Endourologic management of malignant ureteral obstruction: indications, results, and quality-of-life issues

The challenging management of malignant ureteral obstruction: Analysis of a series of 188 cases

Background

Malignant ureteral obstruction (MUO) is a common condition that complicates the course of advanced malignancies. The aims of this study are to analyze the causes, management, and survival of patients with obstructive nephropathy due to malignant ureteric obstruction and to determine prognostic factors. Furthermore, we studied the complications and outcomes in patients who underwent urinary diversion.

Materials and methods

A retrospective study was conducted on patients with computed tomography-confirmed MUO between January 2016 and November 2020. Demographic, clinical, radiological, laboratory, and management data were collected. Survival curves were estimated using the Kaplan-Meier method, and univariate and multivariate Cox proportional hazards models were used to test the association between parameters and survival.

Results

A total of 188 patients were included. The mean age was 69.01 years (SD, 14.95 years), and the majority (54.8%) were male. The most common mechanism leading to MUO was compression by a pelvic mass (36.9%), and the 3 most frequent tumors causing MUO were prostate (17.6%), bladder (16.5%), and rectal cancer (11.7%).Forty-seven patients (25%) underwent urinary diversion: 23 (48.9%) underwent double-J stenting and 21 (44.7%) underwent percutaneous nephrostomy. The most common reason for urinary diversion was acute kidney injury (53.3%). Recovery of renal function was observed in 55.8% of the patients after urinary diversion. The most frequently identified complications after urinary diversion were urinary tract infection (24.4%), hematuria (17.0%), and urinary sepsis (14.9%). The median survival after hydronephrosis diagnosis was 6.43 months (interquartile range, 1.91-14.81 months). In patients who underwent urinary decompression, the median survival after urinary diversion was 8.67 months (interquartile range, 2.99-17.28 months). In the multivariate analysis, a lower grade of hydronephrosis and cancer cachexia negatively impacted survival.

Conclusions

Cancer patients with MUO have a poor prognosis; therefore, the risk-benefit ratio of urinary diversion should be carefully considered. Cachexia and hydronephrosis grade can be useful in selecting suitable candidates for urinary diversion.

Stent Syndrome: Does the Diameter Matter? Results of a Randomized Trial

Introduction: Double-J (DJ) ureteral stents are used for multiple purposes in urology. Even though they temporize the subsequent treatment of lithiasis, they may cause different symptoms that impact quality of life (QoL). Purpose: In this randomized trial, we assessed whether the diameter of ureteral stents has an impact on catheter-associated symptoms, and their impact on QoL. Methods: A total of 194 consecutive patients undergoing DJ insertion between December 2018 and December 2022 were prospectively enrolled and divided into three categories: 4.7F (Group 1, n = 71), 6F (Group 2, n = 65), and 7F (Group 3, n = 58). Within 1 week after the DJ placement, patients completed the validated Spanish version of the Ureteral Stent Symptoms Questionnaire. Continuous variables were compared using analysis of variance and Student's t-tests. For categorical data, the chi-square test was used. Results: In the domain of "work" and "additional problems," there were significant differences. In the "Work" domain, Group 1 presented the lower symptoms. In the domain "additional problems," patients in Group 1 were prescribed fewer antibiotics owing to low urinary tract symptoms. In question U4 about urinary incontinence, patients in Groups 2 and 3 developed these symptoms more than patients in Group 1. In the "sexual activity" domain, specifically in question S3 (the patient has ever suffered any type of pain during sexual activity?), patients with 4.7F presented lower scores than patients with larger catheters. Conclusion: DJ-related symptoms affect QoL in most cases. Smaller catheters produced significantly less urinary incontinence, faster work reincorporation, fewer symptoms related to sexual activity, and fewer catheter-related symptoms than 7F catheters. In contrast, Group 3 presented fewer outpatient visits because of symptoms related to the DJ.

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

PURPOSE

To determine the effectiveness of exchange and upsizing of malfunctioning small-caliber double-J (JJ) ureteral stents.

MATERIALS AND METHODS

Thirty-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.

RESULTS

JJ 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%).

CONCLUSIONS

Exchange 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.

Malignant upper urinary tract obstruction: A prospective evaluation of patients presenting as an emergency to urology and their long-term real-life outcomes

Objective:

The objective of this study was to evaluate the management and survival outcomes of patients referred to urology as an emergency with malignant upper urinary tract obstruction (MUUTO).

Patients and Methods:

Between 2019 and 2020, the outcomes of all emergency referrals with MUUTO to the Urology team at a single institution were prospectively analysed.

Results:

In total, 119 patients, median age 77 years, were referred to the urology team with MUUTO. Of these, 59% (70/119) had bilateral and 41% (49/119) unilateral obstruction. The three commonest primary underlying malignancies were gladder (41% (49/119)), prostate (19% (23/119)), and colorectal (8% (10/119)) cancer. The commonest indication for referral was acute kidney injury (86% (103/119)), the remainder had sepsis (13% (15/119)), and pain (1% (1/119)). Median in-patient stay for the admission was 7 days. Median estimated glomerular filtration rate (eGFR/1.73 m2) measured on discharge improved irrespective of whether intervention for MUUTO was received. Overall survival of the cohort was 13% (16/119).

Conclusions:

Patients referred with MUUTO as an emergency have a poor prognosis. Renal function does not significantly deteriorate in the short term in this patient group with no intervention, and overall survival is not significantly improved after intervention unless further treatment is received. Multidisciplinary team discussion, including patients and oncologists, should be best practice before intervention in this challenging situation.

Level of evidence:

2b

Interventions for obstructive uropathy in advanced prostate cancer: a population-based study

OBJECTIVES

To develop and validate a coding framework to identify interventions for upper tract obstructive uropathy (UTOU) in men with locally advanced and metastatic prostate cancer (PCa) using administrative hospital data to assess clinical outcomes. There are no population-based studies on the incidence, treatment, and outcomes of this complication.

PATIENTS AND METHODS

Patients newly diagnosed with PCa between April 2014 and March 2019 were identified in the English cancer registry. A coding framework based on procedure (Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures fourth edition) and diagnostic (International Classification of Diseases, 10th edition) codes was developed and validated. Subsequent clinical outcomes were determined using Hospital Episodes Statistics to determine the utility of the intervention.

RESULTS

A total of 77 010 patients newly diagnosed with locally advanced, and 30 083 patients with metastatic PCa were identified. Of these, 1951 (1.8%) patients underwent an intervention for UTOU according to our coding framework: 830 (42.5%) had locally advanced disease and 1121 (57.5%) had metastatic disease. In all, 844 (43.3%) had a percutaneous nephrostomy (PCN), 473 (24.2%) had a PCN with antegrade stent, and 634 (32.5%) had a retrograde stent. The mean follow-up was 43.2 months. The cumulative incidence of the use of these interventions at 1, 3, and 5 years was 2.5%, 3.6% and 4.2% in men with metastases compared to 0.5%, 0.9% and 1.4% in men with locally advanced disease.

CONCLUSION

A new coding framework, developed to identify procedures for UTOU was applied in the largest study to date of UTOU in men with primary locally advanced and metastatic PCa. Results demonstrated that 2% of men with locally advanced PCa and 4% of men with metastatic PCa require an intervention to resolve UTOU within 5 years of their PCa diagnosis.

Management and outcomes of hydronephrosis in patients with metastatic extramammary Paget's disease: A retrospective analysis

Hydronephrosis in extramammary Paget's disease (EMPD) with distant metastasis (metastatic EMPD) has been observed in medical practice; however, its prognosis remains unclear. Retrospective analyses were performed to assess the management and outcomes of hydronephrosis in metastatic EMPD. During a follow-up of 44 patients with metastatic EMPD, 13 (30%) developed hydronephrosis. Ten (77%) of the 13 patients with hydronephrosis had impaired renal function (estimated glomerular filtration rate: <60 ml/min/1.73 m² ), and ureteral stents were placed in every patient with impaired renal function. The stent was placed successfully in all 10 patients, and their renal function recovered within a median period of 7 days. Importantly, each of these patients continued chemotherapy, and none of them experienced stent failure. The median overall survival time (OS) in patients with metastatic EMPD and hydronephrosis (n = 13) was 7.8 months. Treatment for hydronephrosis was not a significant factor for OS, and median OS in patients who underwent ureteral stent replacement (n = 10) was 14.7 months. Collectively, our results indicate that hydronephrosis is relatively common, and ureteral stent placement should be considered in cases of metastatic EMPD with hydronephrosis to maintain renal function and continue chemotherapy toward a better prognosis.

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.

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.

A systematic review of long-duration stents for ureteral stricture: which one to choose?

OBJECTIVE

To define which long-term stent would work best in malignant ureteral obstruction (MUO) and benign ureteral obstruction (BUO), focusing on their mechanisms of action, price and insertion approach.

METHODS

A systematic review was developed using the MEDLINE and Scopus databases and in accordance with the PRISMA checklist. There were no language restrictions for the search. Studies describing the use of metallic ureteric stents for MUO and for BUO in humans were included.

RESULTS

We analyzed five types of metallic stents (35 papers) and also the experience with the tumor and extra-anatomical stents. The Resonance, Memokath and Allium ureteral stents were found to be useful in BUO and MUO. The Uventa stent performed well in chronic ureteral obstruction. The Detour bypass stent was a recommended option in those patients who had complete obstruction of the ureter and were unfit for reconstructive surgery. There was no difference with regard to the insertion technique and both antegrade and retrograde approaches were equally successful. Although tumor stents showed a good performance, there were very few published studies on it.

CONCLUSION

Metallic stents are a suitable option for MUO and BUO. When compared to standard double J stents, although they are relatively high priced, they show a financial benefit in the long-term. The Detour bypass stent seems to be an effective alternative for complete ureteral obstruction or patients unfit for surgery. Further prospective randomized studies should be done on the effectiveness of tumor stents versus metallic stents.

Ureteroiliac artery fistula caused by full-length metallic ureteral stenting in a malignant ureteral obstruction: a case report

Background

The metallic stent is a new device for relieving the urinary tract in patients with malignant ureteral obstruction with short life expectancy and has been used frequently worldwide for its efficacy and safety. A ureteroarterial fistula with indwelling ureteral stent is rare but highly fatal, and there are several reports of ureteroarterial fistula treated by conventional polymer stents, although there are no reports on metallic stents. To our knowledge, this paper describes the first case of a ureteroiliac artery fistula caused by a full-length metallic ureteral stent in malignant ureteral obstruction.

Case presentation

Our patient was a 57-year-old Asian woman with a history of locally advanced cervical cancer who underwent abdominal total hysterectomy and chemoradiotherapy. She was diagnosed with right hydronephrosis and hydroureter secondary to upper ureteral obstruction because of retroperitoneal lymph node metastasis. A urinary tract obstruction after placement of 12 months of polymer stent followed by 18 months of metallic stent was relieved, consequently resulting in intermittent gross hematuria with bladder tamponade and anemia. Contrast-enhanced computed tomography could not reveal a ureteroarterial fistula; however, retrograde pyelography emphasized the existence of a ureteroiliac artery fistula. The patient underwent successful endovascular heparin-bonded stent graft placement, and her gross hematuria disappeared thereafter.

Conclusion

The metallic stent is a useful device for patients with malignant ureteral obstruction with a short life expectancy, although it may impose a higher pressure on the extraureteral tissue than conventional polymer stents due to its properties and may cause a ureteroarterial fistula. The narrowing of the external iliac artery diameter visualized by computed tomography may be helpful for predicting ureteroarterial fistulas.

Is there still a role of balloon dilatation of benign ureteric strictures in 2019?

Introduction and Objectives: Reconstructive surgery for benign ureteric strictures and long term nephrostomy are often invasive and lead to poor quality of life. Balloon dilatation has the potential to bridge this gap. We present the outcome of our series and examine the risk factors of stricture recurrence.Materials and Methods: There were 109 strictures in our series from August 2012 to July 2018 in our single center retrospective cohort analysis. All strictures were dilated retrogradely or antegradely and followed by stenting. Follow-up imaging was done to assess stricture recurrence.Results: Mean patient age was 57.7-years-old (SD ± 12.6). Mean follow-up was 20.2 months (SE ± 1.8). All strictures were successfully dilated and stented. Overall, mean patency rate was 63.7% at mean follow-up of 20.2 months (SE ± 1.8). Strictures caused by stone/inflammation had 28.0% (21/75) risk of recurrence compared to iatrogenic causes, 63.6% (7/11), and radiotherapy, 100.0% (5/5) (p = 0.001). Non-incidental strictures also had significantly higher risk of recurrence at 57.4% (27/47) vs. incidental strictures at 13.6% (6/44) (p = 0.000). The mean length of strictures was 12.5 mm (SE ± 1.7) in the recurrence group vs. 9.6 mm (SE ± 0.7) in those without recurrence (p = 0.001). The presence of ipsilateral atrophic kidney was associated with 72.2% (13/18) risk of recurrence vs. non-atrophic kidney 27.4% (20/73) (p = 0.000). The mean age of stricture was 14.5 months (SE ± 4.6) and 5.2 months (SE ± 2.1) in the recurrence and non-recurrence groups, respectively (p = 0.013).Conclusions: Balloon dilatation of benign ureteric stricture is a feasible option. Its effect can be long-lasting in selected patients, that is, non-irradiated, incidental, short strictures with normal kidneys. This will benefit patients unfit for reconstructive surgery.

Malignant ureteric obstruction decompression: how much gain for how much pain? A narrative review

Over the last thirty years, the management of Malignant Ureteric Obstruction (MUO) has evolved from a single disciplinary decision to a multi-disciplinary approach. Careful consideration must be given to the risks and benefits of decompression of hydronephrosis for an individual patient. There is a lack of consensus of opinion as well as strong evidence to support the decision process. Outcomes that were identified amongst patients undergoing treatment for MUO included prognosis, quality of life (QOL), complications, morbidity and prognostication tools. A total of 63 papers were included. Median survival was 6.4 months in the 53 papers that stated this outcome. Significant predictors to poor outcomes included low serum albumin, hyponatremia, the number of malignancy related events, and performance status of 2 or worse on the European cooperative cancer group. We propose a multi-centre review of outcomes to enable evidence-based consultations for patients and their families.

Urological Management of Extramural Malignant Ureteric Obstruction: A Survey of Irish Urologists

Introduction

The absence of guidelines in the management of extramural malignant ureteric obstruction leads to confusion in decision making and in the interaction between urology and other clinical disciplines. In this study, we surveyed consultant urologists with the goal of achieving a better consensus on optimal management options.

Methods

A multiple choice survey was sent via the online survey tool "SurveyMonkey" to all consultant urologists practicing in the Republic of Ireland.

Results

There was a response rate of 57.5% (n = 23). Twenty-two (96%) consultants consider the use of percutaneous nephrostomy with placement of antegrade ureteric stent but only 22% (n = 5) would consider using a metallic stent. Eleven (48%) respondents favor retrograde stenting in the first instance with an equal proportion choosing an antegrade method. Nine (39%) consultants perform the initial stent change at 4-6 months, 8 (35%) at 2-4 months, and 1 at < 2 months and 6-10 months respectively. Total 59% (n = 13) of respondents felt that the duration of expected patient survival influenced their decision and agreement to stent with 42% (n = 8) saying this survival would need to be > 6 months and 82% (n = 18) were generally happy with the level of ongoing communication between urology and the primary service managing the patient.

Conclusion

There is a lack of consensus regarding the management of this challenging problem, particularly with regard to timing of first stent change and whether to initially use an antegrade or retrograde approach. This reflects the heterogeneous patient cohort and the important factors of life expectancy and patient co-morbidities.

Retrograde pyelography predicts retrograde ureteral stenting failure and reduces unnecessary stenting trials in patients with advanced non-urological malignant ureteral obstruction

Objective

To evaluate predictive factors for retrograde ureteral stent failure in patients with non-urological malignant ureteral obstruction.

Materials and methods

Between 2005 and 2014, medical records of 284 malignant ureteral obstruction patients with 712 retrograde ureteral stent trials including 63 (22.2%) having bilateral malignant ureteral obstruction were retrospectively reviewed. Retrograde ureteral stent failure was defined as the inability to place ureteral stents by cystoscopy, recurrent stent obstruction within one month, or non-relief of azotemia within one week from the prior retrograde ureteral stent. The clinicopathological parameters and first retrograde pyelographic findings were analyzed to investigate the predictive factors for retrograde ureteral stent failure and conversion to percutaneous nephrostomy in multivariate analysis with a statistical significance of p < 0.05.

Results

Retrograde ureteral stent failure was detected in 14.1% of patients. The mean number of retrograde ureteral stent placements and indwelling duration of the ureteral stents were 2.5 ± 2.6 times and 8.6 ± 4.0 months, respectively. Multivariate analyses identified several specific RGP findings as significant predictive factors for retrograde ureteral stent failure (p < 0.05). The significant retrograde pyelographic findings included grade 4 hydronephrosis (hazard ratio 4.10, 95% confidence interval 1.39–12.09), irreversible ureteral kinking (hazard ratio 2.72, confidence interval 1.03–7.18), presence of bladder invasion (hazard ratio 4.78, confidence interval 1.81–12.63), and multiple lesions of ureteral stricture (hazard ratio 3.46, confidence interval 1.35–8.83) (p < 0.05).

Conclusion

Retrograde pyelography might prevent unnecessary and ineffective retrograde ureteral stent trials in patients with advanced non-urological malignant ureteral obstruction.

The profile of patients with obstructive uropathy in Cameroon: case of the Douala General Hospital

Introduction

Obstructive uropathy can lead to irreversible kidney damage. The etiology largely determined by the patient's age can be benign or malignant. This study aimed at determining the profile and outcome of patients with obstructive uropathy in Cameroon.

Methods

A cross sectional study carried out in the urology unit of the Douala General Hospital, including patients with a diagnosis of obstructive uropathy seen from January 2004 to December 2013. Clinical profile, treatment and outcome data were obtained from patients records.

Results

Of the 229 patients included 69% were men, mean age 50 ±18 years. Associated comorbidities were hypertension, diabetes, and HIV. Mean haemoglobin 8,40±2,4g/dl, mean GFR 10,3 ±10ml/min, 94 (41%) patients needed emergency dialysis. Symptoms at presentation: asthenia (57%), anorexia (55%), loin pain (37%), vomiting (28%), oedema (20%), and anuria (15%). Urinary tract infection was present in 33 patients. Main aetiologies of obstruction: urolithiasis (35%), begnin prostatic hypertrophy (27%), prostatic cancer (12%), cervical cancer (16%), and congenital malformations (5%). Drainage was effective in 102 (45%) patients, 63 (28%) recovered completely, 91 (41%) were loss to follow up, 49 (22%) died and more women (p = 0.02). Mortality was associated with prostatic cancer (p = 0.000), cervical cancer (p = 0.004) and radiotherapy (p = 0.03).

Conclusion

Patients with obstructive uropathy presented with significant impaired renal function. Main causes were urinary stones, prostatic hypertrophy, prostatic and cervical cancers. Renal recovery was poor, loss to follow up and mortality high. Specific strategies to target improvement in renal recovery and patient's survival are needed in this patient's group.

A new technique to prevent curling of guide wire in urinary bladder during J stent insertion with flexible cystoscope

Insertion of J stent is a very common procedure performed by urologists. This procedure is often performed to relieve ureteral obstruction due to stones, tumours, ureteral kink, or stricture on urgent basis. An increasing number of urologists are using a flexible cystoscope and local anaesthetic for J stent insertion. Occasionally, the guide wire curls in the bladder, making it impossible to insert the J stent. Here, we describe a simple method to overcome this problem using modified ureteral dilator, which is usually available in the cystoscopy suite.

Predicting the failure of retrograde ureteral stent insertion for managing malignant ureteral obstruction in outpatients

Malignant ureteral obstruction (MUO) is an unpropitious sign that is commonly observed in patients with advanced incurable cancer. The present study aimed to evaluate predictive factors for the failure of retrograde ureteral stent insertion in the management of MUO in outpatients. A total of 164 patients with MUO were retrospectively assessed in this study. Clinical factors, including age, gender, type of malignancy, level of obstruction, cause of obstruction, pre-operative creatinine level, degree of hydronephrosis, condition of the contralateral ureter, prior radiotherapy, Eastern Cooperative Oncology Group performance status (ECOG PS), bladder wall invasion and technical failure, were recorded for each case. Univariate and multivariate logistic regression analyses were used to investigate the risk factors for predicting the failure of retrograde ureteral stent insertion. In total, 38 out of 164 patients experienced bilateral obstruction, therefore, a total of 202 ureteral units were available for data analysis. The rate of insertion failure in MUO was 34.65%. Multivariate analyses identified ECOG PS, degree of hydronephrosis and bladder wall invasion as independent predictors for insertion failure. Overall, the present study found that rate of retrograde ureteral stent insertion failure is high in outpatients with MUO, and that ECOG PS, degree of hydronephrosis and bladder invasion are potential independent predictors of insertion failure.

Evaluation of 18F-FDG excretion patterns in malignant obstructive uropathy

OBJECTIVES

This study aims to evaluate whether (18)F-FDG excretion patterns reflect renal function in malignant obstructive uropathy and to evaluate if these patterns predict internal ureteral stent success.

METHODS

One hundred twelve patients who underwent PET/CT for abdominal tumors and displayed hydronephrosis on CT and 59 patients who underwent PET/CT for cancer screening were included in a retrospective study. Hydronephrosis was graded by initial CT and correlated with visual analysis of (18)F-FDG renal parenchymal uptake and excretion patterns. Stent insertion was performed for 84 patients after PET. Follow-up CT was reviewed for hydronephrosis improvement.

RESULTS

There were 4 PET patterns in obstructive hydronephrosis which correlated linearly with hydronephrosis severity and serum creatinine levels. Patients with no parenchymal retention and renal excretion (PET pattern 1) showed 97% (28/29) hydronephrosis improvement after stent insertion, and patients with no parenchymal retention and no renal excretion showed 0% (0/9) hydronephrosis improvement after stent insertion. Multivariate analysis showed creatinine levels and PET pattern predicted stent success, but CT hydronephrosis did not.

CONCLUSIONS

There are 4 PET patterns of obstructive hydronephrosis which correlated with hydronephrosis grade and creatinine levels. Some of these PET patterns can be useful in the prediction of hydronephrosis improvement after stent insertion. Recognition of these patterns in obstructive hydronephrosis may be helpful in improving patient prognosis and quality of life.

Alleviation of kidney damage induced by unilateral ureter obstruction in rats by Rhodiola rosea

PURPOSE

To evaluate the efficacy of Rhodiola rosea extract in terms of alleviating the renal damage induced by unilateral ureter obstruction (UUO) in rats.

MATERIAL AND METHODS

Thirty Wistar albino male rats were divided into five groups: (I) Control, (II) UUO 7 days, (III) UUO 7 days+extract,(IV) UUO 14 days, and (V) UUO 14 days+extract. Seven or 14 days after the initiation of the experimental procedure, the left kidneys of rats in all five groups were removed for histological examination, and their blood was drawn for biochemical measurements.

RESULT

Median malondialdehyde (MDA) and glutathione peroxidase (GPx) levels were, respectively, 39.4 (5.04) nmol/mL and 25.8 (8.01) nmol/minute/mL in group I, 77.9 (12.38) nmol/mL and 5.8 (1.95) nmol/minute/mL in group II, 48.7 (12.1) nmol/mL and 9.1 (2.3) nmol/minute/mL in group III, 58.5 (23.83) nmol/mL and 8.4 (2.1) nmol/minute/mL in group IV, and 44.8 (4.97) nmol/mL and 13.8 (3.73) nmol/minute/mL in group V. There was a statistically significant difference among the groups in terms of MDA and GPx levels (p<0.05 for both). The median numbers of apoptotic cells were 1 (1), 8 (2.25), 3 (1.25), 23.5 (9), and 7 (I) in groups I, II, III, IV, and V, respectively. There was a statistically siginificant difference among the groups in terms of apoptotic cell number (p<0.05).

CONCLUSION

R. rosea extract was shown to alleviate the renal damage induced by UUO through its antioxidant effects. The mechanism by which R. rosea extract causes these effects merits further investigation.

Predicting factors for stent failure-free survival in patients with a malignant ureteral obstruction managed with ureteral stents

Purpose

To determine predictive factors for stent failure-free survival in patients treated with a retrograde ureteral stent for a malignant ureteral obstruction.

Materials and Methods

We retrospectively reviewed 71 patients who underwent insertion of a cystoscopic ureteral stent due to a malignant ureteral obstruction between May 2004 and June 2011. Performance status, type of cancer, hydronephrosis grade, location of the obstruction, presence of bladder invasion, C-reactive protein (CRP), serum albumin, and inflammation-based prognostic score (Glasgow prognostic score, GPS) were assessed using a Cox proportional regression hazard model as predicting factors for stent failure.

Results

A univariate analysis indicted that hypoalbuminemia (<3.5 g/dL; hazard ratio [HR], 2.43; 95% confidence interval [CI], 1.21 to 4.86; p=0.012), elevated CRP (≥1 mg/dL; HR, 4.79; 95% CI, 2.0 to 11.1; p=0.001), and presence of a distal ureter obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.021) were associated with stent failure-free survival. A multivariate analysis revealed that the presence of a mid and lower ureteral obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.007), GPS ≥1 (HR, 7.22; 95% CI, 2.89 to 18.0; p=0.001), and elevated serum creatinine before ureteral stent placement (>1.2 mg/dL; HR, 2.16; 95% CI, 1.02 to 4.57; p=0.044) were associated with stent failure-free survival.

Conclusions

A mid or lower ureteral obstruction, GPS ≥1, and serum creatinine before ureteral stent insertion >1.2 mg/dL were unfavorable predictors of stent failure-free survival. These factors may help urologists predict survival time.

Clinical experience with ureteral metal stents

Ureteral metal stents (MSs) present a minimally invasive tool to preserve the drainage of renal pelvis whenever ureteral patency is at risk to be obstructed due to extrinsic or intrinsic etiologies. Clinical experience with these stents demonstrates that they impose a promising alternative treatment option in ureteral pathologies that are difficult to be treated via common polymeric stents. Current application of MSs in the treatment of both benign and malignant ureteral obstruction reveals quite promising results. Nevertheless, the ideal MS that would provide uncomplicated long-term effectiveness is still lucking and current MS usage is facing several adverse effects between which stent obstruction, encrustation, infection, migration, and patient discomfort. Ongoing attempts to create more inert stent with sophisticated novel designs are expected to improve current MS efficiency. MSs will play a major role in the future as a routine management of a variety of ureteral pathologies.

Current outcome of patients with ureteral stents for the management of malignant ureteral obstruction

PURPOSE

We analyzed the prognostic factors associated with overall survival and predictive factors of stent failure in patients treated with an indwelling retrograde ureteral stent for malignant ureteral obstruction.

MATERIALS AND METHODS

Among 186 Japanese patients treated with an indwelling retrograde ureteral stent for ureteral obstruction from January 2005 to March 2010, 61 with malignant ureteral obstruction and 95 ureteral units were analyzed retrospectively.

RESULTS

Median survival was estimated at 228 days. Unfavorable prognostic factors of overall survival were no treatment after indwelling retrograde ureteral stent placement (p = 0.023) and a serum creatinine before indwelling retrograde ureteral stent placement of 1.2 mg/dl or greater (p = 0.016). Overall survival differed significantly among cancer groups (p <0.001) as did stent failure-free survival (p = 0.011). Overall survival differed significantly among 3 risk groups divided according to the score calculated with regard to prognostic factors (p <0.001).

CONCLUSIONS

Gynecologic cancer was a significant favorable predictor of stent failure-free survival. Patients treated with an indwelling retrograde ureteral stent for malignant ureteral obstruction were divided into 3 groups, which showed significant differences in overall survival. This risk classification may help urologists predict survival time.