New French heart allocation system: Comparison with Eurotransplant and US allocation systems

Graft allocation rules for heart transplantation are necessary because of the shortage of heart donors, resulting in high waitlist mortality. The Agence de la biomédecine is the agency in charge of the organ allocation system in France. Assessment of the 2004 urgency‐based allocation system identified challenging limitations. A new system based on a score ranking all candidates was implemented in January 2018. In the revised system, medical urgency is defined according to candidate characteristics rather than the treatment modalities, and an interplay between urgency, donor‐recipient matching, and geographic sharing was introduced. In this article, we describe in detail the new allocation system and compare these allocation rules to Eurotransplant and US allocation policies.     

Improved access to histopathology using a digital system could increase the organ donor pool and improve allocation

Improvements in digital slide scanners have reached a stage that digital whole slide images (WSIs) can be used for diagnostic purposes. A digital system for histopathology, analogous to the systems used in radiology, would allow the establishment of networks of subspecialist histopathologists to provide a regional, national or even international rota to support out of hours histopathology for emergency frozen sections, urgent paraffin sections and to generally improve efficiencies with the provision of histopathology services. Such a system would promote appropriate organ utilization by allowing rapid characterization of unexpected lesions in the donor to determine whether donation should occur and further characterization of the organ, such as the degree of fibrosis in the kidney or steatosis in the liver, to determine whether the organ should be used. If introduced across Europe, this would promote safe and effective exchange of organs and support a cost efficient use of pathologist expertise. This review article outlines current issues with the provision of an urgent out of hours histopathology service and focuses on how such a service has the potential to increase organ donors, improve allocation, sharing and the use of available donor organs.     

Rationing scarce organs for transplantation: healthcare provider perspectives on wait‐listing and organ allocation

Ongoing debate about how to maximize the benefit of scarce organs while maintaining equity of access to transplantation exists. This study aims to synthesize healthcare provider perspectives on wait‐listing and organ allocation. MEDLINE, Embase, and PsycINFO were searched till February 21, 2011. Quantitative data were extracted, and a qualitative synthesis of the studies was conducted. Twenty studies involving 4254 respondents were included. We identified two goals underpinning healthcare provider preferences for organ allocation: (i) maximize clinical benefit (quality of life gains, patient survival, treatment adherence, and graft survival) and social outcomes (social support, productivity, and valuation); (ii) achieve equity (waiting time, patient preferences, access to live donation, and medical urgency). Maximizing clinical or social outcomes meant organs would be preferentially given to patients expected to achieve good transplant outcomes or wider social gain. Achieving equity meant all patients should have an equal chance of transplant, or patients deemed more urgent receive higher priority. A tension between equity and efficiency is apparent. Balanced against dimensions of efficiency were considerations to instill a degree of perceived fairness in organ allocation. Ongoing engagement with stakeholders is needed to enhance transparency, a reasonable balance between efficiency and equity, and avoid discrimination against specific populations.     

Liver simulated allocation model does not effectively predict organ offer decisions for pediatric liver transplant candidates

The SRTR maintains the liver-simulated allocation model (LSAM), a tool for estimating the impact of changes to liver allocation policy. Integral to LSAM is a model that predicts the decision to accept or decline a liver for transplant. LSAM implicitly assumes these decisions are made identically for adult and pediatric liver transplant (LT) candidates, which has not been previously validated. We applied LSAM's decision-making models to SRTR offer data from 2013 to 2016 to determine its efficacy for adult (≥18) and pediatric (<18) LT candidates, and pediatric subpopulations—teenagers (≥12 to <18), children (≥2 to <12), and infants (<2)—using the area under the receiver operating characteristic (ROC) curve (AUC). For nonstatus 1A candidates, all pediatric subgroups had higher rates of offer acceptance than adults. For non-1A candidates, LSAM's model performed substantially worse for pediatric candidates than adults (AUC 0.815 vs. 0.922); model performance decreased with age (AUC 0.898, 0.806, 0.783 for teenagers, children, and infants, respectively). For status 1A candidates, LSAM also performed worse for pediatric than adult candidates (AUC 0.711 vs. 0.779), especially for infants (AUC 0.618). To ensure pediatric candidates are not unpredictably or negatively impacted by allocation policy changes, we must explicitly account for pediatric-specific decision making in LSAM.     

Predictors of low risk for dropout from the liver transplant waiting list for hepatocellular carcinoma in long wait time regions: Implications for organ allocation

All patients with hepatocellular carcinoma meeting United Network for Organ Sharing T2 criteria currently receive the same listing priority for liver transplant (LT). A previous study from our center identified a subgroup with a very low risk of waitlist dropout who may not derive immediate LT benefit. To evaluate this issue at a national level, we analyzed within the United Network for Organ Sharing database 2052 patients with T2 hepatocellular carcinoma receiving priority listing from 2011 to 2014 in long wait time regions 1, 5, and 9. Probabilities of waitlist dropout were 18.3% at 1 year and 27% at 2 years. In multivariate analysis, factors associated with a lower risk of waitlist dropout included Model for End‐Stage Liver Disease‐Na < 15, Child's class A, single 2‐ to 3‐cm lesion, and α‐fetoprotein ≤20 ng/mL. The subgroup of 245 (11.9%) patients meeting these 4 criteria at LT listing had a 1‐year probability of dropout of 5.5% vs 20% for all others (P < .001). On explant, the low dropout risk group was more likely to have complete tumor necrosis (35.5% vs 24.9%, P = .01) and less likely to exceed Milan criteria (9.9% vs 17.7%, P = .03). We identified a subgroup with a low risk of waitlist dropout who should not receive the same LT listing priority.     

Coronavirus disease 2019: Utilizing an ethical framework for rationing absolutely scarce health‐care resources in transplant allocation decisions

The novel coronavirus disease 2019 (COVID‐19) is impacting transplant programs around the world, and, as the center of the pandemic shifts to the United States, we have to prepare to make decisions about which patients to transplant during times of constrained resources. In this paper, we discuss how to transition from the traditional justice versus utility consideration in organ allocation to a more nuanced allocation scheme based on ethical values that drive decisions in times of absolute scarcity. We recognize that many decisions are made based on the practical limitations that transplant programs face, especially at the extremes. As programs make the transition from a standard approach to a resource‐constrained approach to transplantation, we utilize a framework for ethical decisions in settings of absolutely scarce resources to help guide programs in deciding which patients to transplant, which donors to accept, how to minimize risk, and how to ensure the best utilization of transplant team members.     

Decision and forecast horizons for one-dimensional optimal control problems: Existence results and applications

This paper obtains decision and forecast horizons for undiscounted, continuous-time one-dimensional control systems. Some general conditions for the existence of horizons arising from the constraints imposed on the system are derived by using the optimality principle. These conditions are applicable to a variety of problems, including those of production planning, machine maintenance and cash management. Also derived are existence results that depend on the interplay between various costs involved in the context of a generalized production-inventory model. Horizons are obtained explicitly in some cases. The model includes as special cases a version of the wheat-trading problem and some other inventory prblems that have appeared in the literature. The paper concludes with an application of the model to a continuous-time concave production-planning problem not yet treated in the horizon context.     

Patterns of geographic variability in mortality and eligible deaths between organ procurement organizations

Eligible deaths are currently used as the denominator of the donor conversion ratio to mitigate the effect of varying mortality patterns in the populations served by different organ procurement organizations (OPOs). Eligible death is an OPO‐reported metric rather than a product of formal epidemiological analysis, however, and may be confounded with OPO performance. Using Scientific Registry of Transplant Recipients and Centers for Disease Control and Prevention data, patterns of mortality and eligible deaths within each OPO were analyzed with the use of formal geostatistical analysis to determine whether eligible deaths truly reflect the geographic patterns they are intended to mitigate. There was a 2.1‐fold difference in mortality between the OPOs with the highest and lowest rates, with significant positive spatial autocorrelation evident in mortality rates (Moran I = .110; P < .001), meaning geographically proximate OPOs tended to have similar mortality rates. The eligible death ratio demonstrated greater variability, with a 4.5‐fold difference between the OPOs with the highest and lowest rates. Contrary to the pattern of mortality rates, the geographic distribution of eligible deaths among OPOs was random (Moran I = ?.002; P = .410). This finding suggests geographic patterns do not play a significant role in eligible deaths, thus questioning its continuing use in OPO performance comparisons.     

Key factors in paediatric organ and tissue donation: an overview of literature in a chronological working model

There is a growing shortage of size-matched organs and tissues for children. Although examples of substandard care are reported in the literature, there is no overview of the paediatric donation process. The aim of the study is to gain insight into the chain of events, practices and procedures in paediatric donation. Method; a survey of the 1990-2010 literature on paediatric organ and tissue donation and categorization into a coherent chronological working model of key events and procedures. Studies on paediatric donation are rare. Twelve empirical studies were found, without any level I or level II-1 evidence. Seventy-five per cent of the studies describe the situation in the United States. Literature suggests that the identification of potential donors and the way in which parental consent is requested may be substandard. We found no literature discussing best practices. Notwithstanding the importance of looking at donation care as an integrated process, most studies discuss only a few isolated topics or sub-processes. To improve paediatric donation, more research is required on substandard factors and their interactions. A chronological working model, as presented here, starting with the identification of potential donors and ending with aftercare, could serve as a practical tool to optimize paediatric donation.     

Transplant Medicine in China: Need for Transparency and International Scrutiny Remains

Previous publications have described unethical organ procurement procedures in the People's Republic of China. International awareness and condemnation contributed to the announcement abolishing the procurement of organs from executed prisoners starting from January 2015. Eighteen months after the announcement, and aligned with the upcoming International Congress of the Transplantation Society in Hong Kong, this paper revisits the topic and discusses whether the declared reform has indeed been implemented. China has neither addressed nor included in the reform a pledge to end the procurement of organs from prisoners of conscience, nor has the government initiated any legislative amendments. Recent reports have discussed an implausible discrepancy of officially reported steady annual transplant numbers and a steep expansion of the transplant infrastructure in China. This paper expresses the viewpoint that, in the current context, it is not possible to verify the veracity of the announced changes, and it thus remains premature to include China as an ethical partner in the international transplant community. Until we have independent and objective evidence of a complete cessation of unethical organ procurement from prisoners, the medical community has a professional responsibility to maintain the academic embargo on Chinese transplant professionals.     

Racial/ethnic disparities in waitlisting for deceased donor kidney transplantation 1 year after implementation of the new national kidney allocation system

The impact of a new national kidney allocation system (KAS) on access to the national deceased‐donor waiting list (waitlisting) and racial/ethnic disparities in waitlisting among US end‐stage renal disease (ESRD) patients is unknown. We examined waitlisting pre‐ and post‐KAS among incident (N = 1 253 100) and prevalent (N = 1 556 954) ESRD patients from the United States Renal Data System database (2005‐2015) using multivariable time‐dependent Cox and interrupted time‐series models. The adjusted waitlisting rate among incident patients was 9% lower post‐KAS (hazard ratio [HR]: 0.91; 95% confidence interval [CI], 0.90‐0.93), although preemptive waitlisting increased from 30.2% to 35.1% (P < .0001). The waitlisting decrease is largely due to a decline in inactively waitlisted patients. Pre‐KAS, blacks had a 19% lower waitlisting rate vs whites (HR: 0.81; 95% CI, 0.80‐0.82); following KAS, disparity declined to 12% (HR: 0.88; 95% CI, 0.85‐0.90). In adjusted time‐series analyses of prevalent patients, waitlisting rates declined by 3.45/10 000 per month post‐KAS (P < .001), resulting in ≈146 fewer waitlisting events/month. Shorter dialysis vintage was associated with greater decreases in waitlisting post‐KAS (P < .001). Racial disparity reduction was due in part to a steeper decline in inactive waitlisting among minorities and a greater proportion of actively waitlisted minority patients. Waitlisting and racial disparity in waitlisting declined post‐KAS; however, disparity remains.     

Maintaining the permanence principle for death during in situ normothermic regional perfusion for donation after circulatory death organ recovery: A United Kingdom and Canadian proposal

There is international variability in the determination of death. Death in donation after circulatory death (DCD) can be defined by the permanent cessation of brain circulation. Post‐mortem interventions that restore brain perfusion should be prohibited as they invalidate the diagnosis of death. Retrieval teams should develop protocols that ensure the continued absence of brain perfusion during DCD organ recovery. In situ normothermic regional perfusion (NRP) or restarting the heart in the donor's body may interrupt the permanent cessation of brain perfusion because, theoretically, collateral circulations may restore it. We propose refinements to current protocols to monitor and exclude brain reperfusion during in situ NRP. In abdominal NRP, complete occlusion of the descending aorta prevents brain perfusion in most cases. Inserting a cannula in the ascending aorta identifies inadequate occlusion of the descending aorta or any collateral flow and diverts flow away from the brain. In thoracoabdominal NRP opening the aortic arch vessels to atmosphere allows collateral flow to be diverted away from the brain, maintaining the permanence standard for death and respecting the dead donor rule. We propose that these hypotheses are correct when using techniques that simultaneously occlude the descending aorta and open the aortic arch vessels to atmosphere.