Palliative Care of Malignant Ureteral Obstruction with Polytetrafluoroethylene Membrane-Covered Self-Expandable Metallic Stents: Initial Experience

PURPOSE: We assessed the efficacy and safety of insertion of a polytetrafluoroethylene membrane-covered self-expandable metallic stent (UVENTA stent) for palliation of malignant ureteral obstruction on the basis of our early results. MATERIALS AND METHODS: Eighteen patients underwent UVENTA stent insertion for extrinsic malignant ureteral obstructions of 20 ureters. The UVENTA stents were deployed retrogradely under cystoscopy and fluoroscopy. Candidates for the procedure had preexisting double-J stents that were nonfunctional or caused excessive bladder irritation. We recorded the success and patency rate in addition to any complications associated with the procedure. RESULTS: The mean length of obstruction was 10.6 cm (range, 2 to 20 cm). Two ureters were obstructed in the upper ureter, 9 in the lower ureter, and 9 in multiple levels of ureter. Simultaneous balloon dilation was performed in 12 ureters. UVENTA stents were successfully inserted in all patients. No obstruction of the UVENTA stents occurred during the mean follow-up period of 7.3 months (patency rate 100%), but de novo ureteral obstruction developed in 4 ureters. There were no instances of stone formation, hyperplastic reaction, encrustation, or migration. Abnormally elevated serum creatinine decreased to normal levels and hydronephrosis gradually resolved during the 4 weeks after UVENTA insertion. No significant complications developed except for transient and self-limiting hematuria and mild lower abdominal pain. CONCLUSIONS: UVENTA stents may relieve malignant ureteral obstruction safely and easily. Long-term follow-up is necessary to assess the role of this stent in the treatment of malignant ureteral obstruction.