Endoscopic-guided laser lithotripsy for removal of an encrusted ureteral stent in a dog

An 8-year-old spayed female Dalmatian was evaluated because of recurrent urinary tract infections following ureteral stent placement 3 years earlier.

Polyuria, pollakiuria, and hematuria were reported by the owner. Abdominal radiography revealed well-defined, faintly mineralized material superimposed over the distal portion of the previously placed ureteral stent. Abdominal ultrasonography revealed thickening of the bladder wall, right hydroureter, and right pyelectasia; the ureteral stent appeared to extend into a region containing cystic calculi. Cystoscopy revealed small uroliths and mineralized encrustation of the distal portion of the ureteral stent.

A holmium:yttrium-aluminum-garnet laser was used to fragment mineralized material from the distal end of the stent and allow endoscopic transurethral removal. Stone analysis revealed ammonium urate as the major component of the mineralized material. The owner was instructed to feed the dog a diet formulated to decrease the likelihood of urate stone recurrence and to administer marbofloxacin for 6 weeks because of suspected pyelonephritis. Follow-up bacterial culture of a urine sample and abdominal ultrasonography revealed resolution of urinary tract infection, pyelectasia, hydroureter, and associated clinical signs.

Results suggested that endoscopic-guided laser lithotripsy can be used as a minimally invasive alternative to surgery for removal of severely encrusted ureteral stents in dogs.