American perspectives for LDLT in 2024.

Living donor liver transplantation (LDLT) was first performed in the US in 1989, primarily benefiting pediatric patients. Its adoption for adults faced setbacks after a donor death in 2001, causing widespread risk aversion. Despite ethical justification and demonstrated safety, LDLT remains underutilized, with fewer than 10% of liver transplants being LDLT. Recent trends indicate improved access to deceased donor liver transplantation (DDLT) due to increased organ donation and technological advances like Normothermic Regional Perfusion (NRP). However, LDLT remains critical, especially for pediatric patients and specific adult populations who benefit significantly from it. Barriers to LDLT include public and clinician apprehensions about donor risks, despite studies showing low-complication rates. Non-directed donations and broader social media engagement have increased donor pools, though the volume of LDLT in the US remains lower than in Asia due to limited training and experience. The A2ALL consortium has been pivotal in studying LDLT safety and outcomes. Currently, around 40 US centers perform LDLT, with high-volume centers leading by example. Training paradigms for LDLT are evolving, with initiatives like the ASTS LDLT master class aiming to enhance surgical expertise. While LDLT is embedded in US liver-transplant practices, its expansion is hampered by risk aversion and the availability of DDLT. Nonetheless, LDLT is essential for addressing the supply-demand mismatch in liver transplantation.

The dangerous precedent of censoring scientific dissemination.

The American Transplant Congress (ATC) is the largest national transplant meeting in the United States jointly sponsored by the American Society of Transplantation and the American Society of Transplant Surgeons. The 2024 ATC was held in Philadelphia, Pennsylvania during which a number of peer-reviewed scientific abstracts were censored from the program by the Health Resources and Services Administration. These abstract presentations were redacted from the program for perceived conflict with current government policy effectively restricting dissemination of highly rated findings and discussion in a scientific forum. In this viewpoint, we describe the content of the abstracts that were withdrawn from the annual ATC meeting and the implications of this censorship by the Health Resources and Services Administration. We further consider the ramifications of this action for the prospective evaluation of government policy and the relationship of the contract agency with the transplant community in the context of ongoing discussions of modernizing the transplant system which has previously been critiqued for lack of transparency.

Crossing national borders for transplantation: A focused evaluation of deceased donor lung exports from the United States.

Organ transplantation is a life-saving treatment for end-stage organ failure patients, but the United States (US) faces a shortage of available organs. US policies incentivize identifying recipients for all recovered organs. Technological advancements have extended donor organ viability, creating new opportunities for long-distance transport and international sharing. We aimed to assess organ exports from deceased US donors to candidates abroad, a component of allocation policy allowed without suitable domestic candidates. Based on the national Scientific Registry of Transplant Recipients data from January 2014 to September 2023, 388 342 organs were recovered for transplantation, with 511 (0.13%) exported. Most exported organs were lungs (80%). Exported lung donors were older (41 vs 34 years, P < .001), more likely hepatitis C positive (22% vs 4%, P < .001), and more likely donors after circulatory death (20% vs 7%, P < .001). Lungs that were eventually exported were offered to more US potential transplant recipients (median = 65) than those kept in the US (median = 21 and 41 for lungs recovered by nonexporting and exporting organ procurement organizations, respectively; P < .001). Our study highlights the necessity for further research and clear policy initiatives to balance the benefits of cross-border sharing while considering potential opportunities for more aggressive organ allocation within the US.

Phase I clinical trial of the feasibility and safety of direct peritoneal resuscitation in liver transplantation.

BACKGROUND: Direct peritoneal resuscitation (DPR) is associated with improved outcomes in trauma. Animal models suggest DPR has favorable effects on the liver. We sought to evaluate its safety and assess for improved outcomes in liver transplantation (LT). METHODS: LT patients with renal dysfunction and/or obesity were enrolled in a phase-I clinical trial. DPR lasted 8-24 â€‹h depending on postoperative disposition. Primary outcome was percent of patients completing DPR. Secondary outcomes evaluated complications. Controls with either obesity (control-1) or both risk factors (obesity â€‹+ â€‹renal dysfunction, control-2) were analyzed. RESULTS: Fifteen patients were enrolled (seven with both criteria and eight with obesity alone). DPR was completed in 87 â€‹% of patients, with one meeting stopping criteria. Controls included 45 (control-1) and 24 (control-2) patients. Return to operating room, graft loss, and late infections were lower with DPR. CONCLUSION: DPR appears to be safe in closed abdomens following LT, warranting a follow-up phase-II trial to assess efficacy.

Consensus Statement: Technical Standards for Thoracoabdominal Normothermic Regional Perfusion.

BACKGROUND: Thoracoabdominal normothermic regional perfusion (TA-NRP) has emerged as a powerful technique for optimizing organ procurement from donation after circulatory death donors. Despite its rapid adoption, standardized guidelines for TA-NRP implementation are lacking, prompting the need for consensus recommendations to ensure safe and effective utilization of this technique. METHODS: A working group composed of members from The American Society of Transplant Surgeons, The International Society of Heart and Lung Transplantation, The Society of Thoracic Surgeons, and The American Association for Thoracic Surgery was convened to develop technical guidelines for TA-NRP. The group systematically reviewed existing literature, consensus statements, and expert opinions to identify key areas requiring standardization, including predonation evaluation, intraoperative management, postdonation procedures, and future research directions. RESULTS: The working group formulated recommendations encompassing donor evaluation and selection criteria, premortem testing and therapeutic interventions, communication protocols, and procedural guidelines for TA-NRP implementation. These recommendations aim to facilitate coordination among transplant teams, minimize variability in practice, and promote transparency and accountability throughout the TA-NRP process. CONCLUSIONS: The consensus guidelines presented herein serve as a comprehensive framework for the successful and ethical implementation of TA-NRP programs in organ procurement from donation after circulatory death donors. By providing standardized recommendations and addressing areas of uncertainty, these guidelines aim to enhance the quality, safety, and efficiency of TA-NRP procedures, ultimately contributing to improved outcomes for transplant recipients.

American Society of Transplant Surgeons Normothermic Regional Perfusion Standards: Ethical, Legal, and Operational Conformance.

BACKGROUND: The American Society of Transplant Surgeons convened a multidisciplinary working group to address operational, ethical, and legal considerations surrounding normothermic regional perfusion (NRP) procurement. METHODS: The working group, comprising members from American Society of Transplant Surgeons and AST across various disciplines including transplant surgery, hepatology, critical care, and bioethics, collaborated to formulate recommendations and guidance for NRP procurement. RESULTS: The following topics were identified by the group as essential standards that need to be addressed for ethical, legal, and operational conformance: terminology; conceptualization of death in the context of NRP; and communication, logistics, and training and competency. CONCLUSIONS: Fourteen recommendations that support the ethical and legal acceptability of NRP in the United States and set expectations for the conduct of NRP procedures are provided.

Consensus Statement: Technical Standards for Thoracoabdominal Normothermic Regional Perfusion.

BACKGROUND: Thoracoabdominal normothermic regional perfusion (TA-NRP) has emerged as a powerful technique for optimizing organ procurement from donation after circulatory death donors. Despite its rapid adoption, standardized guidelines for TA-NRP implementation are lacking, prompting the need for consensus recommendations to ensure safe and effective utilization of this technique. METHODS: A working group composed of members from The American Society of Transplant Surgeons, The International Society of Heart and Lung Transplantation, The Society of Thoracic Surgeons, and The American Association for Thoracic Surgery was convened to develop technical guidelines for TA-NRP. The group systematically reviewed existing literature, consensus statements, and expert opinions to identify key areas requiring standardization, including predonation evaluation, intraoperative management, postdonation procedures, and future research directions. RESULTS: The working group formulated recommendations encompassing donor evaluation and selection criteria, premortem testing and therapeutic interventions, communication protocols, and procedural guidelines for TA-NRP implementation. These recommendations aim to facilitate coordination among transplant teams, minimize variability in practice, and promote transparency and accountability throughout the TA-NRP process. CONCLUSIONS: The consensus guidelines presented herein serve as a comprehensive framework for the successful and ethical implementation of TA-NRP programs in organ procurement from donation after circulatory death donors. By providing standardized recommendations and addressing areas of uncertainty, these guidelines aim to enhance the quality, safety, and efficiency of TA-NRP procedures, ultimately contributing to improved outcomes for transplant recipients.

Survival following liver transplantation: A population-based nested case-control study.

BACKGROUND: Liver transplantation is the gold standard treatment for end-stage liver disease. This study evaluates post-transplantation survival compared with the general population by quantifying standardized mortality ratios in a nested case-control study. METHODS: Controls were noninstitutionalized United States inhabitants from the National Longitudinal Mortality Study. Cases underwent liver transplantation from 1990 to 2007 identified through the Organ Procurement and Transplantation Network database. Propensity matching (5:1, nearest neighbor, caliper 0.1) identified controls based on age, sex, race, and state. The primary endpoint was 10-year survival. RESULTS: 62,788 cases were matched to 313,381 controls. The overall standardized mortality ratio was 2.46 (95% CI â€‹= â€‹2.44-2.48). The standardized mortality ratio was higher for males (2.59 vs. 2.25) and Hispanic patients (4.80). Younger patients and those transplanted earlier (1990-1995) had higher standardized mortality ratios. CONCLUSIONS: Liver recipients have a standardized mortality ratio 2.46 times higher than the general population. Long-term mortality has declined over time.

Association of procurement technique with organ yield and cost following donation after circulatory death.

Donation after circulatory death (DCD) could account for the largest expansion of the donor allograft pool in the contemporary era. However, the organ yield and associated costs of normothermic regional perfusion (NRP) compared to super-rapid recovery (SRR) with ex-situ normothermic machine perfusion, remain unreported. The Organ Procurement and Transplantation Network (December 2019 to June 2023) was analyzed to determine the number of organs recovered per donor. A cost analysis was performed based on our institution's experience since 2022. Of 43 502 donors, 30 646 (70%) were donors after brain death (DBD), 12 536 (29%) DCD-SRR and 320 (0.7%) DCD-NRP. The mean number of organs recovered was 3.70 for DBD, 3.71 for DCD-NRP (P < .001), and 2.45 for DCD-SRR (P < .001). Following risk adjustment, DCD-NRP (adjusted odds ratio 1.34, confidence interval 1.04-1.75) and DCD-SRR (adjusted odds ratio 2.11, confidence interval 2.01-2.21; reference: DBD) remained associated with greater odds of allograft nonuse. Including incomplete and completed procurement runs, the total average cost of DCD-NRP was $9463.22 per donor. By conservative estimates, we found that approximately 31 donor allografts could be procured using DCD-NRP for the cost equivalent of 1 allograft procured via DCD-SRR with ex-situ normothermic machine perfusion. In conclusion, DCD-SRR procurements were associated with the lowest organ yield compared to other procurement methods. To facilitate broader adoption of DCD procurement, a comprehensive understanding of the trade-offs inherent in each technique is imperative.

The American Society of Transplant Surgeons Consensus Statement on Normothermic Regional Perfusion.

On June 3, 2023, the American Society of Transplant Surgeons convened a meeting in San Diego, California to (1) develop a consensus statement with supporting data on the ethical tenets of thoracoabdominal normothermic regional perfusion (NRP) and abdominal NRP; (2) provide guidelines for the standards of practice that should govern thoracoabdominal NRP and abdominal NRP; and (3) develop and implement a central database for the collection of NRP donor and recipient data in the United States. National and international leaders in the fields of neuroscience, transplantation, critical care, NRP, Organ Procurement Organizations, transplant centers, and donor families participated. The conference was designed to focus on the controversial issues of neurological flow and function in donation after circulatory death donors during NRP and propose technical standards necessary to ensure that this procedure is performed safely and effectively. This article discusses major topics and conclusions addressed at the meeting.

Differential in Kidney Graft Years on the Basis of Solitary Kidney, Simultaneous Liver-Kidney, and Kidney-after-Liver Transplants.

BACKGROUND: The number of simultaneous liver-kidney (SLK) transplants has significantly increased in the United States. There has also been an increase in kidney-after-liver transplants associated with 2017 policy revisions aimed to fairly allocate kidneys after livers. SLK and kidney-after-liver candidates are prioritized in allocation policy for kidney offers ahead of kidney-alone candidates. METHODS: We compared kidney graft outcomes of kidney-alone transplant recipients with SLK and kidney-after-liver transplants using paired kidney models to mitigate differences among donor risk factors. We evaluated recipient characteristics between transplant types and calculated differential graft years using restricted mean survival estimates. RESULTS: We evaluated 3053 paired donors to kidney-alone and SLK recipients and 516 paired donors to kidney-alone and kidney-after-liver recipients from August 2017 to August 2022. Kidney-alone recipients were younger, more likely on dialysis, and Black race. One-year and 3-year post-transplant kidney graft survival for kidney-alone recipients was 94% and 86% versus SLK recipients 89% and 80%, respectively, P < 0.001. One-year and 3-year kidney graft survival for kidney-alone recipients was 94% and 84% versus kidney-after-liver recipients 93% and 87%, respectively, P = 0.53. The additional kidney graft years for kidney-alone versus SLK transplants was 21 graft years/100 transplants (SEM=5.0) within 4 years post-transplantation, with no significant difference between kidney-after-liver and kidney-alone transplants. CONCLUSIONS: Over a 5-year period in the United States, SLK transplantation was associated with significantly lower kidney graft survival compared with paired kidney-alone transplants. Most differences in graft survival between SLK and kidney-alone transplants occurred within the first year post-transplantation. By contrast, kidney-after-liver transplants had comparable graft survival with paired kidney-alone transplants.

Management of Established Small-for-size Syndrome in Post Living Donor Liver Transplantation: Medical, Radiological, and Surgical Interventions: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference.

Small-for-size syndrome (SFSS) following living donor liver transplantation is a complication that can lead to devastating outcomes such as prolonged poor graft function and possibly graft loss. Because of the concern about the syndrome, some transplants of mismatched grafts may not be performed. Portal hyperperfusion of a small graft and hyperdynamic splanchnic circulation are recognized as main pathogenic factors for the syndrome. Management of established SFSS is guided by the severity of the presentation with the initial focus on pharmacological therapy to modulate portal flow and provide supportive care to the patient with the goal of facilitating graft regeneration and recovery. When medical management fails or condition progresses with impending dysfunction or even liver failure, interventional radiology (IR) and/or surgical interventions to reduce portal overperfusion should be considered. Although most patients have good outcomes with medical, IR, and/or surgical management that allow graft regeneration, the risk of graft loss increases dramatically in the setting of bilirubin >10 mg/dL and INR>1.6 on postoperative day 7 or isolated bilirubin >20 mg/dL on postoperative day 14. Retransplantation should be considered based on the overall clinical situation and the above postoperative laboratory parameters. The following recommendations focus on medical and IR/surgical management of SFSS as well as considerations and timing of retransplantation when other therapies fail.

Early predictors of prolonged intensive care utilization following liver transplantation.

INTRODUCTION: Creatinine, bilirubin, and fibrinolysis resistance are associated with multi-organ dysfunction and likely risk factors for prolonged intensive care unit (pICU) stay following liver transplantation (LT). We hypothesize postoperative day-1 (POD-1) labs will predict pICU. METHODS: LT recipients had clinical laboratories and viscoelastic testing with tissue plasminogen activator thrombelastography (tPA TEG) to quantify fibrinolysis resistance (LY30) on POD-1. pICU was defined as one week or longer in the ICU. Logistic regression was used to identify the relationship between POD-1 labs and pICU. RESULTS: Of 304 patients, 50% went to the ICU, with 15% experiencing pICU. Elevated creatinine (OR 6.6, P â€‹< â€‹0.001) and low tPA TEG LY30 (OR 3.7, P â€‹= â€‹0.004) were independent predictors of pICU after controlling for other risk factors. A 9-fold increase in the rate of 90-day graft loss (19% vs 2% p â€‹< â€‹0.001) was observed patients who had these risk factors for pICU. CONCLUSION: Elevated creatine and fibrinolysis resistance are associated with pICU and poor outcomes following LT.

The in-vitro influence of urea concentration on thromboelastrography in patients with and without end stage renal disease.

BACKGROUND: End stage renal disease (ESRD) is associated with platelet dysfunction but also thromboembolic complications. The specific role of increased blood urea nitrogen (BUN) on coagulation is unclear. We aimed to characterize thromboelastography (TEG) parameters from males and females with ESRD and normal kidney function and evaluate if exogenous urea in vitro reproduced those TEG differences. METHODS: We collected blood samples from 20 living kidney donors and 20 kidney recipients. TEG was performed without and with two increasing urea concentrations in vitro. TEG parameters were compared between recipients and donors. RESULTS: Blood from kidney recipients showed baseline increased maximum amplitude (MA) and shortened time to maximum amplitude (TMA) compared to donors. These differences were not confirmed in females. In all patients, BUN was inversely correlated with TMA (r = -0.342; p = 0.031). In males, BUN and creatinine concentrations showed a direct correlation with MA (0.583; p = 0.007) and an inverse correlation with TMA (r = -0.520; p = 0.019). Urea in vitro decreased R-time (p = 0.005) and increased LY30 (p = 0.009) in donors but not recipients. CONCLUSIONS: ESRD is associated with increased MA and decreased TMA on TEG. No change in MA was observed with increasing urea concentrations in vitro. Gender-specific variability in TEG parameters were observed.

Reassessing the survival benefit of deceased donor liver transplantation: retrospective cohort study.

INTRODUCTION: Currently in the United States, deceased donor liver transplant (DDLT) allocation priority is based on the model for end-stage liver disease including sodium (MELD-Na) score. The United Network for organ sharing's 'Share-15' policy states that candidates with MELD-Na scores of 15 or greater have priority to receive local organ offers compared to candidates with lower MELD-Na scores. Since the inception of this policy, major changes in the primary etiologies of end-stage liver disease have occurred and previous assumptions need to be recalibrated. METHODS: The authors retrospectively analyzed the Scientific Registry of Transplant Recipients database between 2012 and 2021 to determine life years saved by DDLT at each interval of MELD-Na score and the time-to-equal risk and time-to-equal survival versus remaining on the waitlist. The authors stratified our analysis by MELD exception points, primary disease etiology, and MELD score. RESULTS: On aggregate, compared to remaining on the waitlist, a significant 1-year survival advantage of DDLT at MELD-Na scores as low as 12 was found. The median life years saved at this score after a liver transplant was estimated to be greater than 9 years. While the total life years saved were comparable across all MELD-Na scores, the time-to-equal risk and time-to-equal survival decreased exponentially as MELD-Na scores increased. CONCLUSION: Herein, the authors challenge the perception as to the timing of DDLT and when that benefit occurs. The national liver allocation policy is transitioning to a continuous distribution framework and these data will be instrumental to defining the attributes of the continuos allocation score.

CCR4-IL2 bispecific immunotoxin is more effective than brentuximab for targeted therapy of cutaneous T-cell lymphoma in a mouse CTCL model.

Cutaneous T-cell lymphoma (CTCL) encompasses two main subtypes: mycosis fungoides and Sezary syndrome. Global response rates for the systemic treatment of mycosis fungoides and Sezary syndrome are approximately 30%, and none of these treatments are thought to be curative. C-C chemokine receptor type 4 (CCR4) and CD25 are encouraging targets for the treatment of CTCL and are individually targeted by mogamulizumab and denileukin diftitox, respectively. We developed a novel CCR4-IL2 bispecific immunotoxin (CCR4-IL2 IT) targeting both CCR4 and CD25. CCR4-IL2 IT demonstrated superior efficacy against CCR4+ CD25+ CD30+ CTCL in an immunodeficient NSG mouse tumor model. Investigative New Drug-enabling studies of CCR4-IL2 IT are ongoing, including Good Manufacturing Practice production and toxicology studies. In this study, we compared the in vivo efficacy of CCR4-IL2 IT versus the US Food and Drug Administration-approved drug, brentuximab, using an immunodeficient mouse CTCL model. We demonstrated that CCR4-IL2 IT was significantly more effective in prolonging survival than brentuximab, and combination treatment of CCR4-IL2 IT and brentuximab was more effective than brentuximab or CCR4-IL2 IT alone in an immunodeficient NSG mouse CTCL model. Thus, CCR4-IL2 IT is a promising novel therapeutic drug candidate for CTCL treatment.