Ureteric Stent Use - Part of the Solution and Part of the Problem

Construction of a nomogram for predicting catheter-related bladder discomfort in patients with end-stage renal disease after renal transplantation: a retrospective study

Background

The incidence of catheter-related bladder discomfort (CRBD) is relatively high in the end-stage renal disease (ESRD) patients who underwent renal transplantation (RT). This study was designed to establish a nomogram for predicting CRBD after RT among ESRD patients.

Methods

In this retrospective study, we collected 269 ESRD patients who underwent RT between September 2019 and August 2023 in our hospital. The patients were divided into training set (n = 215) and test set (n = 54) based on a ratio of 8:2. Univariate and multivariate logistic regression analyses were utilized to identify the risk factors associated with CRBD after RT, and then a nomogram model was constructed. Receiver operating characteristic (ROC) and calibration curve were used to evaluate the predicting efficiency of the established nomogram.

Results

Multivariate logistic regression analysis showed that aberrant body mass index (BMI) (underweight: OR = 5.25; 95% CI [1.25-22.15], P = 0.024; overweight: OR = 2.75; 95% CI [1.17-6.49], P = 0.021), anuria (OR = 2.86; 95% CI [1.33-5.88]) and application of double J (DJ) stent with a diameter of >5Fr (OR = 15.88; 95% CI [6.47-39.01], P < 0.001) were independent risk factors for CRBD after RT. In contrast, sufentanil utilization (>100 µg) [OR = 0.39; 95% CI [0.17-0.88], P = 0.023] was associated with decreased incidence of CRBD. A nomogram was then established based on these parameters for predicting the occurrence of CRBD after RT. Area under the ROC curve (AUC) values and calibration curves confirmed the prediction efficiency of the nomogram.

Conclusion

A nomogram was established for predicting CRBD after RT in ESRD patients, which showed good prediction efficiency based on AUC and calibration curves.

The effect of ureteral double J stent insertion on work performance in patients undergoing endoscopic stone treatment

Introduction

Despite the developments in the material of the double J (DJ) stents and the production of thinner ones of desired sizes, patients continue to experience troublesome DJ stent-related symptoms in their lives. This study aimed to determine how DJ stenting affects patients' work performance after endoscopic stone surgery.

Material and methods

A total of 107 patients underwent placement of a ureteral stent after ureterorenoscopy (URS)/retrograde intrarenal surgery (RIRS), and only active and full-time working patients were included. All patients were asked to complete the validated Turkish version of the work performance score (WPS) questionnaire in the Ureteral Stent Symptom Questionnaire (USSQ) the day before stent removal and again one month after stent removal.

Results

Of the participants, 32.7% (n = 35) were female and 67.3% (n = 72) were male; the mean age was 41 (19-80) years. The workday loss had no statistically significant correlation with patient BMI, stone size, or stent indwelling time (p >0.005); however, a statistically significant negative correlation was detected with patient age (r = -0.335, p <0.001). The medians of WPSs with the stent and without the stent were 6 (3-15) and 3 (3-12), respectively (p <0.001).

Conclusions

Although DJ catheterization is a crucial tool for urological practice, it may increase the social and economic burden of patients due to reduced work performance and lost workdays. Therefore, limiting the duration of the DJ stent's stay and providing treatments to minimize patient symptoms will positively impact their professional lives. It would be beneficial to avoid DJ stenting in routine practice unless medically necessary.

Can we predict the incidence of high-grade Clavien-Dindo complications in patients with forgotten encrusted stents undergoing endourologic management?

Objective

Ureteral stents are customarily inserted to facilitate urinary drainage, but they come with their own glitches of being forgotten and/or encrusted leading to serious consequences. The present study aimed to report the complications in patients with forgotten and encrusted stents according to the Clavien-Dindo system specific to urological procedures and identify the factors leading to high-grade (Clavien-Dindo Grade 4A or above) complications.

Methods

The hospital records of patients with forgotten encrusted double-J stents over a period of 8 years were reviewed. The parameters recorded included patient demographics, indwelling time, need for percutaneous nephrostomy, hemodialysis, urine culture, blood culture, total blood counts, serum creatinine, radiologic findings, management techniques, number of surgical interventions, modified Clavien-Dindo complications, follow-up, and mortality, if any.

Results

Forty patients were included in the study. The median age was 52 (range 6-85) years. Of the total, 25 (62.5%) patients had a "significant" stent load; 31 (77.5%) had renal failure or acute kidney injury on presentation; 19 (47.5%) patients had sepsis at presentation. Among the patients presented with sepsis, 11 (57.9%) patients demonstrated a positive urine culture; and 7/11 (63.6%) patients exhibited pan-resistant organisms. Twelve out of 40 (30.0%) patients in our series developed high-grade Clavien-Dindo complications. On univariate analysis, sepsis at presentation (p=0.007), stent load (p=0.031), diabetes (p=0.023), positive urine culture (p=0.007), and stent indwelling time of more than 1 year (p=0.031) were found to be significant. On multivariate logistic regression analysis, sepsis at presentation (p=0.017) and positive urine culture (p=0.016) were significant predictors for high-grade complications.

Conclusion

It is prudent to identify specific risk factors, namely sepsis at presentation and positive urine culture to triage and optimize these patients before surgical management.

Management of infected indwelling ureteral stents An international survey of urologists

INTRODUCTION

There are no clinical guidelines for the manipulation of chronic indwelling ureteral stents. The goal of this study was to survey, through a simulated case, how urologists initially manage a patient with a chronic ureteral stent presenting with urosepsis.

METHODS

An online questionnaire was shared from July 1 to August 31, 2021, through social media (Twitter) and email lists. The scenario described a 50-year-old female, known for a chronic indwelling ureteral stent, presenting to the emergency department with fever, tachycardia, and flank pain. In the scenario, the stent was in adequate position and the last exchange had been performed one month prior. Respondents could choose between treating with antibiotics and keeping the same exchange schedule, urgent stent exchange, or an alternative management that they defined. P<0.05 was considered significant.

RESULTS

A total of 396 participants completed the survey. Responses from 48 countries were collected, with 135 (34.1%) respondents from Canada. Half (50%) of respondents had more than 10 years of experience. Most (79.3%) respondents opted for initial empiric antibiotic therapy, while 16.2% opted for urgent stent exchange. A total of 19 (4.9%) medical specialists completed the survey. Non-urologists opted more frequently than urologists (42.1% vs. 16.2%) for urgent stent exchange (p=0.0111).

CONCLUSIONS

This questionnaire allowed us to explore the various managements proposed by urologists in a patient with urosepsis and chronic indwelling ureteral stent. Most urologists opted for initial medical management. Further clinical studies could help determine the necessity for ureteral stent manipulation in urosepsis, and, if present, its ideal timing.

Functional Properties of Polyurethane Ureteral Stents with PLGA and Papaverine Hydrochloride Coating

Despite the obvious benefits of using ureteral stents to drain the ureters, there is also a risk of complications from 80-90%. The presence of a foreign body in the human body causes disturbances in its proper functioning. It can lead to biofilm formation on the stent surface, which may favor the development of urinary tract infections or the formation of encrustation, as well as stent fragmentation, complicating its subsequent removal. In this work, the effect of the polymeric coating containing the active substance-papaverine hydrochloride on the functional properties of ureteral stents significant for clinical practice were assessed. Methods: The most commonly clinically used polyurethane ureteral Double-J stent was selected for the study. Using the dip-coating method, the surface of the stent was coated with a poly(D,L-lactide-glycolide) (PLGA) coating containing the papaverine hydrochloride (PAP). In particular, strength properties, retention strength of the stent ends, dynamic frictional force, and the fluoroscopic visibility of the stent during X-ray imaging were determined. Results: The analysis of the test results indicates the usefulness of a biodegradable polymer coating containing the active substance for the modification of the surface of polyurethane ureteral stents. The stents coated with PLGA+PAP coating compared to polyurethane stents are characterized by more favorable strength properties, the smaller value of the dynamic frictional force, without reducing the fluoroscopic visibility.

Outcomes and Cost Evaluation Related to a Single-Use, Disposable Ureteric Stent Removal System: a Systematic Review of the Literature

PURPOSE OF REVIEW

To present the latest evidence related to the outcomes and cost of single-use, disposable ureteric stent removal system (Isiris).

RECENT FINDINGS

Our review suggests that compared to a reusable flexible cystoscope (re-FC), a disposable flexible cystoscope (d-FC) with built-in grasper (Isiris) significantly reduced procedural time and provided a cost benefit when the latter was used in a ward or outpatient clinic-based setting. The use of d-FC also allowed endoscopy slots to be used for other urgent diagnostic procedures. Disposable FCs are effective and safe for ureteric stent removal. They offer greater flexibility and, in most cases, have been demonstrated to be cost-effective compared to re-FCs. They are at their most useful in remote, low-volume centres, in less well-developed countries and in centres where large demand is placed on endoscopy resources.

Does potassium citrate administration change the type and composition of encrusted material on Double-J stent compared to primary stone?

Purpose

To evaluate the effect of potassium citrate administration on the composition of encrusted material on the ureteral stent after Double-J insertion.

Methods

We designed a randomized clinical trial for our study; 65 patients that underwent transurethral lithotripsy and Double-J stent insertion were included in the study after informed consent and divided into two groups. In the first group (33 patients) potassium citrate was prescribed after surgery till stent removal and the second group (32 patients) followed without prescribing this medication. After stent removal, encrusted materials on removed stents were analyzed then the type and composition of encrusted material compared with the primary stone that was removed.

Results

Our results revealed that the type and composition of primary stone and encrusted stone were similar in patients that do not receive potassium citrate (p-value of 0.073, 0.251 and 0.944 for calcium oxalate, uric acid, and calcium phosphate respectively). In patients that taking potassium citrate rate of calcium oxalate (p-value < 0.001) and uric acid (p-value < 0.001) material on encrusted stent significantly decreased compared with the non-intervention group.

Conclusion

Results of this study revealed that taking of potassium citrate after ureteral stent insertion significantly decreases the formation of calcium oxalate and uric acid encrusted material on Double-J stent so it could be recommended for prevention of stent encrustation in patients that primary stone analysis are calcium oxalate and uric acid stone.

Prophylactic Ureteral Localization Stent with Guidewire Assistance Decreases Urologic-Induced Complication Rates: Quality Improvement Initiative and Review of Literature

Background: We previously reported a 2% Clavien IIIb urologic-induced complication rate associated with blind (no guidewire, no fluoroscopy) prophylactic ureteral localization stent (PULSe) placement. As part of a quality improvement initiative, mandatory guidewire placement before PULSe was performed and urologic-induced Clavien IIIb or greater complication rates were evaluated. A systematic review was performed to elicit the overall urologic-induced complication rate in the literature. Materials and Methods: A retrospective review of all patients who underwent guidewire-assisted PULSe placement before colorectal surgery was performed. The contemporary cohort was compared with those in the prior cohort using age, body mass index (BMI), American Society of Anesthesiologists (ASA) score, preoperative creatinine, postoperative creatinine, pre-/postoperative creatinine difference, and Clavien IIIb urologic-induced complication rates. A review of literature from 1982 to 2019 was performed using 14 unique search terms. Of 38 studies reviewed, 18 met predetermined inclusion criteria. Results: One hundred thirty-two patients underwent bilateral PULSe placement with mandatory guidewire utilization. Mean age and BMI were 55.78 (18-89) and 27.02, respectively, with zero Clavien IIIb complications, compared with a rate of 2% (P < .001) in our prior study. Our contemporary cohort yielded a more favorable postoperative creatinine (P < .022) and pre-/postoperative creatinine difference (P < .003). A review of literature identified a mean Clavien IIIb complication rate of 0.38%. Conclusions: Mandatory guidewire utilization before PULSe placement reduced the Clavien IIIb complication rate to zero, compared with a rate of 2% from our prior cohort. Guidewire utilization can decrease Clavien IIIb urologic-induced complication rates. A review of the literature shows a lack of uniformity concerning the technique of PULSe placement.

Association between ureteric stent dwell time and urinary tract infection

BACKGROUND

Ureteric stone obstruction commonly presents to the emergency department, with definitive management often involving ureteroscopy and laser lithotripsy. Insertion of a ureteric stent prior to staged lithotripsy is commonly performed in the public healthcare system. Foreign bodies in the urinary tract are also known to increase urinary tract infection (UTI) risk. This study aims to evaluate the association between stent dwell time and UTI prior to lithotripsy.

METHODS

The medical records of all patients who were treated for ureteric stones with initial stent insertion and staged lithotripsy, from 1 January 2018 to 30 June 2019 at a single tertiary centre, by eight urologists were retrospectively reviewed. Demographic features, disease factors and urine culture data were collected and analysed.

RESULTS

Of the 172 patients (median age 56.7 years) identified, one-third had a positive pre-stent urine culture. Twenty-three percent had a positive pre-lithotripsy urine culture with 38% of females compared with 15% of males having a positive culture (P = 0.001). Only 4.3% of patients had a pre-lithotripsy UTI when the stent dwell time was less than 1 month compared with 26.2% when ureteric stents were in situ for longer than 1 month (P = 0.021). The correlation between ureteric stent dwell time and pre-lithotripsy UTI was not linear. Patient comorbidities, stone size, burden and location were not statistically correlated to pre-lithotripsy UTI.

CONCLUSION

In delayed two-staged surgical management of acute urolithiasis, optimal ureteric stent dwell time is less than 1 month to reduce pre-lithotripsy UTI. Female gender is an independent risk factor for pre-lithotripsy UTI.

Comparison of ureteric stent removal procedures using reusable and single-use flexible cystoscopes following ureteroscopy and lasertripsy: a micro cost analysis

Introduction

Diagnostic pressure on endoscopy suite can lead to delay in flexible cystoscopic stent removal. We compare the cost and organizational impact of reusable flexible cystoscope versus single-use, flexible cystoscope with a built-in stent grasper (Isiris^®).

Material and methods

Data for the reusable cystoscopic stent removal performed in endoscopy room, group A (period 1) were compared to Isiris disposable stent removal performed in outpatient clinic, group B (period 2). We chose the same calendar months in successive years for these two different groups (9 months each). A micro cost analysis was performed evaluating the impact on costs, complications and organizational benefit.

Results

A total of 72 patients (37, group A; 35, group B) were included with no significant differences in age and gender ratio. The mean procedure time was 14.4 and 2.2 minutes, and the mean stent dwell time was 26.8 and 15.4 days in groups A and B respectively (p <0.001). In group A, 5 patients (14%) developed stent encrustation, of which 3 needed a ureteroscopic removal subsequently. No complication occurred in group B. More staff on average were needed for procedures done in group A, than group B (p <0.001).

The number of patients who had cancer diagnostic wait of >2 weeks for flexible cystoscopy and the mean number of days they waited, reduced from 16 to 3, and 21 days to 3 days respectively between period 1 to period 2. The cost per procedure between group A and group B was £267.2 and £252.62 (p <0.05) if the cost of managing complications was not considered, and £365.40 and £252.62 (p <0.001) if the cost of managing complications was also considered.

Conclusions

Isiris significantly reduced stent dwell time, procedural time and staff needed to carry out the stent removals. It also allowed the procedures to be done in the outpatient setting thereby reducing the organizational pressure on endoscopy related diagnostic procedures.

Life-threatening Double-J stent migration with helicoidal appearance: Length matters

BACKGROUND

The Double-J stent is one of the most commonly used devices in urologic practice. Due to its widespread use, numerous common complications have been reported, such as irritative symptoms, infection, and encrustation. More rare complications have also been described, such as up or downward migration and displacement outside the urinary tract. We present a rare case of downward migration of a Double-J stent in a 21-year-old Caucasian female.

CASE PRESENTATION

A 21-year-old female with a solitary kidney presented to the emergency department with acute renal failure, left flank pain, and fever. She had undergone left Double-J stenting 1 week earlier in her homeland for left renal colic and anuria. A kidney-ureter-bladder X-ray revealed a 10-mm lumbar ureteral stone and the proximal coil of the Double-J stent making multiple loops along the ureter, resulting in a helical appearance. She underwent surgery to remove the previous stent and to place a new one. She was discharged 2 days later and her renal function had returned to normal values at her 1-week follow-up.

CONCLUSIONS

Double-J Stent placement is a common procedure in the management of urinary tract diseases but is not devoid of life-threatening complications. Regular follow-up of stents and on-time evaluation of clinical complaints are mandatory for an aggressive treatment of complications.

Freeze-casting porous chitosan ureteral stents for improved drainage

As a new strategy for improved urinary drainage, in parallel to the potential for additional functions such as drug release and self-removal, highly porous chitosan stents are manufactured by radial, bi-directional freeze-casting. Inserting the porous stent in to a silicone tube to emulate its placement in the ureter shows that it is shape conforming and remains safely positioned in place, also during flow tests, including those performed in a peristaltic pump. Cyclic compression tests on fully-hydrated porous stents reveal high stent resilience and close to full elastic recovery upon unloading. The drainage performance of the chitosan stent is evaluated, using effective viscosity in addition to volumetric flow and flux; the porous stent's performance is compared to that of the straight portion of a commercial 8 Fr double-J stent which possesses, in its otherwise solid tube wall, regularly spaced holes along its length. Both the porous and the 8 Fr stent show higher effective viscosities, when tested in the silicone tube. The performance of the porous stent improves considerably more (47.5%) than that of the 8 Fr stent (30.6%) upon removal from the tube, illustrating the effectiveness of the radially aligned porosity for drainage. We conclude that the newly-developed porous chitosan ureteral stent merits further in vitro and in vivo assessment of its promise as an alternative and complement to currently available medical devices. STATEMENT OF SIGNIFICANCE: No papers, to date, report on porous ureteral stents, which we propose as a new strategy for improved urinary drainage. The highly porous chitosan stents of our study are manufactured by radial, bi-directional freeze casting. Cyclic compression tests on fully-hydrated porous stents revealed high stent resilience and close to full recovery upon unloading. The drainage performance of the chitosan is evaluated, using effective viscosity in addition to volumetric flow and flux, and compared to that of the straight portion of a commercial 8 Fr double-J stent. The performance of the porous stent improves considerably more (47.5%) than that of the 8 Fr stent (30.6%) upon removal from the tube, illustrating the effectiveness of the radially aligned porosity for drainage. While further studies are required to explore other potential benefits of the porous stent design such as antimicrobial behavior, drug release, and biodegradability, we conclude that the newly-developed porous chitosan ureteral stent has considerable potential as a medical device.