was a significant discordance in the prevalence and mortality based on these criteria. EASL-CLIF criteria appeared to be more sensitive to identify acute-on-chronic liver failure, and were better at predicting all-cause and short-term mortality.

A review of split liver transplantation with full right/left hemi-liver grafts for 2 adult recipients

Liver transplantation has become a routine operation in many transplantation centers worldwide. However, liver graft availability fails to meet patient demands. Split liver transplantation (SPLT), which divides a deceased donor liver into 2 partial liver grafts, is a promising strategy for increasing graft availability for transplantation and ameliorating organ shortage to a certain degree. However, the transplantation community has not yet reached a consensus on SPLT because of the variable results. Specifically, SPLT for 2 adult recipients using full right/left hemi-liver grafts is clinically more challenging in terms of surgical technique and potential postoperative complications. Therefore, this review summarizes the current status of SPLT, focusing on the transplantation of adult recipients. Furthermore, the initiation of the SPLT program, donor allocation, surgical aspects, recipient outcomes, and obstacles to developing this procedure will be thoroughly discussed. This information might help provide an optimal strategy for implementing SPLT for 2 adult recipients among current transplantation societies. Meanwhile, potential obstacles to SPLT might be overcome in the near future with growing knowledge, experience, and refinement of surgical techniques. Ultimately, the widespread diffusion of SPLT may increase graft availability and mitigate organ donation shortages.

Computational Eurotransplant kidney allocation simulations demonstrate the feasibility and benefit of T-cell epitope matching

The EuroTransplant Kidney Allocation System (ETKAS) aims at allocating organs to patients on the waiting list fairly whilst optimizing HLA match grades. ETKAS currently considers the number of HLA-A, -B, -DR mismatches. Evidently, epitope matching is biologically and clinically more relevant. We here executed ETKAS-based computer simulations to evaluate the impact of epitope matching on allocation and compared the strategies. A virtual population of 400,000 individuals was generated using the National Marrow Donor Program (NMDP) haplotype frequency dataset of 2011. Using this population, a waiting list of 10,400 patients was constructed and maintained during simulation, matching the 2015 Eurotransplant Annual Report characteristics. Unacceptable antigens were assigned randomly relative to their frequency using HLAMatchmaker. Over 22,600 kidneys were allocated in 10 years in triplicate using Markov Chain Monte Carlo simulations on 32-CPU-core cloud-computing instances. T-cell epitopes were calculated using the www.pirche.com portal. Waiting list effects were evaluated against ETKAS for five epitope matching scenarios. Baseline simulations of ETKAS slightly overestimated reported average HLA match grades. The best balanced scenario maintained prioritisation of HLA A-B-DR fully matched donors while replacing the HLA match grade by PIRCHE-II score and exchanging the HLA mismatch probability (MMP) by epitope MMP. This setup showed no considerable impact on kidney exchange rates and waiting time. PIRCHE-II scores improved, whereas the average HLA match grade diminishes slightly, yet leading to an improved estimated graft survival. We conclude that epitope-based matching in deceased donor kidney allocation is feasible while maintaining equal balances on the waiting list.

Kidney transplantation is the best treatment option for patients suffering permanent loss of kidney function. High degrees of histocompatibility between patients and organ donors improve long-term function of transplanted kidneys. In order to ensure fair access to transplantation whilst maximising utility of each donor kidney, organ allocation organizations established recipient waiting lists and well-balanced algorithms to allocate donors to patients. Changing the allocation algorithms requires careful consideration of side-effects to avoid disadvantages of certain groups of patients. In this study, we evaluated the feasibility of modifying the existing Eurotransplant Kidney Allocation System (ETKAS) to incorporate indirect T-cell epitope matching, a novel technique for assessing functional histocompatibility. Using Markov chain Monte Carlo simulations, we compared the modified allocation to the current algorithm and found an overall improvement of indirect T cell epitope compatibility. Simultaneously, we observed no negative impact on allocation fairness or waiting times. Our simulation framework may serve as a basis to evaluate further adjustments to ETKAS in the future. From our results, we conclude that epitope matching can be safely incorporated into ETKAS.

Updated safety precautions and guidance on eye banking procedures during the coronavirus disease 2019 pandemic

PURPOSE OF REVIEW

severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly infectious coronavirus causing the COVID-19 pandemic. Although airborne spread through infectious respiratory droplets is the primary source of transmission, recent literature has suggested the ocular surface may be able to harbor viral particles. Here, we aim to discuss how SARS-CoV-2 affects the ocular surface and updated guidance on how SARS-CoV-2 transmission should be considered in the setting of eye banking and corneal transplantation procedures.

RECENT FINDINGS

SARS-CoV-2 RNA can be found on the ocular surface, which may suggest the eye as a site of viral replication. However, there is poor correlation between PCR positivity on the ocular surface and ocular symptoms. To date, although viral particles can be found on the ocular surface, use of standard antiseptic procedures during corneal tissue procurement appears to sufficiently reduce viral load. In addition, preprocedure testing may further decrease the chances of transplanting an infected cornea without significantly impacting the overall accessibility to corneal tissue by decreasing the donor pool.

SUMMARY

Corneal transplantation remains a well tolerated and highly successful procedure with no evidence of viral transmission with transplantation. Although the ocular surface has the required receptors to allow for viral replication, there is no clear evidence that the eye is a site for primary viral infection.

New models for donor-recipient matching in lung transplantations

Objective

One of the main problems of lung transplantation is the shortage of organs as well as reduced survival rates. In the absence of an international standardized model for lung donor-recipient allocation, we set out to develop such a model based on the characteristics of past experiences with lung donors and recipients with the aim of improving the outcomes of the entire transplantation process.

Methods

This was a retrospective analysis of 404 lung transplants carried out at the Reina Sofía University Hospital (Córdoba, Spain) over 23 years. We analyzed various clinical variables obtained via our experience of clinical practice in the donation and transplantation process. These were used to create various classification models, including classical statistical methods and also incorporating newer machine-learning approaches.

Results

The proposed model represents a powerful tool for donor-recipient matching, which in this current work, exceeded the capacity of classical statistical methods. The variables that predicted an increase in the probability of survival were: higher pre-transplant and post-transplant functional vital capacity (FVC), lower pre-transplant carbon dioxide (PCO2) pressure, lower donor mechanical ventilation, and shorter ischemia time. The variables that negatively influenced transplant survival were low forced expiratory volume in the first second (FEV1) pre-transplant, lower arterial oxygen pressure (PaO2)/fraction of inspired oxygen (FiO2) ratio, bilobar transplant, elderly recipient and donor, donor-recipient graft disproportion requiring a surgical reduction (Tailor), type of combined transplant, need for cardiopulmonary bypass during the surgery, death of the donor due to head trauma, hospitalization status before surgery, and female and male recipient donor sex.

Conclusions

These results show the difficulty of the problem which required the introduction of other variables into the analysis. The combination of classical statistical methods and machine learning can support decision-making about the compatibility between donors and recipients. This helps to facilitate reliable prediction and to optimize the grafts for transplantation, thereby improving the transplanted patient survival rate.

Lower beta cell yield from donor pancreases after controlled circulatory death prevented by shortening acirculatory warm ischemia time and by using IGL-1 cold preservation solution

Organs from donors after controlled circulatory death (DCD III) exhibit a higher risk for graft dysfunction due to an initial period of warm ischemia. This procurement condition can also affect the yield of beta cells in islet isolates from donor pancreases, and hence their use for transplantation. The present study uses data collected and generated by our Beta Cell Bank to compare the number of beta cells in isolates from DCD III (n = 141) with that from donors after brain death (DBD, n = 609), before and after culture, and examines the influence of donor and procurement variables. Beta cell number per DCD III-organ was significantly lower (58 x 106 versus 84 x 106 beta cells per DBD-organ; p < 0.001) but their purity (24% insulin positive cells) and insulin content (17 μg / 106 beta cells in DCD III-organs versus 19 μg / 106 beta cells in DBD-organs) were similar. Beta cell number correlated negatively with duration of acirculatory warm ischemia time above 10 min; for shorter acirculatory warm ischemia time, DCD III-organs did not exhibit a lower beta cell yield (74 x 106 beta cells). Use of Institut Georges Lopez-1 cold preservation solution instead of University of Wisconsin solution or histidine-tryptophan-ketoglutarate also protected against the loss in beta cell yield from DCD III-organs (86 x 106 for IGL-1 versus 54 x 106 and 65 x 106 beta cells respectively, p = 0.042). Multivariate analysis indicates that both limitation of acirculatory warm ischemia time and use of IGL-1 prevent the reduced beta cell yield in islet cell isolates from DCD III-organs.

[Viability testing of discarded donor livers; More livers fit for transplantation because of machine perfusion]

In the Netherlands, the average quality of donor organs continues to decrease as a result of the increasing life expectancy, as well as higher incidence of obesity, diabetes mellitus, and other comorbidities in the general population. Storing donor organs on ice, the current standard practice, appears to be inadequate for preserving these high-risk donor livers. Consequently, an increasing number of donor organs is discarded for transplantation. Over the past years, a novel dynamic preservation technique using a machine perfusion device has been developed. Preservation by machine perfusion enables optimisation and viability testing of high-risk donor livers prior to liver transplantation. A large proportion of initially declined donor livers appeared to be suitable for transplantation after evaluation during machine perfusion. Testing of donor livers has led to a significant increase in the number of liver transplantations performed in the Netherlands. This technique has the potential for use in other organs, such as kidney allografts.

The Impact of Donor Asphyxiation or Drowning on Pediatric Lung Transplant Recipients

BACKGROUND

Donors with drowning or asphyxiation (DA) as a mechanism of death (MOD) are considered high risk in pediatric lung transplantation. We sought to evaluate whether recipients of DA donors had negatively impacted outcomes.

METHODS

Pediatric recipients recorded in the United Network for Organ Sharing registry between 2000 and 2019 were included. Primary stratification was donor MOD. Propensity matching with a 1:1 ratio was performed to balance the DA and non-DA MOD donor cohorts. Cox multivariable regression was used to determine the risk-adjusted impact of donor MOD. A subanalysis of the effect of lung allocation score was also evaluated.

RESULTS

A total of 1016 patients underwent bilateral lung transplantation during the study period, including 888 (85.6%) from non-DA donors and 128 (14.4%) from DA donors. Survival at 90 days, 1 year, and 2 years were similar in the matched and unmatched cohorts regardless of the donor MOD. Moreover, separate risk-adjusted analysis of drowning and asphyxiated donors was similar to other MOD donors at 30 days, 1 year, and 5 years. Similar survival findings persisted regardless of pretransplant lung allocation score. Although the rates of posttransplant stroke (1.0% versus 3.1%, P = 0.04) and the length of hospital stay (19 versus 22 d, P = 0.004) were elevated in the unmatched DA MOD recipients, these differences were mitigated after propensity matching.

CONCLUSIONS

This study evaluated the impact of DA MOD donors in pediatric lung transplant recipients and found similar rates of complications and survival in a propensity-matched cohort. These data collectively support the consideration of DA MOD donors for use in pediatric lung transplantation.

Determining the willingness of Australians to export their corneas on death

Background

12.7 million people await a corneal transplant, but 53% are without access to corneal tissue. Sharing corneal tissue across nations can provide some access, however the willingness of export populations, like Australians, to export their donation on death, has never been evaluated. Our research samples the Australian population, determining their willingness to export.

Materials and method

We conducted e-surveys. N = 1044 Australians participated. The sample represented the Australian population, based on population demographics. Chi-Square and bivariate correlation coefficients examined associations between categorical variables, with a sample size of N = 1044, power of 0.80, and alpha of p = 0.05. Outcome measures were based on population sampling, by exploring willingness export, through the e-survey method.

Results

38% (n = 397) of respondents said yes to exportation, 23.8% (n = 248) said no, and 38.2% (n = 399) were undecided. We found no relationship between willingness to export and general demographics, though those registered on the Donatelife Register (p = < .001), and those already willing to donate their eyes (p = < .001) were significantly more willing to export.

Discussion

More Australians are willing to export their corneas than not, though a significant portion remain undecided. The Donatelife Register, and donation awareness, are key components of respondent decision making. Therefore, the provision of information about exportation prior to, and at the point-of-donation, is essential for assisting Australian’s to decide to export or not. Further examination and development of consent-for-export systems are necessary before routine exportation is undertaken.

Evaluation and selection of the liver transplant candidate: updates on a dynamic and evolving process

PURPOSE OF REVIEW

Although conceptually unchanged, the evaluation and selection of the liver transplant candidate has seen significant recent advances. Expanding criteria for transplant candidacy, improved diagnostics for risk stratification and advances in prognostic models have paralleled recent changes in allocation and distribution that require us to revisit core concepts of candidate evaluation and selection while recognizing its now dynamic and continuous nature.

RECENT FINDINGS

The liver transplant evaluation revolves around three interrelated themes: candidate selection, donor selection and transplant outcome. Introduction of dynamic frailty indices, bariatric surgery at the time of liver transplant in obese patients and improved therapies and prognostic tools for hepatobiliary malignancy have transformed candidate selection. Advances in hypothermic organ preservation have improved outcomes in marginal donor organs. Combined with expansion of hepatitis C virus positive and split donor organs, donor selection has become an integral part of candidate evaluation. In addition, with liver transplant for acute alcohol-related hepatitis now widely performed and increasing recognition of acute-on-chronic liver failure, selection of critically ill patients is refining tools to balance futility versus utility.

SUMMARY

Advances in liver transplant candidate evaluation continue to transform the evaluation process and require continued incorporation into our clinical practice amidst a dynamic backdrop of demographic and policy changes.

Heart transplantation candidacy

PURPOSE OF REVIEW

Timely referral of eligible candidates for consideration of advanced therapies, such as a heart transplantation or mechanical circulatory support is essential. The characteristics of heart transplantation candidates have changed significantly over the years, leading to a more complex evaluation process. The present review summarizes recent advances in the evaluation process for heart transplantation eligibility.

RECENT FINDINGS

The heart transplantation allocation policy was recently reviewed in the USA in an effort to reduce waitlist mortality and to ensure fair geographic allocation of organs to the sickest patients. Moreover, patients with chronic infectious diseases, as well as malignancies, are being currently considered acceptable candidates for transplantation. Listing practices for heart transplantation vary between programmes, with a greater willingness to consider high-risk candidates at higher-volume centres.

SUMMARY

The ultimate decision to place high-risk candidates on the heart transplantation waitlist should be based on a combination of quantitative and qualitative data analysis informed by clinical judgement, and the chronic shortage of organ donors makes this process an important ethical concern for any society. Future guidelines should discuss approaches to achieve fair organ allocation while preserving improved outcomes after transplantation.

Ischemia and reperfusion injury to mitochondria and cardiac function in donation after circulatory death hearts- an experimental study

The ultimate treatment for patients with end-stage heart failure is heart transplantation. The number of donor hearts which are primarily procured from donation after brain death (DBD) donors is limited, but donation after circulatory death (DCD) donor hearts can increase the heart donor pool. However, ischemia and reperfusion injuries associated with the DCD process causes myocardial damage, limiting the use of DCD hearts in transplantation. Addressing this problem is critical in the exploration of DCD hearts as suitable donor hearts for transplantation. In this study, rat hearts were procured following the control beating-heart donor (CBD) or DCD donation process. Changes in mitochondria and cardiac function from DCD hearts subjected to 25 or 35 minutes of ischemia followed by 60 minutes of reperfusion were compared to CBD hearts. Following ischemia, rates of oxidative phosphorylation and calcium retention capacity were progressively impaired in DCD hearts compared to CBD hearts. Reperfusion caused additional mitochondrial dysfunction in DCD hearts. Developed pressure, inotropy and lusitropy, were significantly reduced in DCD hearts compared to CBD hearts. We, therefore, suggest that interventional strategies targeted before the onset of ischemia and at reperfusion could protect mitochondria, thus potentially making DCD hearts suitable for heart transplantation.

Defining best practices for tissue procurement in immuno-oncology clinical trials: consensus statement from the Society for Immunotherapy of Cancer Surgery Committee

Immunotherapy is now a cornerstone for cancer treatment, and much attention has been placed on the identification of prognostic and predictive biomarkers. The success of biomarker development is dependent on accurate and timely collection of biospecimens and high-quality processing, storage and shipping. Tumors are also increasingly used as source material for the generation of therapeutic T cells. There have been few guidelines or consensus statements on how to optimally collect and manage biospecimens and source material being used for immunotherapy and related research. The Society for Immunotherapy of Cancer Surgery Committee has brought together surgical experts from multiple subspecialty disciplines to identify best practices and to provide consensus on how best to access and manage specific tissues for immuno-oncology treatments and clinical investigation. In addition, the committee recommends early integration of surgeons and other interventional physicians with expertise in biospecimen collection, especially in clinical trials, to optimize the quality of tissue and the validity of correlative clinical studies in cancer immunotherapy.

Cost-utility analysis of normothermic liver perfusion with the OrganOx metra compared to static cold storage in the United Kingdom

BACKGROUND

Rising numbers of patients on the liver transplant waiting list has led to the utilization of organs from higher-risk donors that are more likely to be discarded and are prone to post-transplant complications. Storage and transportation of these livers at low temperatures can cause damage. OrganOx metra is a portable device intended to preserve and maintain the donated liver in normothermic conditions for up to 24 h prior to transplantation.

OBJECTIVE

To evaluate the cost-utility of normothermic machine perfusion with OrganOx metra in liver transplantation compared to the current practice of static cold storage (SCS).

METHODS

A de novo decision analytic model (a decision tree along with a Markov model), based on current treatment pathways, was developed to estimate the costs and outcomes. Results from a randomized clinical trial and national standard sources were used to inform the model. Costs were estimated from the National Health Service and Personal Social Services perspective. Deterministic and probabilistic sensitivity analyses (PSA) were conducted to explore uncertainty surrounding input parameters.

RESULTS

Over a lifetime time horizon, liver transplantation with OrganOx metra was more costly and more effective than the current practice of static cold storage. The total costs per patient were £37,370 vs £46,711, and the total effectiveness per patient was 9.09 QALYs vs 10.27 QALYs for SCS and OrganOx metra groups, respectively. The estimated ICER was £7,876 per each QALY gained. Results from the PSA showed that use of OrganOx metra has 99% probability of being cost-effective at a £20,000 willingness-to-pay threshold. OrganOx metra led to the utilization of 54 additional livers with patients experiencing lower rates of early allograft dysfunction and adverse events.

CONCLUSIONS

Use of OrganOx metra for the perfusion and transportation of livers prior to transplantation is a cost-effective strategy. KEY POINTS FOR DECISION MAKERS Introduction of OrganOx metra into NHS could increase the utilisation of donated livers with patients experiencing lower rates of early allograft dysfunction and adverse events, compared with current practice. Results of the economic analysis indicate that the OrganOx metra is highly likely to be cost-effective and result in improved patient outcomes.

Transplantation during the COVID-19 pandemic: nothing noble is accomplished without danger

The global health crisis due to the fast spread of coronavirus disease (COVID-19) has caused major disruption in all aspects of healthcare. Transplantation is one of the most affected sectors, as it relies on a variety of services that have been drastically occupied to treat patients affected by COVID-19. With this report from two transplant centers in Italy, we aim to reflect on resource organization, organ allocation, virus testing and transplant service provision during the course of the pandemic and to provide actionable information highlighting advantages and drawbacks.To what extent can we preserve the noble purpose of transplantation in times of increased danger? Strategies to minimize risk exposure to the transplant population and health- workers include systematic virus screening, protection devices, social distancing and reduction of patients visits to the transplant center. While resources for the transplant activity are inevitably reduced, new dilemmas arise to the transplant community: further optimization of time constraints during organ retrievals and implantation, less organs and blood products donated, limited space in the intensive care unit and the duty to maintain safety and outcomes.

Donation after circulatory death liver transplantation: What are the limits for an acceptable DCD graft?

The utilization of donation after circulatory death (DCD) livers has been growing over the last decade. In large-volume centers, survival outcomes have improved and are comparable to outcomes with brain death donor (DBD) liver transplantation (LT). The relatively concentrated success with DCD LT demonstrated by high-volume transplant centers has rekindled international enthusiasm. The combination of increasing expertise in DCD LT and ongoing shortage in transplantable organs has promoted expansion of the DCD donor pool with regards to donor age, body mass index and donor warm ischemia time. In this review, we focused on the practice patterns in DCD liver graft utilization in the last decade, along with the possibilities for further expansion of DCD liver graft utilization and new technologies, such as machine perfusion.

Alginate microencapsulated human hepatocytes for the treatment of acute liver failure in children

BACKGROUND & AIMS

Liver transplantation (LT) is the most effective treatment for patients with acute liver failure (ALF), but is limited by surgical risks and the need for life-long immunosuppression. Transplantation of microencapsulated human hepatocytes in alginate is an attractive option over whole liver replacement. The safety and efficacy of hepatocyte microbead transplantation have been shown in animal models. We report our experience of this therapy in children with ALF treated on a named-patient basis.

METHODS

Clinical grade human hepatocyte microbeads (HMBs) and empty microbeads were tested in immunocompetent healthy rats. Subsequently, 8 children with ALF, who were awaiting a suitable allograft for LT, received intraperitoneal transplantation of HMBs. We monitored complications of the procedure, assessing the host immune response and residual function of the retrieved HMBs, either after spontaneous native liver regeneration or at the time of LT.

RESULTS

Intraperitoneal transplantation of HMBs in healthy rats was safe and preserved synthetic and detoxification functions, without the need for immunosuppression. Subsequently, 8 children with ALF received HMBs (4 neonatal haemochromatosis, 2 viral infections and 2 children with unknown cause at time of infusion) at a median age of 14.5 days, range 1 day to 6 years. The procedure was well tolerated without complications. Of the 8 children, 4 avoided LT while 3 were successfully bridged to LT following the intervention. HMBs retrieved after infusions (at the time of LT) were structurally intact, free of host cell adherence and contained viable hepatocytes with preserved functions.

CONCLUSION

The results demonstrate the feasibility and safety of an HMB infusion in children with ALF.

LAY SUMMARY

Acute liver failure in children is a rare but devastating condition. Liver transplantation is the most effective treatment, but it has several important limitations. Liver cell (hepatocyte) transplantation is an attractive option, as many patients only require short-term liver support while their own liver recovers. Human hepatocytes encapsulated in alginate beads can perform the functions of the liver while alginate coating protects the cells from immune attack. Herein, we demonstrated that transplantation of these beads was safe and feasible in children with acute liver failure.

Knowledge, attitude and willingness of different ethnicities to participate in cadaver donation programs

Knowledge, attitude and willingness of ethnic minorities in China towards cadaver donation programs were assessed. Questionnaire and interviews were conducted to investigate Yi, Bai, Hani, Dai and Han ethnicities. Educational level and per capita income of ethnic minorities were lesser than those of Han ethnicity (p<0.01). Agriculture was the primary occupation and proportions of technical personnel and public officials was lesser among ethnic minorities (p<0.01). Surveyed ethnic minorities universally practice religious traditions, Bai and Dai ethnicities practice Buddhist beliefs also (p<0.01). Knowledge of Yi, Bai, Hani and Dai ethnic respondents was lesser than those of Han ethnicity (p<0.01). Over 83.8% of Yi, Bai, Hani and Dai ethnicity residents were unwilling to register for body donation programs with receiving a driver's license (p<0.01). Less than 46.9% of ethnic minorities supported use of honorary certificates (p<0.01). Ethnic minorities were supportive of financial compensation for body donations and denied that financial compensation led to the commercialization of cadaver donation (p<0.01, p<0.01). Willingness of ethnic minorities to participate in cadaver donation programs was primarily related to religious beliefs (p<0.01), economic status (p<0.01). Knowledge, attitude and willingness of ethnic minorities to participate in cadaver donation programs were markedly different from those of Han ethnicity, and the religious belief and economic status played a decisive role. To increase participation, programs based on respecting religious belief should be developed to support improvements in economy, education, medical care and social security system.

Portable Normothermic Cardiac Perfusion System in Donation After Cardiocirculatory Death: A Health Technology Assessment

BACKGROUND

Heart transplantation is the most effective treatment for people experiencing end-stage heart failure whose quality of life and life expectancy are unacceptable. However, there is a chronic shortage of donor hearts to meet the demand, so it is essential to expand the donor pool and increase supply. Heart donation mainly occurs after brain death (neurological determination of death [NDD]), but it may also be feasible after cardiocirculatory death (when the heart has stopped beating and there is no longer blood flow or a pulse), provided specialized preservation techniques are used. An investigational device, a portable normothermic cardiac perfusion system, could make it possible to procure, preserve, and transport hearts donated after cardiocirculatory death (DCD). We conducted a health technology assessment of a portable normothermic cardiac perfusion system for the preservation and transportation of DCD hearts for adult transplantation. This included an evaluation of the effectiveness, safety, value for money, and budget impact of publicly funding this system, as well as an evaluation of patient preferences and values.

METHODS

We performed a systematic review of the clinical literature published since 1998 that examined the clinical safety and effectiveness of a portable normothermic cardiac perfusion system for DCD heart transplantation. We assessed the risk of bias of each included study and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We also reviewed the economic evidence published during the same time period for the cost-effectiveness of a portable normothermic cardiac perfusion system for DCD hearts compared with cold storage for NDD hearts. We further estimated the 5-year net budget impact of publicly funding a normothermic cardiac perfusion system for DCD heart transplantation for adults on Ontario's waitlist. To contextualize the potential value of a portable normothermic cardiac perfusion system, we spoke with people waiting for a heart transplant, people who had received a heart transplant, and family members of organ donors.

RESULTS

We screened 2,386 clinical citations. One study and two case reports met the inclusion criteria. The survival of recipients of DCD hearts procured with a portable normothermic cardiac perfusion system did not differ significantly from the survival of recipients of hearts donated after NDD at 30 days or 90 days, nor was there a significant difference in cumulative survival at 1 year post-transplant (GRADE: Very Low). The occurrence of rejection and graft failure also did not significantly differ between the groups (GRADE: Very Low). Cardiac function in the early post-operative period was better in DCD hearts than NDD hearts (GRADE: Very Low). There were no differences in outcomes between DCD procurement techniques.The economic literature search yielded 62 citations. One report met the inclusion criteria but was not directly applicable to the Ontario context. Given the lack of clinical and economic evidence on long-term outcomes, we did not conduct a primary economic evaluation. In the budget impact analysis, based on the number of DCD donors under 40 years of age in the last 5 years, we estimated that the increased availability of donor hearts made possible by the technology would result in an additional seven transplants in year 1, increasing to 12 in year 5. The annual net budget impact of publicly funding a normothermic cardiac perfusion system for the transplantation of DCD hearts in Ontario over the next 5 years is about $2.0 million in the first year and about $0.9 million in each of years 2 through 5, yielding a total net budget impact of about $5.6 million. This number increases to about $10.3 million if the transplant volume increases to 18 hearts in year 1 (meaning a subsequent increase of up to 21 hearts in year 5). If transplantation were limited to people who do not qualify for a ventricular assistive device or who qualify but do not wish to receive one, the total 5-year net budget impact would be about $7.9 million.People waiting for a heart transplant or who had received a heart transplant and family members of organ donors expressed no substantial concerns about the potential use of a portable normothermic cardiac perfusion system. They hope that it may increase the number of donor hearts available for transplant. For family members of organ donors, a perfusion system may provide comfort and value if it can increase the successful procurement of donor hearts.

CONCLUSIONS

Based on very low quality of evidence, the outcomes for recipients of DCD hearts preserved using a portable normothermic cardiac perfusion system appear to be similar to outcomes for recipients of NDD hearts. Owing to a lack of evidence relevant to the Ontario context, we were unable to determine whether a portable normothermic perfusion system may be cost-effective. We estimate that publicly funding a portable normothermic cardiac perfusion system for DCD heart transplantation over the next 5 years will cost about $5.6 million. The people we spoke with believe that the system may increase the number of hearts available for transplant and therefore increase the number of heart transplants that can be done.

Expanding pancreas donor pool by evaluation of unallocated organs after brain death: Study protocol clinical trial (SPIRIT Compliant)

BACKGROUND

Pancreas graft quality directly affects morbidity and mortality rates after pancreas transplantation (PTx). The criteria for pancreas graft allocation are restricted, which has decreased the number of available organs. Suitable pancreatic allografts are selected based on donor demographics, medical history, and the transplant surgeon's assessment of organ quality during procurement. Quality is assessed based on macroscopic appearance, which is biased by individual experience and personal skills. Therefore, we aim to assess the histopathological quality of unallocated pancreas organs to determine how many unallocated organs are potentially of suitable quality for PTx.

METHODS AND ANALYSIS

This is a multicenter cross-sectional explorative study. The demographic data and medical history of donor and cause of rejection of the allocation of graft will be recorded. Organs of included donors will be explanted and macroscopic features such as weight, color, size, and stiffness will be recorded by 2 independent transplant surgeons. A tissue sample of the organ will be fixed for further microscopic assessments. Histopathologic assessments will be performed as soon as a biopsy can be obtained. We will evaluate up to 100 pancreata in this study.

RESULT

This study will evaluate the histopathological quality of unallocated pancreas organs from brain-dead donors to determine how many of these unallocated organs were potentially suitable for transplantation based on a histopathologic evaluation of organ quality.

CONCLUSION

The comprehensive findings of this study could help to increase the pancreas graft pool, overcome organ shortage, reduce the waiting time, and also increase the number of PTx in the future. Registration number: ClinicalTrials.gov: NCT04127266.

Association of Deceased Donor Acute Kidney Injury With Recipient Graft Survival

IMPORTANCE

The shortage of deceased donor kidneys for transplants is an ongoing concern. Prior studies support transplanting kidneys from deceased donors with acute kidney injury (AKI), but those investigations have been subject to selection bias and small sample sizes. Current allocation practices of AKI kidneys in the United States are not well characterized.

OBJECTIVES

To evaluate the association of deceased donor AKI with recipient graft survival and to characterize recovery and discard practices for AKI kidneys by organ procurement organizations.

DESIGN, SETTING, AND PARTICIPANTS

Registry-based, propensity score-matched cohort study from January 1, 2010, to December 31, 2013, in the United States. The dates of analysis were March 1 to November 1, 2019. From 2010 to 2013, a total of 6832 deceased donors with AKI and 15 310 deceased donors without AKI had at least 1 kidney transplanted. This study used a 1:1, propensity score-matched analysis to match deceased donors with AKI to deceased donors without AKI and investigated outcomes in their corresponding kidney recipients.

EXPOSURE

Deceased donor AKI, defined as at least 50% or 0.3-mg/dL increase in terminal serum creatinine level from admission.

MAIN OUTCOMES AND MEASURES

Recipients were assessed for the time to death-censored graft failure and the following secondary outcomes: delayed graft function, primary nonfunction, and the time to all-cause graft failure.

RESULTS

Ninety-eight percent (6722 of 6832) of deceased donors with AKI were matched to deceased donors without AKI. The mean (SD) age of the 13 444 deceased donors was 40.4 (14.4) years, and 63% (8529 of 13 444) were male. A total of 25 323 recipients were analyzed (15 485 [61%] were male), and their mean (SD) age was 52.0 (14.7) years. Recipients were followed up for a median of 5 (interquartile range, 4-6) years. Deceased donor AKI status had no association with death-censored graft failure (hazard ratio, 1.01; 95% CI, 0.95-1.08) or all-cause graft failure (hazard ratio, 0.97; 95% CI, 0.93-1.02). The results were consistent after examining by AKI stage and adjusting for recipient and transplant characteristics. More recipients of AKI kidneys developed delayed graft function (29% vs 22%, P < .001). Few recipients (120 of 25 323 [0.5%]) developed primary nonfunction regardless of deceased donor AKI status. Recovery and transplantation of AKI kidneys varied by organ procurement organization; most (39 of 58) had high recovery and high discard of AKI kidneys.

CONCLUSIONS AND RELEVANCE

Deceased donor AKI kidneys transplanted in the study period had recipient graft survival comparable to that of non-AKI kidneys. This study's findings suggest that the transplant community should evaluate whether currently discarded AKI kidneys from donors without substantial comorbidities can be used more effectively.

Outcomes After Declining Increased Infectious Risk Kidney Offers for Pediatric Candidates in the United States

BACKGROUND

Kidneys from infectious risk donors (IRD) confer substantial survival benefit in adults, yet the benefit of IRD kidneys to pediatric candidates remains unclear in the context of high waitlist prioritization.

METHODS

Using 2010-2016 Scientific Registry of Transplant Recipients data, we studied 2417 pediatric candidates (age <18 y) who were offered an IRD kidney that was eventually used for transplantation. We followed candidates from the date of first IRD kidney offer until the date of death or censorship and used Cox regression to estimate mortality risk associated with IRD kidney acceptance versus decline, adjusting for age, sex, race, diagnosis, and dialysis time.

RESULTS

Over the study period, 2250 (93.1%) pediatric candidates declined and 286 (11.8%) accepted an IRD kidney offer; 119 (41.6%) of the 286 had previously declined a different IRD kidney. Cumulative survival among those who accepted versus declined the IRD kidney was 99.6% versus 99.4% and 96.3% versus 97.8% 1 and 6 years post decision, respectively (P = 0.1). Unlike the substantial survival benefit seen in adults (hazard ratio = 0.52), among pediatric candidates, we did not detect a survival benefit associated with accepting an IRD kidney (adjusted hazard ratio: 0.791.723.73, P = 0.2). However, those who declined IRD kidneys waited a median 9.6 months for a non-IRD kidney transplant (11.2 mo among those <6 y, 8.8 mo among those on dialysis). Kidney donor profile index (KDPI) of the eventually accepted non-IRD kidneys (median = 13, interquartile range = 6-23) was similar to KDPI of the declined IRD kidneys (median = 16, interquartile range = 9-28).

CONCLUSIONS

Unlike in adults, IRD kidneys conferred no survival benefit to pediatric candidates, although they did reduce waiting times. The decision to accept IRD kidneys should balance the advantage of faster transplantation against the risk of infectious transmission.

Lessons from a pilot for uncontrolled donation after circulatory death in the ED in the UK

Worldwide there is a shortage of available organs for patients requiring transplants. However, some countries such as France, Italy and Spain have had greater success by allowing donations from patients with unexpected and unrecoverable circulatory arrest who arrive in the ED. Significant advances in the surgical approach to organ recovery from donation after circulatory death (DCD) led to the establishment of a pilot programme for uncontrolled DCD in the ED of the Royal Infirmary of Edinburgh. This paper describes the programme and discusses the lessons learnt.

Ethics of organ procurement from the unrepresented patient population

The shortage of organs for transplantation by its nature prompts ethical dilemmas. For example, although there is an imperative to save human life and reduce suffering by maximising the supply of vital organs, there is an equally important obligation to ensure that the process by which we increase the supply respects the rights of all stakeholders. In a relatively unexamined practice in the USA, organs are procured from unrepresented decedents without their express consent. Unrepresented decedents have no known healthcare wishes or advance care planning document; they also lack a surrogate. The Revised Uniform Anatomical Gift Act (RUAGA) of 2006 sends a mixed message about the procurement of organs from this patient population and there are hospitals that authorise donation. In addition, in adopting the RUAGA, some states included provisions that clearly allow organ procurement from unrepresented decedents. An important unanswered question is whether this practice meets the canons of ethical permissibility. The current Brief Report presents two principled approaches to the topic as a way of highlighting some of the complexities involved. Concluding remarks offer suggestions for future research and discussion.

Predicting chance of liver transplantation for pediatric wait-list candidates

Information about wait-list time has been reported as one of the single most frequently asked questions by individuals awaiting a transplant but data regarding wait-list time have not been processed in a useful way for pediatric candidates. To predict chance of receiving a DDLT, we identified 6471 pediatric (<18 years), non status-1A, liver-only transplant candidates between 2006 and 2017 from the SRTR. Cox regression with shared frailty for DSA level effect was used to model the association of blood type, weight, allocation PELD and MELD, and DSA with chance of DDLT. Jackknife technique was used for validation. Median (interquartile range) wait-list time was 100 (34-309) days. Non-O Blood type, higher PELD/MELD score at listing, and DSA were associated with increased chance of DDLT, while age 1-5 years and 10-18 years was associated with lower chance of DDLT (P < 0.001 for all variables). Our model accurately predicted chance of transplant (C-statistic = 0.68) and was able to predict DDLT at specific follow-up times (eg, 3 months). This model can serve as the basis for an online tool that would provide useful information for pediatric wait-list candidates.

Analysis of the Trend Over Time of High-Urgency Liver Transplantation Requests in Italy in the 4-Year Period 2014-2017

BACKGROUND

The national protocol for the handling of high-urgency (HU) liver organ procurement for transplant is administered by the Italian National Transplant Center. In recent years, we have witnessed a change in requests to access the program. We have therefore evaluated their temporal trend, the need to change the access criteria, the percentage of transplants performed, the time of request satisfaction, and the follow-up.

METHODS

We analyzed all the liver requests for the HU program received during the 4-year period of 2014 to 2017 for adult recipients (≥18 years of age): all the variables linked to the recipient or to the donor and the organ transplants are registered in the Informative Transplant System as established by the law 91/99. In addition, intention to treat (ITT) survival rates were compared among 4 different groups: (1) patients on standard waiting lists vs (2) patients on urgency waiting lists, and (3) patients with a history of transplant in urgency vs (4) patients with a history of transplant not in urgency.

RESULTS

Out of the 370 requests included in the study, 291 (78.7%) were satisfied with liver transplantation. Seventy-nine requests (21.3%) have not been processed, but if we consider only the real failures, this percentage falls to 13.1% and the percentage of satisfied requests rises to 86.9%. The average waiting period for liver transplantation (LT) is 1.7 days and most requests (74%) are met in less than 24 hours, if we consider the hours between the registration of the request and the donor reporting . The percentage of late retransplantations is 2.1%. The clinical indication for HU-LT that appears to improve over time is hepatic artery thrombosis (82.5%). The overall 1-year patient survival is 68.3%. The overall 1-year graft survival, performed on all the patients, is 89% and all the indications for HU-LT appear to go well over time with an average survival rate greater than 85%.

CONCLUSIONS

The indications for HU-LT are changing according to the changes in the hepatologic field in recent years. The centralized management of requests has proven to be successful in optimizing responses. Urgent LT is confirmed to be lifesaving in its timeliness.

Evaluation of Risk Factors for Heart-Lung Transplant Recipient Outcome: An Analysis of the United Network for Organ Sharing Database

BACKGROUND

Heart-lung transplantation (HLTx) is an effective treatment for patients with advanced cardiopulmonary failure. However, no large multicenter study has focused on the relationship between donor and recipient risk factors and post-HLTx outcomes. Thus, we investigated this issue using data from the United Network for Organ Sharing database.

METHODS

All adult patients (age ≥18 years) registered in the United Network for Organ Sharing database who underwent HLTx between 1987 and 2017 were included (n=997). We stratified the cohort by patients who were alive without retransplant at 1 year (n=664) and patients who died or underwent retransplant within 1 year of HLTx (n=333). The primary outcome was the influence of donor and recipient characteristics on 1-year post-HLTx recipient death or retransplant. Kaplan-Meier curves were created to assess overall freedom from death or retransplant. To obtain a better effect estimation on hazard and survival time, the parametric Accelerated Failure Time model was chosen to perform time-to-event modeling analyses.

RESULTS

Overall graft survival at 1-year post-HLTx was 66.6%. Of donors, 53% were male, and the mean age was 28.2 years. Univariable analysis showed advanced donor age, recipient male sex, recipient creatinine, recipient history of prior cardiac or lung surgery, recipient extracorporeal membrane oxygenation support, transplant year, and transplant center volume were associated with 1-year post-HLTx death or retransplant. On multivariable analysis, advanced donor age (hazard ratio [HR], 1.017; P=0.0007), recipient male sex (HR, 1.701; P=0.0002), recipient extracorporeal membrane oxygenation support (HR, 4.854; P<0.0001), transplant year (HR, 0.962; P<0.0001), and transplantation at low-volume (HR, 1.694) and medium-volume centers (HR, 1.455) in comparison with high-volume centers (P=0.0007) remained as significant predictors of death or retransplant. These predictors were incorporated into an equation capable of estimating the preliminary probability of graft survival at 1-year post-HLTx on the basis of preoperative factors alone.

CONCLUSIONS

HLTx outcomes may be improved by considering the strong influence of donor age, recipient sex, recipient hemodynamic status, and transplant center volume. Marginal donors and recipients without significant factors contributing to poor post-HLTx outcomes may still be considered for transplantation, potentially with less impact on the risk of early postoperative death or retransplant.