A Silicone-Covered Self-Expanding Metal Stent with Antimigration Features for Treating Malignant Ureteral Obstruction

Abstract

Purpose: To evaluate the effectiveness and safety of the Urexel stent for treating malignant ureteral obstruction (MUO).

Materials and methods: This retrospective study included 129 patients (mean age: 57.9 ± 11.8 years; men: n = 64, 49.6%; ureteral units [UUs]: N = 175) who underwent Urexel stent placement to treat MUO between March 2013 and April 2021. The Urexel stent is a fully covered self-expanding metal stent. To reduce stent migration, the proximal end of the stent has an additional layer of stent mesh and is flared mildly.

Results: Eighty-three patients (64.3%) had unilateral MUO (right side: n = 47, 36.4%; left side: n = 36, 27.9%), and 46 patients (35.7%) had bilateral MUO. Successful Urexel stent placement after successful guidewire passage of the obstructed ureteral segment was achieved in 172 UUs, rendering a technical success rate of 98.3%. Stent malfunction occurred in 37 UUs (21.4%) during follow-up, including tumor overgrowth (n = 29), tumor ingrowth (n = 3), stent migration (n = 3), and stent collapse (n = 2). A total of 120 patients (93.0%) died during a median follow-up of 4.1 months (range: 0.2 - 33.5). The median survival of the patients was 4.4 months (interquartile range [IQR] 2.0 - 8.8). The median malfunction-free survival of the patients was 3.6 months (IQR: 1.6 - 7.9). Fifteen grade 3 or higher complications occurred in 14 patients (10.9%), including flank pain (n = 10), gross hematuria (n = 4), and dysuria (n = 1).

Conclusion: Urexel stent placement may be effective and safe for treating MUO.