Transplantation Network Database Research Articles

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.

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.

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.

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.

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.

Impact of Extracorporeal Membrane Oxygenation Bridging Duration on Lung Transplant Outcomes

BackgroundWe sought to characterize the association between venovenous extracorporeal membrane oxygenation (VV-ECMO) bridging duration and outcomes in patients listed for lung transplantation. MethodsA retrospective observational study was conducted using the Organ Procurement and Transplantation Network (OPTN) database to identify adults (aged ≥18 years) who were listed for lung transplantation between 2016 and 2020 and were bridged with VV-ECMO. Patients were then stratified into groups, determined by risk inflection points, depending on the amount of time spent on pretransplant ECMO: group 1 (≤5 days), group 2 (6-10 days), group 3 (11-20 days), and group 4 (>20 days). Waiting list survival between groups was analyzed using Fine-Gray competing risk models. Posttransplant survival was compared using Cox regression. ResultsOf 566 eligible VV-ECMO bridge-to-lung-transplant patients (median age, 54 years, 49% men), 174 (31%), 124 (22%), 130 (23%), and 138 (24%) were categorized as groups 1, 2, 3, and 4, respectively. Overall, median duration of VV-ECMO was 10 days (interquartile range, 1-211 days), and 178 patients (31%) died on the waiting list. In the Fine-Gray model, compared with group 1, patients bridged with longer ECMO durations in group 2 (subdistribution hazard ratio [SHR], 2.95; 95% CI, 1.63-5.35), group 3 (SHR, 3.96; 95% CI, 2.36-6.63), and group 4 (SHR, 4.33; 95% CI, 2.59-7.22, all P < .001) were more likely to die on the waiting list. Of 388 patients receiving a transplant, pretransplant ECMO duration was not associated with 1-year survival in Cox regression. ConclusionsProlonged duration of ECMO bridging was associated with worse waiting list mortality but did not impact survival after lung transplant. Prioritization of very early transplantation may improve waiting list outcomes in this population.

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.

Lung transplantation following prior cardiac surgical procedures

IntroductionAs lung transplant candidates are older with increased comorbidities, we sought to examine the prevalence and outcomes of lung transplant recipients after prior cardiac surgery. MethodsLung transplants were identified from the United Network for Organ Sharing/Organ Procurement and Transplantation Network Database. Patients were stratified based on prior cardiac surgery (No Surgery [NS], Prior coronary artery bypass grafting [CABG], Prior Valve [Valve]). Unadjusted comparisons were performed amongst all groups, and propensity matching was utilized for adjusted comparisons. Survival was examined with Kaplan-Meier methods. Results28,710 patients were identified, 467 (1.6%) had prior CABG and 84 (0.3%) had prior valvular surgery. Prior to matching, the NS group was significantly younger, less commonly male, and had lower lung allocation scores. There were significantly fewer bilateral lung transplants in the CABG and Valve groups. Length of stay was shortest in the CABG group, but there were no significant differences in postoperative stroke, dialysis, or in-hospital mortality. There was an increased incidence of cardiac/cerebrovascular cause of death in CABG recipients (18.3%) and malignancy death in Valve recipients (23.3%). Following matching, CABG 5-year survival was lower than NS (p<0.01), while there was no significant difference between NS and Valve groups (p=0.4). ConclusionsCABG and Valve recipients had decreased survival, however not at levels prohibitive to transplantation. Due to potentially increased risk of cardiovascular mortality, providers should evaluate the burden of vascular disease in potential recipients with prior CABG to improve patient selection and maximize post-transplant survival.

Kidney after liver transplantation does not have an increased risk of rejection compared to liver alone.

Simultaneous liver kidney (SLK) transplant protects against acute cellular rejection. In 2017, UNOS implemented a "safety net" policy to allow patients with renal recovery to avoid renal transplantation. Whether kidney after liver transplantation (KALT) increases the risk of rejection is unknown. We performed a retrospective analysis of the Organ Procurement and Transplantation Network (OPTN) database of adult patients who received liver transplant, SLK or KALT between 2010 and 2020. We examined rejection of the liver within 6 months and 1 year of the liver transplant, as well as rejection of the kidney within 6 months and 1 year of receiving the kidney, as well as patient and graft loss. Sixty-six thousand seventy-nine patients were transplanted; 60 168 with liver transplant alone, 5627 with SLK, and 284 with KALT. Acute or chronic liver rejection rates within 6 or 12 months were statistically higher in the KALT group (10.0% and 10.9%) compared to the SLK group (6.1% and 7.5%), but comparable to the LTA group (9.3% and 11.1%). Kidney rejection and graft survival rates were not different. Liver graft survival was worse in KALT than SLK or LTA (Kaplan-Meier estimates.61vs..89 and.90), but these patients were more ill at the time of transplantation. KDPI and LDRI scores were notably lower in the SLK than KALT group. Patient survival was not clinically different between the groups. KALT does not increase the risk of acute or chronic kidney rejection. SLK has a lower risk of early liver rejection, but this effect diminishes by one year to being not clinically different compared to KALT. Given that KALT is immunologically safe, and potentially avoids unnecessary renal graft use, it should be preferred over SLK. Patients undergoing sequential kidney after liver transplant do not have an increased risk of liver or kidney rejection when compared to liver transplant alone or simultaneous liver and kidney transplant.

The impact of induction therapy on the risk of posttransplant lymphoproliferative disorder in adult kidney transplant recipients with donor-recipient serological Epstein-Barr virus mismatch

Posttransplant lymphoproliferative disorder (PTLD) poses a significant concern in Epstein-Barr virus (EBV)–negative patients transplanted from EBV-positive donors (EBV R-/D+). Previous studies investigating the association between different induction agents and PTLD in these patients have yielded conflicting results. Using the Organ Procurement and Transplant Network database, we identified EBV R-/D+ patients >18 years of age who underwent kidney-alone transplants between 2016 and 2022 and compared the risk of PTLD with rabbit antithymocyte globulin (ATG), basiliximab, and alemtuzumab inductions. Among the 6620 patients included, 64.0% received ATG, 23.4% received basiliximab, and 12.6% received alemtuzumab. The overall incidence of PTLD was 2.5% over a median follow-up period of 2.9 years. Multivariable analysis demonstrated that the risk of PTLD was significantly higher with ATG and alemtuzumab compared with basiliximab (adjusted subdistribution hazard ratio [aSHR] = 1.98, 95% confidence interval [CI] 1.29-3.04, P = .002 for ATG and aSHR = 1.80, 95% CI 1.04-3.11, P = .04 for alemtuzumab). However, PTLD risk was comparable between ATG and alemtuzumab inductions (aSHR = 1.13, 95% CI 0.72-1.77, P = .61). Therefore, the risk of PTLD must be taken into consideration when selecting the most appropriate induction therapy for this patient population.

The Public Health Service "Increased Risk" 2020 Policy Change Has not Improved Organ Utilization in the United States: A Nationwide Cohort Study.

To assess the effects of the 2020 United States Public Health Service (PHS) "Increased Risk" Guidelines update. Donors labeled as "Increased Risk" for transmission of infectious diseases have been found to have decreased organ utilization rates despite no significant impact on recipient survival. Recently, the PHS provided an updated guideline focused on "Increased Risk" organ donors, which included the removal of the "Increased Risk" label and the elimination of the separate informed consent form, although the actual increased risk status of donors is still ultimately transmitted to transplant physicians. We sought to analyze the effect of this update on organ utilization rates. This was a retrospective analysis of the Organ Procurement and Transplantation Network database which compared donor organ utilization in the 2 years before the June 2020 PHS Guideline update for increased-risk donor organs (June 2018-May 2020) versus the 2 years after the update (August 2020-July 2022). The organ utilization rate for each donor was determined by dividing the number of organs transplanted by the total number of organs available for procurement. Student t test and multivariable logistic regression models were used for analysis. There were 17,272 donors in the preupdate cohort and 17,922 donors in the postupdate cohort; of these, 4,977 (28.8%) and 3,893 (21.7%) donors were considered "Increased Risk", respectively. There was a 2% decrease in overall organ utilization rates after the update, driven by a 3% decrease in liver utilization rates and a 2% decrease in lung utilization rates. After multivariable adjustment, donors in the postupdate cohort had 10% decreased odds of having all organs transplanted. The 2020 PHS "Increased Risk" Donor Guideline update was not associated with an increase in organ utilization rates in the first 2 years after its implementation, despite a decrease in the proportion of donors considered to be at higher risk. Further efforts to educate the community on the safe usage of high-risk organs are needed and may increase organ utilization.

Outcomes of Kidney Transplants From Toxoplasma-Positive Donors: An Organ Procurement and Transplant Network Database Analysis.

There is a need to reconsider the acceptance of organs from donors considered suboptimal, in the absence of data. Toxoplasma antibody-positive donors (TPD) constitute one such group. The objective of our study was to compare graft survival in deceased donor renal transplant (Tx) recipients, stratified by Toxoplasma IgG status, using the Organ Procurement and Transplantation Network (OPTN) database. A log-linear event history regression model for graft failure categorized by Toxoplasma IgG status, adjusting for confounders was applied to first kidney-only Tx recipients from 2018 to 2022. Of the 51,422 Tx, 4,317 (8.4%) were from TPD. Acute rejection and graft failure (5% each) were similar between groups. Crude graft failure was 7.3 failures per 100 person-years for TPD recipients compared to 6.5 failures per 100 person-years for the Toxoplasma-negative group (p 0.008). The crude failure rate ratio was 1.14 with an adjusted hazard rate ratio of 1.04 (95% CI: 0.94, 1.15, p 0.39). In renal Tx recipients, TPD graft recipients have comparable survival to Tx from Toxoplasma-negative recipients. While caution and close monitoring of recipients post-Tx for surveillance of disseminated toxoplasmosis are still warranted, our study suggests that patients can be successfully managed using TPD organs.

Kidney retransplantation outcomes in adults aged 70 and older: Analysis of risk factors and survival.

An increasing number of older patients are undergoing kidney transplant. Because of a finite longevity, more patients will be faced with failing allografts. At present there is a limited understanding of the benefits and risks associated with kidney retransplantation in this challenging population. We performed a retrospective analysis of the Organ Procurement and Transplantation Network database of all adults ≥70 undergoing kidney retransplant from January 1, 2014 to December 31, 2022. We examined patient and graft survival of retransplanted patients compared to first time transplants. We also analyzed the risk factors that impacted the survival. During the study period there has been a significant rise in the number of retransplants performed, with 631 patients undergoing the procedure. Although clinically insignificant, overall graft, and patient survival rates were slightly lower in the retransplant group compared to the primary transplant group. With retransplant, patient survival was 91.3%, 75.6%, and 56.9% compared to 93.4%, 81.4%, and 64.4% with primary transplant at 1, 3, and 5 years, respectively. With retransplant, graft survival was 89.5%, 73.5%, 57.4% compared to 91.5%, 79.0%, and 63.6% in a primary transplant group at 1, 3, and 5 years, respectively. Multivariable analysis showed that factors predicting poor survival included longer time on dialysis before retransplantation and decreased functional capacity. No survival difference was noted between recipients of deceased versus living donor kidneys. Patients who underwent retransplantation before initiating dialysis had better patient and graft survival. Patients aged ≥70 achieve satisfactory outcomes following kidney retransplantation, highlighting that chronologic age should not preclude this medically complex population from this life-saving procedure. Improvement in functional status and timely retransplantation are the key factors to successful outcome.

A propensity score matched analysis of liver transplantation outcomes in the setting of preservation solution shortage

The recent shortage of the University of Wisconsin (UW) solution prompted increased utilization of histidine-tryptophan-ketoglutarate (HTK) solution for liver graft preservation. This contemporary study analyzed deceased donor liver transplant outcomes following preservation with HTK vs UW. Patients receiving deceased donor liver transplantations between January 1, 2019, and June 30, 2022, were retrospectively identified utilizing the Organ Procurement and Transplant Network database, stratified by preservation with HTK vs UW, and a propensity score matching analysis was performed. Outcomes assessed included rates of primary nonfunction, graft survival, and patient survival. There were 4447 patients in each cohort. Primary nonfunction occurred in 60 (1.35%) patients in the HTK group vs 25 (0.54%) in the UW group (P < .001). HTK was associated with lower 90-day graft survival (94.39% vs 96.09%; P < .001) and 90-day patient survival (95.97% vs 97.38%; P = .001). Unmatched donation after cardiac death-specific analysis of HTK vs UW demonstrated respective rates of primary nonfunction of 1.63% vs 0.82% (P = .20), 90-day graft survival of 92.50% vs 95.29% (P = .069), and 90-day patient survival of 93.90% vs 96.35% (P = .077). These results suggest that HTK may not be an equivalent preservation solution for deceased donor liver transplantation.

Survival following liver transplantation: A population-based nested case-control study

BackgroundLiver transplantation is the gold standard treatment for end-stage liver disease. This study evaluates post-transplantation survival compared with the general population by quantifying standardized mortality ratios in a nested case-control study. MethodsControls were noninstitutionalized United States inhabitants from the National Longitudinal Mortality Study. Cases underwent liver transplantation from 1990 to 2007 identified through the Organ Procurement and Transplantation Network database. Propensity matching (5:1, nearest neighbor, caliper 0.1) identified controls based on age, sex, race, and state. The primary endpoint was 10-year survival. Results62,788 cases were matched to 313,381 controls. The overall standardized mortality ratio was 2.46 (95% CI ​= ​2.44–2.48). The standardized mortality ratio was higher for males (2.59 vs. 2.25) and Hispanic patients (4.80). Younger patients and those transplanted earlier (1990–1995) had higher standardized mortality ratios. ConclusionsLiver recipients have a standardized mortality ratio 2.46 times higher than the general population. Long-term mortality has declined over time.

Preserved 2-y Liver Transplant Outcomes Following Simultaneous Thoracoabdominal DCD Organ Procurement Despite Effects on Liver Utilization Rate.

Current techniques for donation after circulatory determination of death (DCD) heart procurement, through either direct procurement and machine perfusion or thoracoabdominal normothermic regional perfusion (NRP), have demonstrated excellent heart transplant outcomes. However, the impact of thoracoabdominal DCD (TA-DCD) heart procurement on liver allograft outcomes and utilization is poorly understood. One hundred sixty simultaneous heart and liver DCD donors were identified using the United Network for Organ Sharing/Organ Procurement and Transplantation Network database between December 2019 and July 2021. Liver outcomes from TA-DCD donors were stratified by heart procurement technique and evaluated for organ utilization, graft survival, and patient survival. Results were compared with abdominal-only DCD (A-DCD; n = 1332) and donation after brain death (DBD; n = 12 891) liver transplants during the study interval. Kaplan-Meier methods with log-rank testing were used to evaluate patient and graft survival. One hundred thirty-three of 160 livers procured from TA-DCD donors proceeded to transplant. TA-DCD donors were younger (mean 28.26 y; P < 0.0001) with lower body mass index (mean 26.61; P < 0.0001) than A-DCD and DBD donors. TA-DCD livers had equivalent patient survival ( P = 0.893) and superior graft survival (P = 0.009) compared with A-DCD. TA-DCD livers had higher rates of organ discard for long warm ischemia time (37.0%) than A-DCD (20.5%) and DBD (0.5%; P < 0.0001), with direct procurement and machine perfusion procurements leading to a higher discard rate (18.5%) than NRP procurements (7.4%). Liver transplants after TA-DCD donation demonstrated equivalent patient outcomes and excellent graft outcomes. NRP procurements resulted in the lowest rate of organ discard after DCD donation and may represent an optimal strategy to maximize organ utilization.

Assessing Kidney Transplantation Using ECMO-Supported Donors Within a KDPI-Based Allocation System.

Organ donors supported by extracorporeal membrane oxygenation (ECMO) have historically been considered high-risk and are judiciously utilized. This study examines transplant outcomes using renal allografts from donors supported on ECMO for nondonation purposes. Retrospective review of the Gift of Life (Pennsylvania, New Jersey, Delaware) organ procurement organization database, cross-referenced to the Organ Procurement and Transplantation Network database, assessed kidney transplants using donors supported on venoarterial (VA) and venovenous (VV) ECMO for nondonation purposes. Transplants using VA- and VV-ECMO donors were compared with Kidney Donor Profile Index (KDPI)-stratified non-ECMO donors. Regression modeling of the entire ECMO and non-ECMO populations assessed ECMO as predictive of graft survival. Additional regression of the ECMO population alone assessed for donor features associated with graft survival. Seventy-eight ECMO donors yielded 128 kidney transplants (VA: 80, VV: 48). Comparing outcomes using these donors to kidney transplants using organs from KDPI-stratified non-ECMO donors, VA- and VV-ECMO donor grafts conferred similar rates of delayed graft function and posttransplant renal function to KDPI-matched non-ECMO counterparts. VA-ECMO kidneys demonstrated superior graft survival compared with the lowest-quality (KDPI 86%-100%) non-ECMO kidneys and similar graft survival to KDPI <85% non-ECMO kidneys. VV-ECMO showed inferior graft survival to all but the lowest-quality (KDPI 86%-100%) non-ECMO kidneys. VV-ECMO, but not VA-ECMO, was associated with increased risk of graft loss on multivariable regression (hazard ratios-VA: 1.02, VV: 2.18). Higher KDPI, advanced age, increased body mass index, hypertension, and diabetes were identified as high-risk features of ECMO donors. Kidney transplantation using appropriately selected ECMO donors can safely expand the donor pool. Ongoing studies are necessary to determine best practice patterns using kidneys from these donors.

The Impact of Ex Situ Heart Perfusion in Pediatric Transplantation: An Analysis of the OPTN Database.

Ex situ heart perfusion (ESHP) has increased the pool of donors in adults. However, this is not true in pediatrics due to lack of devices. Therefore, we sought to understand organ refusal in pediatrics and estimate donor heart usage with ESHP. Donor hearts offered to pediatrics were identified from the Organ Procurement and Transplantation Network Database (2000-2019). A linear regression model was built to predict average travel speed, and the extended maximum permitted distance with ESHP was calculated. This extended distance was compared with the policy for maximum travel distance. There were 33,708 donor offers (n = 10,807 hearts) to pediatric programs [24.1% (n = 2,604) transplanted]. Six percent of the offers (n = 1,832) (n = 771 hearts) were turned down due to distance, with 676 of the hearts never transplanted. Based on the modeling and using an ESHP time of 5.5 hours, 84% (n = 570/676) of hearts turned down due to distance could be utilized by pediatric programs. This proportion increased to 100% with 10 hours of support time. By addressing prolonged ischemic time due to distance, ESHP has the potential to increase the number of donors utilized in pediatric candidates. Although no device exists for pediatrics, this analysis lends support to the importance of developing this technology.

Expanded Criteria Donor Heart Allograft Utilization: National Trends and Outcomes

BackgroundTo examine recent trends in the use of expanded criteria donor organs in heart transplantation, this study assessed center-level variation in acceptance of these allografts and analyzed their posttransplantation outcomes. MethodsAdult (aged ≥18 years) heart transplant recipients between 2011 and 2022 were identified in the Organ Procurement and Transplantation Network database. Expanded criteria allografts were defined using a previously validated risk score. After stratifying centers by cumulative transplantation volume, those centers in the top tertile (≥23/year) were considered high volume. Subsequently, the ratio of transplantations using expanded criteria allografts to total transplantations was calculated for each high-volume center. On the basis of tertiles, centers were then categorized as high-, medium-, and low-use centers. The primary outcome was death after transplantation. ResultsOf 23,290 transplantations performed, 5017 (22%) used expanded criteria donor allografts. High-volume heart transplantation centers performed 72% (3628) of these transplantations—1183 (75%) between 2011 and 2014, 1383 (73%) between 2015 and October 2018, and 1062 (68%) between November 2018 and June 2021. Compared with low-volume programs, undergoing expanded criteria heart transplantation at high-volume centers was associated with a significantly reduced hazard of mortality at 1 year (hazard ratio, 0.78; CI, 0.65-0.94; P = .01) and 5 years (hazard ratio, 0.85; CI, 0.75-0.98; P = .02). During the study period, survival rates 1 year after transplantation were similar across high-volume centers, regardless of their use of expanded criteria allografts. ConclusionsUndergoing heart transplantation with an expanded criteria donor allograft at a high-volume transplantation center provides a significant survival benefit. Further, the use of more expanded criteria criteria organs, in the right clinical settings, does not negatively affect overall patient outcomes at high-volume centers.