Treatment of Upper Urinary Tract Stones With a Diameter≤2cm by Intelligent Pressure-controlled Flexible Ureteroscope

The aim of this trial is to compare the efficacy and safety of flexible ureteroscope with intelligent control of renal pelvic pressure (FURL-ICP) and traditional flexible ureteroscope(f-URL) in the treatment of upper urinary stones ≤ 2cm in diameter. It is designed as a multicenter, parallel randomized controlled trial with two arms. At least 449 patients with upper urinary stones ≤ 2cm in diameter will be invited to participant in this study. Patients will be assigned to intervention group (FURL-ICP group) or control group (f-URL) by a simple random sampling technique with a rate of 1:1. The baseline of participants include demographic data, urine analysis, blood cell analysis, blood biochemical analysis, and urinary computer tomography (CT) with a slice thickness of 2mm. The primary outcomes are postoperative stone-free rate (SFR) of one month by CT scan and postoperative fever rate (body temperature \> 38.5 ℃ within 3 days after operation). Secondary outcomes include operating time, degree of ureteral injury, SFR of one day.