Percutaneous Renal Tumor Cryoablation Effect on Renal Function

Background: Percutaneous cryoablation (PCA) of renal tumors is a well-established alternative to partial nephrectomy, but the effects on renal function after the procedure are not well-documented. The purpose of this study was to evaluate renal function after computed tomography-guided PCA. Materials and Methods: A retrospective cohort study including 259 patients treated with PCA at Odense University Hospital, Denmark from January 1, 2015 to December 31, 2019. Both patients with malignant (96%) and benign tumors (4%) were included. Mean age of patients was 66.5 years (standard deviation [SD] = 10.9, range: 27-91) and 174 (67%) patients were men. Baseline estimated glomerular filtration rate (eGFR) was recorded at baseline and 12 months after cryoablation. Results: Mean tumor size was 27.5 mm (SD = 10.0) distributed in seven different histopathological types, mainly clear cell renal-cell carcinoma (RCC) (64%) and papillary RCC (22%). Mean eGFR at baseline was 73.7 mL/min/1.73 m² (SD = 23.2) with a follow-up mean eGFR of 69.7 (SD = 23.7) (p < 0.0001). At baseline before intervention 190 patients (73%) had eGFR matching chronic kidney disease (CKD) groups 1 and 2 (normal to mild CKD), 64 patients (24%) matching CKD group 3 (average CKD), and 1% in groups 4 and 5. At 12-month follow-up, 171 patients (66%) had eGFR matching CKD groups 1 and 2, 77 patients (30%) matching CKD group 3 and 11 patients (4%) matching CKD groups 4 and 5. In patients with skewed renography who had PCA in the kidney with better excretion, eGFR at baseline was 64.7 and 61.2 at follow-up (p = 0.703). Conclusions: This study showed minimal decline in renal function 12 months after PCA, even for patients with reduced renal function. PCA is therefore considered a safe and relevant intervention.