The British transplantation society guidelines on organ donation from deceased donors after circulatory death

Impact of Donor Warm Ischemia Time on Graft Survival for Donation After Circulatory Death Kidney Transplantation

BACKGROUND

The utilization of kidneys donated after circulatory death (DCD) is an important strategy to address the ongoing shortage of organs suitable for transplantation in the United States. However, the nonuse rate of DCD kidneys remains high compared with kidneys donated after brain death (DBD) because of concerns regarding the injury incurred during donor warm ischemia time (DWIT). Therefore, we investigated the impact of DWIT on the risk of death-censored graft failure after DCD kidney transplantation (KT).

METHODS

Retrospective analysis was conducted on DCD KTs using the Standard Transplant Analysis and Research data set. The association of DWIT with death-censored graft failure was evaluated using multivariable Cox proportional hazard regression, with reference to DCD KTs with Kidney Donor Risk Index (KDRI) of ≤0.78 and the median DWIT of 26 min.

RESULTS

A total of 28 032 DCD kidney-alone transplants between January 2010 and December 2021 were studied. When stratified by KDRI, increasing DWIT was associated with a clinically significant increased risk for death-censored graft failure only in the subset of kidneys with KDRI >1.14 but not in those with KDRI >0.78-≤0.94 and >0.94-≤1.14, compared with the reference group.

CONCLUSIONS

We suggest that clinicians should not decline kidneys on the basis of DWIT in favor of potential offers of DBD or other DCD kidneys with shorter DWIT, provided that their KDRI scores are within an acceptable limit. Our study highlights opportunities for more efficient usage of DCD kidneys and improving the shortage of transplantable organs.

Neuroimaging Augments DCD-N Score in Predicting Time from Withdrawal of Life-Sustaining Measures to Death Among Potential Organ Donors

BACKGROUND

Controlled donation after circulatory determination of death (DCD) is feasible only if circulatory arrest occurs soon after withdrawal of life-sustaining measures (WLSM). When organ recovery cannot proceed because this time interval is too long, there are potential negative implications, including perceptions of "secondary loss" for patients' families and significant resource consumption. The DCD-N score is a validated clinical tool for predicting rapid death following WLSM. We hypothesized that neuroimaging evidence of effaced perimesencephalic cisterns improves prediction of time to death compared with the DCD-N score alone.

METHODS

In a retrospective population-based cohort study, DCD-N scores were prospectively determined in patients for whom consent for DCD had been obtained. Perimesencephalic cisterns on last available neuroimaging were assessed in duplicate and classified as normal, partially effaced, or completely effaced. Multivariable logistic regression assessed the capacity of DCD-N score and effaced cisterns to predict death within 1, 2, or 3 h of WLSM.

RESULTS

Of 164 consecutive patients, 49 (30%) progressed to death by neurologic criteria and were excluded. Of the remaining 115 patients, 81 (70%) died within 2 h of WLSM. When perimesencephalic cisterns were patent, this occurred in 48% of patients, compared with 88% and 93%, respectively, of patients with partially and completely effaced cisterns (p < 0.0001). In multivariable analysis, the odds ratio for prediction of death within 2 h was 7.2 (2.8-18.3) for each incremental DCD-N score and 15.4 (4.1-58.1) for the presence of either partially or completely effaced cisterns (c = 0.92 vs. 0.75-0.84 for univariate models). Results were comparable for prediction of death within 1 or 3 h. With patent cisterns, median time to death was 132.5 (21-420) minutes, compared with 23.5 (16-32) and 22 (19-30) minutes, respectively, with partially and completely effaced cisterns (p = 0.0002).

CONCLUSIONS

Cerebral edema with effaced perimesencephalic cisterns predicts rapid death following WLSM in potential DCD organ donors and improves on performance of the DCD-N score alone. Although originally validated for the prediction of death within 1 h, the DCD-N score remains predictive up to 3 h following WLSM.

Advancing the Scientific Basis for Determining Death in Controlled Organ Donation After Circulatory Determination of Death

In controlled organ donation after circulatory determination of death (cDCDD), accurate and timely death determination is critical, yet knowledge gaps persist. Further research to improve the science of defining and determining death by circulatory criteria is therefore warranted. In a workshop sponsored by the National Heart, Lung, and Blood Institute, experts identified research opportunities pertaining to scientific, conceptual, and ethical understandings of DCDD and associated technologies. This article identifies a research strategy to inform the biomedical definition of death, the criteria for its determination, and circulatory death determination in cDCDD. Highlighting knowledge gaps, we propose that further research is needed to inform the observation period following cessation of circulation in pediatric and neonatal populations, the temporal relationship between the cessation of brain and circulatory function after the withdrawal of life-sustaining measures in all patient populations, and the minimal pulse pressures that sustain brain blood flow, perfusion, activity, and function. Additionally, accurate predictive tools to estimate time to asystole following the withdrawal of treatment and alternative monitoring modalities to establish the cessation of circulatory, brainstem, and brain function are needed. The physiologic and conceptual implications of postmortem interventions that resume circulation in cDCDD donors likewise demand attention to inform organ recovery practices. Finally, because jurisdictionally variable definitions of death and the criteria for its determination may impede collaborative research efforts, further work is required to achieve consensus on the physiologic and conceptual rationale for defining and determining death after circulatory arrest.

The Unified Brain-Based Determination of Death Conceptually Justifies Death Determination in DCDD and NRP Protocols

Organ donation after the circulatory determination of death requires the permanent cessation of circulation while organ donation after the brain determination of death requires the irreversible cessation of brain functions. The unified brain-based determination of death connects the brain and circulatory death criteria for circulatory death determination in organ donation as follows: permanent cessation of systemic circulation causes permanent cessation of brain circulation which causes permanent cessation of brain perfusion which causes permanent cessation of brain function. The relevant circulation that must cease in circulatory death determination is that to the brain. Eliminating brain circulation from the donor ECMO organ perfusion circuit in thoracoabdominal NRP protocols satisfies the unified brain-based determination of death but only if the complete cessation of brain circulation can be proved. Despite its medical and physiologic rationale, the unified brain-based determination of death remains inconsistent with the Uniform Determination of Death Act.