Feasibility and safety of irreversible electroporation (IRE) in patients with small renal masses: Results of a prospective study

Background: Irreversible electroporation (IRE) has the potential to overcome limitations of thermal ablation, enabling small renal mass (SRM) ablation near vital structures. Purpose: To assess feasibility and safety of percutaneous IRE for the treatment of SRMs. Materials and methods: This prospective study is a phase 2 trial (NCT02828709) of IRE for patients with SRMs. Primary endpoints are feasibility and safety. Device-and procedural-adverse events were assessed by Clavien-Dindo and Common Terminology Criteria for Adverse Events version 4.0 grading systems. Technical feasibility was assessed by recording the technical success of the procedures. Technical success was evaluated by performing a CT immediately after ablation where complete tumor coverage and nonenhancement were evaluated. Tumor charcateristics and patient characteristics, procedural and anesthesia details, postprocedural events, and perioperative complications were recorded. Results: Ten SRMs were included with a mean tumor size of 2.2 cm (range 1.1-3.9 cm) were treated with IRE. Renal mass biopsies revealed 7 clear cell and 1 papillary renal cell carcinoma. Two renal mass biopsies were nondiagnostic. The median follow-up was 6 months (range 3-12 months). Technical success was achieved in 9 out of 10 cases. One patient had a grade 3 Clavien-Dindo complication (1/10, 95% Confidence interval (CI) 0.0179-0.4041). Mean anesthesia time was 3.7 hours (range 3-5 hours), mean procedural time was 2.1 hours (range 1 hour 45 minutes-2 hours 30 minutes) and mean ablation time was 50 minutes (range 20 minutes-1 hour 45 minutes). The creatinine preoperative and postoperative (1 week, 3 months, 6 months, and 12 months) did not significantly differ. In total, 8 out of 10 cases did not experience postoperative pain. Conclusion: IRE in SRMs is safe and feasible. Renal function is not affected by IRE and postoperative pain is rare. Anesthesia time and procedural time are a potential concern. (C) 2018 Elsevier Inc. All rights reserved.