Initial Clinical Experience with Percutaneous Irreversible Electroporation of Kidney Tumors
Aaron H. Lay, Monica S.C. Morgan, Noah Canvasser, Asim Ozayar, Jeffrey C. Gahan, Clayton Trimmer, Jeffrey A. Cadeddu
Percutaneous irreversible electroporation (IRE) is a novel minimally invasive technique for the management of small renal masses. Electroporation causes cell death by generating an electric field across the cell, leading to creation of nano-scale pores within cellular membranes, ultimately resulting in cell apoptosis. IRE offers potential advantages to radiofrequency ablation and cryoablation since it does not rely on thermal energy. Dr. Cadeddu’s team from University of Texas, Southwestern reported their inital IRE experience to assess feasibility, safety, effectiveness, and radiographic outcomes of IRE renal tumor ablation.
They performed a retrospective review of all IRE cases between April 2013 and June 2015 that they performed. IRE was performed using the NanoKnife 15 cm monopolar probes and commercial system (AngioDynamics, NY, USA). All procedures were performed under general anesthesia. To prevent cardiac arrhythmias, IRE was synchronized with the cardiac cycle. All patients underwent CT guided ablation. To be included in analysis, patients had a minimum of 6 week follow-up with a contrast-enhanced CT.
This report included a total of 26 tumors that were treated with IRE. Mean follow-up was 11 months (2-25). Mean tumor size was 2.13cm (1.20-3.60cm). Mean nephrometry score was 5.62 (4-9). Biopsy was performed in 53.8% of cases with diagnosis of renal cell carcinoma in 71.4%. There were no complications. Patients were discharged the same day 48.0% of the time, while the rest were discharged the next day. CT scan immediately post procedure typically showed decreased perfusion with an enhancing rim at the ablation site. At 6 weeks, three patients' (11.5%) CT scans demonstrated a persistent rim of enhancement, indicating ablation failure. These patients underwent successful salvage RFA. At 1 year, one patient had a recurrence that was treated with successful partial nephrectomy.
Dr. Canvasser, who presented the report, concluded that percutaneous IRE of kidney tumors has shown to be feasible and safe. Longer-term follow-up is needed to confirm the oncologic efficacy of IRE.
Presented by Noah Canvasser at the 2015 World Congress of Endourology Annual Meeting – October 1-4, 2015, London, United Kingdom.
Written by Zhamshid Okhunov, MD for UroToday.com.