S015: EX VIVO PRESERVATION: KEY PARAMETERS AND DONOR CHARACTERISTICS INFLUENCING LIVER AND KIDNEY GRAFT UTILIZATION.
Vikram J Mahajan, MD1,2; Chamanthi Konidala, BS, MS3; Muhammad N Abou-Samra, MD3; Daniela V Orza, MD, MHA3; John Hodgson, MD3; Enrico M Camporesi, MD3
1University of South Florida Morsani College of Medicine, Department of Anesthesiology and Perioperative Medicine; 2Teamhealth Anesthesia; 3University of South Florida Morsani College of Medicine
Introduction: Ex-vivo organ preservation encompasses global practices to improve the utilization of donated organs and promote graft survival. Despite substantial advances in preservation technology and protocols, their impact on the perioperative management of medically complex transplant recipients remains largely unexamined. Through analysis of liver and kidney transplantation data from our center (the largest by volume in the USA during 2024), we examined correlations between donor characteristics, cause of death, ex-vivo preservation parameters, and organ utilization rates. This study outlines discard criteria in the era of emerging preservation techniques to identify the characteristics of marginal kidney and liver grafts. By refining organ selection criteria, we aim to improve risk, enhance graft utilization, and optimize patient outcomes in transplantation.
Methods: We retrospectively analyzed all liver (n=503) and kidney (n=680) transplants at Tampa General Hospital from October 2022 to February 2025. In the perioperative management during the study period, pumps were used for all organs to optimize graft function. Donor characteristics (e.g., living, brain death, and circulatory death donors) were analyzed for the impact on organ utilization. Data collection included ex-vivo preservation metrics such as perfusion pressures, flow rates, vascular resistance, and perfusate blood gas analyses.
Results: During this study period, thirty-seven livers and also thirty-seven kidneys were discarded. The pre-pump analysis identified donor pH as the only significant predictor of liver discard (7.19 in discarded vs. 7.34 in transplanted; p < 0.05), while enzyme (ALT, AST) levels were not associated with discard rates. Post-pump assessments revealed that discarded livers had significantly higher enzyme levels, lower bile production (51.62 mL vs. 190.57 mL; p < 0.05), higher perfusate lactate levels (4.22 mmol/L vs. 0.68 mmol/L; p < 0.05), lower ex-vivo pH (7.39 vs. 7.49; p < 0.05), and required greater bicarbonate administration (22.3 mL vs. 5.2 mL; p < 0.05). Notably, statistically significant differences in bile production and arterial and portal vein flow rates between transplanted and discarded livers were not observed. Flow rate and Kidney Donor Profile Index (KDPI) were key discard predictors for kidney transplants. Discarded kidneys had lower flow rates (104.97 mL/min vs. 146.05 mL/min; p < 0.05) and higher KDPI scores (0.74 vs. 0.50; p < 0.05). Cold ischemia time was comparable between discarded and transplanted kidneys (21.18 vs. 20.93 hours), and vascular resistance differences were not statistically significant. The chi-square analysis confirmed higher discard rates in donation after circulatory death (DCD) donors compared to brain death and living donors (p < 0.05).
Discussion: Future research should explore how preoperative ex-vivo preservation parameters influence intraoperative complications such as reperfusion injury and coagulopathies. Integrating preservation metrics into anesthesia risk models could refine perioperative risk stratification, guiding intraoperative decision-making and improving graft function. Linking preservation data with anesthesia management can enhance transplant outcomes, optimize resource allocation, and develop predictive to