Safety of CT-guided percutaneous cryoablation in patients treated for clinical T1 renal cell carcinoma with the need for pre-procedural ureteral stenting: An international cohort study

To assess the safety of computed tomography-guided percutaneous cryoablation (PCA) in patients who had pre-procedural ureteral stenting, while they were treated for clinical T1 renal cell carcinoma (RCC) with complex location. This retrospective international multicenter cohort study included patients treated between January 2016 and February 2021 at two University Hospitals, X1 and X2. Patients aged more than 18 years with suspected RCC were included. All patients underwent pre-procedural ureteral stenting. The complications were recorded within 30 days and graded according to the Clavien-Dindo classification and the Society of Interventional Radiology classification of adverse events. Major complications were defined as complications ≥ grade 3 on the Clavien-Dindo classification. The cohort included 61 patients with a median age of 66 years (IQR 55-75 years). The median tumour size was 33 mm (IQR 24-38 mm), with a median R.E.N.A.L score of 8 (IQR 7-10). A complication rate of 36% (n=22) was recorded, and major complications occurred following 10% (n=6) of the procedures. A statistically significant association was found between using more than three cryoprobes and postoperative complications (OR, 4.19; 95% CI: 1.38-12.75; p=0.010). In addition, no associations were found between postoperative complications and prophylactic antibiotics, patient age, tumour complexity, tumour size, histological type, or whether the ice ball was touching the ureter. This multicenter cohort study found a relatively high rate of postoperative complications in patients having a ureteral stent before PCA. However, no complications resulted in a chronic outflow obstruction. The number of high-complexity tumours could explain the high rate of complications.