Kidney function changes following percutaneous cryoablation of renal tumors: A single-center cohort study

BACKGROUND: Percutaneous cryoablation (PCA) is a minimally invasive treatment modality for renal cell carcinoma (RCC) that is often implemented in patients with impaired renal function. However, this procedure inevitably results in the loss of functional renal parenchyma. OBJECTIVES: The objective was to establish the influence of PCA on renal function, presented as a difference in estimated glomerular filtration rate (eGFR). MATERIAL AND METHODS: This study included patients treated with PCA of renal tumors at 1 institution between June 2023 and February 2025. Creatinine was measured 1 day before the procedure and ≥3 months after. Estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease (MDRD) equation. Mean differences in eGFR were assessed for the entire cohort and subgroups. Correlation analyses were performed to assess the relationship between eGFR reduction and tumor volume/diameter. Multiple linear regression analysis was conducted to identify factors independently associated with the change in eGFR. RESULTS: Ninety-two procedures met inclusion criteria. A minor but statistically significant decrease in mean eGFR was observed (66.8-61.1 mL/min/1.73 m2, p < 0.001). Patients with a solitary kidney showed no significant decline in eGFR (56.6-54.5 mL/min/1.73m2, p = 0.200), while those with CKD ≥ G3 experienced a modest but significant reduction (47.2-43.5 mL/min/1.73 m2, p = 0.004). After excluding cases with >10% eGFR improvement, the mean eGFR decline remained statistically significant (68.0-59.9 mL/min/1.73 m2, p < 0.001). Weak negative correlations were identified between eGFR reduction and both tumor volume (r = -0.24, p = 0.024) and tumor diameter (r = -0.21, p = 0.042). Finally, previous partial nephrectomy (PN) was associated with better eGFR preservation after PCA in multiple linear regression analysis (p = 0.014). CONCLUSIONS: Our findings support the nephron-sparing nature of PCA, which is a safe treatment modality of RCC, especially in patients with significant primary comorbidities.