double-J Ureteral Stent Research Articles

Risk factors for bacterial stent colonization in patients with a double J ureteral stent: a prospective study

Background: The increasing use of double-J ureteral stents (DJS) has increased the risk of early intolerance and long-term complications. Studies have reported stent colonization rates ranging from 19% to 90% with various bacterial profiles in the colonization of stents. Objectives: To identify the risk factors associated with bacterial colonization of DJS and report the common microorganisms isolated and drug susceptibility pattern. Methods: This study is a prospective study of patients who underwent DJS. A total of 48 patients from our institution were studied between March 2022 and August 2023. After removal of DJS with a sterile technique, the tips of both ends (renal end and bladder end) of the stent were cut and processed in the microbiology lab. Results: Bacterial colonies were detected in 56.25% (27 out of 48) of the stents. Among the pathogens identified, Enterococcus species, Pseudomonas Aeruginosa and E. coli were the most frequently isolated. The colonization rate increased with the duration of stent placement and albuminuria. Conclusions: The study indicated that prolonged indwelling time and albuminuria are a risk factor for bacterial colonization on the stent therefore, it is advisable to use Double J ureteral stent only when absolutely necessary and to remove them promptly.

The safety and efficacy of through-and-through wire technique for ureteral Double-J stent placement.

To evaluate the efficacy and safety of the through-and-through wire (TTW) technique for antegrade ureteral Double-J stent placement after failure of either antegrade or retrograde ureteral stent placement. This retrospective study analyzed the medical records of consecutive patients who underwent Double-J stent placement with the TTW technique at Asan Medical Center and Gil Medical Center between January 2016 and February 2023. Patient histories, reasons for employing the TTW technique, TTW pathways, and complications were reviewed. Eight patients were included in the study. The reasons for using the TTW technique were failure to advance a larger-diameter catheter, balloon catheter, or Double-J stent passing over the guidewire beyond the stricture (6/8, 75.0%); failure to negotiate the stricture with a guidewire (1/8, 12.5%); and guidewire passing through a ureteropelvic junction defect (1/8, 12.5%). TTW was applied either between a percutaneous nephrostomy (PCN) and the urethral orifice (n=4), between a PCN and an ileostomy pouch (n=3), or between a left and right PCN (n = 1). Urologic assistance was required for retrograde ureteral cannulation in one male patient (12.5%). Subsequently, balloon dilation and/or Double-J stent placement were performed in all eight patients, resulting in 100% technical success. No major or minor complications occurred. The TTW technique was safe and effective in the undertaking of PCN and antegrade Double-J stent placement in patients for whom either antegrade or retrograde access had failed.

The impact of double-J ureteral stenting before radical cystectomy on the development of upper tract urothelial carcinoma.

It is controversial whether the use of a double-J stent (DJ) in patients with bladder cancer before radical cystectomy (RC) increases the risk of tumour seeding in the upper tract and thus the risk of metachronous upper tract urothelial carcinoma (UTUC). The aim of our study is to investigate the risk of upper tract recurrence after RC in patients previously managed with a DJ stent. A total of 699 patients who had undergone RC between January 2003 and March 2022 with complete perioperative data and pathological outcome were included in our study. Patients treated preoperatively with a DJ stent were identified and compared for development of metachronous UTUC with those who did not receive prior internal stenting. Multivariable Cox regression analysis was used to determine predictors of UTUC occurrence among the possible pathological features; risk factors for mortality after RC were also examined. Of 699 patients, 117 (16.7%) were managed preoperatively with a DJ stent. The overall probability of metachronous UTUC was 1%, 4% and 6% at 1, 3 and 5 years, respectively. The groups with and without DJ stenting were comparable regarding their clinicopathologic features, except for the higher incidence of hydronephrosis in the DJ group. At similar follow-up periods (median follow-up 32 months), metachronous UTUC was detected in four (3.4%) patients in the DJ group and in 13 (2.2%) in the non-stented group (P=0.44). The median interval (IQR) from cystectomy to UTUC was 40.5 (20-49) months in the DJ group and 37 (24-82) in the non-stented group (P=0.7). In the multivariable analysis, only presence of CIS (HR 3.83, 95% CI 1.19-12.29, P=0.024) and positive ureteral margin (HR=5.2, 95% CI 1.38-19.57, P=0.015) were predictors of metachronous UTUC. The study is limited by the retrospective nature and relatively short follow-up. Ureteral stenting for management of hydronephrosis in patients with bladder cancer undergoing RC is a viable option, without higher risk for UTUC or mortality. Patients with positive ureteral margin and CIS are considered high-risk groups for upper tract recurrence and should receive long-term, rigorous follow-up.

Comparative Approaches in Treating Double-J Stent Syndrome: Monotherapy or Combination Therapy?

Introduction: The application of double-J ureteral stents in urology is widespread, but their use is often accompanied by complications and bothersome symptoms, affecting patients' quality of life (QoL). While various medications have been tested for alleviating the symptoms associated with double-J stents, consensus on their effectiveness remains elusive. This study aims to investigate the effectiveness of tamsulosin, solifenacin, mirabegron, desloratadine, and combination therapy using a Romanian-adapted version of the Ureteral Stent Symptom Questionnaire (USSQ). Materials and Methods: A prospective, observational, randomised trial was conducted at the Urology and Renal Transplant Clinic of Dr. "C.I. Parhon" Clinical Hospital in Iasi between 1 January 2022 and 1 August 2023. Three hundred twenty seven patients who underwent their first double-J stent insertion were evaluated with the Romanian-adapted USSQ at baseline and 30 days post-insertion. Patients were randomly divided into six groups based on the prescribed medications: control, tamsulosin, mirabegron, solifenacin, desloratadine, and combination therapy. Results: The data suggest a significant reduction in symptoms in patients who received medication compared with the control group. Furthermore, the combined medication of solifenacin 10 mg and tamsulosin 0.4 mg was particularly effective in reducing pain with statistical significance compared to the control group (p = 0.001). The highest mean scores for urinary symptom severity were observed in the control group (12.37 ± 6.82), and the lowest was in the mirabegron group (9.94 ± 5.82). The individuals who received a daily dose of 50 mg of mirabegron saw the most notable influence on their job. Conclusions: While no single medication emerged as a "miracle drug" for managing symptoms related to double-J stent insertion, the combination therapy of solifenacin and tamsulosin is the most promising option for improving symptoms related to double-J stent insertion and QoL. Additional extensive research is required to validate these initial results.

Dynamic renal scans as a modality for follow-up of flexible ureteroscopy.

To determine whether dynamic renal scans - DTPA or MAG3 - routinely performed after flexible ureteroscopies (f-URS) could detect the development of an obstruction and thus promote prompt early intervention for kidney preservation. In this retrospective study, with all the data recorded prospectively between April 2010 and October 2023, 250 renal units in 242 patients with upper urinary tract stones (UUTS) who underwent ureterorenoscopy by one surgeon in the same medical center were evaluated. Stone-free rate (SFR) was defined as no residual fragments at all using an intraoperative "triple test". The following characteristics were examined: gender, BMI, age, Hounsfield unit, stone diameter, laterality, renal/ureteral stones, stone-free rate, and auxiliary procedures per renal unit. The Clavien-Dindo classification was used to report complications. Renal units with residual stones were scheduled for a 2nd f-URS. Post- flexible ureteroscopy ureteral obstruction and renal function were detected using renal scan DTPA or MAG-3. The primary outcome was renal/ ureteral obstruction. The mean patient age was 53 years. The mean stone size was 12.3 mm. Stones in renal pelvis, upper, middle and lower calyces were treated in 9.2% (23), 27.6% (69), and 30.8% (77) of cases, respectively; 44% (110) ureteral stones were also treated. The single- and second-session SFRs were 94.8% and 99.7%, respectively. A third auxiliary procedure was needed in one renal unit (0.4%). The mean number of procedures per renal unit was 1.06 (264/250). Ureteral double-J stents were inserted in 53.6% (134) of the cases. In 37 (14.8%) cases, a stent was placed before surgery. Post-operative complications were minor, with readmission and pain control needed in only two patients (0.8%). No avulsion or perforation of the ureters was observed. In six patients with t1/2 between 10-20 minutes, a second renal scan revealed spontaneous improvement and no obstruction in five patients. One patient with large stones and a history of prior ureteroscopy developed a ureteral stricture (0.4%) and needed treatment with laser endoureterotomy. Post-flexible ureteroscopy obstruction due to ureteral stricture is very rare. A routine renal scan post-operatively may be used in potentially high-risk patients.

Migration of double-J ureteral stent in patients with ureteroileal anastomosis stricture undergoing radical cystectomy and orthotopic neobladder: Analysis risk factors of stent migration.

The objective was to evaluate the incidence and degree of double-J ureteral stent (DJUS) migration. Additionally, we aimed to investigate the risk factors associated with stent migration in the orthotopic neobladder group. In this retrospective study, 61 consecutive patients were included; 35 patients (45 DJUS placements) underwent radical cystectomy with orthotopic neobladder and 26 patients (35 DJUS placements) underwent urinary bladder without cystectomy between July 2021 and March 2023. All the patients were treated with a DJUS for ureteric strictures. The technical success rate was 100% in each group. The DJUS migration was significantly higher in the orthotopic neobladder group, with 22 of 45 cases (48.9%), compared to the urinary bladder group, which had 4 of 35 cases (11.4%) (P ≤ .001). Among the patients in the orthotopic neobladder group who experienced DJUS migration, stent dysfunction occurred in 18 cases (81.8%), which was statistically significant (P = .003). Multivariate logistic regression analysis revealed that only the size of the DJUS was significantly and positively associated with migration (odds ratio:10.214, P = .010). DJUS migration can easily occur in patients undergoing radical cystectomy and orthotopic neobladder, and smaller stent sizes are associated with a higher incidence of migration.

Effect of theophylline on stent-related symptoms in patients undergoing Double-J ureteral stent insertion: a randomized controlled trial.

To investigate the effect of oral theophylline on stent-related syndrome (SRS) after Double-J insertion. Double-J stent is widely using in many urological procedures. Infection, hematuria, and discomfort are some of common complication after stenting. Theophylline is a dimethylated xanthine that inhibits phosphodiesterase and blocks adenosine receptors. To relaxing effect of theophylline on smooth muscles and its effects on the urinary system, it seems it could reduce complications after inserting Double-J stent especially ureteral stent syndrome. In this double-blind placebo-controlled randomized clinical trial, 67 patients were enrolled. Mean (SD) age of control and theophylline group was 51.8 (12.5) and 43.9 (10.4) years old, respectively. Patients were randomized into two groups of control and theophylline. All patients were stenting with silicon Double J. Theophylline group received 100mg of theophylline, twice daily for 30days, while control group received placebo. Stent symptoms were assessed by questionnaire and urine culture was performed before stent removal at removal day. Statistical analysis was performed using Chi-squared test and t test with P < 0.05 considered significant. Logistic regression models were fitted, crudely and adjusted for age and sex. Of 67 eligible patients, 60 completed the study. Theophylline significantly decreased percentages of gross hematuria (P < 0.001), dysuria (P < 0.001), and urinary frequency (P < 0.001). Microscopic hematuria (P = 0.042) and chills (P = 0.042) also decreased after theophylline. Theophylline could be an effective and safe choice for reducing SRS among patients undergoing Double-J stent insertion.

Enhancing Kidney Transplant Outcomes: The Impact of Living Donor Programs.

The protocol for deceased donor kidney transplants has been standardised. The procedure for a living donor has peculiarities derived from the differences in the graft. When a living kidney donor program is implemented, changes occur in both the profile of the kidney transplant candidate and in the postoperative treatments. To discover whether a living donor program influences the functional outcomes of kidney grafts in a longstanding classical deceased donor kidney transplant program and to identify the factors associated with transplant outcomes. Retrospective observational multicentre study. Kidney transplant patients in two urology referral centres for renal transplant in Spain between 1994 and 2019. Groups: TV (living transplant): patients given kidney transplants from living donors (n = 150); TCpre11 (deceased transplant previous to 2011): patients given kidney transplants from deceased donors before the living donor program was implemented (n = 650); and TCpost11 (deceased transplant after 2011): patients given kidney transplants from deceased donors after the living donor program was implemented (n = 500). Mean age was 55.75 years (18-80 years), higher in TCpre11. There were 493 female patients (37.92%) and 1007 male patients (62.08%). Mean body mass index (BMI) was 26.69 kg/m2 (17.50-42.78 kg/m2), higher in TCpre11. Mean ischemia time was 17.97 h (6-29 h), higher in TCpost11. Median duration of urethral catheter: 8 days (6-98 days), higher in TCpost11. Median duration of double-J ureteral stent: 58 days (24-180 days), higher in TCpost11. Pretransplant UTIs: 17.77%, higher in TCpre11 (25.69%) than in TV (12%), higher in TV (12%) than TCpost11 (9.2%), and higher in TCpre11 (25.69%) than TCpost11 (9.2%). Acute renal rejection in 9.33% of TV, 14.77% of TCpre11, and 9.8% of TCpost11. Multivariate analysis: TCpost11 featured higher BMI, more smoking, and chronic renal failure progression time. Lower use of nonantibiotic prophylaxis to prevent recurrent urinary tract infections, increased duration of urethral catheters due to obstructive problems, and favoured deterioration of kidney function was observed in the deceased donor program. The living donor (LD) program had a strong influence on deceased donor transplants in the prelysis phase. Implementation of a LD program was associated with a decrease in the likelihood of acute rejection in TCpost11 and an increase in the tendency towards normal kidney function. Implementing living donor transplant programs affects functional outcomes in deceased donor transplants, reducing the probability of acute rejection and increasing the tendency towards normal kidney function. Preventing recurrent urinary tract infections with measures other than antibiotics, smoking cessation, delaying the removal of the double-J stent from the graft, and pre-emptive transplant (transplant prior to dialysis) are associated with improved renal function of the graft.

Technical feasibility and safety of the alternative snare technique using a 0.018-inch guide wire and 5-French catheter for double-J ureteral stent removal.

To evaluate the technical feasibility of the alternative snare technique using a 0.018-inch guide wire and 5-French (Fr) catheter for double-J ureteral stent (DJUS) removal. In this retrospective study, 11 DJUS were removed in 9 consecutive patients between July 2023 and October 2023. We evaluated patient characteristics, DJUS characteristics, and procedure characteristics. Out of 11 cases, 8 (72.7%) were successful in removing the DJUS using the alternative snare technique without major complications. The average time between DJUS insertion and removal was 47.4 ± 50.0 days. The most common DJUS size was an 8-Fr, with proximal tips predominantly in the proximal ureter and renal pelvis. The mean procedure time for successful cases was 15.2 ± 16.8 minutes. Three failed cases, attributed to obstructions like debris, were later successfully addressed using the ALN inferior vena cava filter removal kit, forceps, and modified snare technique. The alternative snare technique using a 0.018-inch guidewire and Fr catheter is safe and effective in cases of DJUS removal.

Management of Complications from Ureteral Double-J Stents of BioradMedisys and Analysis of Risk Factors

Double-J ureteral stents of Biorad Medisys are widely used to treat urinary blockages. Early consequences with double-J stents often include pain, bladder irritation, and fever; late issues are more bothersome. We examine four instances that demonstrate a range of late problems with double-J stents (encrustation, migration, and fragmentation). Following a review of the literature, recommendations for monitoring potential risk factors are developed, as well as treatment measures for preventing problems while utilising double-J stents.

The importance of preoperative evaluation to predict the outcome of percutaneous nephrostomy

Abstract: Percutaneous nephrostomy (PCN) is an invasive procedure equal to a grade 4 penetrating kidney trauma. It should be carefully considered whether has a greater benefit or risk. There are currently no parameters or scores to predict the outcome of nephrostomy in our center. This study aimed to conduct a review to find out whether there were parameters or scores that could be used to predict the outcome of nephrostomy. This research used relevant studies obtained from Clinical Key, PubMed, Semantic Scholar, Dimensions, and Science Direct published in the last 10 years and written in English. Studies on children and transplant cases were excluded. Studies that met the PICO criteria were selected. The results showed that of the 141 articles collected, and filtered with inclusion criteria, exclusion criteria, and PICO criteria, finally the remaining were three studies selected. The studies discussed about classification, SFU grading system, and complication of nephrostomy; significant variables affecting recoverability of renal function; patients’ characteristics and outcomes of double J ureteral stenting (DJS) and PCN; and 12-month-post-operative creatinine level change. Most patients who failed DJS had increased creatinine level. However, one of the indications for a nephrostomy was stenting failure. In conclusion, predictor factors that can affect the renal recovery after nephrostomy include kidney shape and size, pre-nephrostomy creatinine levels, urine output, state of infection, and degree of hydronephrosis. However, the evidence is still not enough. Further research is needed on the predictor factors for renal recovery after nephrostomy. Keywords: percutaneous nephrostomy; hydronephrosis; kidney function; predictors

Percutaneous Ureteral Stent Insertion in Patients with Benign Uretero-Ileal Anastomosis Strictures Who Underwent Radical Cystectomy: Assessing Risk Factors for Stent Patency.

We aimed to investigate the risk factors of early double-J ureteral stent (DJUS) dysfunction rates and the long-term patency of DJUSs inserted via a percutaneous approach in patients with benign uretero-ileal anastomosis stricture (UIAS) who had undergone radical cystectomy. In this retrospective study, 63 DJUS placements were placed via a percutaneous nephrostomy tract in 42 consecutive patients between May 2020 and March 2023. The technical success rate was 100% in all patients without major complications. The early dysfunction rate and long-term patency rate were 38.1% (24/63) and 84.2% (32/38), respectively. The blood clot retention grade, balloon dilatation, and length of the ureteral stricture exhibited a significant correlation with early DJUS dysfunction (blood clot retention grade: odds ratio (OR) 6.922 in grade two, p = 0.009; balloon dilatation: OR 0.186, p = 0.017; length of ureteral stricture: OR 8.715, p = 0.035 in moderate stenosis, and 7.646, p = 0.028 in severe stenosis). A multivariate Cox's proportional hazard analysis revealed that blood clot retention grade and length of ureteral stricture were independent predictors of long-term DJUS patency. Percutaneous insertion of the DJUSs was safe and effective in patients with benign UIAS.

Efficacy of Pregabalin, Solifenacin, or Combination Therapy for Ureteral Stent Related Symptoms: A Systematic Review and Meta-Analysis

Objective: The Double-J (DJ) ureteral stent is essential in urology but can lead to Ureteral Stent-Related Symptoms (USRS), prompting research into various therapies to enhance patient comfort. The purpose of this study is to assess the efficacy of pregabalin, solifenacin, or combined therapy on ureteral stent-related symptoms. Materials and Methods: We conducted thorough searches in four databases, which included PubMed, Cochrane, EBSCO, and ProQuest. PRISMA Guideline 2020 was applied in this study. The risk of bias was assessed using Newcastle-Ottawa Scale and Cochrane Risk of Bias 2.0. Results: Ten studies consisting of 1477 participants were included in this study. Solifenacin monotherapy could significantly decrease total USSQ (mean difference (MD) -16.62; p=0.001), urinary symptoms (MD -9.16; p=0.002), and sexual matters (MD -0.81; p=0.002). Pregabalin monotherapy could significantly decrease pain (MD -7.29; p&lt;0.00001). Compared to solifenacin monotherapy, combination therapy of pregabalin and solifenacin could significantly decrease total USSQ (MD -12.40; p &lt;0.0001), urinary symptoms (MD -1.88; p=0.007), pain (MD -6.82; p&lt;0.00001), sexual matters (MD -0.77; p &lt;0.00001), and additional problems (MD -1.51; p=0.0007). Conclusion: Combination therapy of pregabalin and solifenacin had the best advantages in lowering USRS, especially urinary symptoms, pain, sexual matters, and some other additional problems.

Analysis of Pathogens of Urinary Tract Infections Associated with Indwelling Double-J Stents and Their Susceptibility to Globularia alypum.

Ureteral double-J stents are frequently used to prevent urinary obstruction. They can develop bacterial colonization and encrustation, which leads to persistent infections that seldom respond to antibiotic treatment. Thus, the goal of this study was to evaluate the local spectrum of bacterial pathogens and their susceptibility to natural compounds. A total of 59 double-J ureteral stents from 59 consecutive patients were examined. The samples were inoculated on agar culture mediums. Extracts of Globularia alypum L. were evaluated for their antibacterial activity with the diffusion and broth dilution methods; for antibiofilm activity, the crystal violet assay was used. The identification and the quantification of the different constituents of extracts were determined by reverse-phase high-performance liquid chromatography (RP-HPLC). Bacterial growth was found in three patients (5.1%). Enterococcus faecalis (1.7%), Acinetobacter baumanii (1.7%), and Pseudomonas putida (1.7%) strains were more commonly detected. They were resistant to several common antibiotics. All extracts presented several components, mainly nepetin-7-glucoside and trans-ferulic-acid, and they had antibacterial activity (MIC = 6.25 mg/mL and MBC = 6.25 mg/mL), and antibiofilm (59.70% at 25 mg/mL) properties, especially against Acinetobacter baumanii. The results achieved confirm the important role of this plant as a source of therapeutic activities.

Fluorescence guidance during robotic resection of bladder wall endometriosis: case report and technique.

The application of indocyanine green (ICG) has recently been reported to aid in the resection of endometriosis in the bladder wall and/or involving the ureters. A symptomatic 41-year-old patient with dysmenorrhea and pollakisuria was referred to our tertiary center. Imaging revealed a 1.5-2cm intramural endometriotic nodule in the posterior bladder wall. She was planned for robotic resection of the endometriotic nodule, under ICG guidance, together with a hysterectomy. After placement of double-J ureteral stents and clamping the bladder, perforation of the bladder mucosa could be avoided whilst performing a circumferential resection of the nodule. By clamping the bladder catheter after instillation of ICG, both the bladder wall thickness and ureters could be visualized with near-infrared imaging during robotic resection of the endometriotic nodule and hysterectomy. With the surgical approach described here, endometriotic nodules/tissue can be removed precisely with enlarged vision at the robot console, safely, and completely without damaging adjacent tissues.

Proximal migration of the ureteral double-J stent into the peritoneal cavity without peritonitis: A Rare Complication

Proximal migration of the ureteral double-J stent into the peritoneal cavity without peritonitis: A Rare Complication

Unilateral Incomplete Bifid Ureter with UPJ Syndromes: A Case Report

Introduction: The ureters are muscular tubes that extend from the kidneys to the urinary bladder. The urine is propelled along the ureter by peristaltic contraction of the muscle coat, assisted by the filtration pressure of the glomeruli. Bifid ureter (BU) are rare congenital anomalies. Is a condition in which the ureter is duplicated, and it can be classified into complete (when they join separately at the urinary bladder) or incomplete –Y ureter- (When they fuse at some point in their trajectory). In the literature, the prevalence of duplicated ureter approximately 0.8%. Case: A 39-year-old woman was presented with history of chronic right-side flank pain and not associated with other urological symptoms. Physical examination revealed right flank tenderness and normal renal function test; urine culture was negative. Contrast- enhanced computed tomography showed right bifid ureters associated with moderate right hydronephrosis with a fine ureters evoking ureteropelvic junction syndromes (UPJ). Cystoscopy with retrograde pyelography revealed a right bifid ureter. The patient consented to open surgery by right mini-incision lombotomy (pyelotmy and anastomos peylo-ureteal latero-lateral) which is after a double-J ureteral stent was placed in the normal right ureter. The postoperative follow up was good. Conclusion: The BU with ureteropelvic junction syndromes are rare congenital anomalies. It is very important to diagnose urinary tract anomalies prior to interventions and supplementary evaluations should be considered. Retrograde pylogram can be a good tool than intravenous pylogram to detect such anomaly. The management can be open or laparoscopic.

Outcomes of primary ureteroscopic lithotripsy: The role of maximum ureteral wall thickness at the site of stone impaction.

To verify if the maximum thickness of the ureteral wall at the stone site (m-UWT) can affect the outcomes of primary retrograde ureteroscopic lithotripsy (P-URSL) within a single-center dataset. We retrospectively reviewed data on 354 consecutive URSL performed from January 2020 to May 2022 at "Fondazione Poliambulanza" in Brescia (Italy). We included patients older than 18 years who underwent URSL for a single ureteral stone with a maximum diameter ranging from 5 to 10 mm. Patients with anatomical abnormalities, a positive preoperative urinary culture, or without a NCCT performed during the acute event were excluded. Patients were treated in an emergency setting (P-URSL within 48 h from the diagnosis of acute ureteral colic) or in a delayed one (D-URSL after a period of maximum 90 days of ureteral double-j stenting). For the resulting 139 patients we recorded demographic, clinical and stone-related features and perioperative data. We processed these data by univariate and multivariate analysis, and with a logistic regression analysis. Of the 139 included procedures, 63 were P-URSL and 76 D-URSL. At the univariate analysis we found that stone diameter (OR 0.845, p = 0.017), stone volume (OR 0.023, p = 0.001), stone density (OR 0.998, p = 0.000) and m-UWT (OR 0.499, p = 0.013) are predictors of P-URSL. Stone density (OR 0.998, p = 0.002) is an independent predictor of P-URSL at the multivariate analysis. At a logistic regression analysis, a distal ureteric position (OR 0.189, p = 0.014), stone diameter (OR 1.289, p = 0.006), and m-UWT (OR 2.297, p = 0.02) were found to be statistically significant predictors of incomplete stone clearance in patients undergoing P-URSL. m-UWT is the only predictor of short-term postoperative adverse events in patients undergoing P-URSL (OR 3.386, p < 0.001). From a descriptive analysis, it emerged that an increased m-UWT (>2 mm) significantly correlates to an endoscopic finding of ureteritis' signs and to an increase in operative time, hospital stay and post-procedural stenting time. A m-UWT greater than 2 mm also correlates with a lower stone free rate (SFR) and with a significant increase in both short and long-term postoperative complications. Our study confirmed a connection between m-UWT and poor endoscopic findings, as well as a direct correlation with the main morphometric parameters of the stone and finally with the outcomes of P-URSL itself. Further studies are necessary to validate our results, so that m-UWT might be routinely considered a useful tool in the decision-making process for P-URSL.

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

PurposeTo determine the effectiveness of exchange and upsizing of malfunctioning small-caliber double-J (JJ) ureteral stents. Materials and MethodsThirty-one patients with malfunctioning cystoscopically placed small-caliber (6 or 7 F) JJ stents underwent transurethral (n = 28) or transrenal (n = 3) exchange and upsizing to a large-caliber (10 F) JJ stent from 2013 to 2022. Ureteral obstruction was malignant in 20 patients (65%) and benign in 11 (35%). Fifteen patients (48%) presented with persistent hydroureteronephrosis and 16 patients (52%) with worsening hydronephrosis. Acute kidney injury (AKI) was present in 19 patients (61%) at the time of stent malfunction. Therapeutic success was defined as resolution of hydronephrosis and AKI, if present. ResultsJJ stent exchange and upsizing was technically successful in 31 patients (100%) with no immediate adverse events. Therapeutic success was achieved in 27 patients (87%). During follow-up (median, 97 days; IQR, 32–205 days), 2 patients who initially achieved therapeutic success had stent malfunction, requiring conversion to percutaneous nephrostomy drainage (2/27, 7%). ConclusionsExchange and upsizing to large-caliber JJ stents can relieve urinary obstruction and resolve AKI in patients with malfunctioning small-caliber JJ stents. Large-caliber JJ stents should be considered as a salvage option for patients who wish to continue internal drainage and avoid percutaneous nephrostomy.

Electromechanically Functionalized Ureteral Stents for Wireless Obstruction Monitoring.

While millions of ureteral stents are placed in patients with urinary tract issues around the world every year, hydronephrosis still poses great danger to these patients as a common complication. In the present work, an intelligent double-J ureteral stent equipped with a micro pressure sensor and antenna circuitry is investigated and prototyped toward enabling continuous wireless monitoring of kidney pressure to detect a ureteral obstruction and the resultant hydronephrosis via the indwelling stent. This electromechanically functionalized "intelligent" ureteral stent acts as a radiofrequency resonator with a pressure-sensitive resonant frequency that can be interrogated using an external antenna to track the local pressure. The prototype passes mechanical bending tests of up to 15 cm radius of curvature and shows wireless sensing with a sensitivity of 3.1 kHz/mmHg in artificial urine, which represents 25× enhancement over the preceding design, using an in vitro model with test tissue layers and a pressure range that functions within the conditions found in hydronephrotic conditions. These promising results are expected to propel intelligent ureteral stent technology into further clinical research.