Stent-related Symptoms Comparison: Polaris Loop vs Vortek Double-J Stents

Comparison Between Symptoms Related to Polaris Loop Stent Versus Vortek Double J Stent After Uncomplicated Flexible Ureterorenoscopy for Renal Stones

Prospective randomized controlled single-blind parallel-group trial in order to compare symptoms related to loop-tail (Polaris Loop) stents versus conventional double J (Vortek) stents after uncomplicated flexible URS.

Patients undergoing RIRS for a single renal stone < 2 cm are asked to participate in a prospective randomized controlled single-blind parallel-group study. Ureteral stent is always placed after flexible URS. Patients are prospectively randomized into two groups with a 1:1 allocation: group LT receive loop-tail stents (Polaris ™ Loop - Boston Scientific, Natick, USA), while group DJ receive conventional double J stents (Vortek ® - Coloplast, Humlebaek, DK). Stent removal is planned 4 weeks after the procedure. Participants are asked to fill in the Italian validated version of the Ureteral Stent Symptoms Questionnaire (USSQ) 2 days and 4 weeks after surgery. The USSQ is further submitted 4 weeks after stent removal (8 weeks after surgery) and these results are used as baseline evaluation, on the assumption that SRS persist for a few days after removal.

Evaluation of significant differences in USSQ domains' scores adjusted for baseline between the two groups

Inclusion Criteria: patients undergoing flexible ureteroscopy and laser lithotripsy for kidney stones < 2 cm given informed consent WHO PS 0-2 Exclusion Criteria: significant residual fragments at the end of the procedure intraoperative complications (i.e. ureteral damage or ureteral stricture) urinary tract infections anatomic abnormalities chronic diseases or medications potentially influencing pain perception and urinary symptoms (i.e. alpha blockers and antimuscarinics) preoperative ureteral stenting.