Machine Perfusion Parameters and 1-Year Outcomes in High KDPI Kidney Transplantation: A Single-Center Cohort Study.

BACKGROUND: Kidney donor profile index (KDPI) was intended as an objective measure of donor organ quality but its utility in kidney allograft assessment has been questioned. High KDPI kidneys (KDPI ≥85) present a source of transplantable allografts. METHODS: A retrospective review was conducted on a single-center database for KDPI ≥85 transplants from 2013 to 2023. Allografts placed on hypothermic machine perfusion (HMP) with a flow ≥100 ml/min and resistance ≤0.2 mm Hg/mL/min (Group A) were compared to those with a flow <100 mL/min and/or resistance >0.2 mm Hg/mL/min (Group B). RESULTS: We identified 71 patients who received KDPI ≥85 kidneys from 59 donors. The average KDPI was 90%. The average donor age was 61 years; 75% had hypertension, 41% had diabetes, 2.4% had hepatitis C, and 35% were donors after circulatory death. Group A included 30 recipients; Group B included 42 recipients. Average flow and resistance were 157 mL/min and 0.17 mm Hg/mL/min in Group A and 115 mL/min and 0.27 mmHg/mL/min in Group B. Mean serum creatinine and eGFR at 1 year were 1.72 mg/dL and 42.4 mL/min/1.73 m² for Group A and 1.74 mg/dL and 43.1 mL/min/1.73 m² for Group B (p = .6). Delayed graft function occurred in 43% of Group A and 61% of Group B (p = .07). Overall, 1-year graft survival and patient survival were 90.0% and 95.1%, respectively. CONCLUSIONS: High KDPI grafts may represent a strategy to mitigate kidney waitlist burden in selected patients. In this single-center retrospective cohort, we observed no statistically significant differences in 1-year graft function, graft survival, or patient survival between grafts stratified by pre-specified HMP flow and resistance thresholds.