The Liver Retransplantation Risk Score: a prognostic model for survival after adult liver retransplantation

High-risk combinations of recipient and graft characteristics are poorly defined for liver retransplantation (reLT) in the current era. We aimed to develop a risk model for survival after reLT using data from the European Liver Transplantation Registry, followed by internal and external validation. From 2006 to 2016, 85 067 liver transplants were recorded, including 5581 reLTs (6.6%). The final model included seven predictors of graft survival: recipient age, model for end-stage liver disease score, indication for reLT, recipient hospitalization, time between primary liver transplantation and reLT, donor age, and cold ischemia time. By assigning points to each variable in proportion to their hazard ratio, a simplified risk score was created ranging 0–10. Low-risk (0–3), medium-risk (4–5), and high-risk (6–10) groups were identified with significantly different 5-year survival rates ranging 56.9% (95% CI 52.8–60.7%), 46.3% (95% CI 41.1–51.4%), and 32.1% (95% CI 23.5–41.0%), respectively (P < 0.001). External validation showed that the expected survival rates were closely aligned with the observed mortality probabilities. The Retransplantation Risk Score identifies high-risk combinations of recipient- and graft-related factors prognostic for long-term graft survival after reLT. This tool may serve as a guidance for clinical decision-making on liver acceptance for reLT.     

Survival Outcomes Following Pediatric Liver Transplantation (Pedi‐SOFT) Score: A Novel Predictive Index

A prognostic index to predict survival after liver transplantation could address several clinical needs. Here, we devised a scoring system that predicts recipient survival after pediatric liver transplantation. We used univariate and multivariate analysis on 4565 pediatric liver transplant recipients data and identified independent recipient and donor risk factors for posttransplant mortality at 3 months. Multiple imputation was used to account for missing variables. We identified five factors as significant predictors of recipient mortality after pediatric liver transplantation: two previous transplants (OR 5.88, CI 2.88–12.01), one previous transplant (OR 2.54, CI 1.75–3.68), life support (OR 3.68, CI 2.39–5.67), renal insufficiency (OR 2.66, CI 1.84–3.84), recipient weight under 6 kilograms (OR 1.67, CI 1.12–2.36) and cadaveric technical variant allograft (OR 1.38, CI 1.03–1.83). The Survival Outcomes Following Pediatric Liver Transplant score assigns weighted risk points to each of these factors in a scoring system to predict 3‐month recipient survival after liver transplantation with a C‐statistic of 0.74. Although quite accurate when compared with other posttransplant survival models, we would not advocate individual clinical application of the index.     

Perspectives on donor lung allocation from both sides of the Atlantic: The United States

Donor lung allocation in the United States focuses on decreasing waitlist mortality and improving recipient outcomes. The implementation of allocation policy to match deceased donor lungs to waitlisted patients occurs through a unique partnership between government and private organizations, namely the Organ Procurement and Transplantation Network under the Department of Health and Human Services and the United Network for Organ Sharing. In 2005, the donor lung allocation algorithm shifted toward the prioritization of medical urgency of waitlisted patients instead of time accrued on the waitlist. This led to the Lung Allocation Score, which weighs over a dozen clinical variables to predict a 1-year estimate of survival benefit, and is used to prioritize waitlisted patients. In 2017, the use of local allocation boundaries was eliminated in favor of a 250 nautical mile radius from the donor hospital as the first unit of distance used in allocation. The next upcoming iteration of donor allocation policy is expected to use a continuous distribution algorithm where all geographic boundaries are eliminated. There are additional opportunities to improve donor lung allocation, such as for patients with high antibody titers with access to a limited number of donors.     

A long‐term experience with expansion of Milan criteria for liver transplant recipients

The Milan criteria (MC) have historically determined eligibility for transplantation for hepatocellular carcinoma (HCC). The United Network for Organ Sharing (UNOS) Region 4 expanded the criteria for transplantation in HCC to include a single tumor ≤6 cm or up to 3 tumors with the largest diameter ≤5 cm and total additive diameter ≤9 cm (R4C). The aim of this study was to report the 10‐year outcomes of this expanded criteria compared to MC. Transplants performed for HCC in Region 4 between October 2007 and December 2016 were reviewed using the UNOS database. Recipients were categorized based on imaging findings at initial evaluation. A total of 2068 patients were included in the study. There was no significant difference in 10‐year patient survival between the groups (53% MC vs 48% R4C, P = .23). There was also no significant difference in recurrence‐free survival (54% MC vs 47% R4C, P = .15) or allograft survival (53% MC vs 48% R4C, P = .16). Finally, there was no significant difference in outcomes between the MC and R4C groups when stratifying patients by locoregional therapy. This study demonstrates promising data that the criteria for liver transplantation in HCC can be safely expanded to the R4C without compromising outcomes.     

Survival and renal function after liver transplantation alone in patients meeting the new United Network for Organ Sharing simultaneous liver-kidney criteria

In 2017, United Network for Organ Sharing (UNOS) implemented a simultaneous liver-kidney transplant (SLK) allocation policy. Our institution uses a more restrictive criteria for SLK; thus, we have a group of patients that would have qualified for SLK under the new allocation policy but received liver transplantation alone (LTA). We compared survival and post-operative renal function in patients that received LTA stratified by whether they met the new UNOS SLK criteria. There was no difference in graft and patient survival. The majority (95%) of LTA patients meeting the UNOS SLK criteria did not need dialysis at 1 year, with a mean eGFR increase from 23 mL/min preoperatively to 48 mL/min at 1 year. Of those with eGFR ≤ 20 mL/min at 1 month after surgery, the majority did regain adequate renal function. The implementation of the UNOS SLK allocation policy was appropriate in the previously unregulated area. This policy provides an excellent framework for those that may benefit from SLK. Our data suggest that a more restrictive policy may be possible in order to promote the best use of donated organs. The current safety net is appropriately positioned to capture patients in need of subsequent kidney transplant.     

Examining the transplant case composition of early-career transplant surgeons

Fellowship training established by the American Society of Transplant Surgeons and certified by the Transplant Accreditation and Certification Council provides trainees with broad exposure and practice readiness for the core aspects of abdominal transplantation. However, the operative case mix of a new transplant surgeon early in practice is unknown. This study examined the volume and composition of the transplant case mix of early-career transplant surgeons to better inform residents interested in transplantation about potential career opportunities following fellowship. cas 209 early-career transplant surgeons were identified from the UNOS database containing encrypted surgeon-specific identifiers and were included in this study. At 5 years into practice, there were 85 (40.7%) kidney-predominant, 38 (18.2%) liver-predominant, and 86 (41.1%) multiorgan transplant surgeons. Comparing surgeon subgroups, multiorgan surgeons performed more transplants in year 5 of practice than both liver-predominant and kidney-predominant surgeons (both p < .05). This is the first study to describe the transplant case composition of the early-career transplant surgeons. This data can be used to inform aspiring transplant surgeons about potential career opportunities and to assist fellowship programs in guiding and mentoring fellows.     

Disparity in utilization of combined kidney–liver transplantation in the United States

Abstract: Background: Orthotopic liver transplantation (OLT) is performed as a definitive treatment of acute and chronic liver failure. The prevalence of acute and chronic kidney diseases is substantially higher in this population secondary to diverse etiologies. Combined kidney–liver transplantation (CKLT) is widely performed in some centers, even though there are no definitive studies which support or contradict this practice. Methods: We comprehensively reviewed OLT as well as CKLT data from US transplant centers provided by United Network of Organ Sharing (UNOS). Results: The incidence of CKLT as a percentage of total OLTs performed has been increasing, especially in the post‐MELD era (2002 and after). Moreover, there is a great disparity among centers in regard to percentage of CKLTs to total OLTs. Conclusion: We conclude that there is much difference of opinion among US transplant centers as to indications for CKLT. A more scientific approach to this problem including studies to assess the role of kidney biopsy in determining renal outcome after OLT is needed.     

Impact of the 2016 revision of US Pediatric Heart Allocation Policy on waitlist characteristics and outcomes

US Pediatric Heart Allocation Policy was recently revised, deprioritizing candidates with cardiomyopathy while maintaining status 1A eligibility for congenital heart disease (CHD) candidates on “high‐dose” inotropes. We compared waitlist characteristics and mortality around this change. Status 1A listings decreased (70% to 56%, P < .001) and CHD representation increased among status 1A listings (48% vs 64%, P < .001). Waitlist mortality overall (subdistribution hazard ratio [SHR] 0.96, P = .63) and among status 1A candidates (SHR 1.16, P = .14) were unchanged. CHD waitlist mortality trended better (SHR 0.82, P = .06) but was unchanged for CHD candidates listed status 1A (SHR 0.92, P = .47). Status 1A listing exceptions increased 2‐ to 3‐fold among hypertrophic and restrictive cardiomyopathy candidates and 13.5‐fold among dilated cardiomyopathy (DCM) candidates. Hypertrophic (SHR 6.25, P = .004) and restrictive (SHR 3.87, P = .03) cardiomyopathy candidates without status 1A exception had increased waitlist mortality, but those with DCM did not (SHR 1.26, P = .32). Ventricular assist device (VAD) use increased only among DCM candidates ≥1 years old (26% vs 38%, P < .001). Current allocation policy has increased CHD status 1A representation but has not improved their waitlist mortality. Excessive DCM status 1A listing exceptions and continued status 1A prioritization of children on stable VADs potentially diminish the intended benefits of policy revision.     

Long-term transplant outcomes of donor hearts with left ventricular dysfunction

Objective

Despite small single-center reports demonstrating acceptable outcomes using donor hearts with left ventricular dysfunction, 19% of potential donor hearts are currently unused exclusively because of left ventricular dysfunction. We investigated modern long-term survival of transplanted donor hearts with left ventricular dysfunction using a large, diverse cohort.

First Report on the OPTN National Variance: Allocation of A2/A2B Deceased Donor Kidneys to Blood Group B Increases Minority Transplantation

In 2002, the Organ Procurement and Transplantation Network (OPTN) Minority Affairs Committee (MAC) implemented a national, prospective, “variance of practice” to allow deceased donor, ABO blood group incompatible, A₂ antigen, kidney transplantation into blood group B recipients; outcomes of this cohort were compared to ABO compatible recipients. The goal of the variance was to increase the number of transplants to B candidates without negatively impacting survival or compromising system equity. Only B recipients with low anti‐A IgG titers (<1:8) were eligible to receive these kidneys. Across eight participating Donation Service Areas (DSA), there were 101 A₂/A₂B to B transplants through 12/31/11, of which the majority of the recipients (61%) were ethnic minorities. At 12, 24, and 36 months, Kaplan–Meier graft survival rates for the B recipients of A₂/A₂B kidneys were 95.0%, 90.6%, and 85.4%, respectively, comparable to outcomes for B recipients of B kidneys, 92.6%, 87.9%, and 82.5%, respectively (p‐value = 0.48). Five DSAs increased the proportion of B transplants during 41 months postvariance, with a lesser proportional decrease in blood group A transplants. The data support the proposition that this allocation algorithm may provide a robust mechanism to increase access of blood group B minority candidates to kidney transplantation.