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

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.