Endoluminal radio-frequency electrocautery for permanent ureteral occlusion in swine

An animal experiment was undertaken to assess the feasibility of using radio-frequency current-mediated thermal injury of the ureter to produce ureteral occlusion by means of an endoluminal approach. Through open pyelotomies, balloon angioplasty catheters coated with gold bipolar electrodes were introduced into the ureters. Doses (at 650 kHz) were delivered for specific energy totals in 13 of 15 ureters in eight pigs. Two ureters served as controls (balloon inflation without current application). In six experimental animals not killed immediately after the procedure, postoperative ureteral manometric studies and nephrostography were performed and nephrostomy drainage was maintained until death (1-8 weeks). Treatment with 200-400 J produced safe, reliable occlusion by 4 weeks. At histopathologic study at 4 and 8 weeks, necrotic muscularis propria had been replaced by fibrous tissue. Cardiac rhythm was not affected during treatment.