Stent Encrustation Research Articles

Does alkalinised urine reduce the rate of encrustation in patients with ureteric stents? A randomised controlled study.

Stent encrustation is not uncommonly encountered with a high number of ureteric stents. The exact pathophysiology is not well understood. Therefore, we investigated the relationship between the use of sodium citrate and likelihood of stent encrustation. This prospective, randomised, intervention study was conducted between October 2018 and October 2019 in a tertiary hospital. Overall, 115 patients with ureteral stents that were inserted after lithotripsy surgeries were recruited. The study subjects were randomised into two groups: one group was administered sodium citrate (Utix sachets) three times per day until stent removal (intervention group), and the second group was not administered Utix sachets (control group). Stents were removed after 1 month and inspected under macroscopic visualisation from the proximal to distal end for any crystallisation; a second inspection was done with a 60 × magnification lens. Any crystallisation observed was considered to be encrustation. Patients who had Utix sachets post-insertion of a ureteric stent constituted 50.4% of the study cohort. The rate of encrustation in the control group was 52.6%. In the intervention group, the rate of encrustation was 46.6%. The difference was not statistically significant with the chi-squared test (p value, 0.514). Alkaline citrate medications had no significant effect on stent encrustation rate. More studies are needed to elucidate different agents and their roles in reducing stent encrustation as it incurs high morbidity.

Quantitative Evaluation of Encrustations in Double-J Ureteral Stents With Micro-Computed Tomography and Semantic Segmentation

Accurate evaluation of stent encrustation patterns, such as volume distribution, from different patient groups are valuable for clinical management and the development of better stents. This study quantitatively compares stent encrustation patterns from stone and kidney transplant patients. Twenty-seven double-J ureteral stents were collected from patients with stone disease or who underwent kidney transplantation. Encrustations on stent samples were quantified by means of micro−Computed Tomography and semantic segmentation using a Convolutional Neural Network model. Luminal encrustation volume per stent unit was derived to represent encrustation level, which did not differ between patient groups in the first six weeks. However, stone patients showed higher encrustation levels over prolonged indwelling times (p = 0.02). Along the stent shaft body, the stone group showed higher encrustation levels near the ureteropelvic junction compared to the ureterovesical junction (p = 0.013), whereas the transplant group showed no such difference. Possible explanations were discussed regarding vesicoureteral reflux. In both patient groups, stent pigtails were more susceptible to encrustations, and no difference between renal and bladder pigtail was identified. The segmentation method presented in this study is also applicable to other image analysis tasks in urology.

Comparison of the effects of potassium citrate and hydrochlorothiazide on the ureteral stent encrustation in patients with long stent survival; a single-blinded clinical trial

Introduction: The probability of encrustation after embedding ureteral stent is 9.6% in six weeks, 47.5% in 6 to 12 weeks and 76.3% in more than 12 weeks. Objectives: This study was designed to evaluate the effect of potassium citrate and hydrochlorothiazide on ureteral stent encrustation as a single-blinded clinical trial. Patients and Methods: After embedding ureteral stent in 130 patients, the individuals were randomly divided into two groups using random allocation software. Convenience sampling method was used in this study. One group was given hydrochlorothiazide and potassium citrate, and the other group did not receive any medication. All stents were the same brand and the maximum time of stents being in situ was six weeks. Four to six weeks after stent implantation, patients were referred for stent removal. Then, ureteral stent encrustation was recorded in the two groups according to the visual appearance and the difficulty in stent removing due to stent encrustation. Results: The mean age of the patients was 42.62±14.86 years. Regarding gender, 78 patients (67.8%) were male and 37 patients (32.2%) were female. In this study, 15 patients (13%) had ureteral stent encrustation, of which 13 patients (20%) were in the group without medication and two patients (4%) were in the group who received hydrochlorothiazide and potassium citrate (P = 0.012). Conclusion: The rate of ureteral stent encrustation in the patients who received hydrochlorothiazide and potassium citrate was significantly lower than the patients in the control group. This can be justified by the diuretic properties of hydrochlorothiazide and the reduction of urinary calcium levels. Additionally, high urinary citrate level and induction of urinary alkalization after the administration of potassium citrate. Are the ameliorating factors. Trial Registration: Registration of trial protocol has been approved by Iranian Registry of Clinical Trials (identifier: IRCT20180625040232N3, https://en.irct.ir/trial/46227, ethical code# IR.UMSU. REC.1396.130).

Experiences in managing different consequences of forgotten ureteral stents.

PurposeWe reported the different consequences of forgotten stents and share our managing experiences.Patients and MethodsFrom July 2011 to August 2019, eight patients (five men and three women) with forgotten encrusted ureteral stents were treated by different endoscopic procedures in our center. Plain-film radiography (kidney, ureter, and bladder [KUB]) and computed tomography were used to evaluate the position of stents, the site of encrustation, and the stone burden. Various sole or combined endoscopic techniques including percutaneous nephrolithotomy, retrograde ureteroscopic lithotripsy, and cystolitholapaxy were used to achieve stent removal.Results:The average age of the patients was 50.9 years (range: 25–72 years). The mean indwelling time of the stents was 32.9 months (range: 12–83 months). Mean stent stone burden was 15 mm × 10 mm. Three patients had stent stone burden larger than 20 mm. Three patients had a preoperative positive urine culture before treatment. The stent was fragmented in two patients. The ureteral stents and related stones were successfully removed without any complications by a sole or combined endoscopic techniques with stone-free status achieved in all patients. There is no complications occurred.Conclusion:Forgotten stents can lead to complicated urinary tract calculi, stent encrustation, urinary tract infection, vesicoureteric reflux, and even ureteral polyps. Various sole or combined endourological techniques can be used to manage the forgotten encrusted ureteral stents.

Encrustation of the ureteral double-J Stents made of styrene/ethylene/butylene and polyurethane before and after implantation

Purpose: The aim of this study was to determine the affinity to crystal, calculi and biofilm deposition on ureteral double-J stents (DJ stents) after ureterorenoscopic–lithotripsy procedure (URS-L). The analysis was performed in two aspects: to determine which material used for fabricating ureteral stents promotes encrustation and which part of the DJ stents is the most vulnerable for blockage. Methods: One hundred and twenty patients with an indwelling DJ stent duration between 7 and 78 days were included in this study. The encrustation of DJ stents was characterized by scanning electron microscopy (SEM), and the mechanical properties of DJ stents were examined using the standard MTS Micro Bionix tensile test. Results: This study showed that polyurethane catheters have a much higher affinity for encrustation than styrene/ethylene/butylene block copolymer. Obtained results indicated the proximal (renal pelvis) and distal (urinary bladder) part is the most susceptible to post-URS-L fragments and urea salt deposition. Both the DJ ureteral stents’ outer and inner surfaces were completely covered even after 7 days of implantation. Conclusions: Performed analysis pointed out that polyurethane DJ stents have a much higher affinity for encrustation of calculi and NaCl crystals compared to the silicone-based copolymer. The surface of the ureteral stents needs improvement to minimize salt and kidney stone deposition, causing pre-biofilm formation and the occurrence of defects and cracks.

Innovation and new technology in ureteral stents

Ureteral stent insertion is a procedure performed extensively by all urologists. Nevertheless, stent-related symptoms and stent encrustation are still common complications pushing the innovation and development of novel ureteral stents. Developments are focussing on three significant aspects: material, design, and removal technique. Various materials including silicone, polymers, and metals are frequently utilized, with or without an additional coating. The use of biodegradable materials is looking promising but these is a lack of proven clinical trials in association with this in humans. The new designs focus on the reduction of stent-related symptoms through the modification of the bladder end. The new stent removal techniques with extraction strings or novel magnetic end may exclude subsequent cystoscopic procedures. Finally, utilization of a ureteral stent tracker application helps in reminding both physicians and patients to remove the stent at the appropriate time.

Stent encrustation or fragmentation? A case report of post stent removal encrustation in postpartum woman and literature review

BackgroundUreteral stents are commonly used in the field of urology to relieve ureteral obstruction. However, complications relating to ureteral stent use, such as encrustation continue to occur, especially with prolonged indwell time.Case presentationHere we present a 37-year-old postpartum woman with a foreign body in her bladder after removing a ureteral stent 1 month before. She insisted that the foreign body was the fragment of stent and asked for medical malpractice indemnity payments while the surgeon of her insisted that the stent was intact during the procedure. Finally, the foreign body was confirmed as an encrustation by cystoscopy and the patient received 10,000 yuan ($ 1500) as indemnity payments after encrustation removal.ConclusionIn the absence of guidelines, stent indwelling time vary with centers’ habits, stent materials and patient’s education. Early detection of stent encrustation and timely removal of the encrusted stent are still the best way to avoid stent retention. Violent stent removal is of danger and not recommended in any case.

The Fate of Double J Stent Used in Pyelolithotomy and Uretero Lithotomy

Background: In Bangladesh there is no complete data which would reflect the idea about the fate of double J stent used in pyelolithotomy and ureterolithotomy. Methods: This was a prospective observational study, conducted at the Department of Surgery, Comilla Medical College Hospital, Comilla, during the 6-month period of June 2013 to November 2013. Fifty patients diagnosed with Nephrolithiasis & ureterolithiasis admitted at the respective hospital were selected as the study sample. Proper informed consent was taken before the data collection from the concerns. Statistical analysis of the results was obtained by using window-based computer software devised with Statistical Packages for Social Sciences (SPSS-22). Result: Among the 50 patients studied, >50% of the patients were distributed among the age group of 31-40 years and next was 21-30 years. 35 patients of the series were male (70%) and 15 were female (30%). In this series, male to female ratio was 2.33:1. Among the 50 stented patients, stone was located in kidney in 30 pts (60%), in upper ureter in 10 pts (20%), in mid and lower ureter in 4(8%) and 6(12%) patients respectively. In this study, the commonest indications of D J stenting were after pyelolithotomy, following ureteroscopy for obstructive uropathy due to ureteric stone. In this study, irritative voiding symptoms like dysuria, frequency/urgency occurred in 20% and 24% respectively, and haematuria in 10% of patients. Stent encrustation in 1 (2%), stent migration in 3 (6%), stent fracture in 1 (2%), urinary infection in 2(4%) and stent colic in 1(2%) were the complications noted. Conclusion: Ureteral stents are a convenient means of drainage for the upper urinary tract. However, their use is not devoid of side effects. Stent placement results in considerable morbidity in the form of irritative lower urinary tract symptoms. The side effects associated with ureteral stents must be kept in mind when deciding on stent placement and dwell time. ............

PD26-01 A PROSPECTIVE, RANDOMIZED, SINGLE-BLIND COMPARISON OF URETERAL STENT BIOMATERIAL ENCRUSTATION

You have accessJournal of UrologyStone Disease: Surgical Therapy III (PD26)1 Sep 2021PD26-01 A PROSPECTIVE, RANDOMIZED, SINGLE-BLIND COMPARISON OF URETERAL STENT BIOMATERIAL ENCRUSTATION Shuzo Hamamoto, Ryosuke Chaya, Masahiko Isogai, Kengo Kawase, Tomoki Okada, Tatsuya Hattori, Teruaki Sugino, Rei Unno, Kazumi Taguchi, Atsushi Okada, and Takahiro Yasui Shuzo HamamotoShuzo Hamamoto More articles by this author , Ryosuke ChayaRyosuke Chaya More articles by this author , Masahiko IsogaiMasahiko Isogai More articles by this author , Kengo KawaseKengo Kawase More articles by this author , Tomoki OkadaTomoki Okada More articles by this author , Tatsuya HattoriTatsuya Hattori More articles by this author , Teruaki SuginoTeruaki Sugino More articles by this author , Rei UnnoRei Unno More articles by this author , Kazumi TaguchiKazumi Taguchi More articles by this author , Atsushi OkadaAtsushi Okada More articles by this author , and Takahiro YasuiTakahiro Yasui More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002019.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ureteral stents are commonly used in endoscopic surgery for urinary calculi but are frequently associated with stent encrustation and stent-related infections. New biomaterials and coatings have been designed to overcome these disadvantages. However, there are no real-world reports comparing biomaterial encrustation of different stents. In this study, we prospectively evaluated the adherence of bacteria, Ca, and Mg to three different ureteral stents after endoscopic surgery for urinary calculi. METHODS: A total of 61 patients requiring insertion of ureteral stents after the treatment of urinary calculi were randomly placed into 3 groups [PercuflexⓇ with a coating composition of Hydroplus, Group 1 (n=21); Tria, with a coating composition of PercushiedⓇ, Group 2 (n=22); InLay OptimaⓇ, which had a proprietary pHreeCoat coating, Group 3 (n=18)]. All stents were removed one month after treatment and evaluated. A stent was immersed in a solution of saline and hydrochloric acid at pH 2 and subsequently vortexed for one hour. Ca and Mg contents were measured using atomic absorption spectrometry. Bacteria were measured using flow cytometry. RESULTS: There were no significant differences about patients and stone characteristics. The incidence of stone encrustation was significantly higher in Group 1 than in Groups 2 and 3 (33.3%, 11.7%, and 7.7%, respectively; p=0.02). The median amount (IQR) of Ca adhered to the stents in Group 1 was significantly higher than that in Groups 2 and 3 (5.51 (2.28-6.18), 1,91 (0.53-4.48), 2.30 (0.76-3.03) mg/dL respectively, p=0.024). The median amount (IQR) of Mg in Group 1 was significantly higher than that in Groups 2 and 3 (0.20 (0.15-0.23), 0.06 (0.04-0.20), 0.03 (0.03-0.13) mg/dL respectively, p=0.005). The median number (IQR) of bacteria was also highest in Group 1 (33.76 (23.13-109.43), 13.80 (6.23-56.25), 8.33 (6.80-21.20), respectively, p=0.056); however, there were no significant differences in bacterial adhesion. CONCLUSIONS: This randomized study showed that stents with Percusheild coating and pHreeCoat coating decreased the adherence of Ca, Mg after endoscopic treatment. These stents could reduce stent encrustation and stent-related infections. Source of Funding: none © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e437-e437 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Shuzo Hamamoto More articles by this author Ryosuke Chaya More articles by this author Masahiko Isogai More articles by this author Kengo Kawase More articles by this author Tomoki Okada More articles by this author Tatsuya Hattori More articles by this author Teruaki Sugino More articles by this author Rei Unno More articles by this author Kazumi Taguchi More articles by this author Atsushi Okada More articles by this author Takahiro Yasui More articles by this author Expand All Advertisement Loading ...

Characteristics of Double-J Stent Encrustations and Factors Associated with their Development.

To evaluate the chemical composition of double-J stent encrustation and to assess risk factors associated with their development. Patients who had double-J stents removed between July 2016 and June 2017 were recruited for this study prospectively. The clinical features of the patients were recorded and the composition of encrustation material was analyzed by infrared spectroscopy. Encrustments from a total of 372 double-J stents were collected. The mean age of patients was 50.4±13.1 years and deposits possible to analyze were obtained from 228 males (61.3%) and 144 females (38.7%). Calcium oxalate monohydrate was the most common constituent of stone and encrustments. The encrustation rate of vesical coils was significantly higher than that of renal coils (P<0.001). There was no significant difference in chemical composition between stone and encrustation regarding renal (P=0.086) and vesical coils (P=0.072). The only predictive risk factor for the development of encrustation on double-J stents was indwelling time. This phenomenon was observed in both renal (P<0.001) and vesical coils (P=0.021). Interestingly, patient with chronic kidney disease (CKD) was associated with less risk of encrustation on both renal (P<0.001) and vesical coils (P=0.001). The chemical composition of double-J stent encrustation was the same as the urinary stone. The prevention strategy for stone composition is also suitable for the prevention of encrustation of double-J stent. The only predictive factor for double-J stent encrustation was the indwelling time. CKD patient was shown to be less at risk for the development of encrustation.

Temporary urethral stent with perineal fixation for posterior urethral stenosis (preliminary results)

Introduction. Urethroplasty is the “gold standard” treatment of urethral stenosis. However, often in connection with old and senile age, as well as due to the presence of concomitant diseases, it is not possible to carry out urethroplasty due to its certain invasiveness. In such cases, one of the methods of treatment is the installation of a urethral stent. But this method has not found practical application due to the frequent migration of stent and the high frequency of its incrustation. The approach developed by us avoids stent migration.Purpose of the study. To evaluate the immediate results of the placement of a urethral stent with fixation through the perineum.Materials and methods. A total of 18 patients with urethral stenosis aged 68 to 84 years have been operated on since February 2019. Ten patients had stenosis of the urethrocystoneoanastomosis after radical prostatectomy, 6 patients had iatrogenic stenosis of the prostatic urethra, 1 patient had post-radiation stenosis of the bulbo-membranous urethra. All patients in the preoperative and postoperative periods underwent: IPSS-QoL questioning, uroflowmetry, bladder ultrasound with residual urine volume evaluation, urethroscopy, ascending and micturition urethrocystography. The first stage was an internal optical urethrotomy according to the standard technique. Then, a urethral stent was installed in the area of dissected stenosis. The second stage was an incision in the perineum, the urethra was isolated, and under optical control, through the perineum, the stent was fixed to the urethra with non-absorbable suture material. The stent was removed endoscopically after 6 months.Results. The median surgery duration averaged 45 minutes. Patients were discharged 2 to 3 days after surgery. The maximum observation period was 20 months. During the observation period, not a single case of stent migration was recorded. All patients showed a persistent increase in Qmax and no residual urine. Six patients had a stress component of urinary incontinence, 4 patients had total urinary incontinence. According to control urethrocystoscopy 6 months after stent removal, clinically insignificant urethral stenosis was noted in all patients. In all cases, moderate signs of stent encrustation were identified. Dysuric phenomena disturbed 5 patients, who were stopped by rectal suppositories with NSAIDs, as well as taking herbal uroseptics. The data from the IPPS-QoL questionnaires confirm the positive effect of the treatment.Conclusions. Temporary placement of a urethral stent for urethral stenosis is an effective minimally invasive treatment. The technique of fixation through the perineum allows preventing migration in all cases. This approach to treatment significantly improves the quality of life of patients who were contraindicated for urethroplasty for one reason or another. However, the technique requires longer observation and analysis.

Risk of chronic kidney disease in patients with retained ureteral stents

Objective: Numerous publications describe the management of stent encrustations, but few address long-term risks. The purpose of this study is to analyze the incidence of new chronic kidney disease attributed to retained ureteral stents in a large multi-institutional patient population. Materials and methods: A retrospective chart review of stone disease patients with ureteral stent placement was done in the nation-wide Cerner Health Facts database between 10 July 2009 and 7 June 2018. The estimated glomerular filtration rate was calculated using serum creatinine and the Modification of Diet in Renal Disease Study equation. The study focused on patients with stent duration longer than 6 months and an estimated glomerular filtration rate above 60 ml/min/1.73 m2 before stent placement. Results: A total of 1234 stent placements were documented in the Cerner database, 108 patients had a normal estimated glomerular filtration rate prior to the retained stent. The median duration of retained stents was 12.1 months (range 6.1 to 77.7 months), and 33 (30.6%) patients developed new onset chronic kidney disease compared to 8.3% in patients with non-retained stents. Conclusion: A new onset of chronic kidney disease was observed in 30.6% of patients with retained ureteral stent, emphasizing the importance of patient counseling and preventive measures to ensure patient compliance and follow-up. Level of evidence: Not applicable in this multi-institutional cohort study.

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

PurposeTo evaluate the effect of potassium citrate administration on the composition of encrusted material on the ureteral stent after Double-J insertion.MethodsWe 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.ResultsOur 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.ConclusionResults 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.

A randomized clinical trial evaluating the short-term results of ureteral stent encrustation in urolithiasis patients undergoing ureteroscopy: micro-computed tomography evaluation

Although many ureteral stents are commercially available, the actuality of encrustation is yet to be elucidated in humans. This study compared the Tria Ureteral Stent with PercuShield and the Polaris Ultra Ureteral Stent with HydroPlus Coating for short-term encrustation formation. Eighty-four patients, who required ureteral stent placement after ureteroscopy, were randomized into two stent groups. After stent removal on postoperative day 14, the encrustation volume on the stent surface was measured by micro-computed tomography. The primary outcome was the inner luminal encrustation volume. Secondary outcomes were encrustation volume on the outer or total surfaces and occurrence of adverse events. Clinical factors related to encrustation were also assessed as a post-hoc analysis. Finally, of the 82 patients analyzed, 75 (91.5%) had encrustation in the inner lumen of the stent. The difference in median inner encrustation volume between the Tria and Polaris Ultra stents was comparable (0.56 vs. 0.37 mm3, P = 0.183). There was no difference observed in the encrustation volume on the outer/total surfaces and stent-related adverse events. In both ureteral stents, the shaft body showed significant inner luminal encrustation compared to the proximal or distal loop (all, P < 0.05). Dyslipidemia (P = 0.027), elevated urine pH (P = 0.046), and crystalluria (P = 0.010) were associated with encrustation formation. The Tria and Polaris Ultra stents had similar efficacy for preventing encrustation in the short-term. Further studies are required to compare their long-term patency.

Atlas of Scoring Systems, Grading Tools, and Nomograms in Endourology: A Comprehensive Overview from the TOWER Endourological Society Research Group.

Introduction: With an increase in the prevalence of kidney stone disease (KSD), there has been a universal drive to develop reliable and user-friendly tools such as grading systems and predictive nomograms. An atlas of scoring systems (SS), grading tools, and nomograms in Endourology is provided in this article. Methods: A comprehensive search of world literature was performed to identify nomograms, grading systems, and classification tools in endourology related to KSD. Each of these was reviewed by the authors and has been evaluated in a narrative format with details on those that are externally validated and their respective citation count on google scholar. Results: A total of 54 endourological tools have been described in our atlas of endourological SS, grading tools, and nomograms. Of the tools, 23 (43%) have been published in the past 3 years showing an increasing interest in this area. This includes five for percutaneous nephrolithotomy, six for flexible ureteroscopy, three for semi-rigid ureteroscopy (URS), nine for extracorporeal shockwave lithotripsy, two for stent encrustations, three for intraoperative appearance at the time of URS, and three to classify intraoperative ureteric injury. There were three tools for renal colic assessment, one each for prediction of future stone event, stone classification, and stone impaction and two for need of emergency intervention in ureteral stone. Two tools are related to stone recurrence, whereas six are related to postprocedural complications. There are now two tools for simulation in endourology and five for patient-reported outcome measures. Conclusions: A number of reliable and established tools currently exist in endourology. Each of these offers their own respective advantages and disadvantages. Although nomograms and SS can help in the decision making, these must be tailored to individual patients based on their specific clinical scenarios, expectations, and informed consent.

Trans-urethral snare stent removal: a novel, self-constructed innovation for simultaneous ureteral stent removal and safety guidewire insertion.

Ureteral stent insertion and subsequent removal remains one of the most common procedures performed in endourology. We aimed to evaluate a novel, one-step method, permitting simultaneous stent removal and guidewire passage using a self-constructed suture snare via standard cystoscopy. This method should be used prior to ureteroscopy, in cases of minimal stent encrustation and peri-ureteral mucosal oedema, where identification and subsequent cannulation of the ureteral orifice may be a challenge. A self-constructed suture snare is constructed using an open-ended ureteral catheter to facilitate this novel 'Switch' technique. Operative duration, cost feasibility and potential complications with this novel method were assessed in patients with an indwelling stent duration above 100 days. Age inclusion in this study ranged from 21 to 35 years, with kidney, ureter and bladder scores below 6, in the five patients assessed. Previous ureteral stent indwelling time ranged from 106 to 315 days. Reasons for (pre-stented) ureteroscopy were mostly stone related. The overall recorded procedure time for the Switch technique was successfully performed in less than 96 s (range 68-95 s) in all cases within this series. No procedure-related complications were reported. Utilizing the suture snare, the novel Switch technique was successfully performed in all cases assessed. This method is both time and cost feasible and could be easily utilized in resource-limited areas, regional centres or in cases where a stent grasper is not available, may have malfunctioned or cannot adequately approximate due to distal ureteral stent encrustation.

Ureteral Stent Encrustation: Epidemiology, Pathophysiology, Management and Current Technology.

Encrustation is a common phenomenon that can occur following placement of a ureteral stent into the urinary tract, and it can lead to serious complications. The following review addresses the mechanism of encrustation, the management of these stents and the newest technology developed to mitigate this issue. We performed a comprehensive literature search on stent encrustation including peer-reviewed publications, public product listings, and material on current and future stent technology. The mechanism of encrustation is complex and multifaceted, including dwell time, patient specific risk factors, conditioning film formation, biofilm formation and mineral deposition. Several technological developments in stent materials and coatings may have a role in reducing the risk of stent encrustation. It is important to identify the extent of stent encrustation and plan treatment strategies accordingly. We propose a novel treatment algorithm for the management encrusted ureteral stents. The ubiquity of ureteral stents in urology practice mandates updated knowledge about the prevention of stent encrustation, identification of high risk patients and preparedness for removal using multimodal techniques.

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.

Endourological management of encrusted ureteral stents: an up-to-date guide and treatment algorithm on behalf of the European Association of Urology Young Academic Urology Urolithiasis Group.

Encrustation of ureteral stents can represent a complex challenge. Patients can require multiple intervention types as well as several operative sessions. Our aim was to establish a practical guide for managing such cases as well as an accompanying treatment algorithm. Nearly all cases can now be successfully managed with minimally invasive methods such as ureteroscopy and/or percutaneous nephrolithotomy. Use of a validated tool for grading burden of encrustation is recommended. Careful patient counselling as well as operative planning are of paramount importance. Identifying high risk patient groups such as pregnancy and implementing prevention strategies are also crucial.

Problems and solutions of stent biofilm and encrustations: A review of literature.

A ureteral stent is a commonly implanted urological device in patients with urinary tract obstruction. The main role of these stents is to allow adequate drainage of urine from the kidney into the bladder. Individuals with strictures, tumors, or obstructions from urinary stones do not have adequate urine flow and require ureteral stents as a part of their treatment to avoid potential hydronephrosis and renal failure. Although ureteral stents are highly effective in treating urinary tract obstructions, they have associated morbidities, such as biofilm formation and encrustation. Researchers have studied about how to diminish these negative outcomes by developing novel stent materials. Different coatings and biomaterials have been developed to reduce bacterial adhesion and crystal deposition onto the stent surfaces. Moreover, new investigation technologies, such as microfluidic platforms and encrustation sensors, have been utilized to better study the stents. Biofilms and encrustations can stem from bacterial origins; therefore, understanding the urinary microbiome will also provide insight into the solutions for treating them. There are still some gaps in our knowledge regarding the exact underlying mechanisms of stent-associated biofilms and encrustation. Future studies should include continuous testing of novel stent biomaterials for safety and efficacy, developing new technologies for identifying and extracting biofilms, enriching the assessment of stent encrustation, and diving deeper into understanding the urinary microbiome.