Efficacy and safety of a novel, double-layered, coated, self-expandable metallic mesh stent (uventa™) in malignant ureteral obstructions

Background and Purpose: Malignant ureteral obstruction (MUO) is a common condition and an intractable situation for patients with advanced cancer. There is currently no ideal ureteral stent to release the obstruction. Our purpose was to evaluate the clinical efficacy and safety of a novel, double-layered, coated, self-expandable metallic mesh stent (Uventa™) in MUO. Patients and Methods: In a retrospective design, a total of 71 ureter units (54 patients) were included from December 2009 to March 2012. Indications were those who had MUO with a polymeric Double-J stent malfunction, severe polymeric stent irritation, or severe pain during periodic stent change. Patients underwent Uventa placement using a retrograde approach. Results: All stents were positioned at the proper site without procedure-related complications. The overall success (no obstruction and no additional intervention except supplementary Uventa placement) and primary success (no obstruction and no additional intervention) rates were 81.7% (58/71 ureter units) and 64.8% (46/71 ureter units) during the follow-up period, which had a median of 308 (35-802) days. The most common reason for primary failure was tumor progression beyond the stent segment (75.0%), followed by reactive hyperplasia at the stent tips (12.5%), bladder invasion of the primary tumor (8.0%), and stent-related pain (8.0%). Twelve patients had overall success after secondary Uventa placement. There were no severe complications. The complications included persistent flank pain (15.5%), lower urinary tract symptoms (7.0%), acute pyelonephritis (2.8%), stent migration (2.8%), and persistent hematuria (2.8%). Conclusions: These data show that Uventa can be an effective and safe option for palliative treatment of patients with MUO in a large series of patients.