Sex-based Disparities in Access to Liver Transplantation for Waitlisted Patients With Model for End-stage Liver Disease Score of 40.

OBJECTIVE: To determine the association of sex with access to liver transplantation among candidates with the highest possible model for end-stage liver disease score (MELD 40). BACKGROUND: Women with end-stage liver disease are less likely than men to receive liver transplantation due in part to MELD's underestimation of renal dysfunction in women. The extent of the sex-based disparity among patients with high disease severity and equally high MELD scores is unclear. METHODS: Using national transplant registry data, we compared liver offer acceptance (offers received at match MELD 40) and waitlist outcomes (transplant vs death/delisting) by sex for 7654 waitlisted liver transplant candidates from 2009 to 2019 who reached MELD 40. Multivariable logistic and competing-risks regression was used to estimate the association of sex with the outcome and adjust for the candidate and donor factors. RESULTS: Women (N = 3019, 39.4%) spent equal time active at MELD 40 (median: 5 vs 5 days, P = 0.28) but had lower offer acceptance (9.2% vs 11.0%, P < 0.01) compared with men (N = 4635, 60.6%). Adjusting for candidate/donor factors, offers to women were less likely accepted (odds ratio = 0.87, P < 0.01). Adjusting for candidate factors, once they reached MELD 40, women were less likely to be transplanted (subdistribution hazard ratio = 0.90, P < 0.01) and more likely to die or be delisted (subdistribution hazard ratio = 1.14, P = 0.02). CONCLUSIONS: Even among candidates with high disease severity and equally high MELD scores, women have reduced access to liver transplantation and worse outcomes compared with men. Policies addressing this disparity should consider factors beyond MELD score adjustments alone.

Association of Implantation Biopsy Findings in Living Donor Kidneys With Donor and Recipient Outcomes.

RATIONALE & OBJECTIVE: Some living donor kidneys are found to have biopsy evidence of chronic scarring and/or glomerular disease at implantation, but it is unclear if these biopsy findings help predict donor kidney recovery or allograft outcomes. Our objective was to identify the prevalence of chronic histological changes and glomerular disease in donor kidneys, and their association with donor and recipient outcomes. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Single center, living donor kidney transplants from January 2010 to July 2022. EXPOSURE: Chronic histological changes, glomerular disease in donor kidney implantation biopsies. OUTCOME: For donors, single-kidney estimated glomerular filtration rate (eGFR) increase, percent total eGFR loss, ≥40% eGFR decline from predonation baseline, and eGFR<60mL/min/1.73m2 at 6 months after donation; for recipients, death-censored allograft survival. ANALYTICAL APPROACH: Biopsies were classified as having possible glomerular disease by pathologist diagnosis or chronic changes based on the percentage of glomerulosclerosis, interstitial fibrosis/tubular atrophy, and vascular disease. We used logistic regression to identify factors associated with the presence of chronic changes, linear regression to identify the association between chronic changes and single-kidney estimated glomerular filtration rate (eGFR) recovery, and time-to-event analyses to identify the relationship between abnormal biopsy findings and allograft outcomes. RESULTS: Among 1,104 living donor kidneys, 155 (14%) had advanced chronic changes on implantation biopsy, and 12 (1%) had findings suggestive of possible donor glomerular disease. Adjusted logistic regression showed that age (odds ratio [OR], 2.44 per 10 years [95% CI, 1.98-3.01), Hispanic ethnicity (OR, 1.87 [95% CI, 1.15-3.05), and hypertension (OR, 1.92 [95% CI, 1.01-3.64), were associated with higher odds of chronic changes on implantation biopsy. Adjusted linear regression showed no association of advanced chronic changes with single-kidney eGFR increase or relative risk of eGFR<60mL/min/1.73m2. There were no differences in time-to-death-censored allograft failure in unadjusted or adjusted Cox proportional hazards models when comparing kidneys with chronic changes to kidneys without histological abnormalities. LIMITATIONS: Retrospective, absence of measured GFR. CONCLUSIONS: Approximately 1 in 7 living donor kidneys had chronic changes on implantation biopsy, primarily in the form of moderate vascular disease, and 1% had possible donor glomerular disease. Abnormal implantation biopsy findings were not significantly associated with 6-month donor eGFR outcomes or allograft survival. PLAIN-LANGUAGE SUMMARY: Kidney biopsies are the gold standard test to identify the presence or absence of kidney disease. However, kidneys donated by healthy living donors-who are extensively screened for any evidence of kidney disease before donation-occasionally show findings that might be considered "abnormal," including the presence of scarring in the kidney or findings suggestive of a primary kidney disease. We studied the frequency of abnormal kidney biopsy findings among living donors at our center. We found that about 14% of kidneys had chronic abnormalities and 1% had findings suggesting possible glomerular kidney disease, but the presence of abnormal biopsy findings was not associated with worse outcomes for the donors or their recipients.

Kidney Transplant Clinicians' Perceptions of Palliative Care for Patients With Failing Allografts in the US: A Mixed Methods Study.

RATIONALE & OBJECTIVE: Kidney transplant patients with failing allografts have a physical and psychological symptom burden as well as high morbidity and mortality. Palliative care is underutilized in this vulnerable population. We described kidney transplant clinicians' perceptions of palliative care to delineate their perceived barriers to and facilitators of providing palliative care to this population. STUDY DESIGN: National explanatory sequential mixed methods study including an online survey and semistructured interviews. SETTING & PARTICIPANTS: Kidney transplant clinicians in the United States surveyed and interviewed from October 2021 to March 2022. ANALYTICAL APPROACH: Descriptive summary of survey responses, thematic analysis of qualitative interviews, and mixed methods integration of data. RESULTS: A total of 149 clinicians completed the survey, and 19 completed the subsequent interviews. Over 90% of respondents agreed that palliative care can be helpful for patients with a failing kidney allograft. However, 46% of respondents disagreed that all patients with failing allografts benefit from palliative care, and two-thirds thought that patients would not want serious illness conversations. More than 90% of clinicians expressed concern that transplant patients and caregivers would feel scared or anxious if offered palliative care. The interviews identified three main themes: (1) transplant clinicians' unique sense of personal and professional responsibility was a barrier to palliative care engagement, (2) clinicians' uncertainty regarding the timing of palliative care collaboration would lead to delayed referral, and (3) clinicians felt challenged by factors related to patients' cultural backgrounds and identities, such as language differences. Many comments reflected an unfamiliarity with the broad scope of palliative care beyond end-of-life care. LIMITATIONS: Potential selection bias. CONCLUSIONS: Our study suggests that multiple barriers related to patients, clinicians, health systems, and health policies may pose challenges to the delivery of palliative care for patients with failing kidney transplants. This study illustrates the urgent need for ongoing efforts to optimize palliative care delivery models dedicated to kidney transplant patients, their families, and the clinicians who serve them. PLAIN-LANGUAGE SUMMARY: Kidney transplant patients experience physical and psychological suffering in the context of their illnesses that may be amenable to palliative care. However, palliative care is often underutilized in this population. In this mixed-methods study, we surveyed 149 clinicians across the United States, and 19 of them completed semistructured interviews. Our study results demonstrate that several patient, clinician, system, and policy factors need to be addressed to improve palliative care delivery to this vulnerable population.

Association between donor kidney cysts and donor and recipient outcomes after living donor kidney transplantation.

INTRODUCTION: Incidental kidneys cysts are typically considered benign, but the presence of cysts is more frequent in individuals with other early markers of kidney disease. We studied the association of donor kidney cysts with donor and recipient outcomes after living donor kidney transplantation. METHODS: We retrospective identified 860 living donor transplants at our center (1/1/2011-7/31/2022) without missing data. Donor cysts were identified by review of pre-donation CT scan reports. We used linear regression to study the association between donor cysts and 6-month single-kidney estimated glomerular filtration rate (eGFR) increase, and time-to-event analyses to study the association between donor cysts and recipient death-censored graft failure. RESULTS: Among donors, 77% donors had no kidney cysts, 13% had ≥1 cyst on the kidney not donated, and 11% only had cysts on the donated kidney. In adjusted linear regression, cysts on the donated kidney and kidney not donated were not significantly associated with 6-month single-kidney eGFR increase. Among transplants, 17% used a transplanted kidney with a cyst and 6% were from donors with cysts only on the kidney not transplanted. There was no association between donor cyst group and post-transplant death-censored graft survival. Results were similar in sensitivity analyses comparing transplants using kidneys with no cysts versus 1-2 cysts versus ≥3 cysts. CONCLUSIONS: Kidney cysts in living kidney donors were not associated with donor kidney recovery or recipient allograft longevity, suggesting incidental kidney cysts need not be taken into account when determining living donor candidate suitability or the laterality of planned donor nephrectomy.

Increased volume of organ offers and decreased efficiency of kidney placement under circle-based kidney allocation.

The newest kidney allocation policy kidney allocation system 250 (KAS250) broadened geographic distribution while increasing allocation system complexity. We studied the volume of kidney offers received by transplant centers and the efficiency of kidney placement since KAS250. We identified deceased-donor kidney offers (N = 907,848; N = 36,226 donors) to 185 US transplant centers from January 1, 2019, to December 31, 2021 (policy implemented March 15, 2021). Each unique donor offered to a center was considered a single offer. We compared the monthly volume of offers received by centers and the number of centers offered before the first acceptance using an interrupted time series approach (pre-/post-KAS250). Post-KAS250, transplant centers received more kidney offers (level change: 32.5 offers/center/mo, P < .001; slope change: 3.9 offers/center/mo, P = .003). The median monthly offer volume post-/pre-KAS250 was 195 (interquartile range 137-253) vs. 115 (76-151). There was no significant increase in deceased-donor transplant volume at the center level after KAS250, and center-specific changes in offer volume did not correlate with changes in transplant volume (r = -0.001). Post-KAS250, the number of centers to whom a kidney was offered before acceptance increased significantly (level change: 1.7 centers/donor, P < .001; slope change: 0.1 centers/donor/mo, P = .014). These findings demonstrate the logistical burden of broader organ sharing, and future allocation policy changes will need to balance equity in transplant access with the operational efficiency of the allocation system.

Identifying and understanding variation in population-based access to liver transplantation in the United States.

We aimed to identify variations in liver transplant access across transplant referral regions (TRRs), accounting for differences in population characteristics and practice environments. Adult end-stage liver disease (ESLD) deaths and liver waitlist additions from 2015 to 2019 were included. The primary outcome was listing-to-death ratio (LDR). We modeled the LDR as a continuous variable and obtained adjusted LDR estimates for each TRR, accounting for clinical and demographic characteristics of ESLD decedents, socioeconomic and health care environment within the TRR, and characteristics of the transplant environment. The overall mean LDR was 0.24 (range: 0.10-0.53). In the final model, proportion of patients living in poverty and concentrated poverty was negatively associated with LDR; organ donation rate was positively associated with LDR. The R2 was 0.60, indicating that 60% of the variability in LDR was explained by the model. Approximately 40% of this variation remained unexplained and may be due to transplant center behaviors amenable to intervention to improve access to care for patients with ESLD.

The Perspectives of General Nephrologists Toward Transitions of Care and Management of Failing Kidney Transplants.

The management of failing kidney allograft and transition of care to general nephrologists (GN) remain a complex process. The Kidney Pancreas Community of Practice (KPCOP) Failing Allograft Workgroup designed and distributed a survey to GN between May and September 2021. Participants were invited via mail and email invitations. There were 103 respondents with primarily adult nephrology practices, of whom 41% had an academic affiliation. More than 60% reported listing for a second kidney as the most important concern in caring for patients with a failing allograft, followed by immunosuppression management (46%) and risk of mortality (38%), while resistant anemia was considered less of a concern. For the initial approach to immunosuppression reduction, 60% stop antimetabolites first, and 26% defer to the transplant nephrologist. Communicating with transplant centers about immunosuppression cessation was reported to occur always by 60%, and sometimes by 29%, while 12% reported making the decision independently. Nephrologists with academic appointments communicate with transplant providers more than private nephrologists (74% vs. 49%, p = 0.015). There are heterogeneous approaches to the care of patients with a failing allograft. Efforts to strengthen transitions of care and to develop practical practice guidelines are needed to improve the outcomes of this vulnerable population.

Deceased donor kidneys allocated out of sequence by organ procurement organizations.

Deceased donor kidney allocation follows a ranked match-run of potential recipients. Organ procurement organizations (OPOs) are permitted to deviate from the mandated match-run in exceptional circumstances. Using match-run data for all deceased donor kidney transplants (Ktx) in the US between 2015 and 2019, we identified 1544 kidneys transplanted from 933 donors with an OPO-initiated allocation exception. Most OPOs (55/58) used this process at least once, but 3 OPOs performed 64% of the exceptions and just 2 transplant centers received 25% of allocation exception Ktx. At 2 of 3 outlier OPOs these transplants increased 136% and 141% between 2015 and 2019 compared to only a 35% increase in all Ktx. Allocation exception donors had less favorable characteristics (median KDPI 70, 41% with history of hypertension), but only 29% had KDPI ≥ 85% and the majority did not meet the traditional threshold for marginal kidneys. Allocation exception kidneys went to larger centers with higher offer acceptance ratios and to recipients with 2 fewer priority points-equivalent to 2 less years of waiting time. OPO-initiated exceptions for kidney allocation are growing increasingly frequent and more concentrated at a few outlier centers. Increasing pressure to improve organ utilization risks increasing out-of-sequence allocations, potentially exacerbating disparities in access to transplantation.

Influence of organ quality on the observed association between deceased donor kidney procurement biopsy findings and graft survival.

Deceased donor kidney procurement biopsies findings are the most common reason for kidney discard. Retrospective studies have found inconsistent associations with post-transplant outcomes but may have been limited by selection bias because kidneys with advanced nephrosclerosis from high-risk donors are typically discarded. We conducted a retrospective cohort study of kidneys transplanted in the United States from 2015 to 2019 with complete biopsy data available, defining "suboptimal histology" as glomerulosclerosis ≥11%, IFTA ≥mild, and/or vascular disease ≥mild. We used time-to-event analyses to determine the association between suboptimal histology and death-censored graft failure after stratification by kidney donor profile index (KDPI) (≤35%, 36%-84%, ≥85%) and final creatinine (<1 mg/dl, 1-2 mg/dl, >2 mg/dl). Among 30 469 kidneys included, 36% had suboptimal histology. In adjusted analyses, suboptimal histology was associated with death-censored graft failure among kidneys with KDPI 36-84% (HR 1.22, 95% CI 1.09-1.36), but not KDPI≤35% (HR 1.24, 0.94-1.64) or ≥ 85% (HR 0.99, 0.81-1.22). Similarly, suboptimal histology was associated with death-censored graft failure among kidneys from donors with creatinine 1-2 mg/dl (HR 1.39, 95% CI 1.20-1.60) but not <1 mg/dl (HR 1.07, 0.93-1.23) or >2 mg/dl (HR 0.95, 0.75-1.20). The association of procurement histology with graft longevity among intermediate-quality kidneys that were likely to be both biopsied and transplanted suggests biopsies provide independent organ quality assessments.

Association of transplant center market concentration and local organ availability with deceased donor kidney utilization.

Although there is a shortage of kidneys available for transplantation, many transplantable kidneys are not procured or are discarded after procurement. We investigated whether local market competition and/or organ availability impact kidney procurement/utilization. We calculated the Herfindahl-Hirschman Index (HHI) for deceased donor kidney transplants (2015-2019) for 58 US donation service areas (DSAs) and defined 4 groups: HHI ≤ 0.32 (high competition), HHI = 0.33-0.51 (medium), HHI = 0.53-0.99 (low), and HHI = 1 (monopoly). We calculated organ availability for each DSA as the number kidneys procured per incident waitlisted candidate, grouped as: <0.42, 0.42-0.69, >0.69. Characteristics of procured organs were similar across groups. In adjusted logistic regression, the HHI group was inconsistently associated with composite export/discard (reference: high competition; medium: OR 1.16, 95% CI 1.11-1.20; low 1.01, 0.96-1.06; monopoly 1.19, 1.13-1.26) and increasing organ availability was associated with export/discard (reference: availability <0.42; 0.42-0.69: OR 1.35, 95% CI 1.30-1.40; >0.69: OR 1.83, 95% CI 1.73-1.93). When analyzing each endpoint separately, lower competition was associated with higher export and only market monopoly was weakly associated with lower discard, whereas higher organ availability was associated with export and discard. These results indicate that local organ utilization is more strongly influenced by the relative intensity of the organ shortage than by market competition between centers.

Community Based Participatory Research (CBPR): An Underutilized Approach to Address Surgical Disparities.

Disparities are well-documented across the continuum of surgical care. Counteracting such disparities requires new multidisciplinary approaches that utilize the expertise of affected individuals, such as community-based participatory research (CBPR). CBPR is an approach to research that is anchored in equitable, sustainable community-academic partnerships, and has been shown to improve intervention implementation and outcomes. In this article, community stakeholders and researchers outline the principles and benefits of CBPR, examples of CBPR in trauma and transplant, and future directions for CBPR within surgery.

Impact of Extending Eligibility for Reinstatement of Waiting Time After Early Allograft Failure: A Decision Analysis.

RATIONALE & OBJECTIVE: The shortage of deceased donor kidneys identified for potential transplantation in the United States is exacerbated by a high proportion of deceased donor kidneys being discarded after procurement. We estimated the impact of a policy proposal aiming to increase organ utilization by extending eligibility for waiting time reinstatement for recipients experiencing early allograft failure after transplantation. STUDY DESIGN: Decision analysis informed by clinical registry data. SETTING & POPULATION: We used Organ Procurement and Transplantation Network data to identify 76,044 deceased-donor kidneys procured in the United States from 2013 to 2017, 80% of which were transplanted and 20% discarded. INTERVENTION: Extend waiting time reinstatement for recipients experiencing allograft failure from the current 90 days to 1 year after transplantation. OUTCOME: Net impact to the waitlist, defined as the estimated number of additional transplants minus estimated increase in waiting list reinstatements. MODEL, PERSPECTIVE, & TIMEFRAME: We estimated (1) the number of additional deceased donor kidneys that would be transplanted if there was a 5%-25% relative reduction in discards, and (2) the number of recipients who would regain waiting time under a 6-, 12-, 18-, and 24-month reinstatement policy. RESULTS: Reinstating a waiting time for recipients experiencing allograft failure up to 1 year after transplantation yielded more additional transplants than growth in additions to the waiting list for all model assumptions except the combination of a very low relative reduction in discards (5%) and a very high failure rate of transplanted kidneys that would previously have been discarded (≥5 times the rate of currently transplanted kidneys). LIMITATIONS: Lack of empirical evidence supporting the proposed impact of such a policy change. CONCLUSIONS: A policy change reinstating waiting time for deceased donor kidneys recipients with allograft failure up to 1 year after transplantation should explored as a decision science-based intervention to improve organ utilization.

A Population Health Approach to Transplant Access: Challenging the Status Quo.

Transplant referral and evaluation are critical steps to waitlisting yet remain an elusive part of the transplant process. Despite calls for more data collection on pre-waitlisting steps, there are currently no national surveillance data to aid in understanding the causes and potential solutions for the extreme variation in access to transplantation. As population health scientists, epidemiologists, clinicians, and ethicists we submit that the transplant community has an obligation to better understand disparities in transplant access as a first necessary step to effectively mitigating these inequities. Our position is grounded in a population health approach, consistent with several new overarching national policy and quality initiatives. The purpose of this Perspective is to (1) provide an overview of how a population health approach should inform current multisystem policies impacting kidney transplantation and demonstrate how these efforts could be enhanced with national data collection on pre-waitlisting steps; (2) demonstrate the feasibility and concrete next steps for pre-waitlisting data collection; and (3) identify potential opportunities to use these data to implement effective population-level interventions, policies, and quality measures to improve equity in access to kidney transplantation.

Willingness of Kidney and Liver Transplant Candidates to Receive HCV-Infected Organs.

INTRODUCTION: Transplantation of organs exposed to hepatitis C virus (HCV) into uninfected patients has yielded excellent outcomes and more widespread adoption may lead to fewer discarded organs and more transplants. Patient perceptions may shed light on acceptability and likely the uptake of HCV+/HCV- transplantation, gaps in understanding, and perceived benefits/risks. METHODS: We surveyed 435 uninfected kidney and liver transplant candidates at four centers about their attitude towards HCV-infected organs. RESULTS: The percentage of patients willing to accept HCV-infected organs increased from 58% at baseline, to 86% following education about HCV, direct-acting antiviral agents (DAAs), and HCV+/HCV- transplantation benefits/risks. More willingness to accept an organ from an intravenous drug user (P < 0.001), age >50 y old (P = 0.02), longer waiting time (P = 0.02), more trust in the transplant system (P = 0.03), and previous awareness of DAAs (P = 0.04) were associated with higher willingness to accept an HCV-infected organ. The most important reasons for accepting an HCV-infected organ were a decrease in waiting time (65%), lower mortality and morbidity risk while on the waiting list (63%), effectiveness of DAAs (54%), and a quicker return to higher functional status (51%). CONCLUSIONS: Presenting patients with information about HCV+/HCV- transplantation in small doses that are calibrated to account for varying levels of health and numerical literacy is recommended.

Racial disparities in living donor kidney transplantation in the United States.

Living donor kidney transplant (LDKT) is the best treatment for end-stage kidney disease, but there are racial disparities in LDKT rates. To study putative mechanisms of these disparities, we identified 58 752 adult kidney transplant candidates first activated on the United States kidney transplant waitlist 2015-2016 and defined four exposure groups by race/primary payer: African American/Medicaid, African American/NonMedicaid, Non-African American/Medicaid, Non-African American/NonMedicaid. We performed competing risk regression to compare risk of LDKT between groups. Among included candidates, 30% had African American race and 9% had Medicaid primary payer. By the end of follow up, 16% underwent LDKT. The cumulative incidence of LDKT was lowest for African American candidates regardless of payer. Compared to African American/Non-Medicaid candidates, the adjusted likelihood of LDKT was higher for both Non-African American/Medicaid (HR 1.60, 95%CI 1.43-1.78) and Non-African American/Non-Medicaid candidates (HR 2.66, 95%CI 2.50-2.83). Results were similar when analyzing only candidates still waitlisted > 2 years after initial activation or candidates with type O blood. Among 9639 candidates who received LDKT, only 13% were African American. Donor-recipient relationships were similar for African American and Non-African American recipients. These findings indicate African American candidates have a lower incidence of LDKT than candidates of other races, regardless of primary payer.

Greater complexity and monitoring of the new Kidney Allocation System: Implications and unintended consequences of concentric circle kidney allocation on network complexity.

The deceased donor kidney allocation system in the United States has undergone several rounds of iterative changes, but these changes were not explicitly designed to address the geographic variation in access to transplantation. The new allocation system, expected to start in December 2020, changes the definition of "local allocation" from the Donation Service Area to 250 nautical mile circles originating from the donor hospital. While other solid organs have adopted a similar approach, the larger number of both kidney transplant centers and transplant candidates is likely to have different consequences. Here, we discuss the incredible increase in complexity in allocation, discuss some of the likely intended and unintended consequences, and propose metrics to monitor the new system.

Wait expectations: The impact of delisting as an outcome from the kidney transplant waitlist.

BACKGROUND: While kidney transplantation is optimal for the treatment of end-stage kidney disease, available organs do not meet demand. Little is known about the outcomes of patients who are delisted (removed from the waitlist) and unable to benefit from transplant. We describe patients who are delisted and their life expectancy after delisting. METHODS: Patients ≥ 18 years listed for deceased donor kidney transplant between 01/2003 and 12/2013 were identified in the Scientific Registry of Transplant Recipients and followed through 12/2018. A competing risk model was used to measure the association of demographic and clinical factors with waitlist outcomes of delisting, transplant, and death. Multivariate Cox modeling was used to evaluate factors associated with death after delisting. RESULTS: Of 324,582 patients listed, 18.0% were delisted, most common reasons were "too sick" or "other." After delisting, half (49.7%) had died by end of follow-up; time to death after removal was 5 years. Increasing age and public insurance were associated with increased risk of death. CONCLUSIONS: Nearly one in five patients will be delisted from the kidney transplant waitlist. These patients live a surprisingly long time after removal. Much remains unknown about these patients, which could be improved through data collection. Delisting is an important patient outcome that warrants further exploration.

Variations in deceased donor kidney procurement biopsy practice patterns: A survey of U.S. organ procurement organizations.

BACKGROUND: Procurement biopsies have become a common practice in the evaluation and allocation of deceased donor kidneys in the United States despite questions about their value and reproducibility. We sought to determine the extent of OPO-level differences in criteria used to decide which deceased donor kidneys undergo a procurement biopsy and to assess the degree of variability in procurement biopsy technique and interpretation across OPOs. METHODS: Each of the country's 58 OPOs were invited to participate in the survey. OPOs were divided into two groups based on organ availability ratio and deceased donor kidney discard rate. RESULTS AND CONCLUSIONS: Fifty-out-of-fifty-eight invited OPOs (86% response rate) responded to the survey between November 2020 and December 2020. Thirty (60%) OPOs reported that they have formal criteria for performing kidney procurement biopsy, but for 29 of these OPOs, transplant centers can request biopsy on kidneys that do not meet criteria. OPOs used a total of seven different variables and 12 different numerical thresholds to define impaired kidney function that would prompt a procurement biopsy. Additionally, wide variability was seen in biopsy technique and procedures for biopsy interpretation and reporting of findings to transplant programs. These findings identify a clear opportunity for standardization of procurement biopsies to best practices.

Association of balanced abdominal organ transplant center volumes with patient outcomes.

BACKGROUND: The volume-outcome relationship for organ-specific transplantation is well-described; it is unknown if the relative balance of kidney compared with liver volumes within an institution relates to organ-specific outcomes. We assessed the association between relative balance within a transplant center and outcomes. METHODS: National retrospective analysis of isolated kidney and liver transplants in United States 2005-2014 followed through 2019. Latent class analysis defined transplant center phenotypes. Multivariate Cox models estimated death-censored graft loss and mortality. RESULTS: Latent class analysis identified four phenotypes: kidney only (n = 117), kidney dominant (n = 36), mixed/balanced (n = 90), and liver dominant (n = 13). Compared to mixed centers, the risk of kidney graft loss was higher at kidney-dominant (HR 1.07, p < .001) and liver-dominant (HR 1.10, p < .001) centers, while kidney-only (HR 1.06, p = .01) centers had higher mortality. Liver graft loss was not associated with phenotype, but risk of patient death was lower (HR 0.93, p = .02) at liver dominant and higher (HR 1.06, p = .02) at kidney-dominant centers. CONCLUSIONS: A mixed phenotype was associated with improved kidney transplant outcomes, whereas liver transplant outcomes were best at liver-dominant centers. While these findings need to be verified with center-level resources, optimization of shared resources could improve patient and organ outcomes.