Size does matter: ureteral stents with a smaller diameter show advantages regarding urinary symptoms, pain levels and general health

Pain management in percutaneous nephrolithotomy - an approach rooted in pathophysiology

Pain related to percutaneous nephrolithotomy (PCNL) is multifactorial and poorly elucidated. However, understanding the pathophysiology of pain can enable a practical approach to pain management, which can be tailored to each patient. A number of potential mechanisms underlie pain perception in PCNL, and these mechanisms can be leveraged at various points on the perioperative care pathway. These interventions provide opportunities for modulation of pain associated with PCNL but must take into account various technical, pharmacological and patient-related considerations. Technical considerations include the influence of percutaneous access, stone removal and drainage techniques. Pharmacological aspects include the use of various analgesics and anaesthesia approaches. Patient factors include consideration of the biopsychosocial model in pain experience to understand each individual's response to pain. By understanding the contemporary evidence surrounding the physiology of postoperative pain and identifying tangible intervention points, we can seek to mitigate postoperative pain in patients undergoing PCNL.

Effect of indwelling ureteral stents on sexual function: a real-world observational study

BACKGROUND

Ureteral DJ stents are commonly used devices in urology. However, stent placement may cause LUTS and affect the quality of life. We evaluated the direct relationship between ureteral stents and sexual function.

METHODS

From October 2022 to December 2023, 82 male and 90 female sexually active patients who underwent ureteroscopy at Beijing Tiantan Hospital, Capital Medical University, were enrolled. The basic information, surgical data, and two questionnaire data including the International Index of Erectile Function-5 and the Female Sexual Function Index of patients before the operation (baseline, T0), on the day of the ureteral DJ tube extraction (T1), and 4 weeks after ureteral DJ tube extraction (T2) were collected to analyze the changes in the patients' sexual function.

RESULTS

The average age of male patients was 36 years and of female patients 39 years. Before the ureteral DJ stent placement, the mean ± SD IIEF-5 score was 22.86 ± 0.91, and the average FSFI score was 31.66 ± 1.44. On the day of the ureteral DJ stent removal, the IIEF-5 score was 16.37 ± 2.62 (p < 0.01) and the FSFI score was 15.83 ± 4.05 (p < 0.01). Four weeks after ureteral DJ stent removal, the average IIEF-5 score was 22.77 ± 1.06 (p = 0.61) and the average FSFI score was 30.99 ± 1.79 (p = 0.78).

CONCLUSIONS

Indwelling ureteral stents after ureteroscopy can temporarily affect the sexual function of both male and female patients, typically recovering within 4 weeks after stent removal.

Does coiling of the proximal end of the ureteral stent affect stent-related symptoms?

OBJECTIVE

To evaluate the impact of coiling of the proximal end of the ureteral stent on stent-related symptoms (SRS) in in subgroup of patients undergoing preoperative ureteral stenting preceding flexible retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

We performed a prospective comparative study including patients undergoing stent placement 7-10 days prior to RIRS. Patients were divided into 2 groups; in Group 1 coiling of proximal end of the DJ was present, while in Group 2 coiling was absent. Bladder pain, flank pain, hematuria, urgency, frequency, nocturia, and urge incontinence were evaluated on the day of surgery using Visual Analog Score (VAS).

RESULTS

In total, 81 patients, 45 males (55.6%) and 36 (44.4%) females were included. Patients in Group 2 had statistically significant severe representation of flank (43.2% vs. 22.7%, p-value = 0.049) and bladder pain compared to Group 1 (48.4% vs. 25.0%, p-value = 0.027). Additionally, they required analgesic medications more frequently (64.9% vs. 34.1%, p-value = 0.006), and experienced significantly more pronounced frequency (p-value = 0.012) and urgency (2.7 vs. 2.1, p-value = 0.033) compared to Group 1. Patients in group 1 recovered from their symptoms more frequently (52.3% vs. 29.7%, p-value = 0.041), occurring on day 4 and 5 following ureteral stenting.

CONCLUSION

Coiling of the proximal end of the DJ stent impacts stent-related symptoms significantly. Better outcomes of post-procedural frequency, urgency, bladder and flank pain were observed in patients in whom coiling was achieved. Moreover, those patients reported faster recovery from SRSs.

Stent Syndrome: Does the Diameter Matter? Results of a Randomized Trial

Introduction: Double-J (DJ) ureteral stents are used for multiple purposes in urology. Even though they temporize the subsequent treatment of lithiasis, they may cause different symptoms that impact quality of life (QoL). Purpose: In this randomized trial, we assessed whether the diameter of ureteral stents has an impact on catheter-associated symptoms, and their impact on QoL. Methods: A total of 194 consecutive patients undergoing DJ insertion between December 2018 and December 2022 were prospectively enrolled and divided into three categories: 4.7F (Group 1, n = 71), 6F (Group 2, n = 65), and 7F (Group 3, n = 58). Within 1 week after the DJ placement, patients completed the validated Spanish version of the Ureteral Stent Symptoms Questionnaire. Continuous variables were compared using analysis of variance and Student's t-tests. For categorical data, the chi-square test was used. Results: In the domain of "work" and "additional problems," there were significant differences. In the "Work" domain, Group 1 presented the lower symptoms. In the domain "additional problems," patients in Group 1 were prescribed fewer antibiotics owing to low urinary tract symptoms. In question U4 about urinary incontinence, patients in Groups 2 and 3 developed these symptoms more than patients in Group 1. In the "sexual activity" domain, specifically in question S3 (the patient has ever suffered any type of pain during sexual activity?), patients with 4.7F presented lower scores than patients with larger catheters. Conclusion: DJ-related symptoms affect QoL in most cases. Smaller catheters produced significantly less urinary incontinence, faster work reincorporation, fewer symptoms related to sexual activity, and fewer catheter-related symptoms than 7F catheters. In contrast, Group 3 presented fewer outpatient visits because of symptoms related to the DJ.

Outcomes following Exchange and Upsizing of Malfunctioning Small-Caliber Double-J Ureteral Stents

PURPOSE

To determine the effectiveness of exchange and upsizing of malfunctioning small-caliber double-J (JJ) ureteral stents.

MATERIALS AND METHODS

Thirty-one patients with malfunctioning cystoscopically placed small-caliber (6 or 7 F) JJ stents underwent transurethral (n = 28) or transrenal (n = 3) exchange and upsizing to a large-caliber (10 F) JJ stent from 2013 to 2022. Ureteral obstruction was malignant in 20 patients (65%) and benign in 11 (35%). Fifteen patients (48%) presented with persistent hydroureteronephrosis and 16 patients (52%) with worsening hydronephrosis. Acute kidney injury (AKI) was present in 19 patients (61%) at the time of stent malfunction. Therapeutic success was defined as resolution of hydronephrosis and AKI, if present.

RESULTS

JJ stent exchange and upsizing was technically successful in 31 patients (100%) with no immediate adverse events. Therapeutic success was achieved in 27 patients (87%). During follow-up (median, 97 days; IQR, 32-205 days), 2 patients who initially achieved therapeutic success had stent malfunction, requiring conversion to percutaneous nephrostomy drainage (2/27, 7%).

CONCLUSIONS

Exchange and upsizing to large-caliber JJ stents can relieve urinary obstruction and resolve AKI in patients with malfunctioning small-caliber JJ stents. Large-caliber JJ stents should be considered as a salvage option for patients who wish to continue internal drainage and avoid percutaneous nephrostomy.

Development and Validation of a Model to Predict Ureteral Stent Placement Following Ureteroscopy: Results From a Statewide Collaborative

OBJECTIVE

To develop and validate a model to predict whether patients undergoing ureteroscopy (URS) will receive a stent.

METHODS

Using registry data obtained from the Michigan Urological Surgery Improvement Collaborative Reducing Operative Complications from Kidney Stones initiative, we identified patients undergoing URS from 2016 to 2020. We used patients' age, sex, body mass index, size and location of the largest stone, current stent in place, history of any kidney stone procedure, procedure type, and acuity to fit a multivariable logistic regression model to a derivation cohort consisting of a random two-thirds of episodes. Model discrimination and calibration were evaluated in the validation cohort. A sensitivity analysis examined urologist variation using generalized mixed-effect models.

RESULTS

We identified 15,048 URS procedures, of which 11,471 (76%) had ureteral stents placed. Older age, male sex, larger stone size, the largest stone being in the ureteropelvic junction, no prior stone surgery, no stent in place, a planned procedure type of laser lithotripsy, and urgent procedure were associated with a higher risk of stent placement. The model achieved an area under the receiver operating characteristic curve of 0.69 (95% CI 0.67, 0.71). Incorporating urologist-level variation improved the area under the receiver operating characteristic curve to 0.83 (95% CI 0.82, 0.84).

CONCLUSION

Using a large clinical registry, we developed a multivariable regression model to predict ureteral stent placement following URS. Though well-calibrated, the model had modest discrimination due to heterogeneity in practice patterns in stent placement across urologists.

Modified endoluminal ureteral stenting for the management of proximal ureteral obstruction in two cats

Case series summary

Two cases of placement of modified endoluminal ureteral stents are described, for revision of a subcutaneous ureteral bypass (SUB) and for primary treatment of obstructive ureterolithiasis. Modified endoluminal stents were inserted through the ureterotomy, anchored in the renal pelvis with a single pigtail and shortened to a length sufficient to span the proximal ureter and ureterotomy site.

Relevance and novel information

The advantages of this approach as a surgical option for feline obstructive ureterolithiasis are demonstrated, including the avoidance of disruption, or bypass, of the ureterovesicular junction, minimisation of implanted foreign material and avoidance of intravesicular stent mass, maintenance of the physiological route of urine flow, including preservation of active distal ureteral function, and limitation of the potential complications of ureterotomy. The clinical efficacy of this adaptation of the previously published endoluminal stenting technique is demonstrated with its applicability de novo and in the revision of other stenting procedures.

Effect of ureteral stent length and implantation position on migration after implantation

BACKGROUND

Ureteral obstruction is a urinary system disease that causes urinary retention, renal injury, renal colic, and infection. Ureteral stents are often used for conservative treatment in clinics, and their migration usually results in ureteral stent failure. The migrations include proximal migration to the kidney side and distal migration to the bladder side, but the biomechanism of stent migration is still unknown.

METHOD

Finite element models of stents with lengths from 6-30 cm were developed. The stents were implanted into the middle of the ureter to analyze the effect of stent length on its migration, and the effect of stent implantation position on 6-cm-long stent migration was also observed. The stents' maximum axial displacement was used to assess the ease of stent migration. A time-varying pressure was applied to the ureter outer wall to simulate peristalsis. The stent and ureter adopted friction contact conditions. The two ends of the ureter were fixed. The radial displacement of the ureter was used to evaluate the effect of the stent on peristalsis.

RESULTS AND DISCUSSION

The maximum migration occurs in the positive direction for a 6-cm-long stent implanted at the proximal ureter (CD and DE), but in the negative direction at the distal ureter (FG and GH). The 6-cm-long stent demonstrated almost no effect on ureteral peristalsis. The 12-cm-long stent diminished the radial displacement of the ureter from 3-5 s. The 18-cm stent diminished the radial displacement of the ureter from 0-8 s, and the radial displacement within 2-6 s was weaker than other time. The 24-cm stent diminished the radial displacement of the ureter from 0-8 s, and the radial displacement within 1-7 s was weaker than other time.

CONCLUSION

The biomechanism of stent migration and ureteral peristalsis weakening after stent implantation was explored. Shorter stents were more likely to migrate. The implantation position had less influence on ureteral peristalsis compared with the stent length, which provided a reference for stent design aimed at reducing stent migration. Stent length was the main factor affecting ureteral peristalsis. This study provides a reference for the study of ureteral peristalsis.

Can ureteral stents with a different format reduce patients' symptomatology? A single-blinded, randomized, controlled study comparing smooth-walled and grooved ureteral stents

INTRODUCTION

The true benefits of perioperative JJ stent placement are being widely studied due to its known side effects. However, no consensus has been reached in the literature regarding the best type of stent. This prospective, randomized, single-blinded study therefore aimed to compare the symptomatology associated with two JJ stent designs: smooth-walled and grooved.

MATERIALS AND METHODS

The study prospectively recruited 42 patients who underwent JJ stent placement between July 2019 and August 2020. The patients were randomly divided into two groups according to the JJ stent design used: the smooth-walled stent (control) and grooved stent (intervention) groups. After surgery, all patients completed the Portuguese-validated Ureteral Stent Symptom Questionnaire at three timepoints (days 7 and 30 post-surgical procedure, and day 30 post-stent removal).

RESULTS

No significant differences in gender, age, median body mass index, laterality, type of surgical procedure (flexible, semi-rigid or mixed ureteroscopy) were found. Smooth-walled JJ stents were associated with a higher incidence of flank pain (52.38% vs. 10%, P = .006) and suprapubic pain (57.14% vs. 30%, P = .04) on the 7th post-procedure day. Linear mixed regression showed significantly lower flank (P < .001) and suprapubic pain (P < .01), and significantly better sexual performance in the intervention group (P = .03).

CONCLUSIONS

Ureteral stent with a grooved format are associated with a lower incidence of flank and suprapubic pain and had less impact on the sexual performance of patients.

Magnetic resonance imaging of in vitro urine flow in single and tandem stented ureters subject to extrinsic ureteral obstruction

OBJECTIVE

To quantify the relative volumetric flows in stent and ureter lumina, as a function of stent size and configuration, in both unobstructed and externally obstructed stented ureters.

METHODS

Magnetic resonance imaging was used to measure flow in stented ureters using a phantom kidney model. Volumetric flow in the stent and ureter lumina were determined along the stented ureters, for each of four single stent sizes (4.8F, 6F, 7F, and 8F), and for tandem (6F and 7F) configurations. Measurements were made in the presence of a fully encircling extrinsic ureteral obstruction as well as in benchmark cases with no extrinsic ureteral obstruction.

RESULTS

Under no obstruction, the relative contribution of urine flow in single stents is 1-10%, while the relative contributions to flow are ~6 and ~28% for tandem 6F and 7F, respectively. In the presence of an extrinsic ureteral obstruction and single stents, all urine passes within the stent lumen near the extrinsic ureteral obstruction. For tandem 6F and 7F stents under extrinsic ureteral obstruction, relative volumetric flows in the two stent lumina are ~73% and ~81%, respectively, with the remainder passing through the ureter lumen.

CONCLUSIONS

Magnetic resonance imaging demonstrates that with no extrinsic ureteral obstruction, minimal urine flow occurs within a stent. Stent lumen flow is significant in the presence of extrinsic ureteral obstruction, in the vicinity of the extrinsic ureteral obstruction. For tandem stents subjected to extrinsic ureteral obstruction, urine flow also occurs in the ureter lumen between the stents, which can reduce the likelihood of kidney failure even in the case of both stent lumina being occluded.

Randomized controlled trial of NSAID prior to cystoscopic ureteral stent removal in a pediatric population

INTRODUCTION

Ureteral spasm, common with ureteral stents, is partially mediated by prostaglandins and may be suppressed by cyclooxygenase inhibitors like non-steroidal anti-inflammatory (NSAIDs). Practices currently vary widely for pain management in patients with ureteral stents, sometimes including opioids.

OBJECTIVE

We aimed to determine if NSAID given prior to stent removal would reduce postoperative pain. We hypothesized there would be at least a 75% reduction in postoperative severe pain (pain score ≥7) in patients receiving ibuprofen compared to placebo.

STUDY DESIGN

We performed a double-blind, placebo-controlled randomized controlled trial on pediatric urology patients with an indwelling ureteral stent undergoing removal in the operating room from 2014 to 2019. 20 patients in each arm were needed to achieve 80% power to detect a 75% reduction in the estimated 55% incidence of severe postoperative pain (α = 0.05). Patients ≥4 years old who had a unilateral stent placed after treatment of urolithiasis or ureteropelvic junction obstruction were randomized to NSAID or placebo in a 1:1 ratio at least 15 min prior to scheduled stent removal. Patients estimated pain using Faces Pain Scale-Revised (FPS-R) or visual analogue scale (VAS) prior to and 24 h after stent removal.

RESULTS

254 patients undergoing stent removal were assessed for eligibility, and 44 randomized patients were analyzed using intention to treat analysis. The cohorts were demographically similar and received similar anesthesia treatment. There was no significant difference in maximum post anesthesia care unit pain score (p = 0.269) or use of in-hospital opioids (p = 0.626) between the two groups. No difference was seen in the incidence of severe postoperative pain (p = 1.0), thus rejecting the hypothesis. Significant worsened postoperative pain (pain score increases of ≥2 between time points) decreased from 22.7% to 13.6% between placebo and NSAID, but this did not reach significance (p = 0.410).

DISCUSSION

There was no difference in postoperative pain for patients undergoing ureteral stent removal given preoperative NSAID versus placebo. The incidence of severe pain before and after stent removal was low, ranging from 4.5 to 9.1%.

CONCLUSION

Research to understand the etiology of pain after stent removal and techniques to minimize or prevent discomfort should continue in order to optimize patient outcomes.

Translation and Validation of the Ureteral Stent Symptoms Questionnaire in Urdu

Introduction

In endourology, ureteric stenting is a common procedure, and stent placement is not without adverse health consequences. A ureteric stent symptoms questionnaire (USSQ) was devised to objectively evaluate the symptoms related to it. The original questionnaire is in English and translated into various languages worldwide. We translated the questionnaire into Urdu and validated it in an Urdu-speaking population with a stent in situ.

Materials and methods

The English version of USSQ was translated and back-translated by experts in both languages. Content validity was checked by sending Urdu version to five experts, and their scores were used to calculate the content validity index. The final version was filled by patients with stents on three different occasions, two with stents in situ at one and two weeks post stent placement, and a third time two weeks after stent removal. Discriminant validity was checked by filling of USSQ by 64 healthy individuals. Statistical analysis was done with mean and standard deviation, Cronbach’s alpha, Spearman’s coefficient, and paired sample t-test.

Results

A total of 64 patients filled the complete questionnaire at all times with mean age of 35.31 ± 8.853. All subdomains of USSQ have significant drop in scores with stent in situ in comparison to post stent removal. Reliability was checked by Cronbach’s alpha in all subdomains (71.5-91.1) and test-retest reliability by Spearman’s coefficient (80.5-94.7). Symptoms change in stent in situ with post stent removal checked with paired sample t-test with a p-value of <0.005 in all domains, except body pain. Discriminant validity was checked with healthy controls, and a p-value of <0.005 was found in all subdomains of USSQ, except pain. 

Conclusion

The Urdu version of the USSQ is a reliable and valid instrument that can be used in clinical practice and future research in an Urdu-speaking population.

Drainage of infected kidneys with ureteral stents: does size matter?

PURPOSE

The purpose of our study was to evaluate the ability of ureteral stents with different diameters to drain pus that accumulates in an obstructed kidney using an in vitro model.

METHODS

We developed an in vitro model of an obstructed kidney filled with pus. The model included a silicon kidney unit based on computed tomography (CT) data, a 3D printed ureteral stone based on a real extracted ureteral stone, a latex ureter model, a bladder vessel, and a fluid with qualities resembling pus. Identical printed stones were inserted into four ureter models containing stents with varying diameters (4.8F, 6F, 7F, 8F), each of which was connected to the kidney unit and the bladder vessel. The kidney unit was filled with artificial pus to pressures of 30 cmH₂O to simulate an infected and obstructed kidney. The obstruction was relieved with stents in place, while artificial urine was pumped into the kidney; pressure in the kidney and remaining pus were measured continuously.

RESULTS

The rate of pressure drop and the final pressure measured in the kidney were unaffected by the diameter of the stent. For all stent diameters, the pressure reached non-obstructed levels within 30 s, final pressure was reached within 90-120 s, and minimal amounts of pus remained in the kidney after 120 min.

CONCLUSIONS

In vitro experiments demonstrate that all stent diameters drain pus-filled, obstructed kidneys with the same efficacy. The common perception that larger diameter tubes are more effective under such circumstances should be re-examined.

Patients’ life quality during ureterorenoscopy, ureterorenoscopy plus JJ insertion and shock wave lithotripsy in the management of distal ureteral stone: a prospective clinical study

Background

To clarify the effects of ureterorenoscopy (URS) and shock wave lithotripsy (SWL) on patients’ life quality in the management of distal ureteral stone (DUS) with using Short Form 36 (SF 36).

Methods

The present study was conducted in a prospective manner between July 2018 and July 2021. Patients who had DUS stone smaller than 1.5 cm were accepted as candidates for the study. Preoperative patient characteristics and treatment outcomes were recorded. Also, the SF-36 form was completed one day before the procedure and one month after the procedure. Patients were divided into three groups according to treatment modality as SWL, only URS, and URS including JJ stent insertion.

Results

Totally, 44 patients were treated with SWL, 27 patients were treated with URS, and 31 patients were treated with URS including JJ insertion. Hospitalisation period was significantly shorter in the SWL group (p = 0.001). Additionally, patients treated with SWL had a significantly lower analgesia requirement rate (31.8% in SWL group, 77.8% in URS group and 64.5% in URS + JJ stent group, p = 0.001). Stone-free status and complications did not significantly differ between groups (p = 0.846 and p = 0.096). Physical functioning score and role physical domains were significantly increased in patients treated with SWL (p = 0.005 and p = 0.031). Similarly, highest improvement for the body pain domain was achieved in the SWL group (p = 0.006).

Conclusion

The present study showed that URS, URS with JJ insertion and SWL are safe and reliable procedures for the management of DUS. However, hospitalisation time was significantly shorter and analgesia requirements were significantly lower in favour of SWL. Additionally, SWL was related with better SF-36 domains including physical functioning, role physical and body pain.

Are All Stent Bearers Equal? Ureteral Stent Symptoms in Kidney Transplant Patients: A Case-Control Prospective Study

Purpose: The aim of this study is to conduct a prospective, controlled single-center study to determine the prevalence and types of ureteral stent symptoms in kidney transplant (KTx) recipients and compare them with nontransplant subjects. Materials and Methods: From December 2012 to June 2019, a total of 102 patients having undergone a KTx and Double-J stent (DJS) placement and 88 patients having undergone endourological lithotripsy and DJS placement were enrolled. The Ureteral Stent Symptom Questionnaire (USSQ) was administered to patients with a median of 25 (KTx) and 31 (urolithiasis) days after stent placement. USSQ scores were used to compare symptoms between the two groups. Results: Of the 190 patients enrolled, 88 belonged to the lithotripsy group (control group) and 102 to the KTx recipients' group. Mean score for urinary symptoms was 21.42 for KTx patients vs 27.53 for control patients with statistical significance (p < 0.001, CI -7.792 to -4.433). The visual analog scale, overall bother, pain at voiding, flank pain at voiding, and frequency of painkiller use scores were significantly higher for control patients than for KTx patients (p = 0.024, <0.001, <0.001, <0.001, and 0.014, respectively). Frequency of rest, changes in work duration, work domain score, suspicion of urinary tract infection (UTI), and need for professional assistance scores were significantly lower for KTx patients than the control. There were no significant differences in general health and sexual domains between groups. Conclusions: KTx recipients have significantly fewer urinary symptoms, pain, work-related disturbances, suspected UTIs, and hospitalizations associated with stent placement than urolithiasis patients.

Impact of differential ureteral stent diameters on clinical outcomes after ureteroscopy intracorporeal lithotripsy: A systematic review and meta-analysis

In this meta-analysis we assessed whether the diameter of ureteral stents (4.7-5-Fr, 6-Fr) has an impact on the rate of occurrence of urinary tract symptoms and complications after successful URS and intracorporeal lithotripsy. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A rigorous search for relevant studies published in MEDLINE, Embase, and the Cochrane Controlled Trials Register was conducted to find informative randomized controlled trials. The reference lists of relevant articles were also manually searched and reviewed. The protocol was prospectively registered at PROSPERO (CRD42020202164). All statistical evaluations were performed using RevMan software version 5.3.0. Seven articles comprising 547 patients were included in the meta-analysis. After placement of ureteral stents with different diameters for approximately 1 week, we found that ureteral stents with smaller diameters (4.7-5-Fr) were associated with significant improvements in the main domain scores on the Ureteral Stent Symptom Questionnaire, such as urinary symptoms (mean difference -4.47, 95% confidence interval -5.87 to -3.08; P < 0.00001) and body pain (mean difference -2.48, 95% confidence interval -4.37 to -0.59; P = 0.01), but poor outcomes in stent migration compared to ureteral stents with a 6-Fr diameter (odds ratio 3.00, 95% confidence interval 1.06-8.51; P = 0.04). However, there were no significant differences in Ureteral Stent Symptom Questionnaire scores with regard to work performance (mean difference -0.56, 95% confidence interval -2.52 to 1.40; P = 0.58), general health (mean difference -2.29, 95% confidence interval -4.95 to 0.37; P = 0.09), additional problems (mean difference -0.43, 95% confidence interval -1.02 to 0.15; P = 0.15), and complications such as fever (odds ratio 0.75, 95% confidence interval 0.24-2.39; P = 0.63). Ureteral stents with a diameter of 4.7-5-Fr have better outcomes than those with a diameter of 6-Fr, based on the Ureteral Stent Symptom Questionnaire pain and urinary tract symptoms scores. However, they are more prone to migration compared to those with a larger diameter.

Preoperative estimate of natural ureteral length based on computed tomography and/or plain radiography

To predict natural ureter lengths based on clinical images. We reviewed our image database of patients who underwent multiphasic computed tomography urography from January 2019 to April 2020. Natural ureteral length (UL_CTU) was measured using a three-dimensional curved multiplanar reformation technique. Patient parameters including age, height, and height of the lumbar spine, the index of ureteral length using kidney/ureter/bladder (KUB) radiographs (C-P and C-PS) and computed tomography (UL_CT) were collected. UL_CTU correlated most strongly with UL_CT. R square and adjusted R square values from multivariate regression were 0.686 and 0.678 (left side) and 0.516 and 0.503 (right side), respectively. UL_CTU could be estimated by the regression model in three different scenarios as follows:

UL_CT + C-P

UL_CTUL = 0.405 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× UL_CTL\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$+$$\end{document}+ 0.626 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× C-P_L – 0.508 cm

UL_CTUR = 0.558 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× UL_CTR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$+$$\end{document}+ 0.218 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× C-P_R + 6.533 cm

UL_CT

UL_CTUL = 0.876 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× UL_CTL\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$+$$\end{document}+ 6.337 cm

UL_CTUR = 0.710 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× UL_CTR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$+$$\end{document}+ 9.625 cm

C-P

UL_CTUL = 0.678 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× C-P_L\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$+$$\end{document}+ 4.836 cm

UL_CTUR = 0.495 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document}× C-P_R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$+$$\end{document}+ 10.353 cm

We provide equations to predict UL_CTU based on CT, KUB or CT plus KUB for different clinical scenarios. The formula based on CT plus KUB provided the most accurate estimation, while the others had lower validation values but could still meet clinical needs.

Effects of mirabegron on JJ stent-related symptoms: A multicentric study

AIMS OF THE STUDY

To investigate the effect of mirabegron 50 mg/daily for JJ stent-related symptoms after ureteroscopic stone surgery.

METHODS

Medical records of 145 patients who were given a single daily oral dose of 50 mg of mirabegron for relieving stent-related symptoms were retrospectively analysed. Demographic and clinical data and stone parameters were recorded. All participants completed the Turkish version of the Ureter Symptom Score Questionnaire (USSQ-T) on the postoperative 7th day, and again after at least 3 weeks, before JJ stent removal. The severity of stent-related symptoms was statistically compared before and after the mirabegron treatment.

RESULTS

The mean urinary symptoms score decreased significantly from 30.87 ± 9.43 to 22.61 ± 6.78 (P < .0001), mean body pain score decreased significantly from 21.82 ± 11.22 to 14.03 ± 7.52 (P < .0001), mean work performance score decreased from 10.50 ± 8.61 to 7.02 ± 6.51 (P < .0001) and mean general health score decreased significantly from 15.43 ± 6.50 to 11.12 ± 3.70 (P < .0001). The mean sexual matters score significantly decreased from 3.88 ± 3.40 to 2.48 ± 2.03 (P < .0001), the additional problem score decreased from 9.31 ± 4.61 to 6.51 ± 2.83 (P < .0001) and the overall quality of life (QoL) score decreased from 5.18 ± 1.94 to 4.23 ± 1.71 after mirabegron use (P < .0001).

CONCLUSION

Daily use of 50 g of mirabegron significantly improved stent-related symptoms, sexual matters and quality of life.

Comparison of the Effects of Four Treatment Techniques Commonly Used in Ureteral Stone Treatment on Patients' Daily Physical Functioning: An Observational Randomized-Controlled Study

Objective: To investigate the effect of four different techniques used in the treatment of ureteral stones on patients' daily physical functioning (PF) and quality of life (QoL). Materials and Methods: Patients who underwent ureterorenoscopy (URS)-with or without Double-J stenting (DJS)-and extracorporeal shock wave lithotripsy (SWL) were divided into four groups: Group I: SWL (n = 29), Group II: URS (n = 43), Group III: URS +4.8F DJS (n = 39), Group IV: URS +6F DJS (n = 42), and Group V: Control (n = 30). Short Form-36 (SF-36) was administered to each participant both preoperatively and 14 days after operation. Based on the SF-36 results, the changes in patients' PF and QoL were evaluated. Results: Ureteral stone treatment was performed in 202 patients. Of these, 153 patients who underwent an effective SWL or URS procedure in the first attempt were included in the study. Success rates in the first session were 53.7% (29/54) and 83.8% (124/148) for SWL and URS, respectively (p < 0.001). All the four groups were similar with regard to age, gender, body mass index, stone size, preoperative PF, and QoL. However, although postoperative PF, role limitations due to physical health, and energy/fatigue scores were similar in Group I, III, and IV, they were significantly higher in Group II. No major complication associated with SWL or URS occurred in any patient. However, in Group 2, DJS was inserted in three (7.7%) patients in the early postoperative period (within the first 48 hours) due to renal colic attacks secondary to ureterovesical junction mucosal edema. Conclusion: URS without DJS seems to be the most advantageous technique in the treatment of ureteral stones in terms of daily PF and QoL. However, it should be noted that patients undergoing URS may require postoperative emergency stenting, although rarely.

Surface analysis of ureteral stent before and after implantation in the bodies of child patients

The aim of this work was to determine which part of a double-J ureteral stent (DJ stents) showed the highest tendency to crystal, calculi, and biofilm deposition after ureterorenoscopic-lithotripsy procedure (URS-L) to treat calcium oxalate stones. Additionally, the mechanical strength and the stiffness of DJ stents were evaluated before and after exposure to urine. Obtained results indicated that the proximal (renal pelvis) and distal (urinary bladder) part is the most susceptible for post-URS-L fragments and urea salt deposition. Both, the outer and inner surfaces of the DJ ureteral stents were completely covered even after 7 days of implantation. Encrustation of DJ stents during a 31-day period results in reducing the Young’s modulus by 27–30%, which confirms the loss of DJ stent elasticity and increased probability of cracks or interruption. Performed analysis pointed to the need to use an antibacterial coating in the above-mentioned part of the ureteral stent to prolong its usage time and to prevent urinary tract infection.

Histological Inflammation in Human Ureter either Healthy or Fitted with Double-Pigtail Stent or a Thin 0.3 F Suture Thread: A Preliminary Study

Background

Ureteral stent intolerance reduces patients' quality of life. It has been suggested that changes in the shape of stents could decrease discomfort. In previous studies, the innovative pigtail-suture stent (i.e., JFil® or MiniJFil®) with a thin 0.3 F suture thread significantly decreased stent-related symptoms. Fortuitously, a dilation of the ureter containing the sutures was discovered. In addition, no inflammation was seen on the ureter wall around the suture in endoscopy. In this preliminary study, we assessed ureteral inflammation in the human ureter when it was healthy or when fitted with a double-pigtail stent or a thread.

Materials and Methods

After consent and inclusion of patients in the protocol, fifteen segments of ureters were collected during cystectomy procedures for bladder tumors. Ureteral inflammation was assessed on the histological section stained with hematoxylin-eosin. Histological grading (cumulative range of 0 to 6) assessing inflammation was performed on the ureter section for mucosa inflammation and inflammation in the muscle layer.

Results

A marked ureteral inflammatory reaction was observed in all cases of ureters fitted with a double-pigtail stent with a mean inflammation score of 4.8 ± 0.4. The ureter fitted with the thin suture thread showed inflammation in only one case with a mean inflammation score of 1.8 ± 1.3 (p=0.001).

Conclusion

Although the study was limited by the small number of patients, it confirmed that the double-pigtail stent induced ureteral inflammation in all cases and the thin 0.3 F suture thread caused less ureteral inflammation than the double-pigtail stent. The concept of material reduction within the urinary tract seems necessary in order to decrease mucosal irritation. The JFil® or the MiniJFil® thread could meet this requirement.

Indwelling ureteric stents: Patterns of use and nomenclature

Objectives: To evaluate ureteric stenting practice patterns amongst a range of academic and community urologists, and to examine the nomenclature used to identify an indwelling ureteric stent from both our questionnaire and from a review of the literature.

Subjects and methods: A 16-question, peer-reviewed online survey was distributed to members of the Mid-Atlantic American Urological Association. Responses were collected over a 1-month period. Questions included demographics, ureteric stenting practice patterns, and utilization of stenting nomenclature. Inappropriate use of nomenclature was defined as a mismatch between the visually depicted stents and the written description amongst urologists. Trends in ureteric stenting and nomenclature usage were tabulated and analyzed.

Results: Of 863 members, 105 (12.2%) responded to the survey. There was a wide variety of practice settings, with the single-specialty group (44.2%) and academic/university (27.9%) being the two most common. Most providers used both cystoscopy and fluoroscopy to place stents (87.5%) as compared to fluoroscopy alone (12.5%). Most urologists (63.5%) removed stents with cystoscopy as compared to using a stent string (36.5%). While about half (51.0%) of the respondents left stents in situ for ≤3 months, many respondents (43.3%) felt comfortable with maximum dwell times of up to 6 months. The most commonly placed stent was the double pigtail stent (80.8%). However, most respondents inappropriately described this stent design as a Double J stent (72.1%). In the recent literature, 80% of articles clearly defined as using double pigtail stents, incorrectly identified their stent as a ‘Double J’.

Conclusions: Variations in ureteric stenting practice patterns exist amongst community and academic urologists. Although most urologists utilize double pigtail ureteric stents, the majority inaccurately identified this stent design as a Double J. We propose use of the term ‘indwelling ureteric stent’ (IUS) unless describing any specific stent design.

A New Customized Ureteral Stent with Nonrefluxing Silicone End-piece to Alleviate Stent-related Symptoms in Malignant Diseases

OBJECTIVE

To evaluate the stent-related symptoms using a new customized ureteral stent with a nonrefluxing silicone end-piece.

METHODS

By decreasing the amount of material within the bladder, it should be possible to attenuate the stent-related symptoms. To minimize the amount of material, 17 consecutive patients already fitted with a double-pigtail stent for malignant ureteral obstruction agreed to be fitted with a customized stent where the bladder loop was replaced by a nonrefluxing silicone end-piece. The ureteral stent symptom questionnaire was prospectively administered to patients at baseline with double-pigtail stent and Day 15 after customized stent placement.

RESULTS

No difficulty in the placement of the customized stent was encountered. No stent failure, no dislodgment and no calcification were observed 6 months after stenting. The scores for the main domain "Urinary symptoms" (34.4 ± 3.6 vs 23.0 ± 7.0; P = .0004) and the question "Global quality of life" (4.4 ± 2.0 vs 2.4 ± 2.1; P = .01) were significantly decreased by the replacement of the double-pigtail stent by the customized stent.

CONCLUSION

The customized ureteral stent may constitute an improvement in the field of stent-related symptoms and seems fit for use in its current shape. Studies exploring and exploiting new concepts are greatly required to reduce stent-related symptoms in all patients including those with cancer.

Challenges To Attenuate Ureteric Stent-Related Symptoms: Reflections On The Need To Fashion A New Dynamic Stent Design Consequent Upon A Case Report

Double-pigtail stent has been widely used in urology for half a century now, but this device reduces the patient’s quality of life. Moreover, indwelling stent-related symptoms induce additional suffering to the pre-existing bladder disease. Novel concepts to prevent stent-related symptoms are greatly required. It has been suggested that changes in the size, form and stent positioning could ease discomfort. By decreasing the amount of material within the bladder, it should be possible to attenuate the stent-related symptoms. A customized stent has been developed to alleviate bladder symptoms. The major characteristic of this stent was in the replacement of the bladder part of the double-pigtail stent by a nonrefluxing silicone end-piece. Three months after stenting, the patient complained of sudden discomfort in the bladder area. On the X-ray, the end-pieces of the customized stents seemed to have slipped in the bladder. The customized stents were replaced by new ones after truncating and adjusting their lengths to the exact ureteric length and stent-related symptoms were then improved again. In the field of stent-related symptoms, stent mobility needs more attention than its intravesical position. The case hereby reported illustrates the variations of the symptoms which seem related to the stent mobility, the necessary shaping of the stent and, the possible research avenues for an innovative dynamic ureteric stent.