Objectives: Persistent organ shortages have driven increased use of marginal criteria liver grafts in transplants. We conducted a retrospective single-center analysis of liver transplants performed from November 1, 2023, through January 31, 2025, to compare short-term outcomes between marginal criteria grafts and standard criteria grafts.
Materials and Methods: Donors were classified according to established definitions of extended criteria, and the assessed outcomes included peak liver enzymes, Model for End-Stage Liver Disease scores, and posttransplant complications.
Results: Of 18 transplants, 12 (66.6%) were marginal criteria grafts. Peak levels of alanine transaminase and aspartate transaminase, Model for End-Stage Liver Disease scores, and overall complication rates were comparable between groups. One recipient of a marginal criteria graft died from primary graft failure, and 1 required a retransplant.
Conclusions: Our findings suggest that, with careful donor-recipient selection and perioperative management, marginal criteria liver grafts can achieve acceptable short-term outcomes and safely expand the donor pool. Key words: Extended criteria donor, Liver transplantation, Marginal criteria graft, Model for End-Stage Liver Disease

Introduction
The persistent shortage of suitable donor organs remains a significant challenge in liver transplantation, prompting increased utilization of marginal criteria liver grafts. Marginal criteria donors, defined by factors such as advanced age, prolonged cold ischemia time (CIT), positive status for hepatitis C virus, substantial hepatic steatosis, donation after cardiac death (DCD), shared grafts, or elevated serum sodium, have been associated with higher risks of graft dysfunction and recipient complications. Advancements in perioperative management and recipient selection have led to improved outcomes, warranting a reevaluation of safety and efficacy of marginal criteria grafts. We compared clinical outcomes between recipients of marginal criteria liver grafts and standard criteria liver grafts in a single-center cohort, thereby providing insight into expanding donor criteria in liver transplants.

Materials and Methods
This retrospective analysis included liver transplants performed at our center from November 1, 2023, through January 31, 2025. Donors were categorized as marginal or standard based on established criteria. The marginal criteria donors were defined by 1 or more of the following: age >70 years, CIT >12 hours, positive status for hepatitis C virus, hepatic steatosis >30%, DCD, split liver graft, or peak serum sodium >155 mmol/L. Recipients were followed through January 2025, with data collected on demographic variables, liver function indexes (peak levels of alanine transaminase [ALT] and aspartate transaminase [AST]), Model for End-Stage Liver Disease (MELD) scores, and posttransplant complications. Statistical comparisons were made between the groups to assess differences in outcomes.

Results
A total of 18 liver transplants were performed during the study period, consisting of 12 (66.6%) marginal criteria grafts and 6 (33.3%) standard criteria grafts. The mean recipient age was 57.5 years in the marginal group and 52.1 years in the standard group. Among marginal criteria donors, 11 donors had peak serum sodium levels exceeding 155 mmol/L (range 158-179 mmol/L), 1 donor was a DCD donor, and 1 donor was 70 years old. There were no significant differences in peak ALT (mean ± SD: 776.75 ± 626 IU/L for marginal criteria donors vs 1349 ± 770 IU/L for standard criteria donors; P = .¹) or peak AST (1951 ± 2101 IU/L for marginal criteria donors vs 2012 ± 1529 IU/L for standard criteria donors; P = .⁹⁵) between the groups. The MELD scores were also similar (21.4 ± 7.5 for marginal criteria donors vs 18.5 ± 10.3 for standard criteria donors; P = .⁵). Incidence of posttransplant complications did not differ significantly between groups. Among the marginal criteria group, a recipient with acute fulminant liver failure who received a DCD graft died from primary graft failure, and another recipient developed hepatic artery thrombosis that required a retransplant.

Discussion
The persistent imbalance between organ demand and availability continues to drive the expansion of donor selection criteria in liver transplants.^1,2 In this single-center experience, marginal criteria liver grafts accounted for two-thirds of transplants performed during the early phase of a new program, reflecting real-world reliance on organs from extended criteria donors to maintain transplant activity. Despite the higher theoretical risk associated with marginal criteria donors, our findings demonstrated comparable short-term biochemical outcomes and complication rates between recipients of marginal criteria grafts and recipients of standard criteria grafts. Historically, extended criteria donor characteristics, such as advanced donor age, DCD, prolonged CIT, hypernatremia, steatosis, and positive status for hepatitis C virus, have been associated with increased risks of early allograft dysfunction and inferior graft survival.^2,3 The development of the donor risk index emphasized the cumulative effect of donor-related variables on graft outcomes.² However, more recent studies have suggested that the adverse effects of individual marginal factors may be mitigated by careful donor-recipient matching, advances in surgical technique, and improved perioperative management.^3,5 In our present cohort, peak ALT and AST levels did not differ significantly between recipients of marginal criteria grafts and recipients of standard criteria grafts, suggesting comparable degrees of early hepatocellular injury. Similar findings have been reported in contemporary series for which selected marginal criteria grafts demonstrated acceptable early biochemical function and survival outcomes.^4,5 These results support the evolving view that extended criteria donor selections should not be considered absolute contraindications in isolation. Donor hypernatremia was the predominant marginal characteristic in our study. Earlier reports have linked severe donor hypernatremia to an increased risk of graft dysfunction and reduced survival.¹ However, subsequent analyses have challenged the independent prognostic reliability of this reported risk factor, particularly when ischemia times are controlled and other donor risk factors are absent.^3,5 The absence of increased early graft dysfunction in our hypernatremia donor cohort aligns with this more recent evidence. There was 1 death in the marginal criteria group, who was a recipient of a DCD graft to treat acute fulminant liver failure. Liver transplant with DCD is known to carry higher risks of ischemia-reperfusion injury, primary nonfunction, and biliary complications, particularly in recipients with high MELD scores or in critically ill recipients.⁶ This outcome highlights the importance of cautious recipient selection when utilizing high-risk grafts, especially in the early stages of a transplant program. In addition, 1 recipient of a marginal criteria graft required retransplant due to hepatic artery thrombosis, which is a recognized complication associated with technically complex grafts and characteristics of marginal criteria donors.³ Recipient MELD scores and baseline demographics were comparable between our groups, suggesting that appropriate recipient selection played a crucial role in achieving acceptable outcomes. This finding is particularly relevant for newly established transplant programs, where institutional experience and resource optimization are critical factors. Emerging strategies such as machine perfusion technologies may further improve outcomes by reducing ischemia-reperfusion injury and allowing better assessment of marginal criteria graft viability prior to implantation.⁷ This study was limited by its retrospective design, small sample size, and short duration of follow-up, all of which limited the assessment of long-term graft survival and biliary complications. In addition, the heterogeneity of characteristics associated with marginal criteria donors precluded analysis of individual risk factors. Nonetheless, our findings contribute to the growing body of evidence supporting the judicious use of grafts from extended criteria donors to safely expand the donor organ pool, even during the early phase of a liver transplant program.^3-5

Conclusions
Our results suggest that use of organs from marginal criteria donors, as defined by established definitions of extended criteria donors, can yield short-term outcomes comparable to outcomes achieved with organs from standard criteria donors. Although complications were observed, no significant differences in liver function indexes or overall complication rates were shown between groups. These results support judicious use of marginal criteria grafts to address organ shortages, provided that careful donor and recipient selection and vigilant perioperative management are maintained. Further studies with larger cohorts and longer follow-up are warranted to confirm these findings and optimize protocols for marginal criteria graft utilization.