Presented by: Filip Kowalski PhD
A.Jurasz Memorial University Hospital No 1 in Bydgoszcz, Poland

Introduction

Treatment of ureteral strictures is challenging for urologists due to its high recurrence rate. The effectiveness of endoscopic treatment of ureteral strictures varies from 60 to 85%. In complex (e.g. ureterointestinal anastomotic strictures) or complicated cases the effectiveness drops to 10-30%. The promising tools regarding the effectiveness of endoscopic treatment seems to be self-expanding ureteral stents, its unique construction (elastic nitinol alloy covered by a polymer) allows to keep it in the urinary system up to three years. The objective of our study was to investigate if novel stents improve results of endoscopic treatment of ureteral strictures.

Materials

In the years 2020-2023, 56 patients with ureteral strictures underwent implantation of self-expanding ureteral stents in our department. 58 stents were implemented. 47 out of 56 patients (84%) had iatrogenic ureteral strictures (secondary to surgery or radiotherapy). Strictures were divided into complicated and uncomplicated. Uncomplicated stricture was defined as a single stricture, up to 2cm long. Mean impantation time was 38 minutes. Mean explantation time was 24 minutes. Before implantation of the stent, the stricture was dilatated (min.9F, max.14F).

Implantation of stent was performed under endoscopic vision and fluoroscopy. 20cm / 9F and 12cm / 10F stents were used. 32 of 58 stents were explanted (55%). 17 of 32 stents (53%) were explanted before scheduled time. Average indwelling time was 10 months. In the follow up, 69% of patients had renoscyntygraphy before and after the procedures (implantation and explantation). 95% of patients had ultrasound before and after the procedures (implantation and explantation).

Results

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Average renal function before implantation of the stent was 43% (GFR 33,8 ml/min). Average renal function with ureteral stent was 35% (GFR 33,3 ml/min). Average renal function after explantation of the stent was 42,3% (32 ml/min).

Average creatinine level before implantation of the stent was 1,13 ml/min/1,73m2. Average creatinine level with ureteral stent was 1,24 ml/min/1,73m2. Average creatinine after explantation was 1,65 ml/min/1,73m2.

Major complications (Clavien-Dindo >2) occurred in 23% of patients (3A:11 patients, 3B: 1 patient, 5: 1 patient). Stent migration was observed in 34% cases.

Improvement in the quality of life was reported by 74% of patients, while 24% of patients estimated their quality of life as the same as before the procedure. Ultrasound urine retention in renal collecting system was observed in 70% of patients with implemented stent. 76% of patients had ultrasound urine retention after stent explantation.

Full therapeutic success (no need of renal stenting and good renal outflow proved in renoscyntygraphy) was achieved in 23 of 38 patients (60%), however in uncomplicated strictures group full therapeutic success was achieved in 19 of 21 cases (90%). 4 patients in uncomplicated strictures group were patients with ureterointestinal anastomotic strictures, and they achieved 100% full therapeutic success rate. In complicated strictures group, full therapeutic success was achieved in 5 of 18 patients (27%) but feasible renal outflow during stenting in that group was achieved in 21 of 25 patients (84%).

Conclusion

High efficiency of self-expanding stents is limited to uncomplicated strictures (single, <2cm). With regard to complicated strictures, they can be used as kidney drainage system but won’t be effective in full recovery of a stricture. In most of the cases stents improved the quality of life of patients with ureteral strictures. Decrease in renal function should be discussed with the patient due to hydronephrosis during and after the stenting.

Funding

None

Lead Authors

Tomasz Drewa, Prof.
A.Jurasz Memorial University Hospital No 1