Optimal utilization of donor grafts with extended criteria: a single-center experience in over 1000 liver transplants

Abstract

Objective: Severely limited organ resources mandate maximum utilization of donor allografts for orthotopic liver transplantation (OLT). This work aimed to identify factors that impact survival outcomes for extended criteria donors (ECD) and developed an ECD scoring system to facilitate graft-recipient matching and optimize utilization of ECDs.

Methods: Retrospective analysis of over 1000 primary adult OLTs at UCLA. Extended criteria (EC) considered included donor age (>55 years), donor hospital stay (>5 days), cold ischemia time (>10 hours), and warm ischemia time (>40 minutes). One point was assigned for each extended criterion. Cox proportional hazard regression model was used for multivariate analysis.

Results: Of 1153 allografts considered in the study, 568 organs exhibited no extended criteria (0 score), while 429, 135 and 21 donor allografts exhibited an EC score of 1, 2 and 3, respectively. Overall 1-year patient survival rates were 88%, 82%, 77% and 48% for recipients with EC scores of 0, 1, 2 and 3 respectively (P < 0.001). Adjusting for recipient age and urgency at the time of transplantation, multivariate analysis identified an ascending mortality risk ratio of 1.4 and 1.8 compared to a score of 0 for an EC score of 1, and 2 (P < 0.01) respectively. In contrast, an EC score of 3 was associated with a mortality risk ratio of 4.5 (P < 0.001). Further, advanced recipient age linearly increased the death hazard ratio, while an urgent recipient status increased the risk ratio of death by 50%.

Conclusions: Extended criteria donors can be scored using readily available parameters. Optimizing perioperative variables and matching ECD allografts to appropriately selected recipients are crucial to maintain acceptable outcomes and represent a preferable alternative to both high waiting list mortality and to a potentially futile transplant that utilizes an ECD for a critically ill recipient.

FIGURE 1. One-year graft and patient survival with extended criteria donors. A and B, Graft survival at 1 year as a function of recipient age for nonurgent and urgent recipients, respectively. Outcomes for recipients of grafts with Extended Criteria Donor Scores (DS) of 0, 1, 2, and 3 are shown. C and D, One-year patient survival versus recipient age for nonurgent and urgent recipients, respectively, for allografts of varying donor scores.

FIGURE 2. Graft failure risk based on donor score and recipient acuity. The risk of graft loss at 1 year as a function of recipient age is shown for allografts with Donor Scores (DS) of 0, 1, 2, and 3. The lower curves represent nonurgent recipients. The uppermost curve represents the graft failure hazard ratio in urgent recipients who are transplanted with allografts with a DS of 3.

FIGURE 3. Mortality risk based on Donor Score and recipient acuity. Overall recipient mortality at 1 year after transplant is shown versus recipient age for varying Donor Scores (DS). The lower curves represent recipients with a nonurgent status at the time of transplant. The uppermost curve shows the mortality risk when an urgent recipient receives an allograft with a Donor Score of 3.