Impact of short warm ischemic time on longitudinal kidney function and survival rate after partial nephrectomy for renal cell carcinoma in patients with pre-existing chronic kidney disease stage III: A multi-institutional propensity score-matched study

Purpose: It remains unclear whether a short warm ischemic time (WIT) improves long-term renal function after partial nephrectomy (PN) for patients with pre-existing chronic kidney disease (CKD). We evaluated renal function after PN according to WIT duration in patients with stage III CKD. Materials and methods: We identified 277 patients with stage III CKD who underwent PN during 2004–2017. Propensity score matching was used to created two matched groups of patients: Group A (WIT of <25 min) and Group B (WIT of ≥25 min). The outcomes of interest were longitudinal kidney function change, new-onset stage IV CKD (eGFR <30 mL/min/1.73 m²) and overall survival. Results: The two matched groups contained 85 patients each. The median follow-up durations were 49 months in Group A and 42 months in Group B. The median pre-treatment eGFRs were 52.4 mL/min/1.73 m² in Group A and 52.6 mL/min/1.73 m² in Group B. There were no differences in kidney function between the two groups throughout the follow-up period (P > 0.05). The 5-year rates of new-onset stage IV CKD were not significantly different between Group A and Group B (8.2% vs. 7.1%), with no significant difference in the risk of developing stage IV CKD in Group A (vs. group B, hazard ratio: 0.527, 95% confidence interval: 0.183–1.521; P = 0.236). The 5-year overall survival rates were 90.3% for Group A and 96.2% for Group B (P = 0.549). Conclusions: A short WIT was not associated with better postoperative kidney function or survival after PN in patients with stage III CKD.