OPTN/SRTR 2020 Annual Data Report: DOD

Prevascularized spongy-like hydrogels maintain their angiogenic potential after prolonged hypothermic storage

The chronic shortage of organs and tissues for transplantation represents a dramatic burden on healthcare systems worldwide. Tissue engineering offers a potential solution to address these shortages, but several challenges remain, with prevascularization being a critical factor for in vivo survival and integration of tissue engineering products. Concurrently, a different challenge hindering the clinical implementation of such products, regards their efficient preservation from the fabrication site to the bedside. Hypothermia has emerged as a potential solution for this issue due to its milder effects on biologic systems in comparison with other cold preservation methodologies. Its impact on prevascularization, however, has not been well studied. In this work, 3D prevascularized constructs were fabricated using adipose-derived stromal vascular fraction cells and preserved at 4 °C using Hypothermosol or basal culture media (α-MEM). Hypothermosol efficiently preserved the structural and cellular integrity of prevascular networks as compared to constructs before preservation. In contrast, the use of α-MEM led to a clear reduction in prevascular structures, with concurrent induction of high levels of apoptosis and autophagy at the cellular level. In vivo evaluation using a chorioallantoic membrane model demonstrated that, in opposition to α-MEM, Hypothermosol preservation retained the angiogenic potential of constructs before preservation by recruiting a similar number of blood vessels from the host and presenting similar integration with host tissue. These results emphasize the need of studying the impact of preservation techniques on key properties of tissue engineering constructs such as prevascularization, in order to validate and streamline their clinical application.

Implications of drug intoxication on donor utilization and outcomes in liver transplantation

INTRODUCTION

This study evaluates the implications of drug intoxication (DI) on donor utilization and outcomes in liver transplantation (LT).

METHODS

The UNOS STAR database was evaluated for all potential donors and adult, first-time, whole LT between 2005 and 2019. Logistic regression analyses evaluated liver utilization; proportional hazards modeling assessed risk of 1-year graft loss.

RESULTS

A total of 132 783 potential donors (10 205, 7.7% from DI), and 90 612 adult LT were identified (7490, 8.3% from DI). DI donors had median age 32 years (IQR 26-40 years, p < .001), were 42.6% female (n = 4346), and 15.5% were DCD donors (n = 1583). Utilization of DI donors changed over time, such that by 2015-2019 they were the most likely donor cause of death (COD) to be utilized. Among LT recipients, there were insignificant differences (<2% variance) in age, gender, ethnicity, and etiology of liver disease according to donor COD. Recipients with MELD scores >30 more frequently received grafts from donors with trauma (23.8%) and DI (21.8%) versus cardiovascular (20.0%) and CVA/stroke (19.9%, p < .001). Among DBD donors, DI-COD was associated with superior 1-year graft survival compared to donors from trauma (HR 1.172, 95% CI 1.057-1.300) and CVA/stroke (HR 1.404, 95% CI 1.264-1.561, p < .001). Donor COD was not significantly associated with 1-year graft loss among DCD donors.

CONCLUSIONS

There is an increased likelihood of donor utilization when COD is drug overdose and an increased likelihood of 1-year graft survival compared to donors from trauma, CVA/stroke, and other COD.

Augmenting the Unites States transplant registry with external mortality data: A moving target ripe for further improvement

The Organ Procurement and Transplantation Network conducts a robust death verification process when augmenting the United States transplant registry with external sources of data. Process enhancements added over 35,000 externally verified deaths across waitlist candidates and transplant recipients for all organs beginning in April 2022. Ninety-four percent of added posttransplant deaths occurred beyond 5 years posttransplant, and over 74% occurred beyond 10 years. Deceased donor solid organ recipients transplanted from January 1, 2010, through October 31, 2020, were analyzed from January and July 2022 Organ Procurement and Transplantation Network Standard Transplant Analysis and Research and the Scientific Registry of Transplant Recipients Standard Analysis Files to quantify the impact of including vs excluding unverified deaths (not releasable to researchers) on posttransplant patient survival estimates. Across all organs, 1- and 5-year posttransplant survival rates were not substantially impacted; meaningful differences were observed in 10-year survival among kidney recipients. These findings bear important implications for anyone who utilized transplant registry data to examine long-term outcomes prior to the updated verification process. Users of transplant surveillance data should interpret results of long-term outcomes cautiously, particularly differences across subpopulations, and the transplant community should identify ways to improve data quality and minimize the reporting burden on transplant institutions.

Decreased Utilization Rate of Grafts for Liver Transplantation After Implementation of Acuity Circle-based Allocation

BACKGROUND

The allocation system for livers began using acuity circles (AC) in 2020. In this study, we sought to evaluate the impact of AC policy on the utilization rate for liver transplantation (LT).

METHODS

Using the US national registry data between 2018 and 2022, LTs were equally divided into 2 eras: pre-AC (before February 4, 2020) and post-AC (February 4, 2020, and after). Deceased potential liver donors were defined as deceased donors from whom at least 1 organ was procured.

RESULTS

The annual number of deceased potential liver donors increased post-AC (from 10 423 to 12 259), approaching equal to that of new waitlist registrations for LT (n = 12 801). Although the discard risk index of liver grafts was comparable between the pre- and post-AC eras, liver utilization rates in donation after brain death (DBD) and donation after circulatory death (DCD) donors were lower post-AC ( P  < 0.01; 79.8% versus 83.4% and 23.7% versus 26.0%, respectively). Recipient factors, ie, no recipient located, recipient determined unsuitable, or time constraints, were more likely to be reasons for nonutilization after implementation of the AC allocation system compared to the pre-AC era (20.0% versus 12.3% for DBD donors and 50.1% versus 40.8% for DCD donors). Among non-high-volume centers, centers with lower utilization of marginal DBD donors or DCD donors were more likely to decrease LT volume post-AC.

CONCLUSIONS

Although the number of deceased potential liver donors has increased, overall liver utilization among deceased donors has decreased in the post-AC era. To maximize the donor pool for LT, future efforts should target specific reasons for liver nonutilization.

In vivo lung perfusion for prompt recovery from primary graft dysfunction after lung transplantation

BACKGROUND

No proven treatment after the development of primary graft dysfunction (PGD) is currently available. Here, we established a novel strategy of in vivo lung perfusion (IVLP) for the treatment of PGD. IVLP involves the application of an in vivo isolated perfusion circuit to an implanted lung. This study aimed to explore the effectiveness of IVLP vs conventional post-lung transplant (LTx) extracorporeal membrane oxygenation (ECMO) treatment using an experimental swine LTx PGD model.

METHODS

After 1.5-hour warm ischemia of the donor lungs, a left LTx was performed. Following the confirmation of PGD development, pigs were divided into 3 groups (n = 5 each): control (no intervention), ECMO, and IVLP. After 2 hours of treatment, a 4-hour functional assessment was conducted, and samples were obtained.

RESULTS

Significantly better oxygenation was achieved in the IVLP group (p ≤ 0.001). Recovery was confirmed immediately and maintained during the following 4-hour observation. The IVLP group also demonstrated better lung compliance than the control group (p = 0.045). A histologic evaluation showed that the lung injury score and terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed significantly fewer injuries and a better result in the wet-to-dry weight ratio in the IVLP group.

CONCLUSIONS

A 2-hour IVLP is technically feasible and allows for prompt recovery from PGD after LTx. The posttransplant short-duration IVLP strategy can complement or overcome the limitations of the current practice for donor assessment and PGD management.

National utilization, trends, and lung transplant outcomes of static versus portable ex vivo lung perfusion platforms

BACKGROUND

This study compared utilization and outcomes of the 2 widely utilized ex vivo lung perfusion (EVLP) platforms in the United States: a static platform and a portable platform.

METHODS

Adult (age 18 years or older) bilateral lung-only transplants utilizing EVLP between February 28, 2018, and December 31, 2022, in the United Network for Organ Sharing database were included. Predischarge acute rejection, intubation at 72 hours posttransplant, extracorporeal membrane oxygenation at 72 hours posttransplant, primary graft dysfunction grade 3 at 72 hours posttransplant, 30-day mortality, and 1-year mortality were evaluated using multivariable regressions.

RESULTS

Overall, 607 (6.3%) lung transplants during the study period used EVLP (51.2% static, 48.8% portable). Static EVLP was primarily utilized in the eastern United States, whereas portable EVLP was primarily utilized in the western United States. Static EVLP donors were more likely to be donation after circulatory death (33.4% vs 26.0%; P = .005), have a >20 pack-year smoking history (13.5% vs 6.5%; P = .005), and be extended criteria donors (92.3% vs 85.0%; P = .013), whereas portable EVLP donors were more likely to be older than age 55 years (14.2% vs 8.0%; P = .02). Transplants utilizing the static and portable platforms had similar risk of acute rejection, intubation at 72 hours, extracorporeal membrane oxygenation at 72 hours, primary graft dysfunction grade 3 at 72 hours, and posttransplant mortality at 30 days and 1 year (all P values > .05).

CONCLUSIONS

The static and portable platforms had significant differences in donor characteristics and geographic distributions of utilization. Despite this, posttransplant survival was similar between the 2 EVLP platforms.

Characteristics of donor lungs declined on site and impact of lung allocation policy change

OBJECTIVE

National and institutional data suggest an increase in organ discard rate (donor lungs procured but not implanted) after a new lung allocation policy was introduced in 2017. However, this measure does not include on-site decline rate (donor lungs declined intraoperatively). The objective of this study is to examine the impact of the allocation policy change on on-site decline.

METHODS

We used a Washington University (WU) and our local organ procurement organization (Mid-America Transplant [MTS]) database to abstract data on all accepted lung offers from 2014 to 2021. An on-site decline was defined as an event in which the procuring team declined the organs intraoperatively, and the lungs were not procured. Logistic regression models were used to investigate potentially modifiable reasons for decline.

RESULTS

The overall study cohort comprised 876 accepted lung offers, of which 471 donors were at MTS with WU or others as the accepting center and 405 at other organ procurement organizations with WU as the accepting center. At MTS, the on-site decline rate increased from 4.6% to 10.8% (P = .01) after the policy change. Given the greater likelihood of non-local organ placement and longer travel distance after policy change, the estimated cost of each on-site decline increased from $5727 to $9700. In the overall group, latest partial pressure of oxygen (odds ratio [OR], 0.993; 95% confidence interval [CI], 0.989-0.997), chest trauma (OR, 2.474; CI, 1.018-6.010), chest radiograph abnormality (OR, 2.902; CI, 1.289-6.532), and bronchoscopy abnormality (OR, 3.654; CI, 1.813-7.365) were associated with on-site decline, although lung allocation policy era was unassociated (P = .22).

CONCLUSIONS

We found that nearly 8% of accepted lungs are declined on site. Several donor factors were associated with on-site decline, although lung allocation policy change did not have a consistent impact on on-site decline.

Small extracellular vesicles from HO-1-modified bone marrow-derived mesenchymal stem cells attenuate ischemia-reperfusion injury after steatotic liver transplantation by suppressing ferroptosis via miR-214-3p

Donor shortage is a major problem that limits liver transplantation availability. Steatotic donor liver presents a feasible strategy to solve this problem. However, severe ischemia-reperfusion injury (IRI) is an obstacle to the adoption of steatotic transplanted livers. Evidence from our prior studies indicated that bone marrow mesenchymal stem cells modified with heme oxygenase-1 (HMSCs) can attenuate non-steatotic liver IRI. However, the contribution of HMSCs in transplanted steatotic liver IRI is unclear. Here, HMSCs and their derived small extracellular vesicles (HM-sEVs) alleviated IRI in transplanted steatotic livers. After liver transplantation, there was significant enrichment of the differentially expressed genes in the glutathione metabolism and ferroptosis pathways, accompanied by ferroptosis marker upregulation. The HMSCs and HM-sEVs suppressed ferroptosis and attenuated IRI in the transplanted steatotic livers. MicroRNA (miRNA) microarray and validation experiments indicated that miR-214-3p, which was abundant in the HM-sEVs, suppressed ferroptosis by targeting cyclooxygenase 2 (COX2). In contrast, COX2 overexpression reversed this effect. Knockdown of miR-214-3p in the HM-sEVs diminished its ability to suppress ferroptosis and protect liver tissues/cells. The findings suggested that HM-sEVs suppressed ferroptosis to attenuate transplanted steatotic liver IRI via the miR-214-3p-COX2 axis.

Adeno-associated virus mediates gene transduction after static cold storage treatment in rodent lung transplantation

OBJECTIVE

Adeno-associated virus is a clinically used gene therapy vector but has not been studied in lung transplantation. We sought to determine the efficacy of adeno-associated virus delivery during static cold storage via the airway versus the pulmonary artery before lung transplantation in a rodent model.

METHODS

Lewis rat lung grafts were treated with a dose of 8e8 or 4e9 viral genome/μL recombinant adeno-associated virus subtype-9 vectors containing firefly luciferase genomes administered via the pulmonary artery or airway during cold storage. A control group did not receive adeno-associated virus. Recipient syngeneic rats then underwent single left lung transplantation. Animals underwent bioluminescence imaging on postoperative days 7, 14, 28, and 56. Explanted tissues were prepared as lysates to quantify luciferase activity. Immunohistochemistry was performed to evaluate cellular transgene expression patterns.

RESULTS

Control animals with no luminescent signal produced a background radiance of 6.1e4 p/s/cm2/sr. In the airway delivery group, mean radiance was greater than the control at 4e9 viral genome/μL postoperative day 7 radiance 6.9e4 p/s/cm2/sr (P = .04). In the pulmonary artery delivery group, we observed greater in vivo luminescence in animals receiving 4e9 viral genome/μL compared with all other groups. However, analysis of tissue lysate revealed greater luminescence in the airway delivery group and suggested off-target expression in heart and liver tissue in the pulmonary artery delivery group. Immunohistochemistry demonstrated transgene staining in distal airway epithelium and alveoli but sparing of the vasculature in the airway delivery group.

CONCLUSIONS

Adeno-associated virus mediates gene transduction during static cold storage in rat lung isografts when administered via the airway and pulmonary artery. Airway administration leads to robust transgene expression in respiratory epithelial cells, whereas pulmonary artery administration targets alternative cell types and increases extrapulmonary transgene expression.

Transplantation Outcomes with Donor Hearts after Circulatory Death

BACKGROUND

Data showing the efficacy and safety of the transplantation of hearts obtained from donors after circulatory death as compared with hearts obtained from donors after brain death are limited.

METHODS

We conducted a randomized, noninferiority trial in which adult candidates for heart transplantation were assigned in a 3:1 ratio to receive a heart after the circulatory death of the donor or a heart from a donor after brain death if that heart was available first (circulatory-death group) or to receive only a heart that had been preserved with the use of traditional cold storage after the brain death of the donor (brain-death group). The primary end point was the risk-adjusted survival at 6 months in the as-treated circulatory-death group as compared with the brain-death group. The primary safety end point was serious adverse events associated with the heart graft at 30 days after transplantation.

RESULTS

A total of 180 patients underwent transplantation; 90 (assigned to the circulatory-death group) received a heart donated after circulatory death and 90 (regardless of group assignment) received a heart donated after brain death. A total of 166 transplant recipients were included in the as-treated primary analysis (80 who received a heart from a circulatory-death donor and 86 who received a heart from a brain-death donor). The risk-adjusted 6-month survival in the as-treated population was 94% (95% confidence interval [CI], 88 to 99) among recipients of a heart from a circulatory-death donor, as compared with 90% (95% CI, 84 to 97) among recipients of a heart from a brain-death donor (least-squares mean difference, -3 percentage points; 90% CI, -10 to 3; P<0.001 for noninferiority [margin, 20 percentage points]). There were no substantial between-group differences in the mean per-patient number of serious adverse events associated with the heart graft at 30 days after transplantation.

CONCLUSIONS

In this trial, risk-adjusted survival at 6 months after transplantation with a donor heart that had been reanimated and assessed with the use of extracorporeal nonischemic perfusion after circulatory death was not inferior to that after standard-care transplantation with a donor heart that had been preserved with the use of cold storage after brain death. (Funded by TransMedics; ClinicalTrials.gov number, NCT03831048.).

Beyond donation to organ utilization in the USA

PURPOSE OF REVIEW

The deceased donor organ pool has broadened beyond young, otherwise healthy head trauma victims. But an abundance of donated organs only benefits patients if they are accepted, expeditiously transported and actually transplanted. This review focuses on postdonation challenges and opportunities to increase the number of transplants through improved organ utilization.

RECENT FINDINGS

We build upon recently proposed changes in terminology for measuring organ utilization. Among organs recovered for transplant, the nonuse rate (NUR REC ) has risen above 25% for kidneys and pancreata. Among donors, the nonuse rate (NUR DON ) has risen to 40% for livers and exceeds 70% for thoracic organs. Programme-level variation in offer acceptance rates vastly exceeds variation in the traditional, 1-year survival benchmark. Key opportunities to boost utilization include donation after circulatory death and hepatitis C virus (HCV)+ organs; acute kidney injury and suboptimal biopsy kidneys; older and steatotic livers.

SUMMARY

Underutilization of less-than-ideal, yet transplant-worthy organs remains an obstacle to maximizing the impact of the U.S. transplant system. The increased risk of inferior posttransplant outcomes must always be weighed against the risks of remaining on the waitlist. Advanced perfusion technologies; tuning allocation systems for placement efficiency; and data-driven clinical decision support have the potential to increase utilization of medically complex organs.

Cost-effectiveness of Interventions to Increase Utilization of Kidneys From Deceased Donors With Primary Brain Malignancy in an Australian Setting

Kidneys from potential deceased donors with brain cancer are often foregone due to concerns of cancer transmission risk to recipients. There may be uncertainty around donors' medical history and their absolute transmission risk or risk-averse decision-making among clinicians. However, brain cancer transmissions are rare, and prolonging waiting time for recipients is harmful.

Methods

We assessed the cost-effectiveness of increasing utilization of potential deceased donors with brain cancer using a Markov model simulation of 1500 patients waitlisted for a kidney transplant, based on linked transplant registry data and with a payer perspective (Australian government). We estimated costs and quality-adjusted life-years (QALYs) for three interventions: decision support for clinicians in assessing donor risk, improved cancer classification accuracy with real-time data-linkage to hospital records and cancer registries, and increased risk tolerance to allow intermediate-risk donors (up to 6.4% potential transmission risk).

Results

Compared with current practice, decision support provided 0.3% more donors with an average transmission risk of 2%. Real-time data-linkage provided 0.6% more donors (1.1% average transmission risk) and increasing risk tolerance (accepting intermediate-risk 6.4%) provided 2.1% more donors (4.9% average transmission risk). Interventions were dominant (improved QALYs and saved costs) in 78%, 80%, and 87% of simulations, respectively. The largest benefit was from increasing risk tolerance (mean +18.6 QALYs and AU$2.2 million [US$1.6 million] cost-savings).

Conclusions

Despite the additional risk of cancer transmission, accepting intermediate-risk donors with brain cancer is likely to increase the number of donor kidneys available for transplant, improve patient outcomes, and reduce overall healthcare expenditure.

Temporal changes in the utilization of kidneys from hepatitis C virus-infected donors in the United States

Despite data demonstrating increased utilization of kidneys from hepatitis C virus (HCV)-infected donors, it is unknown whether this is due to an increase in the donor pool or improved organ utilization and whether data from early pilot trials were temporally associated with changes in organ utilization. We used data from the Organ Procurement and Transplantation Network on all kidney donors and recipients of kidney transplants from January 1, 2015, to March 31, 2022 to evaluate temporal changes using joinpoint regression. Our primary analyses compared donors on the basis of their HCV viremic status (HCV-infected vs HCV-negative). Kidney utilization changes were assessed by evaluating the kidney discard rate and kidneys transplanted per donor. A total of 81 833 kidney donors were included in the analysis. There was a statistically significant decrease in the discard rates of HCV-infected kidney donors from 40% to just over 20% over a 1-year period, with a concurrent increase in kidneys transplanted per donor. This increased utilization occurred in tandem with the publication of pilot trials involving HCV-infected kidney donors in HCV-negative recipients rather than an increase in the donor pool. Ongoing clinical trials may strengthen existing data, which could result in this practice becoming the accepted standard of care.

Declining Medicare reimbursement in abdominal transplantation from 2000 to 2021

BACKGROUND

The Centers for Medicare and Medicaid Services is a major payer for abdominal transplant services. Reimbursement reductions could have a major impact on the transplant surgical workforce and hospitals. Yet government reimbursement trends in abdominal transplantation have not been fully characterized.

METHODS

We performed an economic analysis to characterize changes in inflation-adjusted trends in Medicare surgical reimbursement for abdominal transplant procedures. Using the Medicare Fee Schedule Look-Up Tool, we performed a procedure code-based surgical reimbursement rate analysis. Reimbursement rates were adjusted for inflation to calculate overall changes in reimbursement, overall year-over-year, 5-year year-over-year, and compound annual growth rate from 2000 to 2021.

RESULTS

We observed declines in adjusted reimbursement of common abdominal transplant procedures, including liver (-32.4%), kidney with and without nephrectomy (-24.2% and -24.1%, respectively), and pancreas transplant (-15.2%) (all, P < .05). Overall, the yearly average change for liver, kidney with and without nephrectomy, and pancreas transplant were -1.54%, -1.15%, -1.15%, and -0.72%. Five-year annual change averaged -2.69%, -2.35%, -2.64%, and -2.43%, respectively. The overall average compound annual growth rate was -1.27%.

CONCLUSION

This analysis depicts a worrisome reimbursement pattern for abdominal transplant procedures. Transplant surgeons, centers, and professional organizations should note these trends to advocate sustainable reimbursement policy and to preserve continued access to transplant services.

Long-term outcomes of kidney transplantation from deceased donors with terminal acute kidney injury: Single center experience and literature review

INTRODUCTION

Long-term outcomes of kidney transplantation from deceased donors (DDKTs) with terminal acute kidney injury (AKI) are not well defined.

METHODS

Single center retrospective review of DDKTs from 1/31/07-12/31/19. AKI kidneys were defined by a doubling of the donor's admission serum creatinine (SCr) level AND a terminal SCr ≥2.0 mg/dl.

RESULTS

A total of 188 AKI DDKTs were performed, including 154 from brain-dead standard criteria donors (SCD). Mean donor age was 36 years and mean Kidney Donor Profile Index was 50%; mean admission and terminal SCr levels were 1.3 and 3.1 mg/dl, respectively. With a mean follow-up of 94 months (median 89 months), overall patient (both 71.3%) and graft survival (54% AKI vs. 57% non-AKI) rates were comparable to concurrent DDKTs from brain-dead non-AKI SCDs (n = 769). Delayed graft function (DGF) was higher in AKI kidney recipients (47% vs. 20% non-AKI DDKTs, p < .0001). DGF was associated with lower graft survival in recipients of both AKI and non-AKI SCD kidneys but the impact was earlier and more pronounced in non-AKI recipients.

CONCLUSIONS

Despite having more than twice the incidence of DGF, kidneys from deceased donors with terminal AKI have long-term outcomes comparable to non-AKI SCD kidneys and represent a safe and effective method to expand the donor pool.

Expanding heart transplantation in 2022 and beyond

PURPOSE OF REVIEW

Despite advances in the technology of mechanical circulatory support, the need for heart transplantation continues to grow. The longevity of heart transplants continues to be superior to mechanical solutions, though the short-term differences are shrinking. In this review, we cover three timely developments and summarize the recent literature.

RECENT FINDINGS

After stagnant rates of heart transplant activity for some years, recently, transplant volume has increased. The developments that have ignited interest have been the use of hepatitis C infected donors, which can now be safely transplanted with the advent of curative oral regimens, and the worldwide use of donors following withdrawal of life support as opposed to traditional brain death donors. In addition, the recent experience of human cardiac xenotransplantation has been very exciting, and though it is not of clinical utility yet, it holds the promise for a virtually unlimited supply of organs at some time in the future.

SUMMARY

Much work remains to be done, but together, all three of these developments are exciting and important to be aware of in the future. Each will contribute to additional donors for human heart transplantation and hopefully will alleviate suffering and death on the waiting list.

Normothermic Regional Perfusion Can Improve Both Utilization and Outcomes in DCD Liver, Kidney, and Pancreas Transplantation

Normothermic regional perfusion (NRP) has gained widespread adoption in multiple European countries. The aim of this study was to examine the influence of thoracoabdominal-NRP (TA-NRP) on the utilization and outcomes of liver, kidney, and pancreas transplantation in the United States.

Methods

Using the US national registry data between 2020 and 2021, donation after circulatory death (DCD) donors were separated into 2 groups: DCD with TA-NRP and without TA-NRP. There were 5234 DCD donors; among them 34 donors were with TA-NRP. After 1:4 propensity score matching, the utilization rates were compared between DCD with and without TA-NRP.

Results

Although the utilization rates of kidney and pancreas were comparable (P = 0.71 and P = 0.06, 94.1% versus 95.6% and 8.8% versus 2.2%, respectively), that of liver in DCD with TA-NRP was significantly higher (P < 0.001; 70.6% versus 39.0%). Among 24 liver transplantations, 62 kidney transplantations, and 3 pancreas transplantations from DCD with TA-NRP, there were 2 liver grafts and 1 kidney graft that failed within 1 y after transplantation.

Conclusions

TA-NRP in the United States significantly increased the utilization rate of abdominal organs from DCD donors with comparable outcomes after transplantation. Increasing use of NRP may expand the donor pool without compromising transplant outcomes.

Time to discard the term "discard"

The 2022 Scientific Registry of Transplant Recipients Consensus Conference "People Driven Transplant Metrics" offered an opportunity for a diverse group of stakeholders in the solid organ transplant community to exchange ideas about what information and metrics are important to different stakeholders. Participating patients and family members called on the transplant community to cease using the term "discards" to refer to donated organs that are not transplanted.

Remote ex vivo lung perfusion at a centralized evaluation facility

BACKGROUND

In the US, only 23% of lungs offered for transplantation are transplanted. Ex vivo lung perfusion (EVLP) allows for evaluation of additional donor lungs; its adoption has been limited by resources and expertise. Dedicated facilities with a centralized lung evaluation system (CLES) could expand access to EVLP.

METHODS

In this unblinded, nonrandomized, traditional feasibility study, 7 US transplant centers referred lungs declined for standard transplantation to a dedicated EVLP facility, which utilized a CLES. EVLP was remotely monitored by the transplant teams. CLES lungs were matched with contemporaneous conventional static cold-preserved controls at each center.

RESULTS

A total of 115 recipients were enrolled, and 66 received allografts from 63 donors after EVLP at the dedicated CLES facility. Forty-nine contemporaneous patients served as controls. Primary graft dysfunction grade 3 at 72 hours (PGD3-72 hours) was higher in the CLES group with 16 (24%) vs 2 (4%) in the control (common RD 95% CI, 0.07-0.32; p = 0.0009). All recipients survived to 30 days and 1-year survival was similar for both groups (92% controls vs 89% CLES; common RD 95% CI, -0.14-0.08; p = 0.58). Total preservation time, hospital and ICU lengths of stay, and time to first extubation were longer in the CLES group.

CONCLUSIONS

Remote ex vivo perfusion of lung allografts declined for conventional transplantation at a dedicated CLES facility is feasible and resulted in additional transplants. Recipients of allografts assessed with a CLES had a higher rate of PGD3-72 hours, but similar 30-day and 1-year outcomes compared to conventional lung recipients. (NCT02234128).

Kidney utility and futility

Changes in kidney allocation coupled with the COVID-19 pandemic have placed tremendous strain on current systems of organ distribution and logistics. Although the number of deceased donors continues to rise annually in the United States, the proportion of marginal deceased donors (MDDs) is disproportionately growing. Cold ischemia times and kidney discard rates are rising in part related to inadequate planning, resources, and shortages. Complexity in kidney allocation and distribution has contributed to this dilemma. Logistical issues and the ability to reperfuse the kidney within acceptable time constraints increasingly determine clinical decision-making for organ acceptance. We have a good understanding of the phenotype of "hard to place" MDD kidneys, yet continue to promote a "one size fits all" approach to organ allocation. Allocation and transportation systems need to be agile, mobile, and flexible in order to accommodate the expanding numbers of MDD organs. By identifying "hard to place" MDD kidneys early and implementing a "fast-track" or open offer policy to expedite placement, the utilization rate of MDDs would improve dramatically. Organ allocation and distribution based on location, motivation, and innovation must lead the way. In the absence of change, we are sacrificing utility for futility and discard rates will continue to escalate.