Knowing When to Ignore the Numbers: Single-Center Experience Transplanting Deceased Donor Kidneys with Poor Perfusion Parameters

Abstract

BACKGROUND: Hypothermic machine perfusion is frequently used in evaluating marginal kidneys with poor perfusion parameters (PPP) contributing to delays in kidney placement or discard. We examined outcomes in deceased donor kidney transplants with PPP compared with those with optimal perfusion parameters (OPP). STUDY DESIGN: We conducted a retrospective single-center cohort study from 2001 to 2021 comparing PPP (n = 91) with OPP (n = 598) deceased donor kidney transplants. PPP was defined as terminal flow ≤80 mL/min and terminal resistance ≥0.40 mmHg/mL/min. OPP was defined as terminal flow ≥120 mL/min and terminal resistance ≤0.20 mmHg/mL/min. RESULTS: Mean terminal flow was PPP 66 ± 16 vs OPP 149 ± 21 mL/min and resistance was PPP 0.47 ± 0.10 vs OPP 0.15 ± 0.04 mmHg/mL/min (both p < 0.001). Donor age, donation after cardiac death, and terminal serum creatinine levels were similar between groups. Mean Kidney Donor Profile Index was higher among PPP donors (PPP 65 ± 23% vs OPP 52 ± 27%, p < 0.001). The PPP transplant group had more females and lower weight and BMI. Delayed graft function was comparable (PPP 32% vs OPP 27%, p = 0.33) even though cold ischemia times trended toward longer in PPP kidneys (PPP 28 ± 10 vs OPP 26 ± 9 hours, p = 0.09). One-year patient survival (PPP 98% vs OPP 97%, p = 0.84) and graft survival (PPP 91% vs OPP 92%, p = 0.23) were equivalent. PPP did predict inferior overall and death-censored graft survival long-term (overall hazard ratio 1.63, 95% CI 1.19 to 2.23 and death-censored hazard ratio 1.77, 95% CI 1.15 to 2.74). At 1 year, the estimated glomerular filtration rate was higher with OPP kidneys (PPP 40 ± 17 vs OPP 52 ± 19 mL/min/1.73 m2, p < 0.001). CONCLUSIONS: Short-term outcomes in PPP kidneys were comparable to OPP kidneys despite higher Kidney Donor Profile Index and longer cold ischemia times, suggesting a role for increased utilization of these organs with careful recipient selection.

Single center experience and literature review of kidney transplantation from non‐ideal donors with acute kidney injury: Risk and reward

“…To increase the size of the deceased donor pool, programs such as the Organ Donor Breakthrough Collaborative and other national initiatives were implemented in the early 2000s. These projects resulted in an upturn in the number of NIDDs such as ECDs, DCD donors, dual kidneys from donors at the extremes of age, and donors with terminal AKI 1–5,18–50 . Changes in the Kidney Allocation System, including application of the KDPI and use of concentric circles for allocation based on the donor hospital location have further contributed to equity in allocation.…”

“…Whenever possible, AKI donor kidneys were placed on hypothermic perfusion preservation to minimize preservation injury, maintain functional reserve, and provide another means of assessment 41–47 . Most of the imported kidneys in this experience were shipped to us in cold storage and placed on the Organ Recovery Systems pump by our local organ procurement organization for a variable period prior to implantation 48 .…”

“…Because of concerns for a higher risk of DGF in AKI donor kidneys, initial recipient selection was restricted to those patients who could predictably tolerate and manage a variable period of DGF 3,5,41–50 . However, with increasing experience, these criteria were gradually liberalized and recipients were selected for transplantation in a similar manner to recipients of kidneys without AKI.…”

“…Most of the imported kidneys in this experience were shipped to us in cold storage and placed on the Organ Recovery Systems pump by our local organ procurement organization for a variable period prior to implantation 48 . Although pump parameters were not exclusively applied to not use kidneys, a terminal flow rate >80 mL/min and a resistance <.40 mmHg/mL/min after a minimum of 4–6 h on the machine perfusion apparatus were considered thresholds for single kidney utilization 45–48 . However, again with increased experience and application of dual kidney transplantation, these criteria were liberalized and included 17 cases with a terminal flow rate <80 mL/min and 13 with a terminal resistance ≥.4 mmHg/mL/min.…”

“…18,19,45 Whenever possible, AKI donor kidneys were placed on hypothermic perfusion preservation to minimize preservation injury, maintain functional reserve, and provide another means of assessment. [41][42][43][44][45][46][47] Most of the imported kidneys in this experience were shipped to us in cold storage and placed on the Organ Recovery Systems pump by our local organ procurement organization for a variable period prior to implantation. 48 Although pump parameters were not exclusively applied to not use kidneys, a terminal flow rate >80 mL/min and a resistance <.40 mmHg/mL/min after a minimum of 4-6 h on the machine perfusion apparatus were considered thresholds for single kidney utilization.…”