Use of a Ureteral Access Sheath During Ureteroscopy and Its Effect on Stone Free Rate

Patients with upper ureteral or renal stones will be randomized to undergoing ureteroscopy with or without a ureteral access sheath. The sheath is designed to facilitate ureteroscope insertion and re-insertion, thus allowing fragments to be basketed out. Stone free rates at 3 months will be determined between the two groups. The investigators hypothesize that the use of the ureteral access sheath with ureteroscopy will result in improved stone free rates at 3 months compared to ureteroscopy without use of a sheath.