Determining the Appropriate Length of a Double-Pigtail Ureteral Stent by Both Stent Configurations and Related Symptoms

Outcomes of a non-randomised audit of single pigtail suture stents in urolithiasis management of Asian patients in Singapore

Objective

Double-J (DJ) ureteric stents are commonly placed perioperatively for semirigid or flexible ureteroscopic renal surgery. It is believed that lesser stent material within the bladder mitigates stent-related symptoms. This study aimed to evaluate the J-Fil ureteral stent, a single pigtail suture stent compared with conventional DJ stent in relation to stent symptoms in an Asian population undergoing ureterorenal intervention.

Methods

Based on internal audit committee recommendation approval, the records of 50 patients retrieved, available data of 41 patients who were prospectively enrolled into two groups (Group 1 [J-Fil stent group], n=21 and Group 2 [DJ stent group], n=20) between August 2020 to January 2021, were analysed. Parameters compared were nature of procedure, stone location and size, ease of deployment or removal, and complications. A modified universal stent symptom questionnaire was used to assess morbidity of stent symptoms within 48 h of insertion and at removal.

Results

Both groups had similar median age, distribution in male to female ratio, and stone size. The overall median universal stent symptom questionnaire score at insertion was similar for bladder pain, flank or loin pain, and quality of life between Group 1 and 2; however, at removal Group 1 fared significantly better than Group 2, especially for flank or loin pain and pain at voiding. Both groups had similar ease in insertion with no hospital readmissions.

Conclusion

Our audit favoured the single pigtail suture stent in Asian ureters in mitigating stent-related issues. It showed a good safety profile with easy deployment and removal. It promises a new standard in stenting.

Prevention of complications in endourological management of stones: What are the basic measures needed before, during, and after interventions?

Objective

This narrative review aims to describe measures to minimise the risk of complications during percutaneous nephrolithotomy (PCNL), ureteroscopy, and retrograde intrarenal surgery.

Methods

A literature search was conducted from the PubMed/PMC database for papers published within the last 10 years (January 2012 to December 2022). Search terms included "ureteroscopy", "retrograde intrarenal surgery", "PCNL", "percutaneous nephrolithotomy", "complications", "sepsis", "infection", "bleed", "haemorrhage", and "hemorrhage". Key papers were identified and included meta-analyses, systematic reviews, guidelines, and primary research. The references of these papers were searched to identify any further relevant papers not included above.

Results

The evidence is assimilated with the opinions of the authors to provide recommendations. Best practice pathways for patient care in the pre-operative, intra-operative, and post-operative periods are described, including the identification and management of residual stones. Key complications (sepsis and stent issues) that are relevant for any endourological procedure are then be discussed. Operation-specific considerations are then explored. Key measures for PCNL include optimising access to minimise the chance of bleeding or visceral injury. The role of endoscopic combined intrarenal surgery in this regard is discussed. Key measures for ureteroscopy and retrograde intrarenal surgery include planning and technique to minimise the risk of ureteric injury. The role of anaesthetic assessment is discussed. The importance of specific comorbidities on each step of the pathway is highlighted as examples.

Conclusion

This review demonstrates that the principles of meticulous planning, interdisciplinary teamworking, and good operative technique can minimise the risk of complications in endourology.

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.

Complete intraureteral stent placement reduces stent-related symptoms: Systemic review and meta-analysis

PURPOSE

The distal coil of a double-J ureteral stent is considered the major cause of stent-related symptoms. We noticed that some recent studies investigated whether complete intraureteral stent placement (CIU-SP) reduced these symptoms. The current systemic review and meta-analysis aimed to evaluate the safety and the effectiveness of CIU-SP, as compared to conventional stent placement (C-SP).

METHODS

We retrieved relevant trials published before December 2021 from three databases, including PubMED, Embase, and Web of Science. The following medical subject heading were used ((complete intraureteral stent) OR (suture stent)) AND (symptom OR pain) AND (randomized OR randomised). The above search was limited to English language publication.

RESULTS

We identified six prospective randomized trials, all of which investigated a short-term (1-2 weeks) stent placement following uncomplicated ureteroscopic lithotripsy. The meta-analysis revealed that CIU-SP significantly reduced stent-related symptoms: CIU-SP had lower USSQ (Ureteral Stent Symptom Questionnaire) Urinary Symptom Index score (MD -5.13; 95%CI [-5.82,-4.44]; P < 0.00001), lower USSQ Pain Index score (MD -4.21; 95%CI [-5.25,-3.17]; P < 0.00001), and lower VAS pain scale (MD -1.93; 95%CI [-2.17,-1.69]; p < 0.00001). Besides, patients with CIU-SP were less likely to have pain (RR 0.78; 95%CI [0.67,0.91]; p = 0.001). There was no significant difference regarding the USSQ General Health and Work Performance. Both CIU-SP and C-SP had similarly few complications of Clavien-Dindo grade ≥2.

CONCLUSION

This meta-analysis reveals that CIU-SP significantly decreases stent-related urinary symptoms and pain. Based on the current evidence, CIU-SP is ready to be applied in clinical practice, at least in those requiring short-term stent placement following uncomplicated ureteroscopic lithotripsy.

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.

The intraureteral placement of the stent's distal end decreases stent-related urinary symptoms: a prospective randomized clinical trial

PURPOSE

We compared intraureteral stent placement (CIU-SP) with conventional stent placement (C-SP) regarding the stent-related symptoms.

METHODS

We randomized patients who underwent ureteroscopic lithotripsy into two groups. In CIU-SP group, a 16-cm or 18-cm stent was placed with its distal end above the ureterovesical junction. In C-SP group, a 22-cm or 24-cm stent was placed in a conventional method. Stent-related symptoms were assessed with the Ureteral Stent Symptom Questionnaire (USSQ) before the stent was removed, around 7 days after the operation. The primary outcome was the urinary symptoms; the secondary outcomes included postoperative pain and quality of life.

RESULTS

We randomized 103 patients, of which 91 (45 in CIU-SP and 46 in C-SP) entered the final analysis. Regarding the primary endpoint, the CIU group had less urinary symptoms; the mean USSQ urinary symptom score was significantly lower in the CIU-SP versus C-SP group (25.5 ± 6.3 vs 31.7 ± 5.9, P < 0.001). The CIU-SP group also had more favorable profiles in the following outcomes: lower USSQ body pain score (15.5 ± 5.3 vs 20.1 ± 5.2, P < 0.001), lower overall pain score (3.2 ± 2.2 vs 5.7 ± 2.3, P < 0.001), less number of pain site (1.0 ± 0.9 vs 1.7 ± 0.9, P = 0.001, lower USSQ general health score (10.4 ± 3.7 versus 13.9 ± 3.4, P < 0.001), and lower USSQ work performance score (5.2 ± 3.3 versus 6.7 ± 2.8, P = 0.033). In either group, there was no complication of Clavien-Dindo Class 2 or greater.

CONCLUSION

The complete intraureteral placement significantly decreases stent-related urinary symptoms and pain. It is also associated with better postoperative general health condition and is less likely to limit physical activity and work ability.

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.

3D printing advances in the development of stents

3D printing technologies have found several applications within the biomedical sector including in the fabrication of medical devices, advanced visualization, diagnosis planning and simulation of surgical procedures. One of the areas in which of 3D printing is anticipated to revolutionised is the manufacturing of implantable bioresorbable drug-eluting scaffolds (stents). The ability to customize and create personalised tailor-made bioresorbable scaffolds has the potential to help solve many of the challenges associated with stenting, such as inappropriate stent sizing and design, abolish late stent thrombosis and help artery growth; 3D printing offers a rapid prototyping and effective method of producing stents making customization of designs feasible. This review provides an overview of the subjects and summarizes the latest research in the 3D printing technologies employed for the design and fabrication of bioresorbable stents including materials with the required printable and mechanical properties. Finally, we present a regulatory perspective on the development and engineering of 3D printed implantable stents.

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.

The effects of pregabalin, solifenacin and their combination therapy on ureteral double-J stent-related symptoms: A randomized controlled clinical trial

Background:

Many medical therapies have been tested to deal with urinary stent-related symptoms (USRS). Several preventive and pharmaceutical methods have been already used for better compatibility of stents. However, the existing evidence for pharmacological treatment is still controversial. This study aims to evaluate the effects of pregabalin, solifenacin, and combination therapy on ureteral double-J stent-related symptoms following ureteroscopy and transureteral lithotripsy (TUL).

Materials and methods:

In a randomized controlled clinical trial, from November 2017 to March 2019, 256 patients who underwent ureteroscopy were enrolled. Patients were randomly divided into four groups including: group A received pregabalin 75mg BID (twice daily), group B received solifenacin 5mg orally once daily, group C received combination of pregabalin and solifenacin and the group D (control) given no drugs.

Results:

One hundred and fifty-one (58.9%) males and 101 (41.1%) females were enrolled in this study with a mean age of 43.47±7 (p=0.32, p=0.67). USSQ domains score such as urinary symptoms, pain, general condition, work performance, sexual matters and additional problems were significantly differenced during second and fourth week of follow-up among study groups (p <0.0001).

In Tukey's multiple comparison test, urinary symptoms (p=0.735), pain (p=0.954) and sexual matters (p=0.080) in second week and work performance in forth week in group B was not significantly better than group D. Only group C in all indexes of USSQ showed significantly beneficial effects over group D (p <0.0001).

Conclusion:

Combination therapy of pregabalin and solifenacin has a significant effect on stent-related symptoms and is preferred over monotherapy of the respected medications.

Ureteral stent complications - experience on 50,000 procedures

Double J stent is an essential tool in urology, being a basic part of many urological procedures. However, some issues related to their use still occur. Our study aimed to evaluate an important number of procedures, the complications of ureteral stents, and their prevention and treatment retrospectively. We evaluate 50,000 procedures performed between 1996 and 2021 on 36,688 patients. According to the stenting duration, the cases were divided into short-term (less than 6 weeks – 34,213 procedures), respectively long-term stenting (more than 6 weeks – 15,757 procedures). The indications of stenting for both groups were noted. The total number of complications was 41,369. We encountered 153 cases (0.3%) of JJ stent malposition, of which 3 cases were into the retroperitoneum, one case with parenchymal perforation and hematoma. Considering the double J migrations, we found proximal migration in 427 cases (0.9%) and distal double J migrations in 352 (0.7%) cases. The obstruction of the ureteral stent, causing inefficient drainage, was encountered in 925 cases, while irritative bladder symptoms occurred in 16,326 cases (32.7%). Hematuria was observed in 5,213 cases, in 7 cases blood transfusion being necessary. Urinary tract infection was diagnosed in 7,436 cases (14.8%). Stent encrustation and calcification occurred in 832 cases, while stent fragmentation was noted in 52 cases. Double J stent complications should be promptly evaluated and treated. Encrustation and stone formation in forgotten stents often lead to serious complications and should be managed with stent removal and combined endourological techniques.

Study to Enhance Understanding of Stent-Associated Symptoms: Rationale and Study Design

Background: Ureteral stents are commonly employed after ureteroscopy to treat urinary stone disease, but the devices impose a substantial burden of stent-associated symptoms (SAS), including pain and urinary side effects. The NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases) Urinary Stone Disease Research Network sought to develop greater understanding of SAS causes and severity among individuals treated ureteroscopically for ureteral or renal stones. Materials and Methods: We designed a prospective, observational cohort study comprising adolescents and adults undergoing ureteroscopic intervention for ureteral or renal stones. Participants will undergo detailed symptom assessment using validated questionnaires, a psychosocial assessment, and detailed collection of clinical and operative data. Quantitative sensory testing will be utilized to assess pain sensitization. In addition, a small cohort (∼40 individuals) will participate in semi-structured interviews to develop more granular information regarding their stent symptoms and experience. Biospecimens (blood and urine) will be collected for future research. Results: The Study to Enhance Understanding of sTent-associated Symptoms (STENTS) enrolled its first participant in March 2019 and completed nested qualitative cohort follow-up in August 2019. After a planned pause, enrollment for the main study cohort resumed in September 2019 and is expected to be completed in 2021. Conclusion: STENTS is expected to provide important insights into the mechanisms and risk factors for severe ureteral SAS after ureteroscopy. These insights will generate future investigations to mitigate the burden of SAS among individuals with urinary stone disease.

Strategies to Improve Patient Outcomes and QOL: Current Complications of the Design and Placements of Ureteric Stents

Ureteric stents have played a vital role in relieving urinary obstruction in many urological conditions. Although they are extremely successful, stents have been associated with complications and reduced patients' health-related quality of life (HRQoL). There are many factors that may affect the quality and longevity of stents. In this review, we have highlighted the journey and innovation of ureteric stents through the modern day. A literature review was conducted to identify relevant articles over the last 20 years. There is a plethora of evidence with various indications for the use of ureteral stents and how they affect QoL. There is still ongoing research to develop the ideal stent with reduced encrustation, one that resists infection and is also comfortable for the patients. Stents made from metal alloys, polymers and biodegradable materials have unique properties in their own right but also have certain deficiencies. These have been discussed along with an overview of newly developed stents. Certain pharmacological adjuncts have also been highlighted that may be useful to improve patient's tolerance to stents. In summary, this paper describes the features of the different types of stents and the problems that are frequently encountered, including effect on patients' HRQoL and financial burden to healthcare providers.

Ureteric stents: Overview of current clinical applications and economic implications

Ureteric stents are one of the most crucial tools used for various clinical conditions in the urological field. Placement of a ureteric stent, for short- or long-term use, remains one of the commonest urological interventional procedures. In the past few decades, ureteral stents have undergone notable technological advancements. However, an ideal stent without significant side-effects is yet to be engineered. Indwelling ureteric stents are often accompanied by physical distress to the patient and clinical complications, such as bacterial adhesion, encrustation, malpositioning, stent fracture and forgotten stent syndrome, that influence patients' health-related quality of life. In the market, different stent types are available, designed to reduce infections, and improve patient symptoms and tolerance. In this review, we have emphasized the recent developments that have taken place in stent design, size, materials and coating. This overview looks at current practices and problems related to stents, along with clinical and economic considerations. Few trial studies have been enumerated in the context of utilization of a ureteral stent symptom questionnaire and various stent models to compare their effects in patients.

[Is the ureteral length associated with the patient's size?]

OBJECTIVE

To assess the relation between the ureteral length and the patients' size.

PATIENTS AND METHOD

Prospective study made between September 2012 and May 2014, on 87 patients with 42 men and 45 women, in whom the ureteral measure was performed during the various procedures that require the use of a pigtail stent. The average age of the population was 53 years old (±15.9) with an average height of 168.3cm (±8.4). This has been achieved through ureteral catheter combining fluoroscopy and endoscopy.

RESULTS

The ureteral average length was 23.5cm (±2.33). The ureteral average length was 23.8cm (±2.18) for man and 23.2cm (±2.44) for women. In this population, there were a positive correlation between the size of the patients and the length of the ureters (r=0.75; P=0.01). However, this correlation was not found in all subgroups, particularly among women (r=0.16; P=0.30) and on the right side of men (r=0.34; P=0.12). This correlation was still true for the left side in the men's group (r=0.50; P=0.02).

CONCLUSION

In this study, there is a positive correlation between the patients' size and the ureteral length. But this correlation is not found in some subgroups. It is better to perform in vivo the ureteral measurement to have the precise length in order to set up a pigtail stent adapted to the patient.

LEVEL OF EVIDENCE

3.

Simplified method using kidney / ureter / bladder x-ray to determine the appropriate length of ureteral stents

Purpose:

To investigate a method to determine the appropriate length of ureteral stents, given that the stent length may lead to exacerbation of urinary symptoms if the stent crosses the bladder midline.

Materials and Methods:

We retrospectively reviewed the position of the distal curl of the ureteral stent using kidney/ureter/bladder (KUB) radiographs after ureteroscopic lithotripsy in 165 patients who underwent placement of 24- or 26-cm ureteral stents. According to the KUB findings, we categorized the position of the distal curl of the ureteral stent into two groups. In Group 1, the stents did not cross the midline (appropriate length); in Group 2, the stents crossed the midline (inappropriate length). We assessed several patient parameters (sex, height, body mass index, and stone side) and the index of ureteral length using KUB radiographs (“C-P”) and computed tomography (CT, “P-V”). Multivariate analysis was performed to identify the most significant factors affecting the position of ureteral stents. We also calculated the cutoff points of the receiver operating characteristic (ROC) curve of C-P and P-V for the position of ureteral stents.

Results:

The multivariate analysis showed that C-P was the most significant factor affecting the position of ureteral stents (p < 0.001) in patients with 24- and 26-cm ureteral stents. Comparison of the ROC curves of C-P and P-V showed that C-P was superior to P-V (p < 0.01) in patients with 24- and 26-cm stents.

Conclusion:

The use of KUB radiographs was effective and simple in determining the appropriate length of ureteral stents.

The Impact of Technique Standardization on Total Operating and Fluoroscopy Times in Simple Endourological Procedures: A Prospective Study

PURPOSE

To present the positive impact of technique standardization on successful outcome, fluoroscopy, and total operating time (TOT) shortening in a prospective study.

METHODS

Six experienced endourologists participated. To assess whether the adaptation of standardized surgical steps improved their methodology with time, 253 patients were prospectively divided in three consecutive 1-month groups. Patients underwent stent placement and exchange and total operating and fluoroscopy times (FTs) were recorded. All surgeons were unaware of their mean recorded results until the end of the study. At the end of the third month, we evaluated if the suggested technique standardization established a decrease for both FT and TOT. Statistical significance was set to p < 0.05.

RESULTS

Total operating and FTs were significantly reduced with time between all groups of patients. For stent placement, TOT showed significant reduction between Groups A and C (p < 0.001), while between other group comparisons did not reach significance. FT showed a significant reduction (p < 0.001) in all group comparisons. For stent exchange, TOT reached significant improvement (p = 0.003) between Groups A and C, whereas between other groups was insignificant. FT improvement was significant between Groups A and C (p < 0.001) and Groups B and C (p < 0.001), but insignificant between Groups A and B.

CONCLUSIONS

Even in experienced hands, the adaptation of technique standardization results in significant decrease of total operating and FTs and it is independent from feedback regarding their time performance.

A ureteral stent crossing the bladder midline leads to worse urinary symptoms

Introduction

To investigate the correlation between the position of a ureteral stent and stent-related symptoms, excluding the influence of ureteroscopic maneuvers.

Material and methods

From January 2016 to December 2016, we analyzed 130 patients who placed a ureteral stent before ureteroscopic lithotripsy (URSL). A total of 108 patients were enrolled, including 77 (71.3%) men and 31 (28.7%) women, and the mean age was 58.9 ±14.3 years. On the day before URSL, plain radiography (kidney, ureter, bladder X-ray [KUB]) was used to confirm the stone location and ureteral stent position. According to KUB, we defined the crossing midline group as when the distal loop of the ureteral stent was crossing the bladder midline, and the not crossing midline group as when the distal loop of the ureteral stent was not crossing the bladder midline. We assessed urinary symptoms of the two groups using the overactive bladder symptom score (OABSS) on the day before URSL.

Results

The crossing midline group had a worse total OABSS (p <0.001) and worse scores for each item of daytime frequency (p = 0.047), nocturia (p <0.001), urgency (p = 0.002), and urgency incontinence (p = 0.045) than did the not crossing group. In multivariate analysis, stent position had the strongest association with the total OABSS (p = 0.002) among the other factors of age, sex, body mass index, stent side, stent diameter, stent length and stent indwelling time.

Conclusions

This study shows that a ureteral stent crossing the bladder midline leads to worse urinary symptoms. Choosing the appropriate stent length for each patient is important for improving stent-related symptoms.

Impact of loop-tail ureteral stents on ureteral stent-related symptoms immediately after ureteroscopic lithotripsy: Comparison with pigtail ureteral stents

Purpose

To evaluate urination-related quality of life (QoL) in patients with an indwelling ureteral stent immediately after ureteroscopic lithotripsy (URSL) for upper urinary calculi. We compared the effects of loop-tail and pigtail ureteral stents on urination-related QoL.

Materials and Methods

Of 135 patients who underwent URSL between May 2014 and March 2015 at our hospital, we retrospectively analyzed the records of 70 patients (42 men, 28 women; median age, 63 years) in whom the stent tail was positioned inside the bladder without crossing the midline and who completed the core lower urinary tract symptoms score (CLSS) questionnaire pre- and postoperatively.

Results

There were significant differences in incomplete emptying (p=0.048) and bladder pain (p=0.041) between patients with loop-tail versus pigtail ureteral stents after URSL. In the multivariate analysis, stent type had a stronger association with incomplete emptying (p=0.022) and bladder pain (p=0.018) than age, sex, body mass index, stent side, operation time, diameter of ureteral access sheath, and stent type.

Conclusions

Patients with loop-tail ureteral stents had better urination-related QoL in the immediate post-URSL stage than patients with pigtail stents.

Correlation of Bladder Histopathologic Changes Due to Double-J Stenting to the Period of Stenting: A Preliminary Study

OBJECTIVES

To study the histopathologic changes in the urinary bladder associated with Double-J (DJ) stenting and the correlation between these changes and the period of stenting.

METHODS

In a 2-year period, a retrospective study was carried out on 30 patients indicated for DJ stenting. These patients underwent cold-cup cystoscopic biopsies from the ipsilateral ureteral orifice at the time of removal of DJ stents.

RESULTS

The mean age of the 30 patients included in our study was 43.6 ± 8.6 years (range 26-74 years). The stent size used was 4.7 and 6F. The stent duration was 2 weeks in 2 patients, 4 to 6 weeks in 18 patients, 6 to 12 weeks in 6 patients, and more than 12 weeks in the remaining 4 patients. Stent placement was optimum in all patients. The histopathologic study of 30 biopsies showed mild, acute eosinophilic inflammatory reactions with edema in patients with stenting less than 14 days. Acute lymphocytic eosinophilic cystitis with edema was found with stents of 2 to 6 weeks. Brunn's nests were reported with stents more than 6 weeks. Cystitis cystica was seen in those who had stents more than 12 weeks.

CONCLUSIONS

Our study shows that acute and chronic allergic inflammatory changes can be seen around the bladder coil of the DJ stents. It is of major importance for the urologist to limit the use of DJ stents to highly indicated cases only and for a short interval.

Intraoperative Radiographic Determination of Ureteral Length as a Method of Determining Ideal Stent Length

INTRODUCTION

Accurate determination of ureteral length (UL) and appropriate stent length remains a challenge. The objective of this study was to describe an intraoperative technique to measure UL and determine appropriate stent length, and to compare this technique with other methods of determining appropriate stent length.

METHODS

Patients undergoing ureteroscopy requiring postoperative stenting and who had a preoperative CT were prospectively identified. Gender, age, height, body mass index, L1 to L5 lumbar height on CT, and surgeon's estimate of UL were recorded. UL was measured using four methods: direct measurement with a ureteral catheter, ureteropelvic junction (UPJ) to ureterovesical junction distance on axial and coronal CT, and using a novel intraoperative radiographic technique. Radiographic measurement was performed using a radiographic nipple marker affixed to the skin over the ureteral orifice (UO) and an angiographic catheter with radiopaque markings at 1 cm intervals. UL was the distance from the UPJ to the marker at the UO measured using the catheter markers. Correlation between direct measurement and the recorded variables and methods of ureteral measurement were calculated. Stent length was chosen based on radiographic measurement. Stents were deemed of appropriate length if they showed a proximal coil in the renal pelvis and a distal coil in the bladder without crossing midline.

RESULTS

Twenty-five ureters from 23 patients were included. Radiographically measured UL was strongly correlated with direct measurement. (r = 0.873, p < 0.01). Coronal and axial CT ULs were significantly associated with direct measurement (p < 0.05). Height, lumbar height, and surgeon's estimate of UL were not. Stents were deemed of appropriate length in 23/25 cases (92%).

CONCLUSIONS

This new method for radiographic UL measurement is strongly correlated with directly measured UL. A length of stent chosen based on radiographic UL resulted in an appropriate stent length.

Best Stent Length Predicted by Simple CT Measurement Rather than Patient Height

INTRODUCTION AND OBJECTIVES

Ureteral stent length is important, as stents that are too long might worsen symptoms and too short are at higher risk of migration. The purpose of this study was to determine if patient or radiologic parameters correlate with directly measured ureteral length and if directly measured ureteral length predicts proper stent positioning.

METHODS

During stent placement, ureteral length (ureteropelvic junction to ureterovesical junction distance) was directly measured by endoscopically viewing a ureteral catheter (with 1-cm marking) emanating from the ureteral orifice. A 22, 24, or 26 cm stent was chosen to be closest to the measured ureteral length. For ureters >26 cm, a 26 cm stent was chosen. Ends of an "ideally positioned" stent were fully curled in the renal pelvis and bladder, without crossing the bladder midline. Rates of ideal stent position were compared between patients with matching stent and ureteral lengths and those with stent lengths differing by ≥1 cm (mismatched). The measured ureteral length was correlated with patient height, L1-L5 height, and length measured on CT.

RESULTS

Fifty-nine ureters from 57 patients were included. Height was reasonably correlated with L1-L5 height (Spearman correlation coefficient [rho] = 0.79), although both were poorly correlated with directly measured ureteral length (rho = 0.18 for height and 0.32 for lumbar height). Ureteral lengths measured on CT correlated well with direct measurement (rho = 0.63 for axial cuts and rho = 0.64 for coronal cuts). Matched stent length was associated with higher rates of ideal stent position than mismatched (100% vs 70.9%, p = 0.006).

CONCLUSIONS

CT measurements, rather than height, correlate well with measured length and could be used to choose the appropriate stent length. Stents matching directly measured ureteral lengths are associated with high rates of ideal stent position.

Insertion of a single double-J stent for bilateral open ureteral reimplantation: introducing a novel technique and assessment of feasibility

PURPOSE

To propose a novel technique for bilateral placement of a single double-J stent during bilateral open ureteral reimplantation in order to reduce the intravesical length of stent and potentially minimize the irritative symptoms.

METHODS

A retrospective chart review was performed to find patients who underwent bilateral open ureteral reimplantation. According to the patient's age, an appropriate single double-J stent is used for stenting both ureters after open reimplantation using the Politano-Leadbetter technique. The stent is fixed to the bladder wall with a 4-0 chromic absorbable suture in the midline, superior to the intertrigonal ridge. A non-absorbable suture is also fixed to the stent in the midline as an extraction string.

RESULTS

From June 2009 to July 2013, 20 patients underwent bilateral ureteric surgery. Twelve (60 %) were female. Patients' age ranged from 3 months to 2 years. Double-J stents were successfully removed within 2 weeks postoperatively in all patients.

CONCLUSIONS

This technique might reduce the stent-related symptoms after open bladder surgery for bilateral ureteral surgery. Using this technique will reduce the redundant mass of ureteral stents in bladder and potentially minimize the trigonal irritation and subsequent pain and discomfort.

Comparison of Flow Characteristics of Novel Three-Dimensional Printed Ureteral Stents Versus Standard Ureteral Stents in a Porcine Model

PURPOSE

We compared the flow characteristics of novel three-dimensional (3D) printed ureteral stents with four conventional double-pigtail stents in an ex vivo porcine model.

MATERIALS AND METHODS

In six ex vivo porcine urinary systems with kidneys and ureters intact, we deployed a 5F occlusion catheter in an interpolar calix. We tested each system with antegrade irrigation with a 0.9% saline bag placed 35 cm above the renal pelvis. We evaluated four standard stents (6F Universa® Soft, 7F Percuflex,™ 7/10F Applied Endopyelotomy, 8.5F Filiform Double Pigtail) and compared them with a 9F 3D printed prototype stent. For each stent, we measured the total, extraluminal, and intraluminal flow rates.

RESULTS

The mean total flow rates for 3D printed stents were significantly higher than the 6F, 7F, and 7/10F stents (P<0.05). No significant difference was seen in the total flow rate for the 3D printed stent and the 8.5F stent. The mean extraluminal flow rates for the 3D stents were similar to those of 7F stents, but significantly lower than 6F stents (P<0.001) and 8.5F stents (P<0.05) and higher than 7/10F stents (P<0.001). The mean intraluminal flow rates for the 3D printed stents were significantly higher than the 6F, 7F, 7/10F, and 8.5F stents (P<0.05).

CONCLUSIONS

In this pilot study, 3D printed stents manifested a mean total flow rate comparable to the flow rates of contemporary stents. Continued advances in technology and material may permit functionally feasible 3D printed ureteral stents.

Anti-Reflux Ureteral Stent with Polymeric Flap Valve Using Three-Dimensional Printing: An In Vitro Study

PURPOSE

This article aims to describe the design of an anti-reflux ureteral stent with a polymeric flap valve and the fabrication methods using three-dimensional (3D) printing. The stent effectively prevents backward flow with a negligible reduction in forward flow. Fabrication of miniaturized valves was easy with high precision and rapid prototyping.

MATERIALS AND METHODS

The proposed stent comprised a 7F Double-J (DJ) stent and a polymeric flap valve. The valve was made of Tango Plus FLX980 and was fabricated using a 3D printer. Two types of stent were prepared for in vitro tests: DJ stents with (1) an uncoated valve (UCV) stent and (2) a parylene C coated valve (PCV) stent for enhanced biocompatibility. The flow characteristics of each stent were evaluated considering flow direction, parylene coating, and stent side holes, and were compared to the intact DJ stent.

RESULTS

The forward flow rate for the distal portion of the UCV and PCV stents was 9.8 mL/min and 7.8 mL/min at applied pressure of 15 cm H2O (normal anterograde pressure in patients with stents), respectively. Backward flow rate for the distal portion of the UCV and PCV stents was decreased by 28 times and 8 times at applied pressure of 50 cm H2O (maximum bladder pressure), respectively, compared with the distal portion of the intact DJ stent. Forward flow rates of whole stents were 22.2 mL/min (UCV stent) and 20.0 mL/min (PCV stent) at applied pressure of 15 cm H2O, and backward flow rates of whole UCV and PCV stents were decreased by 8.3 times and 4.0 times at applied pressure of 50 cm H2O, respectively, compared with the intact DJ stent.

CONCLUSIONS

The anti-reflux ureteral stent was successfully designed and fabricated using a 3D printer. In vitro studies showed that the stent effectively prevented backward flow while minimizing reduction in forward flow.

Randomized controlled trial to compare the safety and efficacy of tamsulosin, solifenacin, and combination of both in treatment of double-j stent-related lower urinary symptoms

Purpose. We evaluated the effectiveness and safety of tamsulosin, solifenacin, and combination of both in reducing double-J stent-related lower urinary symptoms. Materials and Methods. A total of 338 patients with double-J ureteral stenting were randomly divided, postoperatively, into 4 groups. In group I (n = 84), no treatment was given (control group), group II (n = 85) received tamsulosin 0.4 mg daily, group III (n = 84) received solifenacin 10 mg daily, and group IV (n = 85) received a combination of both medications. Before insertion and 2 weeks after, all patients completed the International Prostate Symptom Score (IPSS), quality of life component of the IPSS (IPSS/Qol), Overactive Bladder Questionnaire (OAB-q), and Visual Analogue Pain Scale (VAPS) questionnaire. Results. The demographics and preoperative questionnaires scores of all groups were comparable. There were statistically significant differences in all scores in favour of groups II, III, and IV as compared to control group (P value < 0.005). Group IV showed statistically significant differences in total IPSS, QoL score, and OAB-q score as compared to groups II and III (P value < 0.001). Conclusions. Combined therapy of tamsulosin and solifenacin significantly alleviated lower urinary symptoms associated with double-J stents as compared to either medication alone.

A prospective evaluation of pain associated with stone passage, stents, and stent removal using a visual analog scale

OBJECTIVE

To investigate the perception of colicky pain due to ureteral stones and double-J (DJ)-associated discomfort and to evaluate the role of clinical parameters that might influence the perception of pain.

MATERIALS AND METHODS

From November 2011 to May 2012, 124 consecutive patients with colicky pain due to ureteral stones and ureteroscopic stone extraction underwent DJ stent placement. A visual analog scale (VAS) was used to assess the pain at ureteral colic, during indwelling DJ stent, and at DJ stent removal. The association of clinical data with pain scores was also analyzed.

RESULTS

Pain perception at the time of colic did not vary according to sex (P = .804), age (P = .674), or DJ stent length (P = .389). Stone size (<4 mm) was a predictor of a high VAS score (P = .001). Patients with recurrent stone formation had significantly less pain at the time of colic (P = .004), and DJ stent removal (P = .004) than those with the first instance of stone formation. The clinical experience at cystoscopic DJ stent removal influenced pain perception (P <.001).

CONCLUSION

Using a VAS for the evaluation of pain perception is a valid method for the objectification of subjective discomfort. The VAS is an easy to administer scale and provides accurate information on the patients' status. Additional studies with larger cohorts focusing on pain perception using the VAS and other validated questionnaires are recommended to produce more consistent data.

Choosing an appropriate length of loop type ureteral stent using direct ureteral length measurement

PURPOSE

The ureteral stent is now a fundamental part of many urological procedures. To decrease ureteral stent-related symptoms, loop type ureteral stent was developed. However the most important factor to decrease urinary symptoms is choosing the optimal length of a ureteral stent. We investigated the relationship between the actual ureteral length and the loop type ureteral stent position.

MATERIALS AND METHODS

A total of 226 loop type polyurethane ureteral stents (156 patients) were inserted with four options for stent length (20, 22, 24 and 26 cm). The ureteral length was measured using a ruled 5-Fr ureteral catheter. The appropriateness of stent position was defined into three groups based on kidney-ureter-bladder films.

RESULTS

Nine stents (3.9%) migrated, 171 stents (75.7%) were in the appropriate position and 46 stents (19.5%) were overlong. The rate of migration rate and overlong stents closely correlated with the ureteral length when the proximal end of the stent was in the renal pelvis.

CONCLUSIONS

It is appropriate to choose a loop type ureteral stent that is the same or 1 cm less than the length of the ureter when the proximal end of the stent will be in the renal pelvis.

Effectiveness of medical treatment in overcoming the ureteral double-J stent related symptoms

BACKGROUND

We investigated whether the frequency of lower urinary tract symptoms (LUTS) increased in patients in whom double-J stents were applied. We also evaluated several medical therapy protocols to treat symptoms related with ureteral stents.

MATERIALS AND METHODS

A total of 108 patients, in whom unilateral double-j stent was applied during ureteral stone treatment, were included. Before the double-J stent was applied, all patients completed storage components of the "International Prostate Symptom Score" (IPSSs), quality of life components of the IPSS (IPSS-QOL) and "Overactive Bladder Questionnaire" (OABq) forms and scores were calculated. After the procedure, cases were randomized into 5 groups, an antiinflammatory was given to Group 1, spasmolytic to Group 2, anticholinergic to Group 3 and α-blocker to Group 4. No additional drug was given to Group 5 as this control group. During the fourth week of the procedure, IPSSs, IPSS-QOL and OABq forms were again completed and scores were compared with the previous ones.

RESULTS

When all the cases were evaluated, the IPSSs, IPSS-QOL and OABq scores of patients in whom the double-J stent was applied were statistically significantly higher the procedure. Compared to the control group, the cases where the double-J stent was applied showed a higher IPSSs, IPSS-QOL and OABq scores and none of the medical therapies could prevent this increase.

INTERPRETATION

The frequency of LUTS increased in cases where the ureteral stent was applied and discomfort continued as long as the stent stayed in the body.

Is there a role for α-blockers in ureteral stent related symptoms? A systematic review and meta-analysis

PURPOSE

We evaluated the efficacy of α-blockers to improve ureteral stent related morbidity and quality of life.

MATERIALS AND METHODS

We performed a search of MEDLINE®, Embase™ and The Cochrane Library plus a hand search of conference proceedings from January 2000 to October 2010 to identify randomized, controlled trials comparing treatment for ureteral stent symptoms with α-blockers. Two reviewers independently screened studies and extracted data. Trial methodological quality was assessed by The Cochrane Collaboration quality assessment tool. Placebo randomized, controlled trials with the ureteral stent symptom questionnaire as the outcome were eligible for meta-analysis. Meta-analysis was done using the mean difference to determine the aggregate effect size.

RESULTS

A total of 12 randomized, controlled trials including 2 α-blockers in a total of 946 patients were eligible, including 4 (33%) presented only as an abstract at a urological meeting and 4 (33%) eligible for meta-analysis. Meta-analysis using a random effects model showed that α-blockers were associated with a significant decrease in urinary symptoms (MD -6.76, 95% CI -11.52 to -2.00, p=0.005), a significant decrease in pain (MD -3.55, 95% CI -5.51 to -1.60, p=0.0004) and significant improvement in general health (MD -1.90, 95% CI -3.05 to -0.75, p=0.001). However, they were not associated with a benefit in work (MD 2.41, 95% CI -1.62 to 6.44, p=0.24) or sexual matters (MD 0.20, 95% CI -1.06 to 1.45, p=0.33). Eight studies were not included in the meta-analysis, of which 7 showed a significant clinical decrease in urinary symptoms and pain.

CONCLUSIONS

Existing evidence from randomized, controlled trials shows that α-blockers are associated with improvement in ureteral stent symptoms and supports their use in routine clinical practice.

Ureteral stent discomfort: Etiology and management

Objectives:

To review the evidence-based literature on the causes, characteristics, and options to manage double J stent-related symptoms.

Methods:

We performed a Medline database assessment on papers that investigated the prevalence, mechanisms, risk factors, bothersome and management of double-J stent-related symptoms. Articles in English were reviewed and summarized.

Results:

Stent-related symptoms have a high prevalence and may affect over 80% of patients. They include irritative voiding symptoms including frequency, urgency, dysuria, incomplete emptying; flank and suprapubic pain; incontinence, and hematuria. Assessment tools are important to determine their intensity and allow for comparisons between different points in the timeline. The Urinary Stent Symptom Questionnaire (USSQ) is the most proper tool used for this purpose. Management should be focused on the prevention and management of symptoms. In this sense, research has focused on new materials and stent designs that would be more compatible to the physiologic properties of the urinary tract and medications that can ameliorate the sensitivity and motor response of the bladder.

Conclusions:

Stent-related symptoms are very common in the Urological clinical setting. It is of major importance for the urologist to understand their physiopathology and to be familiar with ways to avoid or manage them.

Polymers as ureteral stents

Ureteral stents find wide application in urology. The majority of patients with indwelling ureteral stents are at an increased risk of urinary tract infection. Stent encrustation and its associated complications lead to significant morbidity. This review critically evaluates various polymers that find their application as ureteral stents with regard to various issues such as encrustation, bacterial colonization, urinary tract infections, and related clinical issues. A complete literature survey was performed, and all the relevant articles were scrutinized thoroughly. We discuss issues of encrustation/biofilm formation, new approaches to their testing, polymers currently available for use, new biomaterials, coatings, and novel ureteral stent designs, thereby providing a complete update on recent advances in the development of stents. Finally, we discuss the future of biomaterial use in the urinary tract.

Ureteral stent symptoms and associated infections: a biomaterials perspective

Ureteral stents are commonly used in the field of urology, and, given their indwelling nature, are often a nidus for infection and a cause of discomfort. To minimize symptoms, the urologic surgeon should first consider whether a stent needs to be placed at all. Softer stents do not seem to improve patient comfort. Stents that are too long, specifically those that cross the midline of the bladder, significantly increase the frequency of stent-related symptoms. Administering alpha blockers while the stent is indwelling can reduce these symptoms. Antibiotic prophylaxis or concomitant antibiotic administration does not seem to reduce the incidence of stent-related urinary tract infection. At present, drug-eluting stents have shown the most promise for inhibiting bacterial adhesion and biofilm formation. Future stent designs that maintain drainage of the kidney and ureter while minimizing inflammation and contact with the urothelium will improve patient outcomes. By better understanding the basic pathways of bacterial adhesion to biomaterials, new stents and medications that target these mechanisms can be developed to eliminate bacterial adhesion and infection in patients with ureteral stents.