The management of malignant ureteral obstruction treated with ureteral stents

Comparison of percutaneous antegrade double-J ureteral stent placement: first-hand vs. nephrostomy route approaches

OBJECTIVE

This study aimed to conduct a comparative analysis of procedural efficacy, safety, and patient outcomes between 2 distinct approaches for percutaneous antegrade double-J ureteral stent (DJS) insertion: the first-hand approach and via a nephrostomy route.

METHODS

Electronic records of patients undergoing percutaneous antegrade ureteral DJS placement from January 2016 to 2023 were reviewed. Patients were categorized into 2 groups based on stent placement technique: the first-hand group, involving a single-stage approach without prior percutaneous nephrostomy catheter insertion, and the nephrostomy group, where stent placement occurred through a percutaneous nephrostomy tube. Clinical data, including patient demographics, primary diagnoses, procedural details, complication rates, stent placement success, and post-procedural outcomes, were collected and analysed.

RESULTS

Both approaches demonstrated high technical success rates (93.1%). However, the nephrostomy route group exhibited a comparatively higher fluoroscopy exposure rate (8.2 min) than the first-hand group (6.8 min). Moreover, the complication risk increased by 3.08 times in patients treated with the nephrostomy method (P = .047). Notably, in cases of urinary malignancies, the preference was for placing DJS via nephrostomy.

CONCLUSION

The first-hand approach should be prioritized as the initial choice in suitable cases owing to its reduced fluoroscopy time, lower complication rate, and the single-stage nature of the procedure.

ADVANCES IN KNOWLEDGE

With the exception of cases necessitating urgent drainage, such as post-renal acute renal failure and urosepsis, the first-hand method is the primary approach for inserting DJS. This is primarily due to the significantly shorter radiation time and the single-stage nature of the procedure.

Effect of emergent nephrostomy on long-term total and split renal function in patients with upper urinary tract obstruction due to pelvic malignant tumors

PURPOSE

This study aimed to investigate the impact of nephrostomies on the outcome of total renal function (TRF) and split renal function (SRF) in patients with malignant pelvic tumors associated with upper urinary tract obstruction (UUTO).

METHODS

Patients with pelvic tumors suffering severe unilateral hydronephrosis treated at our hospital from 2000 to 2022 were included. Data for nephrostomy placement, short- and long-term renal function, and radiological and nuclear imaging studies were collected. The TRF and SRF of patients who underwent nephrostomy were compared to those who did not.

RESULTS

Seven patients were included (rhabdomyosarcoma: 5, ovarian germ cell tumor: 1, malignant rhabdoid tumor: 1). Nephrostomies were placed in four, which were successfully managed without severe infections. Estimated glomerular filtration rate (eGFR) was significantly improved at the end of treatment in patients with nephrostomy. In contrast, eGFR in patients who did not undergo nephrostomy was not improved. Nuclear imaging studies (renograms or renal scintigrams) revealed impaired SRF of the affected kidney compared to the contralateral kidney, even in patients whose eGFR was within normal levels. Notably, SRF showed a trend to improve over time in one patient treated with nephrostomy.

CONCLUSION

Nephrostomy for UUTO caused by pelvic tumors may improve renal outcome.

3D-Printed Piezoelectric Stents for Electricity Generation Driven by Pressure Fluctuation

Vascular stenting is a common procedure used to treat diseased blood vessels by opening the narrowed vessel lumen and restoring blood flow to ischemic tissues in the heart and other organs. In this work, we report a novel piezoelectric stent featuring a zigzag shape fabricated by fused deposition modeling three-dimensional (3D) printing with a built-in electric field. The piezoelectric composite was made of potassium sodium niobite microparticles and poly(vinylidene fluoride-co-hexafluoropropylene), complementing each other with good piezoelectric performance and mechanical resilience. The in situ poling yielded an appreciable piezoelectricity (d33 ∼ 4.2 pC N-1) of the as-printed stents. In vitro testing revealed that materials are nontoxic to vascular cells and have low thrombotic potential. Under stimulated blood pressure fluctuation, the as-printed piezoelectric stent was able to generate peak-to-peak voltage from 0.07 to 0.15 V corresponding to pressure changes from 20 to 120 Psi, giving a sensitivity of 7.02 × 10-4 V Psi-1. Biocompatible piezoelectric stents bring potential opportunities for the real-time monitoring of blood vessels or enabling therapeutic functions.

Cost-effectiveness of Resonance® metallic ureteral stent compared with standard polyurethane ureteral stents in malignant ureteric obstruction: A cost-utility analysis

Background

Malignant ureteral obstruction (MUO) is a frequent challenge for urologists. Patients have poor prognoses, treatment aims to improve quality-of-life while optimising renal function. Standard practice in the United Kingdom is to use polyurethane stents, which require frequent surgical replacements for blockages and encrustation. More durable metallic stents are available, although these incur an increased initial purchase price.

Aims

We aim to assess whether the use of polyurethane double-J (JJ) or metallic stent, Resonance® is more cost-effective for managing MUO in the UK healthcare setting.

Methods

A Markov model was parameterised to 5 years with costs and health-related quality-of-life consequences for treating MUO with Resonance metallic stent (Cook Medical), versus standard JJ stents, from the UK care system perspective, with 3.5% discounting. Deterministic and probabilistic sensitivity analyses were undertaken to assess the effect of uncertainty.

Results

Over 5 years, approximately four fewer repeat surgical interventions were estimated in the metallic stent arm compared with the JJ stent, driving a 23.4% reduction in costs. The mean estimates of costs and benefits indicate that treatment of MUO with Resonance for 5 years is dominant over JJ stents. Over 5 years a cost-saving of £2164.74 and a health gain of +0.046 quality-adjusted life years (QALYs) per patient is estimated. With a maximum willingness to pay of £20 k per QALY, a net monetary benefit (NMB) of £3077.83 is estimated. Probabilistic sensitivity analysis at a willingness to pay threshold of £20 000 indicates an 89.3% probability of Resonance being cost-effective over JJ stents. Within 1-year savings of £726.53 are estimated driven by a reduction of two fewer repeat surgical interventions when using the metallic stent.

Conclusions

Resonance metallic stents for the treatment of MUO reduce the number of repeat procedures and could be a cost-effective option for the treatment, potentially offering efficiencies to the healthcare system.

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.

Impact of long-term indwelling JJ stent on renal volume and renal function

BACKGROUND

Data is lacking about long-term impact of JJ stents (JJst) on renal parenchyma. The aim of the study was to assess the evolution of renal parenchyma in patients with JJst indwelling for more than two years, and to find predictive factors for the development of renal atrophy.

METHODS

Consecutive patients with JJst indwelled for more than 24 months, with a history of cancer, were retrospectively included. Replacements of JJst were scheduled every six months, or earlier in case of premature obstruction. Patient characteristics at the time of insertion of JJst, history of indwelling JJst and most recent data (serum creatinine, cancer status, definite JJst removal, renal volume (RV) with3D software) were recorded.

RESULTS

With a median follow-up of 4 years, 73 patients were included. The indication of JJst insertion was mostly external compression (65.8%). CT scans were available to assess RV evolution in 66 patients (90.4%). Median shrinkage of RV was higher when JJ stenting was unilateral versus bilateral: -40% (-63; -15) versus -16% (-36; -3), P<0.001. The duration of indwelling JJst was the only statistically significative predictive factor of renal shrinkage in multivariate analysis (OR [CI 95%]: 1.35 [1.10-1.66] P=0.004). Median relative change from baseline in eGFR was -22% (-45%; -5%.). No statistically significant predictive factors of eGFR evolution were found in univariate and multivariate analysis.

CONCLUSIONS

Unilateral JJst for more than 2 years was associated with a significant shrinkage of renal parenchyma, especially since the duration of the indwelling stent was long.

Evaluation of Renal Function and Stent Durability Following Resonance Stent Placement for Benign Disease

Introduction: The metal-based Resonance stent (RS) has traditionally been placed in patients with malignant ureteral obstruction; as such, the long-term utility of RS among patients with benign ureteral obstruction (BUO) remains underinvestigated. Methods: We retrospectively reviewed our database for patients with BUO who underwent RS placement between 2010 and 2020. The impact of chronic RS placement on renal function was evaluated by estimated serum creatinine-based glomerular filtration rate (eGFR), furosemide renal scan, and CT-based renal parenchymal volume measurement. The number of and reason for RS stent exchanges during the follow-up period, incidence of encrustation, and the average indwell time were recorded. A cost analysis of placing the RS vs a polymeric stent was performed. Results: Among 43 RS patients with BUO, at a mean follow-up of 26 months, there was no change in eGFR (p = 0.99), parenchymal volume (p = 0.44), or split renal function of the stent-bearing side on renal scan (p = 0.48). The mean RS indwell time was 9.7 months. Eleven patients (26%) underwent premature stent replacement (6 cases) or removal (5 cases). Stents in 9 patients (32%) were encrusted, of which 4 (44%) required laser lithotripsy. Overall, 25 patients (58%) and 12 patients (28%) had a mean stent indwell time of ≥6 months and ≥12 months, respectively. Placing an RS resulted in a 52%, 37%, and 5.6% cost reduction compared with a regular polymeric stent placement, where it was exchanged every 6, 4, or 3 months, respectively. Conclusions: RS deployment in the patient with a BUO results in cost-effective maintenance of renal function and of renal parenchymal volume at a mean follow-up of 2 years; however, only 28% of patients fulfilled the 1-year criterion for RS indwell time.

Unveiling the Challenges in Tandem Ureteral Stent Management for Malignant Ureteral Obstruction: Failure Rate, Risk Factors, and Durability of Their Replacement

BACKGROUND

Malignant ureteral obstruction (MUO) is a sequela of advanced malignant disease that requires renal drainage, with tandem ureteral stents (TUSs) being a viable option. This study aimed to evaluate the TUS failure rate, associated risk factors, and the feasibility of replacing failed TUSs with a new pair of stents.

METHODS

A retrospective analysis of MUO patients treated with TUS insertion from 2014 to 2022 was conducted. TUS failure was defined as urosepsis, recurrent urinary tract infections, acute kidney failure, or new hydronephrosis on imaging. Cox proportional hazard regression analysis identified the independent predictors of TUS failure.

RESULTS

A total of 240 procedures were performed on 186 patients, with TUS drainage failing in 67 patients (36%). The median time to failure was 7 months. Multivariate analysis revealed female gender (OR = 3.46, p = 0.002), pelvic mass (OR = 1.75, p = 0.001), and distal ureteral obstruction (OR = 2.27, p = 0.04) as significant risk factors for TUS failure. Of the failure group, 42 patients (22.6%) underwent TUS replacement for a new pair. Yet, 24 (57.2%) experienced a second failure, with a median time of 4.5 months. The risk factors for TUS second failure included a stricture longer than 30 mm (OR = 11.8, p = 0.04), replacement with TUSs of the same diameter (OR = 43, p = 0.003), and initial TUS failure within 6 months (OR = 19.2, p = 0.006).

CONCLUSIONS

TUS insertion for the treatment of MUO is feasible and has good outcomes with a relatively low failure rate. Primary pelvic mass and distal ureteral obstruction pose higher risks for TUS failure. Replacing failed TUSs with a new pair has a success rate of 42.8%. Consideration should be given to placing larger diameter stents when replacing failed TUS.

Association between hysterectomy and kidney stone disease: results from the National Health and Nutrition Examination Survey 2007-2018 and Mendelian randomization analysis

PURPOSE

Hysterectomy is one of the most common types of gynecological operations and it is associated with numerous postoperative complications. Few studies have reported a definitive association between hysterectomy and kidney stone disease (KSD). This study aimed to explore whether hysterectomy increases the risk of KSD.

METHODS

This is a cross-sectional study that used six continuous cycles of data obtained from the National Health and Nutrition Examination Survey from 2007 to 2018. The correlations between hysterectomy or age at hysterectomy and the prevalence of KSD were assessed using weighted multivariable-adjusted logistic regression. Further, five methods of two-sample Mendelian randomization (MR) were applied to decrease bias and infer causality in the observational study.

RESULTS

After adjusting for potential confounders, hysterectomy (OR: 1.37, 95% CI 1.04-1.81) was found to be positively associated with the prevalence of KSD, whereas age at hysterectomy was found to be negatively associated with the prevalence of KSD (OR: 0.96, 95% CI: 0.94-0.98). In the inverse-variance weighted method, MR analyses suggested that genetically predicted hysterectomy is causally associated with a higher risk of KSD (OR: 11.961, 95% CI 1.12-1.28E2).

CONCLUSIONS

Hysterectomy could increase the risk of KSD. Younger age at hysterectomy is associated with a higher risk of KSD. Further prospective cohort studies with larger sample sizes and longer follow-up times are needed.

Acute kidney injury due to bilateral malignant ureteral obstruction: Is there an optimal mode of drainage?

There is a well-known relationship between malignancy and impairment of kidney functions, either in the form of acute kidney injury or chronic kidney disease. In the former, however, bilateral malignant ureteral obstruction is a surgically correctable factor of this complex pathology. It warrants urgent drainage of the kidneys in emergency settings. However, there are multiple controversies and debates about the optimal mode of drainage of the bilaterally obstructed kidneys in these patients. This review addressed most of the concerns and provided a comprehensive presentation of this topic from the recent literature. Also, we provided different perspectives on the management of the bilateral obstructed kidneys due to malignancy. Despite the frequent trials for improving the success rates and functions of ureteral stents, placement of a percutaneous nephrostomy tube remains the most recommended tool of drainage due to bilateral ureteral obstruction, especially in patients with advanced malignancy. However, the disturbance of the quality of life of those patients remains a major unresolved concern. Beside the unfavorable prognostic potential of the underlying malignancy and the various risk stratification models that have been proposed, the response of the kidney to initial drainage can be anticipated and evaluated by multiple renal prognostic factors, including increased urine output, serum creatinine trajectory, and time-to-nadir serum creatinine after drainage.

A misplacement of a ureteral stent into the abdominal aorta: a case report of a rare retrograde ureteral stenting complication

Background

Cervical cancer is often associated with malignant ureteral obstruction and consequent hydronephrosis. Hydronephrosis caused in this way can be resolved by placing ureteral stents or performing a percutaneous nephrostomy. Complications that may occur during the retrograde ureteral stent placement are usually mild, but serious complications such as stent migration into the cardiovascular system are also possible. Here we present an unusual case where a ureteral stent entered the abdominal aorta during the cystoscopic ureteral stenting, which was resolved by a cystoscopic stent removal kept in check by endovascular catheters.

Case presentations

The 48-year-old female patient was treated in the regional secondary healthcare facility due to bilateral hydronephrosis caused by cervical cancer. The patient had bilateral percutaneous nephrostomies and ureteral stents. Due to the calcification of the left ureteral stent, an urethrorenoscopy with lithotripsy of the calculus in the left ureter was performed in the regional secondary healthcare facility, and the ureteral stent was cystoscopically replaced. The control radiography of the urinary tract showed a misplacement of the left ureteral stent, and a computed tomography showed that the stent was located in the abdominal aorta. The patient was referred to the University Clinical Center of Serbia, where a ureteral stent was cystoscopically removed from the abdominal aorta under the control of endovascular catheters. The patient was in good general condition at all times, with no signs of bleeding, and she was discharged from the hospital on the fourth postoperative day.

Conclusions

The migration of a ureteral stent into the abdominal aorta and the cardiovascular system in general is a rare type of ureteral stenting complication whose treatment requires a multidisciplinary approach. In order to prevent such complications, it is necessary to strictly adhere to the indications for the ureteral stent placement in the case of malignant ureteral obstruction. Also, this procedure should be performed according to the current guidelines and controlled by an X-ray or ultrasound.

Quality of life with tandem ureteral stents compared to percutaneous nephrostomy for malignant ureteral obstruction

PURPOSE

Malignant ureteral obstruction (MUO) is treated with kidney decompression by a percutaneous nephrostomy (PCN) or internal ureteral stents. The objective of this study was to compare quality of life (QoL) with a PCN compared to tandem ureteral stents (TUS) in cases of MUO.

METHODS

We reviewed the medical records of patients with MUO who were treated by PCN/TUS in our institution between June 2019 and May 2020. Patients were asked to fill out a QoL questionnaire, a tube-symptoms questionnaire, report a general health scale, and asked for a drain preference if they had experience with both drains. Scores of both groups were compared and predictors of all QoL and tube-symptoms measures were searched using multivariate analysis.

RESULTS

Seventy-four patients with a PCN and 30 with TUS were included in the study. No statistically significant difference was found in all QoL and tube-symptoms measurements between the two drains. Type of drain was not found to be a predictor of QoL or tube-related symptoms. Eighty-four percent of patients (11/13) who have experience with both types of drains preferred TUS.

CONCLUSION

TUS and PCN for relief of MUO have a negative and similar effect on various areas of QoL and urinary symptoms. Most patients who had experience with both types of drains preferred TUS over PCN. In this patient population with a grim prognosis, this negative effect must be communicated to patients, and calculated against the potential benefits of drainage.

Incidental Diagnosis of Right Renal Subcapsular Urinoma on an 18 F-FDG PET/CT Scan Performed for Staging of Cervical Cancer

ABSTRACT

A 53-year-old woman with cervical cancer underwent FDG PET/CT staging, which demonstrated an avid cervical mass with right parametrial involvement and presence of bilateral lymph node metastases. The right ureter was encased, resulting in obstruction and renal pelvic dilatation. Avid right renal subcapsular lesions were also noted, which were hyperintense on T2-weighted imaging compatible to encapsulated fluid collections. These lesions were diagnosed as subcapsular urinoma due to transmitted back pressure caused by obstruction of the right ureter.

Can preoperative ureteral stents reduce the incidence of ureteral stricture after radiotherapy in patients with cervical cancer?

Objective

To determine the impact of preoperative stent placement on postradiotherapy stricture rate in patients with cervical cancer after radical resection.

Methods

This study was a retrospective analysis of data collected from 55 cervical cancer patients treated with radiotherapy between June 2016 and June 2020. Patients were divided into the stent and control groups. After 3 months, the stricture rate and the complications related to stent placement between the two groups were compared.

Results

There were 12 (46.2%) and 10 (34.5%) cases of ureteral stricture in the stent (n = 26) and control (n = 29) groups, respectively, three months after the end of radiotherapy. The incidence rates of ureter stricture in the two groups were not significantly different (P = 0.378). Moreover, there were 20 units (38.5%) and 15 units (25.9%) ureteral strictures in the stent and control groups, respectively. No significant difference in the incidence rates of ureteral strictures was found between the two groups (P = 0.157). There were 13 (50.0%) and 10 (34.5%) cases of ureteral stricture in the stent (n = 26) and control (n = 29) groups, respectively, six months after the end of the radiotherapy. The incidence rates of ureter stricture in the two groups were not significantly different (P = 0.244). Moreover, there were 21 units (40.4%) and 15 units (25.9%) ureteral strictures in the stent and control groups, respectively. No significant difference in the incidence rates of ureteral strictures was found between the two groups (P = 0.105). Complications related to stent placement such as urinary tract infections and bladder irritation were statistically significant (P = 0.006 and P = 0.036) between the two groups; while the other complications were not significantly different (P = 0.070, P = 0.092 and P = 0.586).

Conclusions

Ureteral stents may not reduce the incidence of ureteral stricture after radiotherapy in patients with cervical cancer. The stent needs to be replaced regularly, and the complications related to stent placement may occur at any time. Thus, preoperative stent placement should be cautious for the clinical management of cervical cancer patients treated with postoperative radiotherapy.

Bacterial Colonization Incidence before and after Indwelling Double-J Ureteral Stents

The upper urinary tract stenting allows to restore the ureteral patency in various situations. However, one of the main disadvantages of stenting is bacterial contamination, which can be a source of persistent infections that hardly respond to antibiotic therapy. The aim of this study was to investigate the local spectrum of bacterial pathogens and their susceptibility to antibiotics in order to optimize antibacterial therapy after upper urinary tract stenting. A prospective observational study was conducted in which 140 urine samples were examined (70 before stenting and 70 after stenting). Bacterial growth was detected in 37 patients (52.8%) before stenting and in 43 patients (61.4%) after stenting. E. coli (13 (28.8%)) and Streptococcus spp. (8 (17.6%)) strains were more commonly detected before stenting; P. aeruginosa (15 (31.2%)) and E. coli (8 (16.6%)) were usually revealed after stenting. The proportion of P. aeruginosa strains after stenting grew from 4.4% up to 31.2%. E. coli strains were resistant to ampicillin (92.3% before and 100% after stenting). Three strains of E. coli (23.1%) and six strains of P. aeruginosa (40%) were multidrug-resistant. Determination of the bacterial sensitivity to antibiotics and identification of antibiotic-resistant forms of bacteria is a factor in reducing the risk of complications and optimizing antibiotic therapy during the upper urinary tract stenting.

A Silicone-Covered Self-Expanding Metal Stent with Anti-migration Features for Treating Malignant Ureteral Obstruction

PURPOSE

To evaluate the effectiveness and safety of the Urexel stent for treating malignant ureteral obstruction (MUO).

MATERIALS AND METHODS

This retrospective study included 129 patients (mean age: 57.9 ± 11.8 years; men: n = 64, 49.6%; ureteral units [UUs]: N = 175) who underwent Urexel stent placement to treat MUO between March 2013 and April 2021. The Urexel stent is a fully covered self-expanding metal stent. To reduce stent migration, the proximal end of the stent has an additional layer of stent mesh and is flared mildly.

RESULTS

Eighty-three patients (64.3%) had unilateral MUO (right side: n = 47, 36.4%; left side: n = 36, 27.9%), and 46 patients (35.7%) had bilateral MUO. Successful Urexel stent placement after successful guidewire passage of the obstructed ureteral segment was achieved in 172 UUs, rendering a technical success rate of 98.3%. Stent malfunction occurred in 37 UUs (21.4%) during follow-up, including tumor overgrowth (n = 29), tumor ingrowth (n = 3), stent migration (n = 3), and stent collapse (n = 2). A total of 120 patients (93.0%) died during a median follow-up of 4.1 months (range: 0.2 - 33.5). The median survival of the patients was 4.4 months (interquartile range [IQR] 2.0 - 8.8). The median malfunction-free survival of the patients was 3.6 months (IQR: 1.6 - 7.9). Fifteen grade 3 or higher complications occurred in 14 patients (10.9%), including flank pain (n = 10), gross hematuria (n = 4), and dysuria (n = 1).

CONCLUSION

Urexel stent placement may be effective and safe for treating MUO.

Factors Associated with Ureteral Stent Failure in Patients with Malignant Ureteral Obstruction

Introduction: Management of malignant ureteral obstruction (MUO) with ureteral stents remains a clinical challenge, often involving frequent stent exchanges attributable to stent failure or other urological complications. We report our institutional experience with ureteral stents for management of MUO, including analysis of clinical factors associated with stent failure. Methods: We performed a retrospective review of patients treated with indwelling ureteral stents for MUO in nonurothelial malignancies at our tertiary-care institution between 2008 and 2019. Univariate Cox proportional hazards analysis was performed to identify clinical variables associated with stent failure and stent-related complications. Stent failure was defined as need for unplanned stent exchange, placement of percutaneous nephrostomy (PCN), or tandem stents. Results: In our cohort of 78 patients, the median (range) number of stent exchanges was 2 (0-17) during a total stent dwell time of 4.3 (0.1-40.3) months. Thirty-four patients (43.6%) developed a culture-proven urinary tract infection (UTI) during stent dwell time. Thirty-five patients (44.8%) had stent failure. Twenty-two patients (28.2%) underwent unplanned stent exchanges, 23 (29.5%) required PCN after initial stent placement, and 6 (7.7%) required tandem stents. Ten (28.6%) patients with stent failure were treated with upsized stents, which led to resolution in seven patients. Stent failure occurred with 20/44 (45.4%) Percuflex™, 15/27 (55.6%) polyurethane, and 2/3 (66.7%) metal stents. In patients with ≥2 exchanges (N = 45), median time between exchanges was 4.1 (2.0-14.8) months. Bilateral stenting and history of radiation predicted UTI development. Median overall patient survival after initial stent placement was 19.9 months (95% CI 16.5-37.9 months). Conclusions: Ureteral stent failure poses a significant medical burden to patients with MUO. Better methods to minimize stent-related issues and improve patient quality of life are needed. Using a shared decision-making approach, clinicians and patients should consider PCN or tandem stents early in the management of MUO.

Antegrade placement of JJ catheter in the treatment of malignant ureteral obstruction: Retrospective analysis of a single centre

OBJECTIVE

The aim of the present study was to examine the results of antegrade JJ stent placement in upper urinary tract obstruction in patients where retrograde placement was not possible.

METHODS

In this retrospective study, patients who underwent antegrade JJ stent placement for malignant ureteral obstruction in the urology clinic of a university hospital between January 1, 2018 and December 31, 2020 were included in the study. JJ stent was placed under local or general anaesthesia guided by ultrasonography and fluoroscopy. Age, gender, kidney function values, pathologies causing obstruction, and complications of the patients were examined.

RESULTS

In this study, 40 patients (16 men, 24 women) who underwent antegrade JJ stent placement were included. The mean ages of the women and men included were 51 (31-91) years and 62.5 (26-81) years, respectively. In all, antegrade JJ stenting was performed in 61 renal units of these patients. Of these, 21 were bilateral, 11 in the right collecting system and 8 in the left collecting systems. Clinical and technical success was achieved in 59 of the 61 procedures (96.6%). Arteriovenous fistula developed in only one patient, whereas no serious complications such as massive bleeding, resistant hematuria or pseudoaneurysm occurred in the remaining patients. The procedure was completed in a mean time of 15-30 minutes.

CONCLUSIONS

Antegrade JJ stent placement is a procedure with a high success rate and low risk of complications that can be used in patients with severe ureteral obstruction owing to malignant or benign aetiologies. This method should be applied in centres experienced in malignant ureteral obstruction and on patients where retrograde placement was not possible. Furthermore, it should be considered as an alternative treatment option to open surgery as it can be performed under local anaesthesia in patients at a high risk of anaesthesia.

Cystoscopic surveillance protocol for ureteral stents used to manage malignant ureteral obstruction: reducing morbidity of frequent stent changes

PURPOSE

To evaluate a cystoscopic surveillance protocol used to mitigate morbidity associated with chronic ureteral stents for malignant ureteral obstruction (MUO).

MATERIALS AND METHODS

A retrospective cohort study was conducted at a tertiary, referral centre of consecutive MUO patients who were initially managed with a ureteral stent and subsequently followed using a cystoscopic 'MUO stent surveillance protocol'. Multivariable regression models evaluated factors associated with the following outcomes: number of stent changes, time to first stent change, and overall survival.

RESULTS

A total of 120 patients from May 2009 to December 2019 were included; mean age was 63 years, majority (76.7%) were female, and median follow-up for stented patients was 184 days. Majority (72%) of patients did not require a stent change at 3-months follow-up. Only 32% (19/60) required a stent change at their 6-month stent surveillance cystoscopy. Median time to first stent change was 158 days. Of 344 total number of stent surveillance cystoscopies performed, 39.5% (136/344) involved a stent change. Patients with a history of pelvic radiation (subdistribution hazard rate [sHR] 2.12, 95% CI 1.23 to 3.67, p=0.007) and with a history of bowel resection (sHR 2.06, 95% CI 1.05 to 4.03, p=0.036) were independently associated with earlier stent changes. No patients in the MUO stent surveillance protocol required ancillary procedures to deal with encrusted stents.

CONCLUSIONS

A cystoscopic 'MUO stent surveillance protocol' can reduce the morbidity and health care expenditures associated with stent changes among MUO patients, with median time to first stent change being 158 days and only 40% of surveillance cystoscopies involving a stent change. The protocol is safe as no patients required ancillary procedures to manage an encrusted stent while on surveillance. Patients with a history of pelvic radiation or bowel resection were more likely to require a stent change during their stent surveillance visits.

Comparison of Ureteral Stents on Drainage Performance Under Extrinsic Compression

PURPOSE

By investigating deformation and flow velocity of three commonly used, readily accessible ureteral stents under variant compression and surface change at three time points (new, 1 month or 3 months after implantation), we share our center's experience dealing with ureteral obstruction especially the malignant ones.

MATERIALS AND METHODS

Ureteral double-J (DJ) stents including Cook Universa Soft, Kang Yi Bo (KYB) antireflux and Urovision Visiostar ESWL DJ stents went though scanning microscopic (SEM) analysis. Compression-deformation was measured using digital force gauge. Intraluminal flow velocity was tested with the stents under different compression levels.

RESULT

Urovision Visiostar demonstrated significantly better anti-compression capability. Cook Universa Soft and KYB antireflux showed favorable draining velocity without compression, but the velocity dropped heavily under compression; the velocity of KYB antireflux reduced heavily after 3 months of implantation; Urovision Visiostar achieved the best draining effect under compression at all three time points.

CONCLUSION

The Urovision Visiostar DJ stent demonstrated significantly greater resistance to compression than the other two, and better drainage under compression. Patients with benign or malignant ureteral compression might benefit from using the Urovision Visiostar stents. Large prospective clinical trials are needed for confirmation.

Initial Experience of Self-Expanding Metal Ureteral Stent in Recurrent Ureteral Stricture After Ureteroplasty

Background: The aim of this prospective study was to assess the safety and effectiveness of self-expanding metal ureteral stent (MUS) for the treatment of recurrent ureteral stricture after ureteroplasty.

Methods: We prospectively included 24 patients who underwent MUS implantation between February 2019 and August 2020. The inclusion criteria for the procedure were recurrent ureteral strictures after ureteroplasty. A paired T test was used to compare continuous variables before and after surgery.

Results: A total of 24 patients were finally included in this study. The stricture site was most common on the proximal ureter 19 (79.2%), followed by distal ureter 4 (16.7%) and middle ureter 1 (4.2%). The median length of ureteral stricture is 2.5 (range 1–18) cm. The median operative time was 51.5 min, and the median hospital stay time after surgery was 3 days. Post-operative complication included pain 1 (4.2%), urinary tract infection 2 (8.3%) and hematuria 2 (8.3%). After a median follow-up of 12 months, 19/24 (83.3%) patients were clinically and radiologically successful. We endoscopically adjusted or exchanged the failed stents. The volume of hydronephrosis (124.7 ± 132.5 vs. 66.4 ± 73.2 cm³, P = 0.015), blood creatinine level (104.5 ± 45.4 vs. 80.1 ± 23.2 μmol/L, P = 0.044) and urea nitrogen level (6.9 ± 2.4 vs. 4.8 ± 1.5 mmol/L, P = 0.003) decreased significantly after a median follow-up of 12 months.

Conclusions: MUS is a safe and effective way to manage recurrent ureteral strictures after ureteroplasty. This technique provides a new choice for the treatment of recurrent stricture.

Antegrade double-J stenting as an alternative to the retrograde approach: experience of the first 150 cases at a single center in Brazil

Objective

To present our clinical experience with percutaneous antegrade ureteral stenting.

Materials and Methods

This was a single-center retrospective study in which we reviewed the electronic medical records of patients who underwent percutaneous image-guided antegrade ureteral stenting between January 2016 and August 2020. We evaluated 90 patients (48 men). The mean age was 61.4 ± 15 years (range, 30-94 years). Patients were divided into two main groups: those with malignant neoplasms; and those with non-neoplastic disease. Technical and clinical success of the procedure were defined, respectively, as maintenance of the patency of the urinary tract, with a reduction in the degree of hydronephrosis, and as a reduction in the level of nitrogenous waste. Postprocedural complications were categorized as major or minor according to the CIRSE classification.

Results

The study sample comprised 150 antegrade stenting procedures performed in 90 patients, most of whom had previously undergone retrograde stenting that was unsuccessful. The stenting was bilateral in 60 patients and unilateral in 30. Technical success was achieved in 143 (95.3%) of the procedures, whereas seven procedures (4.6%) were unsuccessful. Failed procedures were characterized by inability to place a stent or migration of a stent after its placement. Complications occurred in 12 (8.0%) of the procedures. Of those 12 complications, two were classified as major (bleeding) and 10 were classified as minor (lumbar pain or infection). The most common techniques used were the over-the-wire technique and the modified technique (in 58.0% and 42.0% of the cases, respectively). In seven cases (4.7%), a nephrostomy tube was inserted.

Conclusion

Percutaneous antegrade ureteral stenting is a safe, effective method for the management of ureteral injuries and obstructions, due to malignant or benign causes, when the retrograde approach has failed.

Analysis of Ureteral Tumour Stents for Malignant Ureteral Obstruction: Towards Reshaping an Optimal Stent

Introduction

Ureteral obstruction hinders the management of malignant diseases. Adequate stent placement does not necessarily guarantee renal decompression. The stent stiffness may play a major role to maintain patency. We carried out the present study in order to evaluate drainage efficiency by using stents with distinctive degrees of stiffness and to identify the physical factors that could prevent obstruction of the stent in patients with malignant ureteral obstruction (MUO).

Materials and Methods

We performed an analysis of 150 patients with MUO drainage at a single institution from June 2009 to June 2019. A progressive choice of stents was shaped to overcome each failure by focusing on the criterion of increasingly stiff stents.

Results

During the study period, 556 ureteral stent procedures (USP) were analysed separately. The stent failure with obstruction occurred in 23.0% (128/556) of USP at a mean of 4.4±3.6 months and depended on the type of stent. Stent failure occurred in 34.2% (70/205) of Vortek^® stents, in 42.9% (15/35) of Urosoft stents, in 15.4% (39/254) of Superglide or ureteral catheters and in 6.5% (4/62) of tandem stents. No significant differences were found between Vortek^® and Urosoft stents regarding stent failures, but there were significant differences between Superglide or Tandem stents and Vortek^® or Urosoft stents (p<10⁻⁷). The study demonstrated that ureteral stent obstruction significantly decreased with a larger lumen or a stiffer stent (p<10⁻⁷).

Conclusion

In the present study, Superglide and tandem stents were the best stents against stent failure, and the lumen and the stiffness of the stent have been shown to be critical factors in controlling patency. The results suggest that the lumen seems more important than the stiffness, and the stiffness would be the only means of keeping the lumen intact. Future stents for MUO should integrate the importance of the lumen of the stent.

Self-expanding metal ureteral stent for ureteral stricture: Experience of a large-scale prospective study from a high-volume center - Cross-sectional study

BACKGROUND

The management of ureteral stricture is still a challenge for urologists. The aim of this prospective study was to assess the safety and effectiveness of self-expanding metal ureteral stents (URS) in ureteral strictures.

METHODS

We performed URS placement procedures for ureteral stricture from Jan 2019 to July 2020, and prospectively collect various data before and after the operation. A paired T test was used to compare continuous variables before and after surgery, binary logistic regression analysis was used to identify the independent risk predictors of surgical failure.

RESULTS

A total of 147 patients with 157 renal units received successful placement of URS. The mean operative time was 70.0 min. After a median follow-up time of 15 months, 73.2% (115/157) of stents were kept in situ. The most common complication was hematuria (13, 8.8%), followed by urinary tract infection (11, 7.5%) and pain (8, 5.4%). The volume of hydronephrosis (67.9 ± 34.9 VS 34.9 ± 51.1 cm³, P = 0.0001), serum creatinine level (103.0 ± 54.5 VS 93.8 ± 45.1 μmol/L, P = 0.034) and blood urea nitrogen level (6.6 ± 6.7 VS 5.4 ± 2.4 mmol/L, P = 0.032) decreased significantly at last follow up when compared with baseline. Stricture of the distal ureter was an independent risk factor for stent failure (HR 1.77, 95% CI 1.15, 2.73, P = 0.009).

CONCLUSIONS

URS was found to be safe and effective for ureteral strictures with a limited complications and good long-term results. For those who are not suitable for surgical reconstruction, the URS is an alternative management.

Metal stent for the ureteral stricture after surgery and/or radiation treatment for malignancy

BACKGROUND

To assess the efficacy and safety of self-expanding metal ureteral stent for the stricture following surgery and/or radiation for malignancy.

METHODS

We performed 36 metal ureteral stent insertion procedures (32 patients) between May 2019 and June 2020. The main inclusion criterion was the patients with ureteral stricture due to surgery and/or radiation treatment for malignancy. The diagnosis of stricture was ascertained by history and radiographic imaging. The etiologies underlying the strictures were: surgery and/or radiation therapy for cervical and rectal cancer, surgery for ovarian cancer. The primary outcome was the stent patency rate, and the secondary outcomes were the postoperative complications and glomerular filtration rate (GFR). Stent patency was defined as stent in situ without evident migration, unanticipated stent exchange or recurrent ureteral obstruction. Cost analysis was calculated from stent cost, anesthesia cost and operating room fee.

RESULTS

The pre-metallic stent GFR was 22.53 ± 6.55 mL/min/1.73 m². Eight patients were on double-J stents before insertion of metallic stents. The total annual cost of per patient in our study was $10,600.2 US dollars (range $9394.4-$33,527.4 US dollars). During a median follow-up time of 16 months (range 8-21 months), 27 cases (31 sides, 84%) remained stent patency. Twelve patients died from their primary malignancy carrying a patency stent. Stent migration was observed in 4 patients within 10 months after insertion. Ectopic stents were endoscopically removed and replaced successfully. Three stents were occluded, and no encrustation was seen in our study. Three and four patients had postoperative fever and gross hematuria, respectively. Infection was observed in 2 cases, mandating antibiotics therapy. In addition, postoperative volume of hydronephrosis postoperatively was significantly reduced compared with preoperation (54.18 ± 15.42 vs 23.92 ± 8.3, P = 0.019). However, no statistically significant differences regarding GFR, creatinine levels, blood urea nitrogen and hemoglobin existed between preoperation and last follow-up.

CONCLUSIONS

The current study demonstrated that metal ureteral stent is effective and safe in the treatment of stricture following surgery and/or radiation therapy for malignant cancer. Patients hydronephrosis could be improved by the stent placement.

Clinical factors predicting ureteral stent failure in patients with external ureteral compression

Double-J stent (DJ) placement is usually the treatment of choice for relieving external compression of the ureter. However, in some cases DJ function may become impaired and a percutaneous nephrostomy (PCN) may be required. Previous studies have reported different predictive factors for choosing PCN or DJ insertion as the initial treatment. In this study, we analyzed the risk factors for DJ failure in patients with external ureteral compression. Our results showed that the patients with moderate and severe hydronephrosis (p-value = 0.0171 and 0.0249, respectively), preexisting pyuria (p-value = 0.0128), or lower ureter obstruction (p-value = 0.0305) were more prone to DJ laterality. Age was also an important predictor. Urologists should pay more attention to these patients and consider PCN as the initial treatment.

Antegrade double-J stent placement for the treatment of malignant obstructive uropathy: A retrospective cohort study

Background

Ureteral double- J stent is usually inserted by retrograde approach to treating obstructed upper urinary tract. The antegrade approach, can be suitable alternative in certain situations without general or spinal anesthesia. The present study demonstrates the indications, success rate, and complications of this approach in treatmenting malignant obstructive uropathy.

Methods

Data of consecutive patients with malignant obstructive uropathy who underwent antegrade ureteral stenting in the Department of Interventional Radiology at Sahloul hospital from January 2013 to February 2020 was retrieved and retrospectively analyzed.

Result

A total of 188 attempts of antegrade ureteral stent insertion was performed during the study period (left side = 78, right side = 82, bilateral = 14). The mean age was 54 years (range: 9–91 years). The indication of the antegrade stenting was the failure of retrograde approach in 63 patients.The single-stage approach was performed 103 times. A percutaneous nephrostomy was placed for the average duration of 22.4 days (range: 2–60 days) for subsequent attempts. Only four patients required general anesthesia. Ureteral obstruction was caused by bladder cancer (n = 92), uterine cancer (n = 31), prostate cancer (n = 28), colorectal cancer (n = 15) and retroperitoneal tumor (n = 8). A protective nephrostomy was left in situ in 44 cases for 48 h. Clinical success was achieved in 96% of the cases. Two and three patients required hospitalization for perirenal abscess and hematuria, respectively.

Conclusion

This retrospective study shows that antegrade ureteral stent insertion has a high success rate with minimal complications.

Trial registration

ClinicalTrials.gov Identifier: NCT04649970. Registered december 2, 2020- Retrospectively registered,https://clinicaltrials.gov/ct2/show/NCT04649970;

•

Ureters are easily affected by malignant conditions resulting in the interruption of urinary drainage.

•

Double J (JJ) stents placement is the most common method for relieving urinary obstruction in such cases.

•

The percutaneous antegrade ureteral stenting (PAUS) technique is a relatively newer technique for ureteral stenting.

•

PAUS can be used as an alternative route for relieving ureteral obstruction due to malignancies.

10-Year Experience with Reinforced Ureteral Stents for Malignant Ureteral Obstruction

Introduction

Malignant ureteral obstruction (MUO) hinders the management of malignant diseases. Indwelling stent is a common method to release renal obstruction, but stent failure with obstruction is frequent. The studies conclude that stent obstruction divides survival by 2 or even 4. We carried out the present study in order to evaluate drainage efficiency and overall survival by using stents with distinctive degrees of stiffness.

Materials and Methods

We performed an analysis of 156 patients with MUO drainage at a single institution from June 2009 to June 2019.

Results

Of the 156 patients, 128 (82.1%) died with a mean survival time of 15.3 ± 14.4 months after the first ureteral stent procedure (USP). In order to study stent failure and overall survival, the patients were divided into 3 groups. Group 1 with patients died soon after only one USP (n=37). Group 2 with patients had more than one USP and no obstruction (n=41). Patients in Group 3 had more than one USP and at least one stent obstruction (n=62). During the study period, 556 USPs were analysed separately. The stent failure with obstruction occurred in 23.0% (128/556) of USP at a mean of 4.4 ± 3.6 months. In case of stent failure, a progressive choice of stents was shaped to overcome each failure by focusing on the criterion of increasingly stiff stents. Patients in Group 1 died soon at mean of 4.9 ± 4.8 months. The mean survival time of patients in Groups 2 and 3 were, respectively, 19.4 ± 11.2 and 21.5 ± 16.3 months (P = 0.19).

Conclusion

MUO is a serious disease but this study is the first to prevent survival rate from falling by choosing the stent stiffness suitable for the patient. The active detection of stent failure has been shown to be essential for preserving survival.

Evaluation and Management of Genitourinary Emergencies in Patients with Cancer

Background

Genitourinary emergencies in cancer patients are common. Most cancer treatments are administered in the outpatient setting, and patients with complications often visit the emergency department. However, there is no recent emergency medicine literature review focusing on genitourinary emergencies in the oncologic population. Objective of the review. To increase awareness of common genitourinary emergencies in patients with cancer and enable the prompt recognition and appropriate management of these conditions. Discussion. Genitourinary emergencies in patients with cancer require a multidisciplinary approach to treatment. The most common genitourinary emergencies in patients with cancer are related to infection, obstructive uropathy, hemorrhagic cystitis, and complications associated with urinary diversions. The treatment approach in patients with infections, including viral infections, is similar to those without cancer. Understanding the changes in the anatomy of patients with urinary diversions or fistulas can help with the management of genitourinary emergencies.

Conclusions

Familiarization with the uniqueness of genitourinary emergencies in patients with cancer is important for emergency physicians.

Predictors of antegrade ureteral stenting failure: a single-center experience in patients with malignant and benign ureteral obstruction

OBJECTIVE

To determine the potential predictors of antegrade ureteral stenting (AUS) failure in patients with malignant and benign ureteral obstruction.

METHOD

We retrospectively evaluated 116 AUS procedures performed in 80 patients for ureteral obstruction due to malignant and benign causes. Variables such as etiology for obstruction, ureter shape, previous treatment regimen, history of ileal loop diversion, and presence of percutaneous nephrostomy were recorded. Univariate and multivariate logistic regression methods were used between these variables and stent failure.

RESULTS

Antegrade ureteral stenting was performed as single stage in 24 procedures (n: 24/116, 21%) and performed as a two-step approach after percutaneous nephrostomy in 92 procedures (n: 92/116, 79%). Ureteral stent was successfully deployed in 112 AUS procedures (n: 112/116, 96.5%). In 35 of these successful procedures, the patients were referred to our department due to prior failed retrograde ureteral stenting (RUS). Subsequent stent failure occurred in 40 procedures after a median interval of 39 days. Pre-stenting percutaneous nephrostomy (PN) was a statistically significant risk factor for stent failure (p: 0.041), and age showed an inverse relationship with stent failure (p: 0.008). Complications in early (within the first 30 days after procedure) and late stage occurred in a total of 17 procedures. Early complications included urinary tract infection (n: 11), stent migration (n: 3), and malposition (n: 1). Late complications (after 30 days) were urinary tract infection (n: 1) and stent migration (n: 1).

CONCLUSION

This study suggests that AUS can be performed effectively in both benign and malignant ureteral obstructions including cases with prior failed RUS. Two-step AUS after percutaneous nephrostomy was found to be a significant risk factor for subsequent stent failure in our study cohort.

Subcutaneous nephrovesical bypass in a patient with advanced prostate cancer

In the presence of hydronephrosis, as a result of ureteral malignant invasion, advanced pelvic tumor or retroperitoneal fibrosis, we most often perform a double J stent or percutaneous nephrostomy. In the search for a better quality of life for our patients in recent years in urological practice is increasingly becoming the use of subcutaneous nephrovesical bypass due to its proven safety, effectiveness and minimal invasiveness.

Kidney injury and disease in patients with haematological malignancies

Acute kidney injury (AKI) is common in patients with cancer, especially in those with haematological malignancies. Kidney injury might be a direct consequence of the underlying haematological condition. For example, in the case of lymphoma infiltration or extramedullary haematopoiesis, it might be caused by a tumour product; in the case of cast nephropathy it might be due to the presence of monoclonal immunoglobulin; or it might result from tumour complications, such as hypercalcaemia. Kidney injury might also be caused by cancer treatment, as many chemotherapeutic agents are nephrotoxic. High-intensity treatments, such as high-dose chemotherapy followed by haematopoietic stem cell transplantation, not only increase the risk of infection but can also cause AKI through various mechanisms, including viral nephropathies, engraftment syndrome and sinusoidal obstruction syndrome. Some conditions, such as thrombotic microangiopathy, might also result directly from the haematological condition or the treatment. Novel immunotherapies, such as immune checkpoint inhibitors and chimeric antigen receptor T cell therapy, can also be nephrotoxic. As new therapies for haematological malignancies with increased anti-tumour efficacy and reduced toxicity are developed, the number of patients receiving these treatments will increase. Clinicians must gain a good understanding of the different mechanisms of kidney injury associated with cancer to better care for these patients.

Comparison of a covered metallic ureteral stent and a double-J stent for malignant ureteral obstruction in advanced gastric cancer

AIM

To compare the patency and safety of covered metallic stents (CMS) and the double-J stent (DJS) for treating malignant ureteral obstruction (MUO) in advanced gastric cancer (AGC).

MATERIALS AND METHODS

Between 2016 and 2018, the medical records of 61 patients (84 ureters; CMS, 39 patients, 54 ureters; DJS, 22 patients, 30 ureters) with MUO caused by AGC were reviewed retrospectively. The Kaplan-Meier method and log-rank test were used to evaluate differences of primary or assisted primary patency between groups. Cox regression was conducted separately for early (within 7 days) and late (after 7 days) primary patency.

RESULTS

Technical success of CMS placement was 100% (54/54) and 96.8% (29/30) for DJS (p=0.357). The cumulative stent patency rates at 1, 3, 6, and 12 months were 77%, 74%, 70%, and 70%, in the CMS group and 72%, 60%, 53%, and 26%, in the DJS group. Apart from the period within 7 days (p=0.784), primary patency was consistently higher in the CMS group when compared to the DJS group over the entire follow-up period (p=0.034). Assisted primary patency was consistently higher in the CMS group than in the DJS group over the entire follow-up period (p=0.001). The CMS group was more likely to have complications than the DJS group (48.1% versus 16.7%, p=0.004). Complications were minor, self-limiting events such as haematuria/haematoma.

CONCLUSION

CMS had better late patency and assisted primary patency than DJS. Procedure-related minor complications more frequently occurred with CMS.

Hydronephrosis in patients with cervical cancer is an indicator of poor outcome: A nationwide population-based retrospective cohort study

Cervical cancer is a common malignancy in women. The presence of hydronephrosis in patients with cervical cancer can be a challenging clinical problem. The appropriate management of these patients and the prediction of their outcomes are concerns among gynecologists, urologists, medical oncologists, radiation oncologists, and nephrologists. We enrolled a total of 2225 patients with cervical cancer over a 12-year period from the nationwide database of Taiwan's National Health Insurance Bureau. Among them, 445 patients had concomitant hydronephrosis. The remaining 1780 patients without hydronephrosis were randomly enrolled as a control group for the analysis of associated factors. The results indicated that the proportions of patients with hypertension, chronic kidney disease, and diabetes were significantly higher in the hydronephrosis group. The hydronephrosis group showed a higher all-cause mortality than the non-hydronephrosis group (adjusted hazard ratio 3.05, 95% confidence interval 2.24-4.15, P < .001). The rates of nephrectomy and stone disease were also significantly higher in the hydronephrosis group. A higher percentage of other cancers was also observed in the hydronephrosis group than in the non-hydronephrosis group (12.36% vs 8.99%, respectively). This study shows that cervical cancer with hydronephrosis may have a higher morbidity and mortality than cervical cancer without hydronephrosis. Other factors such as human papilloma virus vaccination, smoking, and cancer staging need to be further studied.

Morbidity and long-term results of subcutaneous pyelovesical bypass in chronic ureteral obstruction

BACKGROUND

We present the long-term results and complications of the DETOUR® prosthesis, a permanent subcutaneous pyelovesical bypass for the treatment of ureteral obstruction.

PATIENTS AND METHODS

Between 2006 et 2018, 34 prosthesis were implanted in 28 patients (mean age 65,8 years) with ureteral obstruction of malignant or benign etiologies. The prosthesis, composed to an inner tube of silicone and an outer tube of expanded polytetrafluoroethylene, is placed subcutaneously between the kidney and the bladder. We are performed infrared spectrophotometry and scanning electron microscopy on two removed prostheses to explore the prosthetic encrustation.

RESULTS

The average follow-up was 25,8 months (Maximum: 64 months). Stent revision was required for early bladder fistula in three patients. The major long-term complications were infection (46%), obstruction (3 patients) and bladder fistula (7 patients). The most frequently infection are non-severe, but two patients died from septic shock after fungic colonization of the prosthesis. The infrared spectrophotometry and scanning electron microscopy analysis showed that the obstruction was favored by urinary infection and an alkaline medium. The functional prosthesis rate at 1,2 and 3 years was 94%, 71% and 62%, respectively.

CONCLUSION

The DETOUR® subcutaneous extra-anatomical urinary bypass is an effective and minimally invasive alternative to permanent percutaneous nephrostomy, for both malignant and benign ureteral obstructions in selected patients.

LEVEL OF EVIDENCE

3.

Tandem ureteral stents drainage lowers renal pelvis pressure in malignant ureteral obstruction: Experimental and computational models

Malignant ureteral obstruction may lead to impaired renal function and requires drainage by a percutaneous nephrostomy tube or an internal ureteric stent. Usage of stiff tandem ureteral stents may decrease stent failure rates. In this paper we combined computational and in vitro models to examine the flow in a malignant ureteral obstruction (MUO) managed by 4 methods of drainage: single soft stent, single stiff stent, soft tandem ureteral stents, and stiff tandem ureteral stents. Pressure at the renal pelvis was the primary outcome of the computational and in vitro models. Different drainage modalities were compared using ANCOVA. Results of computational and in vitro models agreed completely. Drainage by stiff tandem ureteral stents provides lower renal pelvis pressure levels compared with single and soft stents (p < 0.001), especially for high levels of external pressure. Usage of stiff tandem ureteral stents may decrease stent-failure rates and postpone the need for percutaneous nephrostomy tube insertion.

Clinical Outcomes After Urinary Diversion for Malignant Ureteral Obstruction Secondary to Non-urologic Cancer: An Analysis of 778 Cases

BACKGROUND

This study investigated patient outcomes after urinary diversion in order to manage malignant ureteral obstruction caused by non-urologic cancers and to evaluate predictive factors for overall survival.

METHODS

The study retrospectively reviewed patients with non-urologic malignancies who underwent ureteral stenting or percutaneous nephrostomy for ureteral obstruction between 2006 and 2014. The variables for predicting overall survival were identified by Cox regression analysis.

RESULTS

The study enrolled 778 patients, including 522 patients who underwent ureteral stenting and 256 patients who underwent percutaneous nephrostomy. Renal function was assessed immediately and then 2 weeks after urinary diversion. The median survival period was 5 months (interquartile range [IQR] 2-12 months). A total of 708 patients died. The patients who received chemotherapy after urinary diversion had a survival gain of 7 months compared with the patients who did not receive subsequent chemotherapy (p < 0.001). The survival rate did not differ between the various types of urinary diversion (p = 0.451). In the multivariate analysis, lower survival rates were significantly associated with male sex; previous chemotherapy without radiotherapy; an increasing number of events related to malignant dissemination; low preoperative hemoglobin (< 10 mg/dL), albumin (< 3 g/dL), and estimated glomerular filtration (< 60 mL/min/1.73 m²) rates; and no subsequent chemotherapy or radiotherapy.

CONCLUSIONS

In cases of ureteral obstruction caused by non-urologic malignancies, the overall survival was poor. However, the patients who received chemotherapy after urinary diversion had a survival gain of 7 months. Therefore, urinary diversion could be considered to preserve renal function for subsequent chemotherapy, whereas patients with the poor prognostic factors should be presented with the option of no intervention.

Long-Term Outcomes of Two Ipsilateral vs Single Double-J Stent After Laser Endoureterotomy for Bilharzial Ureteral Strictures

Background: Laser endoureterotomy became a preferable choice for managing benign ureteral strictures. Ureteral stricture caused by bilharzias is characterized by focal destruction of ureteral musculature, ending by fibrosis, making it poor responder to endoureterotomy. There is no consensus about the ideal ureteral stent size after endoureterotomy. However, many researches recommend larger stents caliber (12-14F). We assess long-term efficacy of insertion of two ipsilateral Double-J stents vs single Double-J stent after laser endoureterotomy for bilharzial ureteral stricture. Materials and Methods: Within 4 years, 70 patients underwent retrograde laser endoureterotomy for bilharzial ureteral stricture (diagnosed by positive history of bilharziasis, positive serology test, and/or bilharzial cystoscopic finding). Patients with history of stone, urologic or pelvic surgery were excluded. Patients were randomized into two groups: the first group (35 patients) received ipsilateral two Double-J (7F each) postendoureterotomy, whereas the second group (35 patients) received one Double-J (7F). Double-Js were removed after 8 weeks. Follow-up was done regularly by clinical interpretation and imaging studies. Patients' characteristics, operative data, and postoperative outcomes (subjectively and objectively) were compared in both groups. Results: Sixty-three patients completed follow-up >18 months, mean follow-up 30 ± 4 months [19-41], and mean stricture length 1.4 ± 0.6 cm [0.5-3.0], with no statistical significance between both groups. Success proved by relief of symptoms and radiographic resolution of obstruction. The overall success rate was significantly better in 2-Double-J group than in 1-Double-J group (83.9% vs 53.1%) p = 0.009, and also for stricture >1.5 cm (85.7% vs 38.5%) p = 0.018, respectively. Conclusions: Insertion of two ipsilateral Double-J, after laser endoureterotomy for bilharzial ureteral stricture associated with long-term success rate better than insertion of 1-Double-J, especially for stricture segment >1.5 cm.

The Fate of Ureteral Memokath Stent(s) in a High-Volume Referral Center: An Independent Long-Term Outcomes Review

Purpose: To independently assess upper urinary tract Memokath (MMK-051) stent outcomes in a national tertiary referral center. Materials and Methods: Two researchers, completely independent to the treating team, reviewed electronic MMK-051 stent(s) patient management records. Outcomes included time to first complication, complication(s)-severity, MMK-051 stent lifespan and change incidence, salvage therapy, further surgical intervention, and mortality. Results and Limitations: One hundred patients received 162 MMK-051 stent(s) (59% with malignant and 63% with distal ureteral obstruction [UO]) with only three lost to follow-up (FU). At 5-year mean FU, only 25 patients had complication-free original MMK-051 stents (14 alive, 11 dead). Of the remaining 75 patients, 22 had other stents, 12 had major surgery (e.g., nephrectomy), 3 became dialysis dependent, and 14 stabilized without ureteral stenting after original MMK-051 removal. Malignant obstruction patients had greater original MMK-051 stent longevity (p < 0.02), but also 20 of the 21 deaths (95%). The 72% mean 5-year stent complication rate included migration (46%), blockage (34%), nonfunctioning kidney (8%), urosepsis needing intravenous antibiotics (8%), and others (6%), including one postoperative death, one ureteral injury, and two with intractable pain. Median time to first complication was 12.5 months. Conclusions: MMK-051 stents had optimal utility in managing malignant UO and in those unfit for corrective surgery. Longer independently assessed mean 5-year outcomes review revealed much higher complication rates (72%) than previously reported. Future international metallic ureteral stent guidelines should encourage clinicians to adopt patient-centered multidisciplinary assessment and selection, with counseling plus goal-setting, and harmonized long-term protocol-based reporting, for optimized future patient safety and outcomes.

Estimation of successful capping with complete aspiration of bladder via nephroureterostomy tube

BACKGROUND

Ureteral stent and nephroureterostomy tube (NUT) are treatments of ureteral obstruction. Ureteral stent provides better quality of life. Internalization of NUT is desired whenever possible.

AIM

To assess outcomes of capping trial among cancer patients with complete aspiration of retained contrast from bladder via NUT.

METHODS

Our Institutional Review Board approved retrospective review of all NUT placement, NUT exchange and conversion of nephrostomy catheter into NUT performed during June 2013 to June 2015 (n = 578). Cases were excluded due to lack of imaging of bladder (n = 37), incomplete aspiration of bladder (n = 324), no attempt at capping NUT (n = 166), and patients with confounding factors interfering with results of capping trial including non-compliant bladder, bladder outlet obstruction and catheter malposition (n = 14). Study group consisted of 37 procedures in 34 patients (male 19, female 15, age 2-83 years, average 58, median 61) most with cancer (prostate 8, endometrial 5, bladder 4, colorectal 4, breast 2, gastric 2, neuroblastoma 2, cervical 1, ovarian 1, renal 1, sarcoma 1, urothelial 1 and testicular 1) and one with Crohn’s disease. Medical records were reviewed to assess outcomes of capping trial. Exact 95% confidence intervals (95%CI) were calculated.

RESULTS

Among patients with complete aspiration of retained contrast, 30 (81%, 95%CI: 0.65-0.92) catheters were successfully capped (range 12-94 d, average 40, median 24.5) until planned conversion to internal stent (23), routine exchange (5), removal (1) or death unrelated to catheter (1). Seven capping trials (19%, 95%CI: 0.08-0.35) were unsuccessful (range 2-22 d, average 12, median 10) due to leakage (3), elevated creatinine (2), fever/hematuria (1) and nausea/vomiting (1).

CONCLUSION

Capping trial success among patients with complete aspiration of retained contrast/urine from bladder via NUT appears high.

Long-term follow-up results and complications in cancer patients with persistent nephrostomy due to malignant ureteral obstruction

PURPOSE

We aimed to evaluate the long-term complications and predisposing factors for these complications in patients with malignant ureteral obstruction (MUO) treated with percutaneous nephrostomy (PN).

METHODS

The records of patients with MUO treated with PN between January 2015 and 2018 were retrospectively reviewed for PN dislodgement, PN obstruction, PN replacement, pyelonephritis, hospitalizations due to PN complications, and other complications due to PN such as macroscopic hematuria, skin infections, or renal/perirenal abscess.

RESULTS

Data for a total of 147 patients (229 renal units [RU], 107 males, 40 females) were evaluated. In 174 (76%) RU, PN was replaced due to PN dislodgement. The predisposing factors for PN dislodgement were follow-up time, body mass index (BMI), chemotherapy, diabetes mellitus (DM), low educational level (LEL), pyelonephritis, and catheter-related skin infections (CSRI). The PN was replaced in 40 RU due to obstruction. The predisposing factors for obstruction were follow-up time and BMI. Pyelonephritis developed at least once in 61 (41.5%) patients. Follow-up time, BMI, previous surgery, DM, and LEL were the predisposing factors for pyelonephritis. CSRI developed in 16 RU. Follow-up time, BMI, DM, and LEL were the predisposing factors for CSRI. Macroscopic hematuria developed in 11 patients. Follow-up time, previous surgery, DM, chemotherapy, and LEL were predisposing factors for macroscopic hematuria.

CONCLUSION

The most common complication in patients with MUO treated with PN was PN dislodgement. However, life-threatening complications such as macroscopic hematuria and severe infections can also occur. Patients with DM, LEL, and chemotherapy are at high risk of PN-related complications.

Antegrade insertion of a double J catheter in the treatment of malignant ureteral obstruction: a retrospective analysis of the results obtained with a modified technique at a university hospital

OBJECTIVE

To analyze the results obtained with a modified antegrade double J catheter insertion (JJ stenting) technique in patients with urinary tract obstruction due to malignancy.

MATERIALS AND METHODS

This was a retrospective analysis of data collected from patients undergoing antegrade JJ stenting for malignant ureteral obstruction in the interventional radiology department of our institution between March 1, 2017 and May 31, 2019.

RESULTS

Antegrade JJ stenting was performed in 32 patients (20 women and 12 men). The mean age was 66.2 years among the females and 61.5 years among the males. A total of 53 antegrade JJ stenting procedures were performed. The procedure was successful in 50 cases and failed in 3 (due to migration of the double J catheter in 2 and due to technical failure in 1). Complications occurred in 3 patients (low back pain, in 1, subcapsular hematoma, in 1, and pyelonephritis, in 1). The procedure time ranged from 14 min to 55 min.

CONCLUSION

In patients with ureteral obstruction due to malignancy, antegrade JJ stenting is safe and effective. The technique selected in our study is easily reproduced and can be performed by a trained professional.

Management and treatment options when facing malignant ureteral obstruction

Malignant ureteral obstruction is an unfortunate finding that can be caused by a wide-ranging number of malignancies with a prognosis of limited survival. Given its presentation and progression, it can be refractory to treatment by traditional single polymeric ureteral stents. With a higher failure rate than causes of benign ureteral obstruction, a number of other options are available for initial management, as well as in cases of first-line therapy failure, including tandem stents, metallic stents, percutaneous nephrostomies and extra-anatomic stents. We reviewed the literature and carried out a PubMed search including the following keywords and phrases: "malignant ureteral obstruction," "tandem ureteral stents," "metallic ureteral stents," "resonance stent," "metal mesh ureteral stents" and "extra-anatomic stents." The vast majority of studies were small and retrospective, with a large number of studies related to metallic stents. Given the heterogenous patient population and diversity of practice, it is difficult to truly assess the efficacy of each method. As there are no guidelines or major head-to-head prospective trials involving these techniques, it makes practicing up to the specific provider. However, this article attempts to provide a framework with which the urologist who is presented with malignant ureteral obstruction can plan in order to provide the individualized care on a case-by-case basis. What is clear is that prospective, randomized clinical trials are necessary to help bring evidence-based medicine and guidelines for patients with malignant ureteral obstruction.

Clinical outcomes and prognostic factors associated with internal ureteral stent placement for malignant extrinsic ureteral obstruction

PURPOSE

The optimal management of malignant extrinsic ureteral obstruction (MUO) remains unclear. It is necessary to assess the patient prognosis in deciding the adaptation of drainage of renal pelvis. In this study, we investigated the clinical outcomes after ureteral stenting for MUO and the predictive factors for overall survival in order to create a risk-stratification model.

METHODS

We retrospectively analyzed the clinical and laboratory data of 93 patients with radiologically significant hydronephrosis associated with MUO who underwent successful stent placement between May 2005 and May 2018.

RESULTS

The median survival duration after the initial stent insertion was 266 days. Of the 93 patients, 70 died, and the median interval from the first stent insertion to death was 160 days. Multivariate analysis showed that gastric cancer as the primary disease, poor performance status before stenting, and treatment after stent insertion were significant predictors of survival. According to these three factors, we stratified patients into the following four prognostic groups: no-factor (43 patients), one-factor (23 patients), two-factor (23 patients), and three-factor (4 patients) groups. This classification was effective for predicting survival, and the median survival durations in these groups were 807, 269, 44, and 12 days, respectively (p < 0.001).

CONCLUSIONS

Our stratification model of patients with a poor prognosis after ureteral stent placement for MUO may allow urologists and clinicians to identify patients who will benefit from ureteral stenting.

The Challenge of Managing Bladder Cancer and Upper Tract Urothelial Carcinoma: A Review with Treatment Recommendations from the Spanish Oncology Genitourinary Group (SOGUG)

Bladder cancer is the fourth most common cancer in men and the ninth most common in women in the Western world. The management of bladder carcinoma requires a multidisciplinary approach. Optimal treatment depends on several factors, including histology, stage, patient status, and possible comorbidities. Here we review recent findings on the treatment of muscle-invasive bladder carcinoma, advanced urothelial carcinoma, upper tract urothelial carcinoma, non-urothelial carcinoma, and urologic complications arising from the disease or treatment. In addition, we present the recommendations of the Spanish Oncology Genitourinary Group for the treatment of these diseases, based on a focused analysis of clinical management and the potential of current research, including recent findings on the potential benefit of immunotherapy. In recent years, whole-genome approaches have provided new predictive biomarkers and promising molecular targets that could lead to precision medicine in bladder cancer. Moreover, the involvement of other specialists in addition to urologists will ensure not only appropriate therapeutic decisions but also adequate follow-up for response evaluation and management of complications. It is crucial, however, to apply recent molecular findings and implement clinical guidelines as soon as possible in order to maximize therapeutic gains and improve patient prognosis.