Simultaneous multiple double pigtail stents for malignant ureteral obstruction

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.

Long-Term Follow-Up of Yearly Replaced Double Internal Stents for Extrinsic Malignant Ureteral Obstruction

Introduction: To assess long-term outcomes of double internal stents (DIS) for the relief of external malignant ureteral obstruction (MUO). Materials and Methods: DIS (7F each; 12-month indwelling time) were inserted under general anesthesia in 62 consecutive patients (75 renal units) with MUO during 2007-2018. Surveillance was performed every 3 months, and stents were exchanged routinely every year. The need for permanent stent retrieval was considered stent failure. Maintenance of stent patency and disease-specific survival (DSS) were estimated (Kaplan-Meier). Risk factors were also assessed (univariate and multivariable Cox regression analyses). Results: The median follow-up was 27 months (interquartile range [IQR] 20-27). The most frequent tumors causing obstruction were colorectal and ovarian cancers. Six patients (10%) had stent failure caused by sepsis, creatinine elevation, or hematuria. The average time to failure was 15 months (range 1-27). A history of radiation and an estimated glomerular filtration rate (eGFR) ≤45 mL/(min/1.73 m²) were associated with stent failure (p = 0.038 and p = 0.001, respectively). Thirty-nine patients died with a median DSS of 21 months (IQR 8.6-not reached). Multivariate analysis identified eGFR ≤60 mL/(min/1.73 m²) (hazard ratio [HR] 2.1, 95% confidence interval [CI] 1.1-4.2, p = 0.02) and need for balloon dilation (HR 2.1, 95% CI 1.1-4.1, p = 0.02) as independent predictors for disease-related mortality. Twenty-six patients (42%) had stent-related complications, for example, irritative symptoms, hematuria, and infections, of whom only two failed. Conclusions: One-year indwelling DIS provide effective long-term relief of MUO and represent a simple and effective alternative to other methods of urinary diversion. They avoid the need for external tubes and contribute to improved patient satisfaction.

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.

Tandem Resonance metallic double-J ureteral stents in a single ureter for salvage management of chronic ureteral obstruction

For chronic malignant and benign ureteral obstruction, the metal construction of the Resonance ureteral stent has been developed to maintain ureteral patency for up to 12 months, obviating the need for the frequent exchange required for conventional plastic ureteral stents. We report our experience placing tandem Resonance stents (TRS) in a single ureter of patients who failed management with a single Resonance stent. A retrospective review of patients who had TRS for management of ureteral obstruction between February 2014 and May 2017 was performed. Seven renal units from four patients with a median age of 62 years were managed with TRS. All but one renal unit was successfully managed with TRS initially. Hydronephrosis resolved in 80% of renal units at a median of 33 days, and creatinine reached its nadir a median of 38 days after placement, with a median improvement of 0.68 ng/mL. However, the median length of management with TRS was only 123.5 days with one exchange, and there was an overall success rate of 28.5% at 1 year. TRS placement is a feasible option for short-term management in a challenging population that would like to avoid nephrostomy and has failed other modalities.

Comparison of single and tandem ureteral stenting for malignant ureteral obstruction: a prospective study of 104 patients

OBJECTIVES

The aim of this study was to compare single and tandem ureteral stenting in the management of malignant ureteral obstruction (MUO).

METHODS

Our hospital's institutional review board approved this prospective study. Between November 2014 and June 2017, single ureteral stenting was performed in 56 patients (94 renal units) and tandem ureteral stenting in 48 patients (63 renal units) for MUO. A comparative analysis of the technical success rate, patient survival, stent patency, and complications was performed.

RESULTS

Similar demographic data were observed in patients receiving either single or tandem ureteral stenting. The technical success rate was 93.6% (88/94) for single ureteral stenting and 95.2% (60/63) for tandem ureteral stenting. There was no difference in overall survival between patients receiving single or tandem ureteral stenting (p = 0.41), but the duration of stent patency in tandem ureteral stenting was significantly longer (p = 0.022). The mean patency time was 176.7 ± 21.3 days for single ureteral stenting, and 214.7 ± 21.0 days for tandem ureteral stenting. The complications of ureteral stenting were urinary tract infection (n = 18), lower urinary tract symptoms (n = 5), haematuria (n = 3), and stent migration (n = 1).

CONCLUSIONS

Tandem ureteral stenting is a safe and feasible treatment for MUO, and had better efficacy compared to single ureteral stenting.

KEY POINTS

• Ureteral stenting is an established treatment for the management of malignant ureteral obstruction (MUO) • Prospective single-centre study showed that tandem ureteral stenting is a safe and feasible treatment for MUO • Tandem ureteral stenting provides longer stent patency compared to single ureteral stenting in patient with MUO.

Application of resonance metallic stents for malignant ureteral obstruction

Purpose: To determine the effectiveness of the Resonance metallic stent in treating malignant ureteral obstruction (MUO) and clarify the risk factors that lead to stent failure. Material and methods: We retrospectively identified and analyzed the records of patients who had MUO and underwent placement of Resonance metallic stents from November 2014 to June 2017 in our hospital. Stent failure was defined as unexpected interventions including stent exchange, need of percutaneous nephrostomies (PCN) or ureterocutaneostomy. Results: A total of 22 stents were placed in 14 patients with MUO. The median follow-up was 145 days (4.8 months) and the maximum duration of stenting was 21.3 months. The technique success rate was 100%. Two patients experienced early postoperative increasing creatinine with oliguria but only one of them failed to achieve primary patency. The overall success rate was 90% (9/10). Conclusion: Resonance metallic stent is a safe and effective treatment for MUO and can maintain durable patency over 12 months. Preoperative urinary tract infection (UTI) and tumor invasion into the bladder are considered as risk factors of stent blockage and failure. Early postoperative elevated creatinine oliguria, suggestive with intrarenal and prerenal disease, should not be deemed to be stent failure.

Tandem ureteral stents in the management of double-J stent dysfunction in gynecological malignancies

PURPOSE

The goal of this study was to determine the efficacy and safety of tandem ureteral stent placement in the management of malignant ureteral obstruction (MUO) refractory to single ureteral double-J stent drainage in women with gynecological malignancies.

MATERIALS AND METHODS

A retrospective study was performed on 14 women (mean age, 54.5±9.6 [SD] years; range: 38-70 years) who had tandem stent placement following failed single ureteral double-J stent placement from 2012 to 2017. Survival analyses were performed with Kaplan-Meier method.

RESULTS

Twenty-nine successful procedures were performed on 19 ureters (19 primary stent placement and 9 exchange procedures). Technical success of primary tandem stent placement was 95% (19/20 procedures). Mean follow-up was 180.1±173.7 (SD) days (range: 62-616 days). Median estimated survival of the patients was 118 days (Q1: 261, Q3: 95; range: 62-616 days). Primary stent failure rate was 25% and assisted stent failure rate was 21.4%. There was no significant difference among survival of patients with and without tandem stent failure. Mean estimated primary stent patency and assisted stent patency were 171.4±13.8 (SD) days and 409.9±59.8 (SD) days, respectively. Four patients underwent 1 to 3 stent exchanges. Median exchange time was 181 days (Q1: 151, Q3: 191, range: 141-214 days) and technical success rate was 100%. Grade 2 and 3 complication rates were 25% and 3.6%, respectively.

CONCLUSION

Tandem ureteral stent placement is a feasible, safe and effective procedure for the management of failed ureteral double-J stent placement in women with gynecological malignancies.

[Management of ureteral obstruction : Value of percutaneous nephrostomy and ureteral stents]

Ureteral obstruction represents a heterogeneous disease pattern and is treated by ureteral stenting or percutaneous nephrostomy (PCN) depending on the necessity. The benefits of urinary diversion with ureteral stenting or PCN in malignant ureteral obstruction (MUO) for patient survival are only moderate. No differences have been found between ureteral stenting and PCN in MUO with regard to median patient survival and complication rates. In cases of MUO there is currently no evidence that urinary diversion improves the quality of life. Alternative concepts of ureteral stenting, such as tandem ureteral stents, metallic ureteral stents or metal mesh ureteral stents have not yet shown clear benefits. In benign ureteral obstruction, prospective randomized studies have demonstrated comparable quality of life after PCN or ureteral stenting. The method of choice for urinary diversion is influenced by the recommendations, personal experience of the clinician and the availability of the method.

The Role of Tandem Double-J Ureteral Stents in the Management of Malignant Ureteral Obstruction

AIM

The management of malignant ureteral obstruction (MUO) is a challenging but common problem for urologists. The different techniques currently used to address this complicated issue include percutaneous nephrostomy, extra-anatomical stents, retrograde (single) stent insertion, and metallic stents. In those situations where single ureteral stent insertion has failed, retrograde tandem or twin ureteral stent (TUS) insertion can be completed. The aim of this study was to report our clinical experience and also assess the efficacy of TUS insertion within our tertiary referral center.

METHODS

Data were prospectively collected from patients requiring TUSs over an 8-year period between January 1, 2006, and December 31, 2014. A number of variables, including the improvement in renal function following TUS insertion, were recorded.

RESULTS

Twenty-two TUS insertion procedures were performed on 15 patients between the period of January 1, 2006, and December 31, 2014. The mean patient age was 68.0 years (39-85 years). There were 15 primary insertions as well as 7 subsequent stent changes. The average prenephrostomy creatinine was 428 μmol/L; an average improvement of 196 μmol/L was observed after percutaneous drainage. Serum creatinine after TUS remained stable on discharge, 214 μmol/L vs 227 μmol/L preoperatively, p = 0.34. Eleven patients died at a median 131 days post-TUS insertion. TUS failure occurred in three patients; this was characterized by rising creatinine and worsening hydronephrosis. Patients with failing TUS had a median life expectancy of 45.6 days compared with 162.5 days for those with functioning TUS (p < 0.05). Overall, the patency rate at 3 months was 80%.

CONCLUSION

TUS insertion is a technically efficient and effective procedure in the management of MUO, with the majority of patients treated dying of the underlying condition with functioning stents in situ.

Stenting for malignant ureteral obstruction: Tandem, metal or metal-mesh stents

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal-mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms "malignant ureteral obstruction," "tandem ureteral stents," "ipsilateral ureteral stents," "metal ureteral stent," "resonance stent," "silhouette stent" and "metal mesh stent." A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal-mesh stents. Metal and metal-mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost-effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal-mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal-mesh stents for their use in malignant ureteral obstruction.

Tandem ureteral stents for the decompression of malignant and benign obstructive uropathy

PURPOSE

To evaluate the utility of two ipsilateral ureteral stents placed for benign and malignant ureteral obstruction.

METHODS

We performed a retrospective analysis of all cases of tandem ureteral stent (TUS) insertion at our institution from July 2007 through January 2013. Student t, Fisher exact, and log-rank test were used.

RESULTS

TUS insertion or exchange was performed in 187 cases. There were 66 patients (75 renal units) who underwent successful TUS insertion. Malignant ureteral obstruction (MUO) was the cause for obstruction in 39 renal units (34 patients) vs benign ureteral obstruction (BUO) in 36 renal units (32 patients). Four patients with BUO and 15 patients with MUO underwent stent exchanges at a mean 145 and 128 days, respectively. Serum creatinine levels were stable poststent placement (P=0.4). Degree of hydronephrosis improved (paired t test P<0.03) after stent placement for both benign and malignant cohorts. TUS placement was noted to fail (flank pain with worsening hydronephrosis or increasing creatinine level) in five renal units with MUO (12.8%) and none with BUO. Stent failure (either conventional or TUS) suggested worsening survival in those with MUO. Median survival for those with MUO and a history of stent failure (10 of 14 died, 71%) was 66 days compared with 432 days for those without a history of stent failure (8 of 20 died, 40%) (log-rank test P=0.007).

CONCLUSION

Our experience with the TUS, the largest to date, demonstrated that they are highly successful in both benign and malignant causes of obstruction, comparing favorably with metallic ureteral stents. Stent failure may be predictive for shorter survival.

Percutaneous nephrostomy versus indwelling ureteral stent in the management of gynecological malignancies

OBJECTIVES

The aims of this study were to evaluate the efficacy of retrograde ureteral stenting and to identify the predictive factors for potential failure of this technique in women with advanced gynecologic malignancies.

METHODS

From 2006 to 2010, a retrospective analysis was performed on a total of 75 patients with ureteral obstruction due to gynecologic malignancies. This population was divided into group 1 (n = 50) in which retrograde stent placement was successful, and group 2 (n = 25) in which stent placement failed and subsequent percutaneous nephrostomy tube placement was required. Multivariate analysis was done to identify predictors of the failure of ureteral stent insertion.

RESULTS

Multivariate analysis revealed that mean preprocedureal serum cystanin C greater than 2.5 mg/L and length of the ureteral obstruction greater than 3 cm were significant predictors of stent failure. Neither the causes nor location of obstruction predicted the need for percutaneous nephrostomy (PCN). No statistical significance was detected among the subgroups of patients with different degrees of hydronephrosis. Statistical significant differences were found between the 2 groups in procedural time, average cost, and mean interval of stent/catheter replacement. However, no statistically significant difference was found in the median survival time and overall stent-related or catheter-related complications between the 2 groups.

CONCLUSIONS

Retrograde ureteral stenting is a first-line option for managing ureteral obstruction caused by gynecologic malignancies. However, in cases where the preprocedureal mean serum cystanin C is greater than 2.5 mg/L and the length of the ureteral obstruction segment is greater than 3 cm, these patients may be better served by percutaneous drainage.

[Duplex ureteral stenting for intrinsic and extrinsic ureteral strictures: an effective and elegant alternative]

BACKGROUND

Duplex or twin ureteral stenting has previously been described as a viable option for patients where single double-J ureteral stenting has failed in order to avoid nephrostomies or further surgical intervention. We assessed a series of 20 patients at our institution after unsuccessful primary single ureteral stenting where parallel ureteral stents were inserted.

METHODS

Between 2003 and 2009, 20 patients underwent double-J ureteral stenting for ureteral compression or ureteral strictures. After failure of single stenting two ureteral stents were consecutively inserted into the ureter in a parallel fashion after dilating the ureter up to 14 F. The second stent was passed over a hydrophilic guidewire while holding the first stent secure to prevent dislocation.

RESULTS

In all patients the insertion of two parallel stents was technically possible. In 8 of 12 patients with extrinsic tumor compression the stents provided sufficient drainage (67%). When the stricture was due to surgery or radiation two of three patients were successfully diverted with twin stents. In five patients with a ureteral stricture due to malignant disease the stenting did not provide sufficient drainage and a nephrostomy had to be placed after a mean duration of 19 days. Two of those patients were later managed with a pyelovesical bypass. Three patients were later managed with a ureterocystoneostomy (psoas hitch). In four of five patients with benign disease a long-term management was feasible. The patient with retroperitoneal fibrosis developed immediate hydronephrosis and severe flank pain and ultimately underwent an ileal ureter replacement. In three patients with a benign ureteral stenosis after stone therapy, hysterectomy, or colon ureter replacement, a temporary duplex stenting sufficiently resolved the hydronephrosis for spontaneous urine passage. In one patient the duplex stenting prevented a kidney stone from dislocating into the ureter during lithotripsy.

CONCLUSIONS

Duplex or twin (double) ureteral stenting is a valid option in selected patients to avoid the placement of a nephrostomy. Severe stenosis may however demand a nephrostomy insertion or more invasive procedures in the later course. For certain benign ureteral strictures a therapeutic dilating effect of the two ureteral stents that makes further intervention unnecessary can be discussed.

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.

Analysis of ureteral stent compression force and its role in malignant obstruction

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

The significantly higher forces required to compress the Resonance and Silhouette stents may translate into improved success in patients with malignant ureteral obstruction.

Using two ipsilateral double j ureteral stents for extrinsic ureteral obstruction due to colon carcinoma

Although double J (DJ) ureteral stents are widely used in extrinsic ureteral obstruction, there are few studies using ipsilateral two DJ stents in the same ureter. We report using ipsilateral two ureteral DJ stents in the same ureter in a patient with extrinsic ureteral obstruction due to colon carcinoma.

15-year experience with the management of extrinsic ureteral obstruction with indwelling ureteral stents

PURPOSE

We assessed the success of retrograde placement of indwelling ureteral stents in the management of ureteral obstruction due to extrinsic compression.

MATERIALS AND METHODS

Between July 1987 and December 2002 adequate followup was available for 101 patients who underwent primary retrograde ureteral stenting for extrinsic ureteral obstruction. Mean age at presentation was 61.4 years (range 33 to 90). Chart review was performed on all patients for primary diagnosis, symptomatology, degree of hydronephrosis, creatinine levels (baseline, treatment and posttreatment), location of compression, size and number of stents used, progression to percutaneous nephrostomy tube (PNT), stent failure, days to stent failure, post-stent therapy and status at last followup.

RESULTS

Mean length of followup was 11 months (range 1 to 127). In 101 patients 138 ureteral units (UU) were stented. Total stent failure occurred in 41 (40.6%) patients and 58 (42.0%) UU. A total of 40 (29.0%) UU required PNTs at a mean of 40.3 days (range 0 to 330) with 18 PNTs placed in less than 1 week. Cases of stent failure that did not undergo PNT placement included 18 (13.0%) UU at a mean of 52.4 days (range 3 to 128). A total of 90 (89.1%) patients had metastatic cancer at stenting with 32.2% dead at 5.8 months (range 1 to 32). Univariate and multivariate analyses identified cancer diagnosis, baseline creatinine greater than 1.3 mg/dl and post-stent systemic treatment as predictors of stent failure. Proximal location of compression and treatment creatinine greater than 3.11 mg/dl were marginal predictors of failure on univariate analysis, while proximal location of obstruction was also marginally significant on multivariate analysis. No predictors were identified for early stent failure (less than 1 week).

CONCLUSIONS

At almost 1 year followup stent failure due to extrinsic compression occurred in nearly half of treated patients. Analysis of data revealed a diagnosis of cancer, baseline mild renal insufficiency and metastatic disease requiring chemotherapy or radiation as predictors of stent failure. Managing extrinsic compression by retrograde stenting continues to be a practical but guarded decision and should be tailored to each patient.