Purpose: To conduct a randomized, controlled, multicenter study that could compare the efficacy and stent-related symptom scores between 5F and 6F ureteral stents after ureteroscopic lithotripsy (URS). Materials and Methods: From September 2017 to April 2018, 110 patients having a unilateral ureteral stent after URS were prospectively enrolled from three different tertiary medical centers. The patients were randomly assigned to a 5F or 6F ureteral stent group. A ureteral stent symptom questionnaire (USSQ) was administered to patients 2 or 3 weeks after stent placement. The USSQs were used to compare body pain and urinary symptom scores between the two groups. Results: There was no statistically significant difference in body pain between the 5F and 6F ureteral stent groups. There was also no difference in analgesic usage between the groups. However, patients with 5F ureteral stents expressed significantly fewer urinary symptoms. Postoperative hydronephrosis was not observed in either group. Conclusions: Ureteral stents are associated with various morbidities and impaired quality of life. This study demonstrated that 5F ureteral stents may cause fewer urinary symptoms when compared with 6F ureteral stents. Therefore, the placement of ureteral stents with smaller diameters may reduce stent-related urinary symptoms.
Keywords: lithotripsy; randomized controlled trial; stents; ureter.