A Contemporary Analysis of Mental Well-being Among Living Donor Kidney Applicants.

Background: Living donation is paramount for expanding the donor pool. The aim of this study was to assess changes over time in self-reported mental health of living donor kidney applicants in efforts to inform patient-centered discussions with potential donors. Methods: Kidney donor applications from 2017 through 2021 were compiled. Data included age, gender, race, ethnicity, applicant-recipient relationship, medical history, and medications. Trends over time were analyzed and post hoc analyses were performed. Results: During the study period, 2479 applicants to the living donor kidney program were evaluated; 73% of applicants were female individuals. More than half of applicants were not related to their intended recipient; this fraction increased from 46% in 2017 to 58% in 2021 (P < 0.01). A similar decline in family relations was not present among Black and Latino applicants. Of all applicants, 18% reported depression and 18% reported anxiety; 20% reported taking antidepressants or anxiolytics. Depression and anxiety increased 170% (P < 0.001) and 136% (P < 0.001) from 2018 to 2019, respectively; antidepressant and anxiolytic use rose 138% (P < 0.001) between 2018 and 2020. Conclusions: The profile of living donor applicants has changed in recent years, with approximately 1 in 5 requiring antidepressants or anxiolytics. Predonation counseling and postdonation monitoring are imperative to decrease adverse psychological outcomes for living donors.

A contemporary analysis of 20,086 deceased donor liver biopsies.

BACKGROUND: Pre-transplant deceased donor liver biopsy may impact decision making; however, interpretation of the results remains variable and depends on accepting center practice patterns. METHODS: In this cohort study, adult recipients from 04/01/2015-12/31/2020 were identified using the UNOS STARfile data. The deceased donor liver biopsies were stratified by risk based on degree of fibrosis, macrovesicular fat content, and level of portal infiltration (low-risk: no fibrosis, no portal infiltrates, and <30% macrosteatosis; moderate-risk: some fibrosis or mild infiltrates and <30% macrosteatosis; high-risk: most fibrosis, moderate/marked infiltrates, or ≥30% macrosteatosis). Graft utilization, donor risk profile, and recipient outcomes were compared across groups. RESULTS: Of the 51,094 donor livers available, 20,086 (39.3%) were biopsied, and 34,606 (67.7%) were transplanted. Of the transplanted livers, 14,908 (43.1%) were biopsied. The transplanted grafts had lower mean macrovesicular fat content (9.3% transplanted vs. 26.9% non-transplanted, P < 0.001) and less often had any degree of fibrosis (20.9% vs. 39.9%, P < 0.001) or portal infiltration (51.3% vs. 58.2%, P < 0.001) versus non-transplanted grafts. Post-transplant recipient LOS (14.2 days high-risk vs. 15.2 days low-risk, P = 0.170) and 1-year graft survival (90.5% vs. 91.7%, P = 0.137) did not differ significantly between high- versus low-risk groups. Kaplan-Meier survival estimates further revealed no differences in the 5-year graft survival across risk strata (P = 0.833). Of the 5178 grafts biopsied and turned down, PSM revealed 1338 (26.0%) were potentially useable based on biopsy results and donor characteristics. CONCLUSION: Carefully matched deceased donor livers with some fibrosis, inflammation, or steatosis ≥30% may be suitable for transplantation. Further study of this group of grafts may decrease turndowns of potentially useable organs.

Early Graft Failure After Living-Donor Liver Transplant.

BACKGROUND: Living-donor liver transplantation (LDLT) has been increasing in the USA. While data exist on longer-term patient and graft outcomes, a contemporary analysis of short-term outcomes is needed. AIM: Evaluate short-term (30-day) graft failure rates and identify predictors associated with these outcomes. METHODS: Adult (≥ 18) LDLT recipients from 01/2004 to 12/2021 were analyzed from the United States Scientific Registry of Transplant Recipients. Graft status at 30 days was assessed with graft failure defined as retransplantation or death. Comparison of continuous and categorical variables was performed and a multivariable logistic regression was used to identify risk factors of early graft failure. RESULTS: During the study period, 4544 LDLTs were performed with a graft failure rate of 3.4% (155) at 30 days. Grafts from male donors (aOR: 0.63, CI 0.44-0.89), right lobe grafts (aOR: 0.40, CI 0.27-0.61), recipients aged > 60 years (aOR: 0.52, CI 0.32-0.86), and higher recipient albumin (aOR: 0.73, CI 0.57-0.93) were associated with superior early graft outcomes, whereas Asian recipient race (vs. White; aOR: 3.75, CI 1.98-7.10) and a history of recipient PVT (aOR: 2.7, CI 1.52-4.78) were associated with inferior outcomes. LDLTs performed during the most recent 2016-2021 period (compared to 2004-2009 and 2010-2015) resulted in significantly superior outcomes (aOR: 0.45, p < 0.001). CONCLUSION: Our study demonstrates that while short-term adult LDLT graft failure is uncommon, there are opportunities for optimizing outcomes by prioritizing right lobe donation, improving candidate nutritional status, and careful pre-transplant risk assessment of candidates with known PVT. Notably, a period effect exists whereby increased LDLT experience in the most recent era correlated with improved outcomes.

Increasing practice and acceptable outcomes of high-MELD living donor liver transplantation in the USA.

Recent deceased-donor allocation changes in the United States may have increased high-Model for End-Stage Liver Disease (MELD) living donor liver transplantation (LDLT); however, outcomes in these patients remain poorly defined. We aimed to examine the impact of the MELD score on LDLT outcomes. Using UNOS data (January 1, 2010-December 31, 2021), LDLT recipients were identified and stratified into low-MELD (<15), intermediate-MELD (15-24), and high-MELD (≥25) groups. We compared outcomes between MELD-stratified LDLT groups and between MELD-stratified LDLT and donation after brain death liver transplantation recipients. We used Kaplan-Meier analysis to compare graft survival rates and multivariable Cox proportional hazards modeling to identify factors associated with graft outcomes. Of 3558 LDLTs, 1605 (45.1%) were low-MELD, 1616 (45.4%) intermediate-MELD, and 337 (9.5%) high-MELD. Over the study period, the annual number of LDLTs increased from 282 to 569, and the proportion of high-MELD LDLTs increased from 3.9% to 7.7%. Graft survival was significantly higher in low-MELD versus high-MELD LDLT recipients (adjusted HR = 1.36, 95% CI: 1.03-1.79); however, 5-year survival exceeded 70.0% in both groups. We observed no significant difference in graft survival between high-MELD LDLT and high-MELD donation after brain death liver transplantation recipients (adjusted HR: 1.25, 95% CI:0.99-1.58), with a 5-year survival of 71.5% and 77.3%, respectively. Low LDLT center volume (<3 LDLTs/year) and recipient life support requirement were both associated with inferior graft outcomes among high-MELD LDLT recipients. While higher MELD scores confer graft failure risk in LDLT, high-MELD LDLT outcomes are acceptable with similar outcomes to MELD-stratified donation after brain death liver transplantation recipients. Future practice guidance should consider the expansion of LDLT recommendations to high-MELD recipients in centers with expertise to help reduce donor shortage.

Biliary atresia and liver transplantation in the United States: A contemporary analysis.

BACKGROUND: Biliary atresia (BA) remains the number one indication for paediatric liver transplantation (LT) worldwide but is an uncommon indication for older LT recipients. The impact of recent donor allocation changes, pervasive organ shortage and evolving LT practices on the BA LT population is unknown. METHODS: We identified patients who underwent LT between January 2010 and December 2021 using the UNOS database. We compared clinical outcomes between patients with BA and those with non-BA cholestatic liver disease. Groups were stratified by age, <12 years (allocated via PELD system) and ≥12 years (allocated via MELD system). Waitlist outcomes were compared using competing-risk regression analysis, graft survival rates were compared using Kaplan-Meier time-to-event analysis and Cox proportional hazards modelling provided adjusted estimates. RESULTS: There were 2754 BA LT waitlist additions and 2206 BA LTs (1937 <12 years [younger], 269 ≥12 years [older]). There were no differences in waitlist mortality between BA and non-BA cholestatic patients. Among BA LT recipients, there were 441 (20.0%) living-donor liver transplantations (LDLT) and 611 (27.7%) split deceased-donor LTs. Five-year graft survival was significantly higher among BA versus non-BA cholestatic patients in the older group (88.3% vs. 79.5%, p < .01) but not younger group (89.3% vs. 89.5%). Among BA LT recipients, improved graft outcomes were associated with LDLT (vs. split LT: HR: 2, 95% CI: 1.03-3.91) and higher transplant volume (volume >100 vs. <40 BA LTs: HR: 3.41, 95% CI: 1.87-6.2). CONCLUSION: Liver transplant outcomes among BA patients are excellent, with LDLT and higher transplant centre volume associated with optimal graft outcomes.

Liver Transplantation in Elderly Recipients: Is Age Just a Number?

BACKGROUND: The proportion of older patients on the liver transplant waitlist continues to increase. With limited existing data to guide liver transplant evaluation of elderly patients, we aimed to study selection practices and outcomes of patients ≥70 years old. We hypothesized that 1-year patient and graft survival would not differ between appropriately selected elderly patients and those who are younger. METHODS: All patients referred for liver transplantation between 2018 and 2020 were stratified into elderly (age ≥70) and young (age <70) cohorts. Evaluation data pertaining to medical, surgical, and psychosocial risk assessment were reviewed. Recipient characteristics and post-operative outcomes, primarily 1-year graft and patient survival, were compared, with a median follow-up of 16.4 months. RESULTS: 322 patients underwent transplant out of 2331 referred. Elderly patients represented 230 of these referrals and 20 underwent transplant. The most common reasons for denial of elderly patients were multiple medical comorbidities (49%), cardiac risk (15%) and psychosocial barriers (13%). The median MELD of elderly recipients was lower (19 vs 24, P = .02), and proportion of hepatocellular carcinoma was higher (60% vs 23%, P < .001). There was no difference in 1-year graft (elderly 90.9% vs young 93.3%, P = .72) or patient survival (elderly 90.9% vs young 94.7%, P = .88). DISCUSSION: Liver transplant outcomes and survival are not affected by advanced age in carefully evaluated and selected recipients. Age should not be considered an absolute contraindication for liver transplant referral. Efforts should be made to develop guidelines for risk stratification and donor-recipient matching that optimize outcomes in elderly patients.

Normothermic machine perfusion for older transplant recipients.

INTRODUCTION: Elderly patients (≥65 years old) are increasingly undergoing liver transplantation and are more likely to be removed from the waitlist. Normothermic machine perfusion (NMP) holds promise in expanding the number of livers available for transplant and improving outcomes for marginal donors and recipients. We aimed to determine the impact of NMP on outcomes in elderly recipients at our institution and nationally using the UNOS database. METHODS: The use of NMP on outcomes in elderly recipients was reviewed using both the UNOS/SRTR database (2016-2022) and institutional data (2018-2020). Characteristics and clinical outcomes were compared between the NMP and static cold (control) groups within both populations. RESULTS: Nationally, using the UNOS/SRTR database, we identified 165 elderly recipients from 28 centers who received a liver allograft undergoing NMP and 4270 that underwent traditional cold static storage. NMP donors were older (48.3 vs. 43.4 years, p < 0.01), had similar rates of steatosis (8.5% vs 8.5%, p = 0.58), were more likely to be from a DCD (41.8% vs 12.3%, p < 0.01), and had a higher donor risk index (DRI; 1.70 vs. 1.60, p < 0.02). NMP recipients had similar age but had a lower MELD score at transplant (17.9 vs. 20.7, p = 0.01). Despite increased marginality of the donor graft, NMP recipients had similar allograft survival and decreased length of stay, even after accounting for recipient characteristics including MELD. Institutional data showed that 10 elderly recipients underwent NMP and 68 underwent cold static storage. At our institution, NMP recipients had a similar length of stay, rates of complications, and readmissions. CONCLUSIONS: NMP may mitigate donor risk factors that are relative contraindications for transplantation in elderly liver recipients, increasing the donor pool. The application of NMP in older recipients should be considered.

Delayed graft function in pediatric living donor kidney transplantation.

BACKGROUND: Pediatric recipients of living donor kidneys have a low rate of delayed graft function (DGF). We examined the incidence, risk factors and outcomes of DGF in pediatric patients who received a living donor allograft. METHODS: The STARfile was queried to examine all pediatric patients transplanted with a living donor kidney between 2000 and 2020. Donor and recipient demographic data were examined, as were survival and outcomes. Recipients were stratified into DGF and no DGF groups. DGF was defined as the need for dialysis within the first week after transplant. RESULTS: 6480 pediatric patients received a living donor (LD) kidney transplant during the study period. 269 (4.2%) developed DGF post-transplant. Donors were similar in age, creatinine, and cold ischemia time. Recipients of kidneys with DGF were similar in age, sensitization status and HLA mismatch. Focal segmental glomerulosclerosis (FSGS) was the most common diagnosis in recipients with DGF, and allograft thrombosis was the most common cause of graft loss in this group. Small recipients (weight < 15 kg) were found to have a significantly higher rate of DGF. Length of stay doubled in recipients with DGF, and rejection rates were higher post-transplant. Recipients of LD kidneys who developed DGF had significantly worse 1 year allograft survival (67% vs. 98%, p < .0001). CONCLUSIONS: Pediatric living donor kidney transplant recipients who experience DGF have significantly poorer allograft survival. Optimizing the donor and recipient matching to avoid compounding risks may allow for better outcomes.

No Stone Left Unturned: Utilization of an Organ Procurement Organization Donor Surgeon at Procurement Reduces Discards of Marginal Liver Allografts.

BACKGROUND: The recent trend of organ procurement organizations (OPOs) employing independent surgeons for organ procurement has been developed with the goal of improving the supply of suitable organs for transplantation. We investigated the effects that the addition of an OPO-employed, organ-procurement specialist has on liver allograft discard rate, marginal organ utilization, and graft survival. METHODS: Organ Procurement and Transplant Network and OPO data were retrospectively studied between April 1, 2014' and July 31, 2019' within the Southwest Transplant Alliance donor service area. Liver procurements with an OPO-surgeon present (OPO-Present) were compared to those without the involvement of an OPO surgeon (OPO-Absent). Donor and recipient characteristics as well as outcomes were analyzed across groups using propensity score matching. RESULTS: In total 869 OPO-Present liver allografts had similar rates of discard (5.2%) compared to 771 OPO-Absent livers (5.8%). However, after adjusting for donor risk, OPO-Present livers had a lower propensity of discard compared to OPO-Absent (3.4% versus 7.6%, P < 0.05). OPO-Present livers were more likely to be shared nationally (11.0% versus 4.8%, P < 0.001). Outcome analysis showed allograft survival of OPO-Present livers at 5 y was comparable to OPO-Absent livers (79.5% versus 80%, P = 0.34). CONCLUSIONS: The presence of an OPO surgeon was associated with decreased liver allograft discard and increased utilization of marginal donor organs. The OPO surgeon's presence represents a potential strategy to increase organ utilization nationally.

Is there value in volume? An assessment of liver transplant practices in the United States since the inception of MELD.

BACKGROUND: Liver transplantation has increased in volume and provides substantial survival benefit. However, there remains a need for value-based assessment of this costly procedure. METHODS: Model for end stage liver disease era adult recipients were identified using United Network for Organ Sharing Standard Transplant Analysis file data (n = 75,988) and compared across time periods (period A: February 2002 to January 2007; B: February 2007 to January 2013; C: February 2013 to January 2019). Liver centers were divided into volume tertiles for each period (small, medium, large). Value for the index transplant episode was defined as percentage graft survival ≥1 year divided by mean posttransplant duration of stay. RESULTS: All centers increased value over time due to ubiquitous improvement in 1-year graft survival. However, large centers demonstrated the most significant value change (large +17% vs small +7.0%, P < .001) due to a -8.5% reduction in large centers duration of stay from period A to C, while small centers duration of stay remained unchanged (-0.1%). Large centers delivered higher value despite more complex care: older recipients (54.8 ± 10.3 vs 53.0 ± 11.4 years P < .001), fewer model for end stage liver disease exceptions (34.0% vs 38.2%, P < .001), higher rates of candidate portal vein thrombosis (10.1% vs 8.5%, P < .001) and prior abdominal surgery (43.4% vs 37.4%, P < .001), and more marginal donor utilization (donor risk index 1.45 ± 0.38 vs 1.36 ± 0.33, P < .001). Mahalanobis metric matching demonstrated that compared with small centers, large centers progressively shortened recipient duration of stay per transplant in each period (A: -0.36 days, P = .437; B: -2.14 days, P < .001; C: -2.49 days, P < .001). CONCLUSION: There is value in liver transplant volume. Adoption of value-based practices from large centers may allow optimization of health care delivery for this costly procedure.

Short-term kidney transplant outcomes from severe acute respiratory syndrome coronavirus 2 lower respiratory tract positive donors.

OBJECTIVE: In this study, we aim to assess short-term allograft outcomes following deceased donor kidney transplantation from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lower respiratory tract (LRT) nucleic acid testing (NAT) positive donors. METHODS: From September to December 2021, SARS-CoV-2 NAT positive organ donors, whose solid abdominal organs were transplanted at our academic medical center were identified. Donors were stratified into having tested positive for SARS-CoV-2 in an upper respiratory tract (URT) or LRT sample. For this study, the SARS-CoV-2 LRT NAT positive deceased kidney donors and their respective recipients were examined. Donor and recipient demographic data, coronavirus disease 2019 (COVID-19)-related history, patient outcomes, as well as postoperative graft function were evaluated. RESULTS: Thirteen SARS-CoV-2 positive deceased donors were identified. Of these, eight were LRT NAT positive and yielded nine kidneys. These allografts were successfully transplanted into vaccinated and unvaccinated recipients. All recipients received standard induction immunosuppression and did not receive any prophylactic therapy for SARS-CoV-2. Two recipients had delayed graft function. At 1-month post-transplant, there was no clinical evidence of donor-derived COVID-19 or graft loss, and all recipients were free from dialysis. CONCLUSION: We describe the first case series of SARS-CoV-2 LRT NAT positive deceased kidney donors for vaccinated and unvaccinated recipients with excellent short-term allograft outcomes and no clinical evidence of donor-derived COVID-19 post-transplantation. Given the increasing prevalence of SARS-CoV-2 in the population, utilization of SARS-CoV-2 LRT NAT positive deceased donors could be considered an acceptable source of organs for renal transplantation, especially as multi-center experiences and longer-term follow-up emerge.

Normothermic Machine Perfusion in pediatric liver transplantation: A survey of attitudes and barriers.

BACKGROUND: NMP provides a superior strategy for the assessment and preservation of marginal donor livers and has demonstrated increased utilization and enhances organ quality when used in adult liver transplantation. We aimed to evaluate the interest of incorporating the use of NMP in pediatric liver transplantation. METHODS: An anonymous online survey was distributed to pediatric transplant surgeons and hepatologists across the United States. Respondent demographic information, attitudes toward NMP in pediatric liver transplantation, and barriers to utilization were examined. RESULTS: Thirty-two providers (18 transplant surgeons and 14 hepatologists) completed the survey, yielding a response rate of 64%. Half (50%) of respondents indicated prior exposure to NMP. Overall, 96% of respondents believed there was benefit to using NMP in pediatric liver transplantation. DCD (68%) and post-cross-clamp (75%) grafts were the greatest opportunity for NMP use. A role in splitting livers ex vivo (71%) was also seen as a potential major opportunity. Cost was perceived as a barrier to implementation (36%), followed by institutional factors (32%). Cost tolerance was significantly greater in respondents residing in OPTN regions with greater than median wait times (63% vs. 11% in OPTN regions with greater vs. shorter wait times, p = .010). CONCLUSIONS: There is significant interest within the pediatric liver transplant community for NMP to expand the donor pool. Interest appears particularly strong in regions where wait times for suitable pediatric donors are prolonged.

Simultaneous ex vivo normothermic preservation of liver and heart grafts from a donation after circulatory death donor.

Normothermic machine perfusion of organs is growing in popularity and has been used for both abdominal and thoracic organ preservation before transplantation. The use of normothermic machine perfusion for donation after cardiac death organs can reduce cold ischemia time and help prevent ischemia-related complications. We present a successful case of a donation after cardiac death procurement with both liver and heart allografts preserved by normothermic machine perfusion. Both allografts were perfused without complications and transplanted successfully. As the technology continues to become more prevalent, the situation described will become more commonplace, and we offer a view of the future in transplantation.

Duct of Luschka Bile Leak Following Deceased Donor Liver Transplant.

BACKGROUND Biliary leak is a relatively uncommon but potentially severe complication of liver transplantation. Duct of Luschka (also known as subvesical bile ducts) is a term that refers to a number of accessory biliary ducts. While leaks from Ducts of Luschka are well-described in the field of hepatobiliary surgery, only 2 case reports of such leaks exist in the setting of liver transplant. CASE REPORT We report the first case of a Duct of Luschka biliary leak seen after DCD liver transplant in a 41-year-old woman with cirrhosis secondary to primary sclerosing cholangitis. The patient underwent surgical re-exploration in the immediate postoperative period due to bilious output from a surgical drain. A Duct of Luschka was found intraoperatively at the gallbladder fossa and was oversewn. Apart from immunosuppression-related neutropenia, the patient recovered uneventfully. CONCLUSIONS Given the variability in preoperative detection of subvesical bile ducts, accessory bile duct leak remains an important consideration in the liver transplant perioperative period. The prevalence of Ducts of Luschka and the relative risk of leakage from such subvesical bile ducts in liver transplants compared to cholecystectomies are unclear. Further research into anatomical accessory bile duct variants and preoperative techniques for detecting such ducts is warranted.

Enhanced recovery in liver transplantation: A value-based approach to complex surgical care.

BACKGROUND: Value-based healthcare focuses on improving outcomes relative to cost. We aimed to study the impact of an enhanced recovery pathway for liver transplant recipients on providing value. METHODS: In total, 379 liver recipients were identified: pre-enhanced recovery pathway (2017, n = 57) and post-enhanced recovery pathway (2018-2020, n = 322). The enhanced recovery pathway bundle was defined through multidisciplinary efforts and included optimal fluid management, end-of-case extubation, multimodal analgesia, and a standardized care pathway. Pre- and post-enhanced recovery pathway patients were compared with regard to extubation rates, lengths of stay, complications, readmissions, survival, and costs. RESULTS: Pre- and post-enhanced recovery pathway recipient model for end-stage liver disease score and balance of risk scores were similar, although post-enhanced recovery pathway recipients had a higher median donor risk index (1.55 vs 1.39, P = .003). End-of-case extubation rates were 78% post-enhanced recovery pathway (including 91% in 2020) versus 5% pre-enhanced recovery pathway, with post-enhanced recovery pathway patients having decreased median intraoperative transfusion requirements (1,500 vs 3,000 mL, P < .001). Post-enhanced recovery pathway recipients had shorter median intensive care unit (1.6 vs 2.3 days, P = .01) and hospital stays (5.4 vs 8.0 days, P < .001). Incidence of severe (Clavien-Dindo ≥3) complications during the index hospitalization were similar between pre-enhanced recovery pathway versus post-enhanced recovery pathway groups (33% vs 23%, P = .13), as were 30-day readmissions (26% vs 33%, P = .44) and 1-year survival (93.0% vs 94.5%, P = .58). The post-enhanced recovery pathway cohort demonstrated a significant reduction in median direct cost per case ($11,406; P < .001). CONCLUSION: Implementation of an enhanced recovery pathway in liver transplantation is feasible, safe, and effective in delivering value, even in the setting of complex surgical care.

Multidisciplinary Management of Severe Traumatic Hepatic Injury Involving Interventional Radiology Embolization, Trauma Laparotomy, and Liver Transplantation.

This report describes liver transplantation as a successful strategy in the management of a young man who presented to a local emergency room following catastrophic traumatic hepatic vascular injuries. Expeditious multidisciplinary management, including interventional radiology, trauma surgery, and ultimately transplant surgery, provided the patient with definitive therapy following his injuries and early return to normal activity. Our experience highlights the importance of prompt referral of select hepatic trauma patients for liver transplant evaluation as part of their complex trauma management.

Liver Transplantation in the Time of a Pandemic: A Widening of the Racial and Socioeconomic Health Care Gap During COVID-19.

OBJECTIVE: During the initial wave of the COVID-19 pandemic, organ transplantation was classified a CMS Tier 3b procedure which should not be postponed. The differential impact of the pandemic on access to liver transplantation was assessed. SUMMARY BACKGROUND DATA: Disparities in organ access and transplant outcomes among vulnerable populations have served as obstacles in liver transplantation. METHODS: Using UNOS STARfile data, adult waitlisted candidates were identified from March 1, 2020 to November 30, 2020 (n = 21,702 pandemic) and March 1, 2019 to November 30, 2019 (n = 22,797 pre-pandemic), and further categorized and analyzed by time periods: March to May (Period 1), June to August (Period 2), and September to November (Period 3). Comparisons between pandemic and pre-pandemic groups included: Minority status, demographics, diagnosis, MELD, insurance type, and transplant center characteristics. Liver transplant centers (n = 113) were divided into tertiles by volume (small, medium, large) for further analyses. Multivariable logistic regression was fitted to assess odds of transplant. Competing risk regression was used to predict probability of removal from the waitlist due to transplantation or death and sickness. Additional temporal analyses were performed to assess changes in outcomes over the course of the pandemic. RESULTS: During Period 1 of the pandemic, Minorities showed greater reduction in both listing (-14% vs -12% Whites), and transplant (-15% vs -7% Whites), despite a higher median MELD at transplant (23 vs 20 Whites, P < 0.001). Of candidates with public insurance, Minorities demonstrated an 18.5% decrease in transplants during Period 1 (vs -8% Whites). Although large programs increased transplants during Period 1, accounting for 61.5% of liver transplants versus 53.4% pre-pandemic (P < 0.001), Minorities constituted significantly fewer transplants at these programs during this time period (27.7% pandemic vs 31.7% pre-pandemic, P = 0.04). Although improvements in disparities in candidate listings, removals, and transplants were observed during Periods 2 and 3, the adjusted odds ratio of transplant for Minorities was 0.89 (95% CI 0.83-0.96, P = 0.001) over the entire pandemic period. CONCLUSIONS: COVID-19's effect on access to liver transplantation has been ubiquitous. However, Minorities, especially those with public insurance, have been disproportionately affected. Importantly, despite the uncertainty and challenges, our systems have remarkable resiliency, as demonstrated by the temporal improvements observed during Periods 2 and 3. As the pandemic persists, and the aftermath ensues, health care systems must consciously strive to identify and equitably serve vulnerable populations.

Amino acid and lipid profiles following pig-to-primate liver xenotransplantation.

As outcomes in clinical liver transplantation steadily improve, demand continues to exceed supply, leading to a substantial disparity in organ availability. The translation of porcine liver xenotransplantation (LXT) into a clinical reality aims to address this dilemma. Our laboratory has previously established an applicable model of α-1,3-galactosyltransferase knockout (GalT-KO) pig-to-primate LXT with continuous human coagulation factor infusion and costimulation blockade. This report aims to further investigate the post-LXT lipid and amino acid metabolism profile in our longest surviving recipients (25 and 29 days). Experimental samples and control samples, consisting of pre-transplant porcine and baboon serum and plasma, were analyzed for standard lipid profiles and for amino acid levels. Lipid profiles of LXT recipients remained stable following xenotransplantation compared to donor porcine baseline levels. Amino acid concentrations also remained similar to baseline controls, with the exception of a 3-fold increase in l-ornithine and more than a 10-fold decrease in l-arginine post-transplant when compared to both porcine and baboon baseline levels. The observed changes in l-arginine are consistent with prior studies investigating the effects of graft preservation injury following liver transplantation. These results indicate that the porcine liver can maintain most biochemical profiles stably post-operatively in baboons and suggest that arginine supplementation post-LXT may potentially be useful for further prolongation of xenograft survival.