Outcomes of Metallic Stents for Malignant Ureteral Obstruction

Abstract

Purpose: Malignant ureteral obstruction often necessitates chronic urinary diversion and is associated with high rates of failure with traditional ureteral stents. We evaluated the outcomes of a metallic stent placed for malignant ureteral obstruction and determined the impact of risk factors previously associated with increased failure rates of traditional stents. Materials and Methods: Patients undergoing placement of the metallic Resonance® stent for malignant ureteral obstruction at an academic referral center were identified retrospectively. Stent failure was defined as unplanned stent exchange or nephrostomy tube placement for signs or symptoms of recurrent ureteral obstruction (recurrent hydroureteronephrosis or increasing creatinine). Predictors of time to stent failure were assessed using Cox regression. Results: A total of 37 stents were placed in 25 patients with malignant ureteral obstruction. Of these stents 12 (35%) were identified to fail. Progressive hydroureteronephrosis and increasing creatinine were the most common signs of stent failure. Three failed stents had migrated distally and no stents required removal for recurrent infection. Patients with evidence of prostate cancer invading the bladder at stent placement were found to have a significantly increased risk of failure (HR 6.50, 95% CI 1.45-29.20, p ϭ 0.015). Notably symptomatic subcapsular hematomas were identified in 3 patients after metallic stent placement. Conclusions: Failure rates with a metallic stent are similar to those historically observed with traditional polyurethane based stents in malignant ureteral obstruction. The invasion of prostate cancer in the bladder significantly increases the risk of failure. Patients should be counseled and observed for subcapsular hematoma formation with this device.

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

“…However, the incidence of insertion failure is markedly higher in cases of MUO, ranging from 15.0 to 27.5% (3)(4)(5)(6)(7)(8)(9)(10)(11)(12). This high failure rate may be associated with extrinsic compression or invasion of the ureter by tumors, which may lead to the bending and deformation of the ureter, which then increases resistance during intubation in the majority of advanced malignancies (15). In a previous study of 61 advanced malignancies, the stent failed to indwell in 21.3% of patients and 17.9% of UUs (4).…”

Tandem Ureteral Stents for the Decompression of Malignant and Benign Obstructive Uropathy

“…[7][8][9] Nearly a dozen articless have reported on the clinical outcomes of metal ureteral stents since the original report in 2007 by Wah and colleagues. [10][11][12][13][14][15][16][17] The reports range in size from 2 to 59 renal units and cite stent failure rates that range from 0% to 100%. Liatsikos and coworkers 18 reported stent failure rate of 0% for MUO in a prospectively observed cohort of 25 with MUO (50 patents overall).…”

Infections in Cancer Patients with Solid Tumors: A Review

“…Silicone or polyurethane stents are most often used but may be associated with significant failure rates. Metallic stents have also been evaluated and are considered to be effective [16, 93–95]. Alternatively, obstructions can be dealt with the placement of percutaneous nephrostomy tubes.…”