Sheathed flexible retrograde intrarenal surgery without safety guide wire for upper urinary tract stones

To assess the success rate and intraoperative complications of flexible ureterorenoscopy (f-URS) in patients with upper urinary tract (UUT) stones using a ureteral access sheath (UAS) without a safety guide wire (SGW).Between April 2010 and March 2022, 464 renal units in patients with renal stones with and without concomitant ureteral stones (UUT), underwent ureterorenoscopy by one surgeon, and UAS was used in all of them. The primary endpoint was the stone-free rate (SFR). SFR was defined as no residual fragments at all. The following characteristics were examined: age, sex, laterality, renal/ureteral stones, stone diameter, SFR, Hounsfield unit, auxiliary procedures, double-J stent insertion, and intraoperative complications. This study was retrospective, with all the data recorded prospectively. Patients with residual stones were scheduled for the 2nd RIRS. The Clavien-Dindo classification was used to report complications.The mean patient age was 52.9 years. The mean stone size was 13.1 mm. Lower pole, upper and middle calyces, renal pelvis and ureteral stones were found in 51.5% (239), 34.9% (162), 18.3% (85) and 46.9% (218) of cases, respectively. The mean diameter was 8.1 mm, 8 mm, 12.5 mm and 8.1 mm for the lower pole, upper and middle calyces, renal pelvis and ureteral stones, respectively. The single- and second-session SFRs were 90% and 100%, respectively. The mean number of procedures per renal unit was 1.1. Ureteral double-J stents were inserted in 45.7% (212) of patients. In 96 cases, a stent was placed before surgery. Postoperative complications were minor, with no avulsion or perforation of the ureters; readmission and insertion of a DJ stent occurred in one patient. Ureteral stricture developed in one patient (0.2%) and needed treatment with laser ureterotomy.f-URS is a safe and effective mode of surgical management of renal and simultaneous renal and ureteral calculi using the ureteral access sheath without a safety guide wire. A guide wire should not be routinely used in these cases.