Ureteral stents for impassable ureteroscopy

For the narrow ureter that will not accommodate a ureteroscope, it is common practice to place a ureteral stent, to allow subsequent ureteroscopy in the passively dilated ureter. Surprisingly, there are limited data on the effectiveness or safety of these maneuvers. We retrospectively analyzed patients managed with ureteral stent placement followed by another attempt at ureteroscopy after an initial attempt of flexible ureteroscopy failed because the ureteroscope would not pass up an otherwise normal ureter. Of 41 patients with follow-up who underwent ureteral stenting for this reason, the ureteroscope passed with ease poststenting in 29 (71%) and there was continued resistance in 12. Of these 12 patients, the ureteroscopy was continued despite resistance in 9, while another stent was placed in the remaining 3. Of these three patients, the third attempt at ureteroscopy was successful in two, and further attempts at ureteroscopy were not made after the third attempt failed in one. With a mean overall follow-up of 32 months, two patients (5%) developed ureteral strictures. Both were among nine patients in whom repeat ureteroscopy was performed despite resistance, with a rate of obstruction of 22% in this subgroup. Overall, ureteral stenting allowed successful ureteroscopy in 98% of patients. Ureteral stenting with subsequent ureteroscopy is a successful and safe method of addressing a narrow ureter that initially does not allow passage of a flexible ureteroscope, as long as persistent subsequent attempts to insert the ureteroscope are made only if it passes easily.