(Poster 133) The Allium Stent for Ureteral Stricture-deeper Experience of Cases Review

Objectives: Allium stents are widely used in patients with ureteral stricture, with ongoing research continuously evaluating their clinical safety and efficacy. We aim to describe our technique and report the outcomes of Allium stent in the treatment of refractory ureteral strictures.

Methods: We retrospectively collected perioperative data on all patients treated with Allium stents in our department between January 2017 and April 2024, and assessed their clinical outcomes. Surgical procedure: Following ureteroscopy, a guidewire was advanced under fluoroscopic guidance into the renal pelvis. The ureters were performed urograph to determine the location and length of the stricture. Dilation was performed using a ureteral balloon dilator, a flexible ureteroscope sheath, or a rigid ureteroscope. Subsequently, the Allium stent was deployed into the stricture segment and confirmed via fluoroscopic imaging.

Results: A total of 23 patients (25 ureters) were included, with a mean age of 57.7 years (32–76 years). The mean length of ureteral strictures was 4.5 cm (range: 1–18 cm). All stents were successfully positioned. As of December 2024, the stent patency rate was 68%, with a median follow-up of 39.5 months (13–67 months). In 8 patency failure cases, the mean indwelling time was 14 months, with the shortest recorded duration being 2 months. Causes of failure included 4 (50%) stent migration, 1 (12.5%) encrustation, 2 (25%) persistent stenosis, and severe infection (12.5%). Management strategies for these cases included 2 (25%) stent removal, 2 (25%) robot-assisted pyeloureteroplasty, 1 (12.5%) ureterolithotripsy, 1 (12.5%) exchange with a new Allium stent, 1 (12.5%) add new Allium stent, and 1 (12.5%) replacement with a different type of metal stent. Notably, one case of a ruptured ureter was successfully bridged with an Allium stent, and another case of a uretero-vaginal fistula was effectively treated with Allium stent, both without complications.

Conclusions: Allium stents appear to be a feasible and effective treatment for various ureteral strictures, including cases of ureteral perforation and rupture. However, long-term complications such as stent migration and occlusion remain challenges that should not be overlooked.