Short- and Long-term Functional Outcomes in a Large Cohort of Partial Nephrectomy Patients Managed with Prolonged...

To provide a robust analysis of functional recovery after partial nephrectomy (PN) with prolonged ischemia including potential short- and long-term effects. Previous studies suggested that irreversible functional-decline begins after approximately 30 min during clamped PN.

568 PN patients (2011-2020) with prolonged ischemia (>30 min) with necessary data were evaluated. Recovery from ischemia (Rec_ischemia) was defined: ipsilateral GFR preserved normalized by parenchymal volume preserved, and would be 100% if all nephrons recovered from ischemia. The impact of prolonged ischemia on Rec_ischemia, spectrum-score (analogous to AKI), and percent annual decline of ipsilateral GFR and parenchymal volume were assessed. Multivariable models evaluated predictors of Rec_ischemia.

Median tumor size/R.E.N.A.L. were 4.3 cm/8, respectively. Prolonged ischemia was cold (n = 268)/warm (n = 300); median ischemia times were 42/35 min, respectively. Median Rec_ischemia, for cold versus warm ischemia were 96%/85%, respectively (p < 0.01). Rec_ischemia fell ≈9% for each additional 10 min of prolonged warm-ischemia beyond 30 min. Increased spectrum-score associated with prolonged ischemia, whether cold or warm. Compared to new-baseline levels after PN, GFR at 3 years was generally stable (95%/97% preserved) in both the cold/warm cohorts, and substantial atrophy was not observed. On multivariable-analysis, prolonged warm-ischemia and increased spectrum-score associated with reduced Rec_ischemia (both p < 0.01).

Our results confirm the significant negative impact of prolonged warm-ischemia on functional recovery. Early ipsilateral renal dysfunction was mostly dependent on ischemia time, and long-term function generally remained stable despite exposure to prolonged ischemia. Our data suggest that avoidance of prolonged warm-ischemia should be considered in patients with solitary kidneys and/or moderate-severe preexisting CKD, although further study will be required.