Single-Centre Experience with Three Metallic Ureteric Stents (Allium® URS, Memokath™-051 and Resonance®) for Chronic Ureteric Obstruction

Metal ureteral stents for ureteral stricture: 2 years of experience with 246 cases

BACKGROUND

Metal ureteral stents (MUS) has gained popularity as an endoscopic treatment alternative for the management of ureteral strictures. The aim of this study was to evaluate the safety, efficacy, and tolerability of MUS for treating ureteral strictures and to identify any factors that could influence the success of this intervention.

METHODS

This study is a prospective analysis of the efficacy and safety of MUS for treating ureteral strictures in a single-center setting. The study enrolled 246 patients who had been diagnosed with ureteral strictures and had undergone MUS placement between January 2019 and July 2021. The patients were followed-up for a duration of 2 years.

RESULTS

The overall success rate of MUS placement was 71.7%. Furthermore, the success rate of ureteral strictures after kidney transplantation (78.2%) was significantly higher than common ureteral strictures (73.0%) or recurrent ureteral strictures (67.6%). Additionally, postsurgery, there was a considerable reduction in hydronephrosis volume (68.9±96.1 vs. 32.1±48.8 cm 3 ), blood creatinine level (103.7±49.8 vs. 94.4±47.5 mol/l) and urea nitrogen level (6.7±7.2 vs. 5.1±2.4 mmol/l). The study also reported that the rate of adverse events associated with MUS was relatively low, included hematuria (7.9%), pain (6.8%), urinary tract infection (6.4%), and lower urinary tract symptoms (5.3%).

CONCLUSIONS

MUS appear to be a safe and effective treatment option for ureteral strictures, with a high success rate and low complication rate. These results have important implications for the management of ureteral strictures and can help guide clinical decision-making in the selection of treatment options.

Allium® ureteral stent, a new player in the treatment of ureteral stenosis: a prospective cohort study

INTRODUCTION AND OBJECTIVES

Ureteral stricture is a chronic condition that can result in the obstruction of urinary drainage from the affected renal unit, leading to loss of renal function. Treatment methods can be categorized into two main headings: endourological and reconstructive procedures. We aimed to investigate the efficacy and safety of the self-expandable Allium® ureteral stent, which has been used in the minimally invasive treatment of ureteral stenosis in recent years.

MATERIALS AND METHODS

Twenty patients who were applied Allium® ureteral stent between 2017 and 2021 included in the study. The demographic and clinical characteristics of the patients, the details of the treatments applied to the patients, the perioperative and postoperative complications, the treatments applied for the complications and the findings in the follow-up were recorded and evaluated prospectively.

RESULTS

Etiology included urolithiasis in 16 patients (80%), malignancy in 3 patients (15%), and a previous gynecological operation in 1 patient (5%). Stent obstruction was found to be the most common complication in 3 patients (15%). Stent migration was the second most common complication in 2 patients (10%). Our follow-up continues with 15 patients without stent-related complications and stent obstruction. The mean follow-up period was 28 ± 15.7 months.

CONCLUSIONS

Allium ureteral stent is an effective and reliable method in the minimally invasive treatment of ureteral stricture with complications seen at acceptable rates and ease of treatment in the management of complications.

Long-term maintenance treatment of recurrent ureteropelvic junction obstruction with covered metallic ureteral stent

Whether or not the covered metallic ureteral stent can be used as maintenance treatment for recurrent ureteropelvic junction obstruction (UPJO) after pyeloplasty is unknown. Therefore, this study aims to analyze its feasibility. We retrospectively analyzed the records of 20 patients with recurrent UPJO who were treated with the covered metallic ureteral stents from March 2019 to June 2021 at our institution. Then, we assessed their renal function, stent patency and stent-related quality of life by the blood creatinine, renal ultrasound (or computed tomography), and the Chinese version of the ureteral symptom score questionnaire (USSQ). The last follow-up mean blood creatinine dropped from 0.98 ± 0.22 to 0.91 ± 0.21 mg/dL (P = .04), and the median renal pelvic width was reduced from 3.25 (3.10) to 2.00 (1.67) cm (P = .03) compared with the preoperative conditions. Meanwhile, the last follow-up mean USSQ total score of the covered metallic ureteral stent among the 16 patients with preoperative indwelling double-J ureteral stent was 78.56 ± 14.75, significantly lower than the preoperative USSQ total score, which was 102.25 ± 5.57 (P < .001). During the median duration of follow-up of 27.00 (18.00) months, 85% (17/20) of patients maintained unobstructed drainage from the renal pelvis to the ureter. Stent-related complications occurred in 7 patients, 3 of which failed because of complications, including stent migration (1 patient), stent encrustation (1 patient), and stent-related infection (1 patient). The covered metallic ureteral stent is feasible for the long-term maintenance treatment of recurrent UPJO after pyeloplasty.

Long-term Indwelling Tandem Polymeric Ureteral Stents for Benign Ureteral Obstruction

Objective: To assess the outcome of tandem polymeric internal stents (TIS) for benign ureteral obstruction (BUO). Material and Methods: We conducted a retrospective study that included all consecutive patients treated for BUO by means of TIS in a single tertiary center. Stents were replaced routinely every 12 months or earlier, when indicated. The primary outcome was permanent stent failure, and the secondary outcomes included temporary failure, adverse events, and renal function status. Kaplan-Meier and regression analyses were used to estimate outcomes, and logistic regression was used to assess the association between clinical variables and outcomes. Results: Between July 2007 and July 2021, 26 patients (34 renal units) underwent a total of 141 stent replacements, with median follow-up of 2.6 years (interquartile range [IQR] 0.75-5). Retroperitoneal fibrosis was the leading cause of TIS placement (46%). Permanent failures occurred in 10 (29%) renal units, and the median time to permanent failure was 728 days (IQR 242-1532). There was no association between preoperative clinical variables and permanent failure. Temporary failure occurred in four renal units (12%), which were treated by nephrostomy and eventually returned to TIS. Urinary infection and kidney injury rates were one event for every four and eight replacements, respectively. There was no significant alteration in serum creatinine levels throughout the study (p = 0.18). Conclusion: TIS provides long-term relief for patients with BUO and offers a safe and effective solution for urinary diversion, while avoiding the need for external tubes.

Extra-anatomical stents in benign ureteric obstruction; experience and outcomes

Objectives To present our experience with the Patterson-Forester extra-anatomic stent (EAS, Cook Medical) in patients with benign ureteric obstruction. Utilising an EAS in complex ureteric obstruction can have a significant positive impact on quality of life as a result of removing external drainage devices. Materials and methods Between November 2012 and January 2021 10 patients underwent 33 EAS procedures. All patients had benign ureteric obstruction. Mean age at primary procedure was 58 years (range 43-63). Median follow-up was 27.5 months (range 11-100). Results Eight patients were successfully managed with EAS, with 6 patients continuing to have routine EAS exchanges. Two patients had the distal end exteriorised due to refractory bladder symptoms. There were three short-term failures; the distal end migrated out of the bladder requiring reinsertion one week later; one patient developed urosepsis requiring intravenous antibiotics and the stent removing within 30 days; one proximal stent migrated resulting in cutaneous erosion. The patient is now awaiting further EAS insertion. Conclusion The Patterson-Forester EAS is another tool in the endourologists' armamentarium when managing complex ureteric obstruction. In appropriately selected patients, it can improve their quality of life and is a durable long-term strategy in benign obstruction.