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.