United Network For Organ Sharing Region Research Articles

Heterogeneity in transplant center responses to the minimum acceptance criteria across UNOS regions.

Transplantation of organs from increased risk donors for infection transmission (IRDs) is increasing. These organs confer survival benefit to recipients. This study examined transplant center acceptance policies for IRD kidneys across United Network for Organ Sharing (UNOS) regions, based on transplant centers' annual responses to the Minimum Acceptance Criteria (MAC) for acceptance of IRD kidneys, and the association with national and regional IRD kidney utilization. De-identified MAC responses from all transplant centers in the United States from 2007 to 2019 were obtained. Implementation of MAC responses into practice was evaluated based on annual rates of recovery and transplantation of IRD kidneys, by MAC and UNOS region. Nationally, the number of transplant centers willing to accept IRD kidneys across all criteria increased from 22% in 2007 to 64% in 2019. Acceptance rates increased markedly from donors with intravenous drug use and other potential HIV exposures. However, significant heterogeneity exists in transplant center willingness to accept IRD kidneys, both regionally and between criteria. Trends towards increasing acceptance are strongly associated with higher rates of recovery and transplantation of IRD kidneys. Further research on provider- and center-based refusal to consider IRD kidneys for waitlisted patients is needed to improve utilization of this organ pool.

Impact of the Coronavirus Disease 2019 Pandemic on Utilization of Mechanical Circulatory Support As Bridge to Heart Transplantation.

Impact of the Coronavirus Disease 2019 Pandemic on Utilization of Mechanical Circulatory Support As Bridge to Heart Transplantation.

Liver transplantation for alcoholic hepatitis in the United States: Excellent outcomes with profound temporal and geographic variation in frequency.

Medical-refractory severe alcoholic hepatitis (AH) has a high mortality. The national frequency, longer term outcomes and regional practices of AH liver transplantation (LT) in the United States are not well described, despite the increasing mortality from alcohol-associated liver disease. We analyzed the trends in frequency and outcomes of UNOS data on 39455 adult patients who underwent LT from 2014 to 2019, including AH LT recipients. LTs for AH increased 5-fold, from 28 in 2014 to 138 in 2019, varying 8-fold between UNOS regions. Three transplant centers accounted for 50%-90% of AH LTs within each region. The number of transplant centers performing AH LTs increased from 14 in 2014 to 47 in 2019. AH patients were younger (mean=39.4years), had higher MELD scores (mean=36.8), and were more often on dialysis (46.0%) and in ICU (38.4%), compared to other indications (all P<.05). One- and 5-year graft survivals for AH LT recipients were 91.7% and 81.9%, respectively. The frequency of AH LT is increasing rapidly, with excellent medium-term outcomes. An impact of AH recurrence on patient or graft survival is not apparent in this national analysis. There are marked geographic variations in practices, highlighting the lack of selection criteria standardization.

More Money and More Miles: The Hidden Costs of Donor Procurement with the New Heart Allocation System

In October 2018, the United Network for Organ Sharing (UNOS) implemented extensive changes to the adult heart allocation policy. These changes were developed to better stratify medically urgent patients and provide more equitable geographic distribution of donor hearts. Instead of preferential distribution within a local donor service area, hearts are first considered by centers within 500 nautical miles of a donor hospital. We evaluated the impact of the new system on the mode and associated expense of procurement travel. We retrospectively analyzed data from 5 centers across 5 states and 4 UNOS regions (regions 2, 5, 10, 11). Pre-allocation change (pre-change) was considered 10/1/2016-10/17/2018 and post-allocation change (post-change) was considered 10/18/18-8/31/2019. The share of procurements requiring a flight vs local transportation from all centers was compared. Cost of transportation for procurement and distance from donor hospital to transplant center was available from 4 centers. Total of 693 transplants were performed during the study period: 477 pre-change and 216 post-change. Pre-change, there were 274 flights for procurement compared to 182 flights post-change (57 vs 84%, p <0.0001). There were notable differences in these increases by UNOS region (Figure). Average travel increased from 193 miles pre-change to 269 miles post-change (p<0.0001), corresponding with an increase in average transportation costs from $6,812.07 to $12,383.64 (p<0.0001), respectively. Following the 2018 UNOS change to the heart allocation system, the proportion of flights and distance traveled for organ procurements significantly increased across 5 moderate-high volume centers, nearly doubling the average travel cost for procurement. These findings may guide transplant centers, payers, and policy makers regarding necessary procurement resources. Further study is needed to determine how these changes may affect lower volume centers with fewer resources.

Durable mechanical circulatory support device use in the United States by geographic region and minority status

BackgroundDurable mechanical circulatory support device (MCSD) therapy has experienced rapid dissemination in the United States. Few studies have evaluated geographic patterns of its dissemination based upon patient characteristics that could identify potential variation in its application. MethodsA combined Interagency Registry for Mechanically Assisted Circulatory Support and Medicare dataset identified durable MCSD implants from 2008 through 2014. MCSD implant rates were estimated using yearly US Census population data, estimated from the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research database and stratified by age, race, and United Network for Organ Sharing (UNOS) region. ResultsOverall, 16,331 patients received an MCSD implant from 232 unique centers. Annual MCSD implant rate (per 1 million population) significantly increased in each UNOS region (absolute range of increase, 5.3-16.4) with UNOS Region 7 demonstrating the highest overall absolute rate (20.9) in 2014 and UNOS Region 11 demonstrating the greatest relative increase in rate (430.5%). Geographical differences in the rate of MCSD implants were observed among whites and minorities with higher rates of MCSD implants observed for minorities for nearly all UNOS regions across all years. Significantly greater relative increases in MCSD implants for minorities compared with whites were observed within UNOS Regions 2, 3, 6, 7, 8, 9, and 11 (P < .001). ConclusionsGeographical differences exist in rates of MCSD implantation among whites and minorities. The reasons for these differences are unknown, but may reflect underlying differences in disease burden or disparities in access to heart transplantation and warrant further study.

Potential for donation after circulatory death heart transplantation in the United States: Retrospective analysis of a limited UNOS dataset.

Donation after Circulatory Death (DCD) is an alternative to Donation after Brain death (DBD), and is a growing strategy for organ procurement in the United States(US). The purpose of this analysis was to review the number and quality of hearts in one United Network for Organ Sharing (UNOS) Region that were not utilized as a potential consequence of nonheart DCD donation. We retrospectively identified all successful US DCD solid organ donors from 1/2011 to 3/1/2017, defined an ideal heart donor by age and left ventricular ejection fraction (LVEF), and then reviewed the donor charts of unused hearts in New York and Vermont (UNOS Region 9). Of 8302 successful DCD donors across the United States, 5033 (61%) were between 18 and 49years of age, and 872 had a screening echocardiogram, with 573 (66%) measuring an EF>50%. Of these 573 potential donors, 44 (7.7%) were from Region 9. Detailed donor chart review identified 36 ideal heart donors, 24 (66.7%) with anoxic brain injury. Trends in Region 9 DCD donation increased from 4 unused hearts in 2011, to 13 in 2016. In the context of severe organ scarcity, these data indicate that implementation of DCD heart transplantation in the United States would improve overall donation rates and provide a pathway to utilize these ideal donor hearts.

Interactive Maps for UNOS Data Visualization

Purpose In the United States, heart allocation is administered by the United Network for Organ Sharing (UNOS). UNOS collects demographics and clinical data for all transplant candidates, donors, and recipients listed since 1995. While the data is available to the public upon requests; it has been used predominately for research rather than clinical decision making, transplant patient use and policy makers. The aim of this project is to build a web application to visualizes UNOS data and promote easy access to summary statistics for diverse members of the transplant community. Methods This highly interactive web application was developed using the UNOS data between 2006 and 2014 using modern Javascript-based technologies such as Vue.js and Google Maps to show graphs, choropleth and kriging maps. The application is made publicly available on the internet to allow the users to visualize different statistics for different geographic granularity level, (i.e., Transplant center, OPO's donor service area and UNOS region) either by directly selecting locations on the USA map or by selecting an option from a drop-down menu. Several statistics are visualized for different years and for heart-alone or multi-organ transplants. A general map of the US is visible to show the data at the national and OPO levels to give an overall view of the geographic differences across the US states. Drop-down menus are available to select the preferred statistics and indicators by transplant center or UNOS region. Results Several statistics are displayed for different geographic levels and for each year between 2006 and 2014. The set of statistics includes: Probability of receiving a donor heart, % of declined offers because of quality reasons, % of accepted offers of low/medium/high quality, Average cold-ischemic time of the transplanted organs, Average waiting time of a recipient, 1-year, 3-years, 5-years post-transplant mortality rate, 1-year, 3-years, 5-years post-transplant graft failure rate, % of unused organs, % of declined offers because of quality reasons. Conclusion The web application creates maps of several statistics summarizing the available data to provide a useful tool to support decisions for a general audience. The provided interactive maps are a useful tool for improved visual understanding of the heart transplant information for abroad audience, including, patients, OPOs, transplant surgeons and policy makers.

Outcomes of domino liver transplantation compared to deceased donor liver transplantation: a propensity-matching approach.

Domino liver transplantation (DLT) utilizes the explanted liver of one liver transplant recipient as a donor graft in another patient. While there may be unique risks associated with DLT, it is unclear if DLT has less favorable long-term outcomes than deceased donor liver transplantation (DDLT). We used a propensity score matching approach to compare the outcomes of DLT recipients to DDLT recipients. The United Network for Organ Sharing (UNOS) registry was queried for patients undergoing DLT or DDLT in 2002-2016. Each DLT recipient was matched to a unique DDLT recipient to compare mortality and graft failure. There were 126 DLT and 62 835 DDLT recipients meeting inclusion criteria. After propensity score matching on recipient pre-transplant characteristics, 123 DLT cases were matched to DDLT controls from the same UNOS region. On stratified Cox proportional hazards regression, DLT incurred no increase in the hazard of mortality [hazard ratio (HR) = 1.4; 95% confidence interval (CI): 0.8, 2.7; P = 0.265] or graft failure (HR = 1.2; 95% CI: 0.7, 2.1; P = 0.556) compared to DDLT. Using a large national registry, a propensity-matched analysis found no increased risk of mortality or graft failure associated with DLT compared to DDLT.

Prevalence and Distribution of Potential Vascularized Composite Allotransplant Donors, Implications for Optimizing the Donor-recipient Match.

Background:Vascularized composite allotransplantation (VCA) is an emerging and growing field. Little is known about the prevalence and distribution of the adult potential donor population in the United States now that it falls under the oversight of the United Network for Organ Sharing (UNOS).Methods:We assessed the UNOS database from 2008 to 2015 to estimate the prevalence and distribution of adult potential vascularized composite allograft donors. Donor inclusion and exclusion criteria were developed in a way to minimize risk to recipients and were applied to the dataset. Donors were categorized by factors that influence vascularized composite allograft matching including ABO blood type, cytomegalovirus status, and ethnicity (correlate for skin color) and sorted by UNOS region.Results:Just under half of all brain dead donors met the inclusion/exclusion criteria. Blood type O, cytomegalovirus+, White donors represented the most frequent donor profile while blood type AB, cytomegalovirus-, Asian donors were the least common. UNOS region 3 had the most and region 1 had the least potential VCA donors per year. Nearly all potential VCA donors were solid organ donors with the liver being the most commonly donated solid organ in this population.Conclusions:A large portion of the solid organ donor pool would qualify as adult vascularized composite allograft donors in the current UNOS system. These data will assist transplant teams in determining the prevalence and distribution of vascularized composite allograft donors for their individual patients awaiting composite allografts based on relevant matching characteristics in addition to standard transplant criteria.

Recent trends in liver transplantation for alcoholic liver disease in the United States.

AIMTo examine temporal changes in the indications for liver transplantation (LT) and characteristics of patients transplanted for alcoholic liver disease (ALD).METHODSWe performed a retrospective cohort analysis of trends in the indication for LT using the United Network for Organ Sharing (UNOS) database between 2002 and 2015. Patients were grouped by etiology of the liver disease and characteristics were compared using χ2 and t-tests. Time series analysis was used identifying any year with a significant change in the number of transplants per year for ALD, and before and after eras were modeled using a general linear model. Subgroup analysis of recipients with ALD was performed by age group, gender, UNOS region and etiology (alcoholic cirrhosis, alcoholic hepatitis and hepatitis C - alcoholic cirrhosis dual listing).RESULTSOf 74216 liver transplant recipients, ALD (n = 9400, 12.7%) was the third leading indication for transplant after hepatitis C and hepatocellular carcinoma. Transplants for ALD, increased from 12.8% (553) in 2002 to 16.5% (1020) in 2015. Time series analysis indicated a significant increase in the number of transplants per year for ALD in 2013 (P = 0.03). There were a stable number of transplants per year between 2002 and 2012 (linear coefficient 3, 95%CI: -4.6, 11.2) an increase of 177 per year between 2013 and 2015 (95%CI: 119, 234). This increase was significant for all age groups except those 71-83 years old, was observed for both genders, and was incompletely explained by a decrease in transplants for hepatitis C and ALD dual listing. All UNOS regions except region 9 saw an increase in the mean number of transplants per year when comparing eras, and this increase was significant in regions 2, 3, 4, 5, 6, 8, 10 and 11.CONCLUSIONThere has been a dramatic increase in the number of transplants for ALD starting in 2013.

Race/ethnicity is associated with ABO-nonidentical liver transplantation in the United States.

United Network for Organ Sharing (UNOS) policies allow for ABO-nonidentical liver transplantation (LT) in candidates with Model for End-Stage Liver Disease (MELD) scores greater than 30. Previous studies showed ABO-nonidentical LT resulted in an 18% and 55% net gain in livers for B and AB candidates. These results suggested that the current liver ABO allocation policies may need refinement. There are, however, strong associations between ABO blood groups and race/ethnicity. We hypothesized that race/ethnicity is associated with ABO-nonidentical LT and that this is primarily influenced by recipient ABO status. We examined non-status 1 adult candidates registered between July 1, 2013, and December 31, 2015. There were 27835 candidates (70% non-Hispanic White, 15% Hispanic, 9% Black, 4% Asian, 1% Other/Multiracial). A total of 11369 underwent deceased donor LT: 93% ABO identical, 6% ABO compatible, and 1% ABO incompatible. Black and Asian race/ethnicity were associated with increased likelihoods of ABO-nonidentical LT. Adjustment for disease etiology, listing MELD, transplant center volume, and UNOS region did not alter this association. Stepwise inclusion of recipient ABO status did eliminate this significant association of race/ethnicity with ABO-nonidentical LT. Blacks and Asians may be advantaged by ABO-nonidentical LT, and we suspect that changes to the existing policies may disproportionately impact these groups.

New organ allocation policy in liver transplantation in the United States.

New organ allocation policy in liver transplantation in the United States.

Insurance status by region at the time of heart transplantation: Implications for survival

Heart transplantation outcomes differ by health insurance status and geographic region of the United States. We hypothesized that heart transplantation survival would be affected by health insurance status within certain United Network for Organ Sharing (UNOS) regions. We used data from the UNOS thoracic database to classify health insurance status into private or public (private/self-pay or Medicare/Medicaid) for all first-time heart transplant recipients between July 2006 and September 2013. We applied Cox proportional hazards regression to estimate hazard ratio (HR) and 95% confidence interval (CI) for the influences of health insurance status on 1-year and long-term survival in heart transplant recipients by UNOS region. Mean survival time among 10,474 patients was 942 days ± 704. All key demographic and clinical variables varied significantly across UNOS regions. With respect to 1-year survival, patients in Region 2 had a higher hazard of mortality (HR, 1.49; 95% CI, 1.03, 2.15) if they had public vs private insurance. When we restricted the analysis to be conditional on 1-year survival, 2 contiguous regions, Region 10, including Indiana, Ohio, Michigan (HR, 2.30; 95% CI, 1.23, 4.28), and Region 11 (HR, 1.85; 95% CI, 1.15, 2.97), including the upper South, had poor survival associated with public vs private insurance. The data we present invite targeted efforts by certain UNOS regions to improve the standard of care and/or eligibility thresholds for heart transplant recipients.

Racial disparities in reaching the renal transplant waitlist: is geography as important as race?

In the United States, African Americans and whites differ in access to the deceased donor renal transplant waitlist. The extent to which racial disparities in waitlisting differ between United Network for Organ Sharing (UNOS) regions is understudied. The US Renal Data System (USRDS) was linked with US census data to examine time from dialysis initiation to waitlisting for whites (n = 188,410) and African Americans (n = 144,335) using Cox proportional hazards across 11 UNOS regions, adjusting for potentially confounding individual, neighborhood, and state characteristics. Likelihood of waitlisting varies significantly by UNOS region, overall and by race. Additionally, African Americans face significantly lower likelihood of waitlisting compared to whites in all but two regions (1 and 6). Overall, 39% of African Americans with ESRD reside in Regions 3 and 4--regions with a large racial disparity and where African Americans comprise a large proportion of the ESRD population. In these regions, the African American-white disparity is an important contributor to their overall regional disparity. Race remains an important factor in time to transplant waitlist in the United States. Race contributes to overall regional disparities; however, the importance of race varies by UNOS region.

Impact of geographic location on access to liver transplantation among ethnic minorities.

Recent reports have documented ethnic disparity in access to health care. This disparity appears to exist in organ transplantation and the contributing factors include lack of insurance as well as poor socioeconomic status. The role of geographic location and ethnic composition on accessibility to liver transplantation (LT) is unclear. Therefore, the aim of this study was to determine ethnic transplantation trends based on United Network for Organ Sharing (UNOS) regions. Using the UNOS database, we identified all adults (> or =18 years) that received LT between 2000 and 2005. We excluded multiorgan transplants and living donor transplantation. The data collected included ethnicity, transplantation rate, and UNOS region. Data were analyzed using the chi test. A total of 30,311 patients received a LT during the study period. Of these, 22,673 (74.8%) were white, 3621 (12%) were Hispanic, 2490 (8.2%) were African Americans, and the rest of other ethnic groups (5%). Liver transplantation based on ethnicity was region specific, with the lowest for African Americans in region 6 (2.7%), for Hispanics in region 11 (2.2%), and for whites in region 5 (57.6%), respectively. There was no consistent correlation between the ethnicity of the recipients and the ethnic composition of the geographic location (region). Significant variations in access to liver transplantation for ethnic minorities exist across geographic lines. Understanding the interaction between ethnic minorities with end-stage liver disease in a geographic location and a transplant center will be invaluable as a first step in identifying the key nonmedical factors that play a role in this disparity.