Malignant Ureteral Obstruction Research Articles

Current status of metal stents for managing malignant ureteric obstruction

Obstruction of the ureters caused by extrinsic compression from a primary tumour or retroperitoneal lymph node masses is not unusual in the course of advanced pelvic malignancies. Most of the cases are of gynaecological or gastrointestinal origin, and the situation can be aggravated by peri-ureteric fibrosis, a long-term adverse event of previous chemotherapy or radiotherapy. Undoubtedly upper urinary tract decompression and maintenance of ureteric patency, even as a palliative measure, is important in managing these patients. Options for upper tract decompression include percutaneous nephrostomy, retrograde stenting and open urinary diversion. Plastic stents have long been used for managing malignant ureteric obstruction, but their overall success remains limited. Plastic stents often fail to be placed correctly, require regular exchange, and are faced with a high incidence of encrustation and migration. For these reasons plastic stents have been unsuccessful for long-term maintenance of ureteric patency. To overcome these limitations metal stents were introduced and recently developed in an effort to ensure better long-term patency of the obstructed ureter, fewer hospital admissions for stent change and better overall quality of life. In the present review the clinical applications of different types of metal stents are discussed, with a specific focus on the latest advances and the future options for managing malignant ureteric obstruction.

Cost analysis and clinical applicability of the Resonance® metallic ureteral stent

The Resonance® metallic stent is a new wire-based ureteral stent that was initially developed for patients with malignant ureteral obstruction. Potential advantages over traditional stents include resistance to encrustation and to external compression, allowing for increased dwell times and the maintenance of upper tract drainage when traditional polymer stents have failed. We present a comparative cost analysis of Resonance metallic and standard polymer stent use in patients with benign urinary obstruction and review the literature regarding the Resonance stent.

Pyelovesical Bypass Graft for Palliative Management of Malignant Ureteric Obstruction: Optimizing the Technique by Percutaneous Access to the Bladder Using a Split Amplatz Sheath

To introduce a simple modification to the original technique of pyelovesical bypass graft placement to make the procedure more minimally invasive. During the study period 2 patients with malignant ureteric obstruction underwent pyelovesical bypass graft placement using Detour stent (Mentor-Porges). The technique simply comprised tract dilatation of the previously placed percutaneous nephrostomy to place the proximal end of the graft in the renal collecting system, making a subcutaneous tunnel from a 1-cm suprapubic incision to the flank area, percutaneous access to the bladder under fluoroscopic guide and placement of the distal end of the stent into the bladder through a split Amplatz sheath. The operative outcome was analyzed prospectively. Both patients tolerated the procedures well with no intra- and postoperative complications. Renal function remained stable during the follow-up period with acceptable urine output through the urethra. Abdominal wall complications such as fistula formation or pain along the subcutaneous tract as well as stent encrustation did not occur during the follow-up period. Despite our small sample size and short follow-up period, percutaneous access to the bladder using a split Amplatz sheath during placement of the Detour stent, may be considered as a promising simple modification to optimize the technique by obviating the need for open cystostomy incision.

Endourologic Management of Malignant Ureteral Obstruction: Indications, Results, and Quality-of-Life Issues

Obstruction of the upper urinary tract is a problem commonly faced by practicing urologists. The constant evolution in endourology has effectively facilitated minimally invasive management of upper-tract obstruction. In a case in which malignancy is the cause of obstruction, however, the situation significantly changes. Questions arise regarding the need for relieving the obstruction, the means to accomplish this, and the benefits and drawbacks of each technique regarding both their efficacy and their impact on the patients well-being and the crucial issue of quality of life in the face of malignancy.

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.

One-stage tubeless antegrade ureteric stenting: a safe and cost-effective option?

Antegrade insertion of ureteric stent has become an established mode of management of upper tract obstruction secondary to ureteric pathology. It is conventionally performed as a two-stage procedure for various reasons but, more recently, a one-stage approach has been adopted. We discuss our experience of primary one-stage insertion of antegrade ureteric stent as a safe and cost-effective option for the management of these difficult cases in this retrospective observational case cohort study of patients referred to a radiology department for decompression of obstructed upper tracts. Data were retrieved from case notes and a radiology database for patients undergoing one-stage and two-stage antegrade stenting. It was followed by telephone survey of regional centres about the prevalent local practice for antegrade stenting. Outcome measures like hospital stay, procedural costs, requirement of analgesia/antimicrobials and complication rates were compared for the two approaches. a one-stage approach was found to be suitable in most cases with many advantages over the two-stage approach with comparable or better outcomes at lower costs. Some of the limitations of the study were retrospective data collection, more than one radiologist performing stenting procedures and non-availability of interventional radiologist falsely raising the incidence of two-stage procedures. In the absence of any clinical contra-indications and subject to availability of an interventional radiologist's support, one-stage antegrade stenting could easily be adopted as a routine approach for the management of benign or malignant ureteric obstruction.

Ureteral Metal Stents: 10-Year Experience With Malignant Ureteral Obstruction Treatment

Ureteral patency in malignant ureteral obstruction cases is a therapeutic challenge. We report our long-term experience with palliative treatment for extrinsic malignant ureteral obstruction with percutaneous placement of metal mesh stents. From January 1996 to December 2005, 90 patients with a mean age of 59 years (range 35 to 80) with ureteral obstruction due to extrinsic ureteral compression and/or encasement by primary or metastatic tumors, or retroperitoneal lymphadenopathy underwent implantation of self-expandable metal mesh stents. A total of 119 ureters were managed. Followup included urinalysis, blood biochemistry tests and transabdominal ultrasound or intravenous urography. The technical success rate of percutaneous antegrade insertion of ureteral self-expandable metal mesh stents was 100%. Renal biochemistry normalized and hydronephrosis gradually resolved 1 to 2 weeks after stent insertion. Median followup was 15 months (range 8 to 38). Hyperplastic reaction and/or encrustation, or tumor ingrowth developed in 45 stents. Secondary intervention, such as repeat balloon dilation and coaxial stenting, was done to improve patency. Migration was observed in 13 metal stents. The primary and secondary patency rates during followup were 51.2% and 62.1%, respectively. A double pigtail or external-internal stent was inserted in 45 cases in which secondary interventions did not ensure patency. Internal drainage of extrinsic malignant ureteral obstruction with metal mesh stents provides long-term decompression of the upper urinary tract in select cases. Certain problems limit the application of metal mesh stents in the ureter. Further studies are warranted to identify independent predictors of ureteral patency after the application of metal stents for malignant obstruction.

MP-04.06: Treatment of Malignant Ureteral Obstruction with Ureteral Stents Offers a High Risk for Microbial Device Colonisation

MP-04.06: Treatment of Malignant Ureteral Obstruction with Ureteral Stents Offers a High Risk for Microbial Device Colonisation

Prognostic factors in malignant ureteric obstruction

To validate a model to stratify patients with obstructive nephropathy due to malignant ureteric obstruction, associated with a poor prognosis, into different prognostic groups, as a recent report identified low serum albumin, degree of hydronephrosis and number of events related to metastatic disease as prognostic indicators before palliative decompression. We retrospectively review the charts to identify all patients who had a nephrostomy tube inserted for malignant ureteric obstruction. Laboratory and clinical factors that might influence prognosis were reviewed to attempt to externally validate the previously identified factors and model for risk stratification. The median (range) age of the 49 patients identified was 71 (36-91) years, and the median survival was 174 (14-602) days. Tumours were of urological origin in 66% of patients. Patients with prostate cancer had nephrostomy tubes indwelling for a mean of 279 days, vs 190 days (P = 0.07) for patients with tumours not of prostatic origin. A serum albumin level of >30 g/L (P ≤ 0.001), serum sodium <135 mmol/L (P = 0.019) and three or more events related to dissemination of cancer (P = 0.04) were factors associated with a significantly shorter mean survival. Complications related to the nephrostomy tube were experienced by 39% of patients. The model proved useful in stratifying these patients into different risk groups (P = 0.002). Consistent with a previous report we showed that a low serum albumin level and events related to metastatic disease were indicative of a poor prognosis. We also found that a low serum sodium level might be associated with a worse prognosis. We externally validated a model for stratifying patients into different prognostic groups. Palliative decompression is associated with significant morbidity.

Ureteral Obstruction: Is the Full Metallic Double-Pigtail Stent the Way to Go?

BackgroundThe Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo. ObjectiveThe current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction. Design, setting, and participantsIn total, 50 patients with extrinsic malignant obstruction (n=25), benign ureteral obstruction (n=18), and previously obstructed mesh metal stents (n=7) were prospectively evaluated. InterventionAll patients were treated by Resonance stent insertion. Twenty stents were inserted in antegrade fashion, and the remaining stents were inserted in a retrograde approach. No patient dropped out of the study. The follow-up evaluation included biochemical and imaging modalities. MeasurementsWe evaluated the technical success rate, stricture patency rate, complications, and the presence and type of encrustation. Results and limitationsThe technical success rate of transversal and stenting of the strictures was 100%. In 19 patients, balloon dilatation was performed prior to stenting. The mean follow-up period was 8.5 mo. The stricture patency rate in patients with extrinsic malignant ureteral obstruction was 100% and in patients with benign ureteral obstruction 44%. Failure of Resonance stents in all cases of obstructed metal stents was observed shortly after the procedure (2–12 d). In nine cases, stent exchange was demanding. Encrustation was present in 12 out of 54 stents. ConclusionsThe Resonance stent provides safe and sufficient management of malignant extrinsic ureteral obstruction. Resonance stent use in benign disease needs further evaluation, considering the untoward results of the present study.

Analysis of Ureteral Stent Compression Force and its Role in Malignant Obstruction

Extrinsic ureteral obstruction can be a challenging entity for the urologist since half of the ureteral stents placed for malignant obstruction fail. We evaluated the resistance to radial compression of various stents. Silhouette(R) 4.6Fr, 6Fr and 8Fr, Sof-Curl Tecoflex 6Fr, Resonance 6Fr, Polaris Ultra 6Fr and 7Fr, and Percuflex 6Fr and 8Fr stents were tested. The force needed to compress the stent to 50% of its original external diameter was measured at 3 locations along the stent length, including proximal, middle and distal. Statistical analysis was performed. Statistically greater force was required to compress the Resonance and Silhouette stents compared to all others tested. These results were maintained at all 3 locations along the stent. Only the Polaris 6Fr stent differed in resistance to compression along the stent length. The significantly higher forces required to compress the Resonance and Silhouette stents may translate into improved success in patients with malignant ureteral obstruction.

Malignant Ureteral Obstruction: The Case for Plastic Ureteral Stents

Malignant Ureteral Obstruction: The Case for Plastic Ureteral Stents

Endoscopic ultrasound-guided ureterosigmoidostomy in malignant ureteral obstruction: description of a new method

Endoscopic ultrasound-guided ureterosigmoidostomy in malignant ureteral obstruction: description of a new method

Malignant Extrinsic Ureteral Obstruction: A Survey of Urologists and Medical Oncologists Regarding Treatment Patterns and Preferences

To investigate and compare practice patterns regarding malignant extrinsic ureteral obstruction among urologists (GU) and oncologists (ONC). We invited members of the American Urological Association and the American Society of Clinical Oncologists to participate in a web-based survey. Participants gave recommendations in clinical scenarios, as well as opinions regarding use of ureteral stents and nephrostomy tubes (PCN). The survey was randomly sent to 1500 GU and 1500 ONC, of whom 226 (15%) and 191 (12.4%) responded, respectively. The groups significantly varied in treatment preferences in all clinical scenarios. Regarding stent failure, ONC preferred PCN (79% versus GU 62%); GU (18% versus 5%) next preferred stent manipulation (eg, increase stent size, dual stents) (P <0.0001). The greatest risk of stents per GU was decreased quality of life (65% versus 13%), whereas ONC were most concerned about infection (43% versus 3%) (P <0.0001). The greatest risk of PCN per GU was dislodgement (48% versus 18%), whereas ONC were most concerned about infection (40% versus 8%) (P <0.0001). Practice patterns vary significantly between GU and ONC in the treatment of malignant extrinsic ureteral obstruction. Further investigation and collaboration are necessary to determine which interventions are best for these patients and how to ensure consistency in their care.

Re: Borin JF, Melamud O, Clayman RV. Initial Experience with Full-Length Metal Stent to Relieve Malignant Ureteral Obstruction. J Endourol 2006;20:300–304

Re: Borin JF, Melamud O, Clayman RV. Initial Experience with Full-Length Metal Stent to Relieve Malignant Ureteral Obstruction. J Endourol 2006;20:300–304

The Clinical Characteristics of Malignant Ureteral Obstruction Secondary to Non-genitourinary Malignancy

Purpose: We assessed the success rate of internal ureteral stenting and the complications for patients with ureteral obstruction secondary to non-genitourinary malignancy. Materials and Methods: Between January 2001 and December 2005, ureteral stenting were attempted in 62 patients with ureteral obstruction secondary to non-genitourinary malignancy. Their medical records were reviewed for the primary diagnosis, the symptoms, the degree of hydronephrosis, the location of obstruction, stent failure, the time period until stent replacement due to stent failure, the complications and the status at the last followup. Results: A total 62 patients underwent an attempt at retrograde ureteral stenting for malignant extrinsic obstruction. The mean patient age was 57.6 years(range: 32-84) and the mean follow-up was 12.6 months. 44 patients(71%) were women, and the most common cancer diagnoses were cervical cancer(19), rectal cancer(16) and stomach cancer(11). A total of 23 patients(37%) required immediate percutaneous nephrostomy(PCN) referral. A total of 14 patients experienced late failure and required PCN. A total of 39 patients underwent stent replacement at a mean interval of 3.5 months. Conclusions: At almost 1 year follow-up, stent failure due to extrinsic compression occurred in 55.7% of the patients(37 of 62). We should carefully monitor patient who undergo ureteral stenting for ongoing obstruction and complication.

The outcome with ureteric stents for managing non‐urological malignant ureteric obstruction

To investigate the clinical outcome using ureteric stents to manage ureteric obstruction in advanced non-urological malignancies. We retrospectively reviewed the use of ureteric stents (Endo-sof, Cook Urological, Spencer, IN, USA) placed for malignant ureteric obstruction from June 2001 to September 2006. The clinical and radiological variables for predicting the failure of stent insertion, functional stent failure and death were analysed. In all, 86 patients with a non-urological malignant ureteric obstruction were treated by ureteric stenting; 13 (15%) had failure of retrograde stent insertion, and of the remaining 73, 12 (16%) had stent failures during the subsequent follow-up. The risk of failure for stent insertion significantly increased with male gender (hazard ratio 6.45, P = 0.028) and the presence of bladder invasion (hazard ratio 27.04, P < 0.001). There was no independent predictor of stent failure in univariate analysis. Of the 86 patients, 54 (63%) died with a mean survival time of 8.6 months after an initial attempt to place a stent, and 41 (48%) died within 1 year. Multivariate analysis showed that low performance status, upper ureteric obstruction and no chemotherapy after stenting were independently associated with a poor prognosis (P = 0.03, 0.004 and 0.003, respectively). The method of diversion for a malignant ureteric obstruction should be carefully discussed with male patients or if there is bladder invasion. Patients with a low performance status, upper ureteric obstruction and no scheduled chemotherapy after stenting had a poor survival time.

Differentiation of Malignant From Benign Distal Ureteral Obstructions

The purpose of this study was to evaluate the feasibility of transrectal ultrasonography (TRUS) and color Doppler ultrasonography (CDUS) in differentiating malignant from benign distal ureteral obstructions. Our study group consisted of 16 malignant distal ureteral obstructions and 12 benign distal ureteral obstructions. The 16 malignant distal ureteral obstructions were transitional cell carcinomas involving the distal ureter. The 12 benign distal ureteral obstructions consisted of benign strictures (n = 4), ureteral edema after stone passage (n = 3), tuberculosis (n = 2), a fibroepithelial polyp (n = 1), amyloidosis (n = 1), and a hematoma (n = 1). Findings from gray scale transabdominal ultrasonography, gray scale TRUS, CDUS, and duplex Doppler imaging were retrospectively evaluated. Gray scale transabdominal ultrasonography and TRUS showed no specific difference between malignant and benign distal ureteral obstructions. On CDUS, malignant distal ureteral obstructions showed dotlike blood flow in 5, moderately increased blood flow in 9, and markedly increased blood flow in 2; and benign distal ureteral obstructions showed absence of blood flow in 5 and dotlike blood flow in 7. Flow spectra could be obtained in 12 malignant distal ureteral obstructions, and they showed arterial waveforms. Duplex Doppler imaging was not tried in 4 malignant distal ureteral obstructions. In 7 benign distal ureteral obstructions with dotlike blood flow, flow spectra could not be obtained. Moderately or markedly increased blood flow within a ureteral mass on CDUS and an arterial waveform within a ureteral mass on duplex Doppler imaging may be helpful in differentiating malignant from benign distal ureteral obstructions.

Cost of malignant ureteral obstruction treated with ureteral stents

Cost of malignant ureteral obstruction treated with ureteral stents

Extreme hyperkalaemia secondary to malignant ureteric obstruction: Case Report

We report a case of a 42 year old patient who collapsed at an airport departure lounge. The patient was investigated and found to have advanced renal failure with serum potassium (K+) of 10.3 mmol/L, creatinine of 3581 pmol/L and urea of 59.9 mmol/L secondary to obstructive uropathy due to advanced bladder cancer. Although these biochemical changes were thought to be incompatible with life, he made a slow recovery following haemodialysis and insertion of bilateral percutaneous nephrostomy tubes.