Abstract No. 514 Renal mass ablation in the octogenarian and nonagenarian population

Abstract

To describe the outcomes of renal mass thermal ablation in the octogenarian and nonagenarian patient population. Our IRB-approved database of percutaneous renal ablations was retrospectively reviewed for patients greater than 80 years old undergoing renal mass ablation between February 2008 and August 2019. A total of 34 renal tumors were ablated in 19 males and 15 females with a mean age of 84.1 ± 3.1 years (range, 80-92 years). Procedural details and laboratory values were reviewed. A total of 10 renal microwave ablations and 24 cryoablations were performed. There were 27 T1a and 7 T1b renal tumors, overall tumor size ranged from 1.4-5.9 cm. Thirty-one ablations were performed as the primary intervention, and 3 were performed for tumor recurrence following partial nephrectomy (2) or prior ablation (1). The average number of probes was 3.3 in cryoablation and 2.7 in microwave ablation. Overall complication rate was 26%. There were three minor complications and five major complications, including two episodes of bleeding requiring red blood cell transfusion and one incidentally detected pseudoaneurysm in the ablation cavity of an asymptomatic patient which was subsequently embolized more than one year following the ablation. The mean pre procedure creatinine and eGFR was 1.20 and 50.9. The mean creatinine and eGFR post procedure was 1.23 and 49.3. Of the 25 patients with at least 3 months of CT or MR follow-up, there was no local recurrence and median follow-up was 23.7 months (range, 1.1-94.9 months). Concurrent biopsies were performed in 31 of the 34 cases. The pathology showed a majority of clear cell renal cell carcinoma (15), followed by oncocytic neoplasm (7), and papillary renal cell carcinoma (3). Four cases were nondiagnostic. The mean Charlson comorbidity index was 6.7. Mean renal nephrometry score was 6.3. Thermal ablation of renal masses in the elderly population is an effective treatment option with a low recurrence rate and without negative impact on renal function. The total complication rate in our cohort is high, but the total number of patients is small, and our reported experience ranges from our early use with percutaneous renal thermal ablation.