Mirabegron administration for the prevention of ureteral injuries during ureteral access sheath insertion

PURPOSE: Urolithiasis is a common condition in urological practice. Retrograde intrarenal surgery (RIRS) is widely accepted as a safe and effective treatment modality. However, acute ureteral injuries during ureteral access sheath (UAS) placement remain a significant concern. Although beta-adrenergic receptors have been identified in the ureteral wall, studies investigating beta-agonists for ureteral protection are lacking. This study aimed to assess whether short-term preoperative administration of mirabegron, a beta-3 adrenoreceptor agonist, can reduce the incidence of UAS-related ureteral injuries during RIRS. METHODS: In this prospective non-randomized study, 60 patients undergoing RIRS were enrolled. Allocation was based on clinical indications due to ethical considerations: 30 patients with existing overactive bladder symptoms received preoperative mirabegron, while 30 patients served as controls. Baseline characteristics were comparable between the groups. Ureteral injuries were assessed endoscopically and graded using the Post-Ureteroscopic Lesion Scale (PULS). RESULTS: The mirabegron group showed a lower incidence of high-grade ureteral injuries compared to the control group, but the difference was not statistically significant (p = 0.123). No adverse events related to mirabegron were reported. Limitations include the lack of randomization, modest sample size, and single-center design. CONCLUSIONS: Short-term preoperative mirabegron use appears to be safe. While our results suggest a potential trend towards reducing high-grade ureteral injuries, this did not reach statistical significance, likely due to the limited sample size of this preliminary cohort. Further large-scale, multicenter studies with longer follow-up are necessary to confirm these findings.