Feasibility of catheter-directed intraluminal irreversible electroporation of porcine ureter and acute outcomes in response to increasing energy delivery.

PURPOSE: To evaluate the feasibility of focal intraluminal irreversible electroporation (IRE) in the ureter with a novel electrode catheter and to study the treatment effects in response to increasing pulse strength. MATERIALS AND METHODS: Five IRE treatment settings were each evaluated twice for the ablation of normal ureter in 5 Yorkshire pigs (n = 1-4 ablations per animal; total of 10 ablations) with the use of a prototype device under ultrasound and fluoroscopic guidance. Animals received unilateral or bilateral treatment, limited to a maximum of 2 ablations in any 1 ureter. Treatment was delivered with increasing pulse strength (from 1,000 V to 3,000 V in increments of 500 V) while keeping the pulse duration (100 µs) and number of pulses (n = 90) constant. Ureter patency was assessed with antegrade ureteropyelography immediately following treatment. Animals were euthanized within 4 hours after treatment, and treated urinary tract was harvested for histopathologic analysis with hematoxylin and eosin and Masson trichrome stains. RESULTS: IRE was successfully performed in all animals, without evidence of ureteral perforation. Hematoxylin and eosin analysis of IRE treatments demonstrated full-thickness ablation at higher field strengths (mucosa to the adventitia). Masson trichrome stains showed preservation of connective tissue at all field strengths. CONCLUSIONS: Intraluminal catheter-directed IRE ablation is feasible and produces full-thickness ablation of normal ureters. There was no evidence of lumen perforation even at the maximum voltages evaluated.