Organ Transplantation Network Research Articles

Ensemble of machine learning techniques to predict survival in kidney transplant recipients

Kidney transplant recipients face a high cardiovascular risk, which is a leading cause of death in this patient group. This article proposes the application of clustering techniques and feature selection to predict the survival outcomes of kidney transplant recipients based on machine learning techniques and mainstream statistical methods. First, feature selection techniques (Boruta, Random Survival Forest and Elastic Net) are used to detect the most relevant variables. Subsequently, each set of variables obtained by each feature selection technique is used as input for the clustering algorithms used (Consensus Clustering, Self-Organizing Map and Agglomerative Clustering) to determine which combination of feature selection, clustering algorithm and number of clusters maximizes intercluster variability. Next, the mechanism called False Clustering Discovery Reduction is applied to obtain the minimum number of statistically differentiable populations after applying a control metric. This metric is based on a variance test to confirm that reducing the number of clusters does not generate significant losses in the heterogeneity obtained. This approach was applied to the Organ Procurement and Transplantation Network medical dataset (n = 11,332). The combination of Random Survival Forest and consensus clustering yielded the optimal result of 4 clusters starting from 8 initial ones. Finally, for each population, Kaplan-Meier survival curves are generated to predict the survival of new patients based on the predictions of the XGBoost classifier, with an overall multi-class AUC of 98.11%.

Strongyloides stercoralis infection in solid organ transplant recipients.

Strongyloides stercoralis infection remains of concern due to its high associated morbidity among solid organ transplant recipients (SOTR) and the risk of donor-derived infection (DDI). We review key aspects of epidemiology to inform screening for and treatment of chronic infection among organ transplant candidates to reduce the risk of infectious complications in the posttransplant setting. In this work, we offer guidance regarding the optimal management of Strongyloides hyperinfection syndrome and disseminated infection and offer recommendations regarding posttreatment surveillance and the potential need for repeat treatment during subsequent periods of augmented immunosuppression. This review also provides updated recommendations for screening of deceased and living donors as recently proposed by the Organ Procurement and Transplantation Network's Ad Hoc Disease Transmission Advisory Committee. Risk reduction of Strongyloides infection in the SOTR population can be further enhanced by optimized treatment of infection, posttreatment surveillance during at-risk periods and recent proposed policy shifts to universal donor screening.

Simultaneous Liver and Kidney Transplantation in Patients Aged 70 y and Older: Proceed With Caution.

The number of elderly patients aged 70 y and older with liver and kidney failure is increasing, mainly because of increasing prevalence of metabolic dysfunction-associated steatohepatitis. At present, limited data are available on the outcomes of elderly patients who fit the criteria for dual organ transplantation since the implementation of the simultaneous liver and kidney (SLK) allocation policy. We performed a retrospective analysis of the Organ Procurement and Transplantation Network database of adults aged 18 y and older undergoing SLK and kidney transplantation only from August 11, 2017, to December 31, 2022. We examined patient and graft survivals and compared the outcomes of the recipients aged 70 y and older undergoing SLK transplantation to those who received kidney transplant alone and kidney after liver transplant. During the study period, there has been a significant rise in the number of patients aged 70 y and older undergoing SLK transplantation, with 6 patients undergoing SLK transplantation in 2017 and 63 in 2021. Patients aged 70 y and older had significantly lower survival with 82.9% at 1 y and 66.5% at 3 y compared with 89.3% and 78.8% in the 50-69 y age group and 93.2% and 88.6% in the 18-49 y age group, respectively. Overall, kidney allograft survival was significantly lower in the 70 y and older group, with 80.9% at 1 y and 66.4% at 3 y compared with 91.1% and 75.5%, respectively, in those undergoing kidney transplant alone. There was no difference in kidney allograft survival in those undergoing SLK and kidney after liver transplantation. Although the outcomes are inferior in recipients of SLK transplant aged 70 y and older, chronologic age should not preclude them from undergoing transplantation. Kidney transplantation after liver transplantation could be considered to avoid futile transplants.

A case of truncus arteriosus with severe heart failure and pulmonary stenosis: bridge to transplant candidacy with surgical correction and a ventricular-assist device.

Ventricular-assist device therapy for small patients with congenital heart disease is challenging due to its complex anatomy and hemodynamics. We describe a 3-year-old patient with heart failure with truncus arteriosus in the palliative stage. The patient underwent palliative right ventricular outflow tract reconstruction following bilateral pulmonary artery banding. At 6months of age, the patient developed severe truncal valve regurgitation and left ventricular dysfunction. Emergent truncal valve replacement with a mechanical valve was performed, but left ventricular dysfunction persisted. At 3years of age, the patient developed acute progression of heart failure triggered by influenza infection. The patient was intubated and transferred to our center to determine the indication for heart transplantation. On the second day after admission, signs of multiorgan failure appeared. Emergent ventricular-assist device implantation for both ventricles was performed with truncal valve closure, ventricular septal defect closure, atrial septal defect closure, and re-right ventricular outflow tract reconstruction. The right ventricular-assist device was successfully removed on the seventh postoperative day. Due to the small pulmonary arteries, severe pulmonary stenosis persisted after ventricular-assist device implantation, but it gradually improved with multiple pulmonary angioplasties. The patient was registered in the Japanese organ transplant network and is awaiting a donor organ in a stable condition.

Lung Donation and Transplant Recipient Outcomes at Independent vs Hospital-Based Donor Care Units

Centralizing deceased organ donor management and organ recovery into donor care units (DCUs) may mitigate the critical organ shortage by positively impacting donation and recipient outcomes. To compare donation and lung transplant outcomes between 2 common DCU models: independent (outside of acute-care hospitals) and hospital-based. This is a retrospective cohort study of Organ Procurement and Transplantation Network deceased donor registry and lung transplant recipient files from 21 US donor service areas with an operating DCU. Characteristics and lung donation rates among deceased donors cared for in independent vs hospital-based DCUs were compared. Eligible participants included deceased organ donors (aged 16 years and older) after brain death, who underwent organ recovery procedures between April 26, 2017, and June 30, 2022, and patients who received lung transplants from those donors. Data analysis was conducted from May 2023 to March 2024. Organ recovery in an independent DCU (vs hospital-based DCU). The primary outcome was duration of transplanted lung survival (through December 31, 2023) among recipients of lung(s) transplanted from cohort donors. A Cox proportional hazards model stratified by transplant year and program, adjusting for donor and recipient characteristics was used to compare graft survival. Of 10 856 donors in the starting sample (mean [SD] age, 42.8 [15.2] years; 6625 male [61.0%] and 4231 female [39.0%]), 5149 (primary comparison group) underwent recovery procedures in DCUs including 1466 (28.4%) in 11 hospital-based DCUs and 3683 (71.5%) in 10 independent DCUs. Unadjusted lung donation rates were higher in DCUs than local hospitals, but lower in hospital-based vs independent DCUs (418 donors [28.5%] vs 1233 donors [33.5%]; P < .001). Among 1657 transplant recipients, 1250 (74.5%) received lung(s) from independent DCUs. Median (range) duration of follow-up after transplant was 734 (0-2292) days. Grafts recovered from independent DCUs had shorter restricted mean (SE) survival times than grafts from hospital-based DCUs (1548 [27] days vs 1665 [50] days; P = .04). After adjustment, graft failure remained higher among lungs recovered from independent DCUs than hospital-based DCUs (hazard ratio, 1.85; 95% CI, 1.28-2.65). In this retrospective analysis of national donor and transplant recipient data, although lung donation rates were higher from deceased organ donors after brain death cared for in independent DCUs, lungs recovered from donors in hospital-based DCUs survived longer. These findings suggest that further work is necessary to understand which factors (eg, donor transfer, management, or lung evaluation and acceptance practices) differ between DCU models and may contribute to these differences.

Donor-derived infections in the United States: Opportunities to learn from the Disease Transmission Advisory Committee's experience.

The Disease Transmission Advisory Committee (DTAC) of the Organ Procurement and Transplantation Network focuses on issues related to the transmission of disease through organ transplantation. Providing a review of potential cases of transmission, translating aggregate data into actionable education and guidance for the transplant community, and providing input for policy development, DTAC aims to improve the safety of organ transplantation through a reduction in donor-derived transmission events. Through its nearly 20-year history, DTAC has provided education, guidance, and policy, addressed numerous emerging infections, and continuously focused on the community's understanding of risk assessment related to donor-derived transmission. By updating the DTAC mission to both decrease transmission and safely expand the donor pool with additional guidance to safely use organs previously not considered for transplantation due to transmission concerns, the Committee's role will remain critical.

Hepatitis B transmission/reactivation associated with Hepatitis B core antibody and Hepatitis C nucleic acid testing positive organs: A report from the Organ Procurement and Transplantation Network Disease Transmission Advisory Committee.

Better access to direct-acting antiviral (DAA) therapy has broadened the utilization of hepatitis C virus (HCV) nucleic acid testing (NAT) positive organs with excellent outcomes. However, DAA therapy has been associated with hepatitis B virus (HBV) reactivation. To determine the risk of HBV transmission or reactivation with utilization of HBV core antibody positive (HBcAb+) and HCV NAT positive (HCV+) organs, which presumably required DAA therapy. The number of HBcAb+ donors with delineated HCV NAT status was obtained from the Organ Procurement and Transplantation Network (OPTN) database. The number of unexpected HBV infections from transplanted organs adjudicated as "proven" or "probable" transmission was obtained from the OPTN Ad Hoc Disease Transmission Advisory Committee database. A chart review of the donors of "proven" or "probable" cases was conducted. From January 1, 2016, to December 31, 2021, 7735 organs were procured from 3767 HBcAb+ donors and transplanted into 7469 recipients; 545 (14.5%) donors were also HCV+. HBV transmission or reactivation occurred in seven recipients. The rate is not significantly different between recipients of HCV+ (0.18%, 2/1115) and the HCV NAT negative (HCV-) organs (0.08%, 5/6354) (p = 0.28) or between recipients of HCV+ and HCV- livers as well as non-liver organs. HBV transmission or reactivation occurred within a median of 319 (range, 41-1117) days post-transplant in the setting of missing, inadequate, or truncated prophylaxis. HBV reactivation associated with DAA therapy for HBcAb+ HCV+ organs is less frequent than reported in the non-transplant population, possibly due to the common use of HBV prophylaxis in the at-risk transplant population.

Machine Learning Approach for Cardiovascular Death Prediction among Nonalcoholic Steatohepatitis (NASH) Liver Transplant Recipients.

Cardiovascular disease is the leading cause of mortality among nonalcoholic steatohepatitis (NASH) patients who undergo liver transplants. In the present study, machine learning algorithms were used to identify important risk factors for cardiovascular death and to develop a prediction model. The Standard Transplant Analysis and Research data were gathered from the Organ Procurement and Transplantation Network. After cleaning and preprocessing, the dataset comprised 10,871 patients and 92 features. Recursive feature elimination (RFE) and select from model (SFM) were applied to select relevant features from the dataset and avoid overfitting. Multiple machine learning algorithms, including logistic regression, random forest, decision tree, and XGBoost, were used with RFE and SFM. Additionally, prediction models were developed using a support vector machine, Gaussian naïve Bayes, K-nearest neighbors, random forest, and XGBoost algorithms. Finally, SHapley Additive exPlanations (SHAP) were used to increase interpretability. The findings showed that the best feature selection method was RFE with a random forest estimator, and the most critical features were recipient and donor blood type, body mass index, recipient and donor state of residence, serum creatinine, and year of transplantation. Furthermore, among all the outcomes, the XGBoost model had the highest performance, with an accuracy value of 0.6909 and an area under the curve value of 0.86. The findings also revealed a predictive relationship between features and cardiovascular death after liver transplant among NASH patients. These insights may assist clinical decision-makers in devising strategies to prevent cardiovascular complications in post-liver transplant NASH patients.

Why partial heart transplantation could be regulated as organ transplantation

Partial heart transplant (PHT) is a recent clinical innovation involving the transplantation of a segment of the heart (valves) directly from the deceased donor into the recipient patient. This procedure holds out the possibility of significant benefit, especially for pediatric patients because these grafts show growth potential after transplant, reducing or eliminating the current need for repeat procedures. The clinical process for donation and transplant of partial heart (PH) grafts generally follows an organ clinical pathway; however, the Food and Drug Administration has recently stated its intent to regulate PH as tissues, raising a host of regulatory considerations. PHT requires donor testing and eligibility determinations within a short, clinically viable timeframe and, similar to organ transplant, involves donor-recipient matching. Waitlist allocation policies that are a regulatory focus of the Organ Procurement and Transplantation Network including equity and efficiency may become relevant. Oversight of PHT by the Organ Procurement and Transplantation Network could be accomplished through interpretation of the vascular composite allograft definition or through designation by the US Department of Health and Human Services of PH grafts as organs. While some clinical questions remain unanswered, it is important to carefully address these regulatory considerations to support the emergence of this innovation and ensure the continued trust of the donating public and the patients who may benefit from PHT.

Surging Liver Transplantation for Nonalcoholic Steatohepatitis from 2000-2022: A National Database Study.

Our aim was to provide an up-to-date, large-scale overview of the trends and clinicodemographics for NASH LTs performed in the United States compared with all other LT indications between 2000 and 2022. We also examined the demographic factors that will predict future demand for NASH LT. Our analysis of NASH LT from the Organ Procurement & Transplantation Network database spanning 2000-2022 consisted primarily of descriptive statistics and hypothesis testing with corrections for multiple testing when necessary. Trend lines and linear correlations were also explored. NASH LTs have experienced a remarkable surge, escalating from 0.12% of all LTs in 2000 to a substantial 14.7% in 2022, marking a 100-fold increase. Examining demographic trends, a significant proportion of NASH LTs recipients fall within the 50- to 64-year-old age group. Moreover, 52% of these recipients concurrently exhibit type 2 diabetes mellitus, a notably higher percentage than the 19% observed in all LT recipients. Type 2 diabetes mellitus emerges as a prominent risk factor for NASH progressing to end-stage liver disease. The phenomenon of repeat transplantation is noteworthy; although 6% of all LTs necessitate repeat procedures, this figure dramatically drops to 0.6% for NASH LTs. Ethnic disparities are apparent, with African Americans representing a mere 2% of NASH LT recipients, significantly lower than their representation in the overall population. Regionally, the East Coast has a higher proportion of NASH LT recipients compared with waitlist additions. This trend holds true across demographics. Our findings underscore the need for increased resources, particularly for minority, uninsured, or noncitizen individuals requiring LT for NASH. This analysis provides valuable insights into the dynamic landscape of LTs in the context of NASH, shaping the trajectory of medical interventions in the 21st century.

Effect of citizenship status on access to pediatric liver and kidney transplantation

Transplantation of non-US citizen residents remains controversial. We evaluate national trends in transplant activity among pediatric noncitizen residents (PNCR). Pediatric liver and kidney transplant data were obtained from the Organ Procurement and Transplantation Network and the Scientific Registry of Transplant Recipients. Data on transplanted organs, region, waitlist additions, procedures, and citizenship status were analyzed from 2012-2022. Rates of PNCR transplantation activity were compared with population rates from the US Census Bureau. On average, 713 ± 47 pediatric liver and 1039 ± 51 kidney patients were added to the waitlist, with 544 ± 32 liver and 742 ± 33 kidney transplants performed annually. Of these, PNCR comprised 1.5% and 3.3% of liver and kidney waitlist additions and 1.5% and 2.9% of liver and kidney transplant procedures, respectively. There were no significant changes in waitlist or transplant activity nationwide over the study period. There was a significant geographic variation in the percentage of waitlist additions and transplants across the United Network for Organ Sharing regions among the PNCR for liver and kidney transplantation. This is the first study to evaluate national trends in transplantation activity among PNCRs. The significant regional variation in transplantation activity for PNCR may suggest multilevel structural and systemic barriers to transplant accessibility.

A Bridge Over Troubled Waters: Insights Into Extracorporeal Membrane Oxygenation Bridge-to-Transplant Outcomes From the Organ Procurement and Transplantation Network Standard Transplant Analysis and Research Database

A Bridge Over Troubled Waters: Insights Into Extracorporeal Membrane Oxygenation Bridge-to-Transplant Outcomes From the Organ Procurement and Transplantation Network Standard Transplant Analysis and Research Database

Heart Transplantation After Donation After Circulatory Death: Early United States Experience

BackgroundGiven the renewed interest in heart transplantation after donation after circulatory death (DCD), a contemporary analysis of trends and longer-term survival is warranted. MethodsAdult heart transplant recipients (December 2019-September 2023) were identified in the Organ Procurement and Transplantation Network. Recipients were stratified as donation after brain death (DBD) or DCD. DCD procurements were further classified as direct procurement and perfusion (DCD-DPP) or normothermic regional perfusion (DCD-NRP), based on the declaration of death to cross-clamp interval (≥40 minutes DCD-NRP). The main outcome was posttransplant survival at 1 and 3 years. ResultsOf 11,625 transplantations, 792 (7%) involved DCD allografts (249 DCD-NRP, 543 DCD-DPP). The proportion of transplants involving DCD allografts significantly increased from 2% (December 2019) to 11% (January-September 2023, P < .001). Upon adjusted analysis, 1-year posttransplant survival was similar for DBD vs DCD-DPP (hazard ratio [HR], 1.00; 95% CI, 0.66-1.66) or DCD-NRP (HR, 0.92; 95% CI, 0.49-1.72). This remained true at 3 years for DCD-DPP (HR, 1.07; 95% CI, 0.77-1.48) and DCD-NRP (HR, 1.04; 95% CI, 0.62-1.73). Incidence of postoperative stroke, dialysis, acute graft rejection, and primary graft dysfunction were similar across groups. Across various strata of recipient risk and center volume, survival was equivalent between the DBD and DCD cohorts. ConclusionsRates of DCD heart transplantation continue to rise. Across various recipient risk and center volume categories, DCD and DBD recipients show comparable posttransplant survival up to 3 years. These findings encourage broader use of such donors in attempts to expand the organ pool.

The Potential Utilization of Machine Perfusion to Increase Transplantation of Macrosteatotic Livers.

The demand for liver transplantation has led to the utilization of marginal grafts including moderately macrosteatotic livers (macrosteatosis ≥30% [Mas30]), which are associated with an elevated risk of graft failure. Machine perfusion (MP) has emerged as a technique for organ preservation and viability testing; however, little is known about MP in Mas30 livers. This study evaluates the utilization and outcomes of Mas30 livers in the era of MP. The Organ Procurement and Transplantation Network database was queried to identify biopsy-proven Mas30 deceased donor liver grafts between June 1, 2016, and June 23, 2023. Univariable and multivariable models were constructed to study the association between MP and graft utilization and survival. The final cohort with 3317 Mas30 livers was identified, of which 72 underwent MP and were compared with 3245 non-MP livers. Among Mas30 livers, 62 (MP) and 1832 (non-MP) were transplanted (utilization of 86.1% versus 56.4%, P < 0.001). Donor and recipient characteristics were comparable between MP and non-MP groups. In adjusted analyses, MP was associated with significantly increased Mas30 graft utilization (odds ratio, 7.89; 95% confidence interval [CI], 3.76-16.58; P < 0.001). In log-rank tests, MP was not associated with 1- and 3-y graft failure (hazard ratio, 0.49; 95% CI, 0.12-1.99; P = 0.319 and hazard ratio 0.43; 95% CI, 0.11-1.73; P = 0.235, respectively). The utilization rate of Mas30 grafts increases with MP without detriment to graft survival. This early experience may have implications for increasing the available donor pool of Mas30 livers.

Implications of Race Adjustment in Lung-Function Equations.

Adjustment for race is discouraged in lung-function testing, but the implications of adopting race-neutral equations have not been comprehensively quantified. We obtained longitudinal data from 369,077 participants in the National Health and Nutrition Examination Survey, U.K. Biobank, the Multi-Ethnic Study of Atherosclerosis, and the Organ Procurement and Transplantation Network. Using these data, we compared the race-based 2012 Global Lung Function Initiative (GLI-2012) equations with race-neutral equations introduced in 2022 (GLI-Global). Evaluated outcomes included national projections of clinical, occupational, and financial reclassifications; individual lung-allocation scores for transplantation priority; and concordance statistics (C statistics) for clinical prediction tasks. Among the 249 million persons in the United States between 6 and 79 years of age who are able to produce high-quality spirometric results, the use of GLI-Global equations may reclassify ventilatory impairment for 12.5 million persons, medical impairment ratings for 8.16 million, occupational eligibility for 2.28 million, grading of chronic obstructive pulmonary disease for 2.05 million, and military disability compensation for 413,000. These potential changes differed according to race; for example, classifications of nonobstructive ventilatory impairment may change dramatically, increasing 141% (95% confidence interval [CI], 113 to 169) among Black persons and decreasing 69% (95% CI, 63 to 74) among White persons. Annual disability payments may increase by more than $1 billion among Black veterans and decrease by $0.5 billion among White veterans. GLI-2012 and GLI-Global equations had similar discriminative accuracy with regard to respiratory symptoms, health care utilization, new-onset disease, death from any cause, death related to respiratory disease, and death among persons on a transplant waiting list, with differences in C statistics ranging from -0.008 to 0.011. The use of race-based and race-neutral equations generated similarly accurate predictions of respiratory outcomes but assigned different disease classifications, occupational eligibility, and disability compensation for millions of persons, with effects diverging according to race. (Funded by the National Heart Lung and Blood Institute and the National Institute of Environmental Health Sciences.).

Differential Effects of Ascites and Hepatic Encephalopathy on Waitlist Mortality in Liver Transplantation by MELD 3.0.

MELD 3.0 introduces changes to address waitlist disparities for liver transplant (LT) candidates. Ascites and hepatic encephalopathy (HE) are important milestones in the natural history of cirrhosis regardless of the Model for End-Stage Liver Disease (MELD) score. We aim to assess the impact of ascites and HE and its interaction with MELD 3.0 on waitlist mortality. This is a retrospective study of patients listed for LT in the Organ Procurement and Transplantation Network database from 2016 to 2021. The primary outcome was waitlist mortality (death/delisting for too sick to LT). Ascites/HE were classified as moderate ascites without moderate HE (mAscites), moderate HE without moderate ascites (mHE), both moderate ascites/HE (mBoth), and neither. MELD 3.0 scores were categorized as <20, 20-29, 30-39, and ≥40. Of 39 025 candidates, 29% had mAscites, 3% mHE, and 8% mBoth. One-year waitlist mortality was 30%, 38%, and 47%, respectively, compared with 17% (all P < 0.001) for those with neither. In multivariable Cox regression, the adjusted risk of waitlist mortality associated with mAscites (versus neither) was a hazard ratio (HR) of 1.76 (95% confidence interval [CI], 1.55-2.00) when the MELD 3.0 score was <20, significantly higher than when the MELD 3.0 score was 20-29 (HR 1.40; 95% CI, 1.27-1.54), 30-39 (HR 1.19; 95% CI, 1.04-1.35), and ≥40 (HR 1.14; 95% CI, 0.91-1.43, interaction P < 0.05 for all). A similar pattern was observed by MELD 3.0 for both moderate ascites/HE. The presence of moderate ascites alone, or combined with moderate HE, not only increases the risk of waitlist mortality but also has a differential effect by MELD 3.0, especially at lower MELD scores. Earlier strategies addressing this group and improving treatment plans or access to LT regardless of MELD remain needed.

Organ donation after extracorporeal cardiopulmonary resuscitation: a nationwide retrospective cohort study

BackgroundLimited data are available on organ donation practices and recipient outcomes, particularly when comparing donors who experienced cardiac arrest and received extracorporeal cardiopulmonary resuscitation (ECPR) followed by veno-arterial extracorporeal membrane oxygenation (ECMO) decannulation, versus those who experienced cardiac arrest without receiving ECPR. This study aims to explore organ donation practices and outcomes post-ECPR to enhance our understanding of the donation potential after cardiac arrest.MethodsWe conducted a nationwide retrospective cohort study using data from the Japan Organ Transplant Network database, covering all deceased organ donors between July 17, 2010, and August 31, 2022. We included donors who experienced at least one episode of cardiac arrest. During the study period, patients undergoing ECMO treatment were not eligible for a legal diagnosis of brain death. We compared the timeframes associated with each donor’s management and the long-term graft outcomes of recipients between ECPR and non-ECPR groups.ResultsAmong 370 brain death donors with an episode of cardiac arrest, 26 (7.0%) received ECPR and 344 (93.0%) did not; the majority were due to out-of-hospital cardiac arrests. The median duration of veno-arterial ECMO support after ECPR was 3 days. Patients in the ECPR group had significantly longer intervals from admission to organ procurement compared to those not receiving ECPR (13 vs. 9 days, P = 0.005). Lung graft survival rates were significantly lower in the ECPR group (log-rank test P = 0.009), with no significant differences in other organ graft survival rates. Of 160 circulatory death donors with an episode of cardiac arrest, 27 (16.9%) received ECPR and 133 (83.1%) did not. Time intervals from admission to organ procurement following circulatory death and graft survival showed no significant differences between ECPR and non-ECPR groups. The number of organs donated was similar between the ECPR and non-ECPR groups, regardless of brain or circulatory death.ConclusionsThis nationwide study reveals that lung graft survival was lower in recipients from ECPR-treated donors, highlighting the need for targeted research and protocol adjustments in post-ECPR organ donation.

Outcome of Organ Procurement and Transplantation Network Policy Allowing for Waiting Time Modification for Candidates Affected by Race-Inclusive eGFR Calculations

Outcome of Organ Procurement and Transplantation Network Policy Allowing for Waiting Time Modification for Candidates Affected by Race-Inclusive eGFR Calculations

Pediatric donor heart utilization variability among organ procurement organizations.

Organ procurement organizations (OPOs) are responsible for the medical management of organ donors. Given the variability in pediatric donor heart utilization among OPOs, we examined factors that may explain this variability, including differences in donor medical management, organ quality, and candidate factors. The Organ Procurement and Transplant Network database was queried for pediatric (<18 years) heart donors and candidates receiving pediatric donor heart offers from 2010 to 2019. OPOs were stratified by pediatric donor heart utilization rate, and the top and bottom quintiles were compared based on donor management strategies and outcomes. A machine learning algorithm, combining 11 OPO, donor, candidate, and offer variables, was used to determine factors most predictive of whether a heart offer is accepted. There was no clinically significant difference between the top and bottom quintile OPOs in baseline donor characteristics, distance between donor and listing center, management strategies, or organ quality. Machine learning modeling suggested neither OPO donor management nor cardiac function is the primary driver of whether an organ is accepted. Instead, number of prior donor offer refusals and individual listing center receiving the offer were two of the most predictive variables of organ acceptance. OPO clinical practice variation does not seem to account for the discrepancy in pediatric donor heart utilization rates among OPOs. Listing center acceptance practice and prior number of donor refusals seem to be the important drivers of heart utilization and may at least partially account for the variation in OPO heart utilization rates given the regional association between OPOs and listing centers.

Wasted Potential: Decoding the Trifecta of Donor Kidney Shortage, Underutilization, and Rising Discard Rates

Kidney transplantation is a life-saving intervention for end-stage renal disease; yet, the persistent gap between organ demand and supply remains a significant challenge. This paper explores the escalating discard rates of deceased donor kidneys in the United States to assess trends, discard reasons, demographical differences, and preservation techniques. Data from the Scientific Registry of Transplant Recipients from 2010 to 2021 was analyzed using chi-squared tests for trend significance and logistic regression to estimate odds ratios for kidney discard. Over the last decade, discard rates have risen to 25% in 2021. Most discarded kidneys came from extended criteria donor (ECD) donors and elevated kidney donor profile index (KDPI) scores. Kidney biopsy status was a significant factor and predictor of discard. Discard rates varied greatly between Organ Procurement and Transplantation Network regions. Of reasons for discard, “no recipient located” reached a high of 60%. Additionally, there has been a twofold increase in hypothermic machine perfusion (HMP) since 2010, with transportation difficulties being the main reason for the discard of perfused kidneys. Our findings suggest a need to recalibrate organ utilization strategies, optimize the use of lower-quality kidneys through advanced preservation methods, and address the evolving landscape of organ allocation policies to reduce kidney discard rates.