Discussion
In the present study, we showed that mirabegron significantly improved JJ stent-related symptoms. For a long time, ureteral JJ stents have been used in urology practice used to prevent ureteral obstruction. However, stent-related pain and urinary symptoms negatively affect the quality of life in patients with JJ stents after ureteroscopic surgery [6, 16]. Several treatment options have been attributed to overcome these problems, including antimuscarinic agents, alpha-adrenergic receptor antagonists, or combination therapies [10, 11]. Alpha-adrenergic receptor antagonists alleviate the symptoms related to the JJ stent and reduce the use of analgesics [11, 17]. Similarly, mirabegron, a beta-3 receptor agonist, is being used in the treatment of overactive bladder disease, and has also been shown to improve urinary symptoms due to JJ stent insertion [18, 19].
Until recently, non-specific questionnaires such as the International Prostate Symptom Score or Overactive Bladder Symptom Score [18, 20] were used to evaluate the effect of mirabegron use for JJ stent-related symptoms. However, the non-specific nature of these questionnaires undermined the value of these studies. Therefore, in the present study, we used the Turkish-validated USSQ-T questionnaire [7]. In addition, the USSQ was used in only two studies to evaluate the effect of mirabegron for JJ stent-related symptoms. Tae et al. showed that mirabegron slightly lowered the mean urinary symptoms score from 32.58 ± 6.67 to 27.92 ± 7.72 (p = 0.582) [19]. Considering that mirabegron shows its maximum antimuscarinic effect after three weeks, a clinically insignificant decrease in mean urinary symptoms score can be explained by the fact that mirabegron was only used for two weeks in that study [19]. Yavuz et al. reported the results of 180 patients regarding the changes on the ureteral stent symptom questionnaire four weeks after ureterolithotripsy plus ureteral stenting. They randomized the patients into three groups receiving placebo, tamsulosin, and mirabegron (50 mg) once a day and found similar rates of urinary symptoms scores between the mirabegron and control patients (27.8 vs 24.5, p = 0.423) [21]. In contrast to that study, we compared the impact of mirabegron on changes of urinary symptoms scores in patients between postoperative first visit and at least four weeks after surgery. For the first time in the literature, we showed that mirabegron monotherapy significantly decreased the SRS compared to pretreatment levels.
In addition to an increased rate of SRS, patients with a JJ stent may also suffer from stent-related pain [22]. Although the mechanism of urinary symptoms and pain has not been exactly defined yet, ureteric spasm, trigonal irritation, and urinary reflux to the renal pelvis may play a role [23]. Trigonal irritation provokes detrusor contractions mediated by muscarinic receptors. Antimuscarinics alone or in combination with an alpha-receptor antagonist have been reported to be effective for SRS reduction [10, 11]. Recent meta-analyses have demonstrated that antimuscarinic monotherapy reduces the SRS and body pain scores [11, 24, 25]. Several reports showed that all subtypes of beta-adrenergic receptors were expressed in the human ureteral smooth muscle [26, 27], and use of beta-1 and beta-3 agonists might help to reduce symptoms secondary to ureteral smooth muscle spasm [18]. In a recent study, mirabegron monotherapy was shown to reduce the USSQ body pain score and the overall pain score compared to the control group [19]. In accordance with the literature, this present study showed that JJ stent placement increased patients’ pain score, and mirabegron monotherapy significantly reduced the stent-related pain score.
Ureteral stenting causes stent-related sexual dysfunction in both genders [3, 28]. Joshi et al. also reported that sexual dysfunction was observed in 38% and work performance was negatively affected in 58% of ureteral stent patients [22]. Deliveliotis et al. showed that alfuzosin, an alpha-adrenergic receptor blocker, improved SRS and sexual function [29]. Another study showed that a tamsulosin and oxybutynin combination restored the work performance, additional problems, and general health scores [30]. In accordance with these studies, our results showed that mirabegron use significantly reversed JJ stent-related decreased work performance and sexual dysfunction, and increased quality of life.
This present study has some limitations:
1. Retrospective design of the study.
2. Lack of a control group.