Prospective randomized controlled trial comparing a ureteral stent crossing versus not crossing the bladder midline

PURPOSE: To evaluate the correlation between the position of a ureteral stent and stent-related symptoms in a single-center randomized study. METHODS: A total of 113 patients who required ureteral stent placement after lithotripsy were randomized at a 1:1 ratio into groups with stents crossing and not crossing the bladder midline. The ureteral stent remained in place until postoperative day 14, when we obtained each patient’s International Prostate Symptom Score (IPSS), overactive bladder symptom score (OABSS), and visual analog scale (VAS) pain score. RESULTS: Comparing changes from baseline IPSS and OABSS scores between the two groups, the midline crossing group had a worse OABSS total score than the not crossing group (3.0 ± 2.8 vs. 2.0 ± 3.3; p = 0.032). There was no significant difference between the crossing and not crossing groups in IPSS total score (6.8 ± 7.6 vs. 5.1 ± 8.5; p = 0.14). The OABSS urgency mean score was significantly lower in the not crossing than in the crossing group (1.1 ± 1.8 vs. 1.6 ± 1.8; p = 0.042). However, there was no significant difference between groups for remaining items of the IPSS and OABSS and the mean VAS total pain score (1.9 ± 2.7 vs. 1.2 ± 1.9; p = 0.14). CONCLUSION: A ureteral stent that crossed the bladder midline led to worse urinary symptoms. Choosing the appropriate stent length for each patient is important to minimize stent-related symptoms. TRIAL REGISTRATION DATE: 1 October 2018; number: UMIN000034067. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00345-022-03978-5.