Use of full-length metallic stents in malignant ureteral obstruction

Malignant ureteral obstruction (MUO) has traditionally been a difficult problem to manage. Indwelling ureteral stents have a failure rate up to 50%, necessitating the placement of percutaneous nephrostomy (PCN) drainage, which has associated complications and impacts on quality of life. Recently, metallic ureteral stents have emerged as a treatment for extrinsic ureteral obstruction. We present our initial experience using Resonance (Cook Urologic, Spencer, IN) full-length metallic stents for MUO.

20 patients (27 renal units) with advanced cancers and MUO were treated with metallic stents. Patients were followed prospectively to evaluate for recurrent obstruction. Perioperative morbidity and overall mortality were recorded.

The mean patient age was 49.9 years (SD 18.9). The primary malignancies causing MUO were gastrointestinal (8), gynecologic (6), genitourinary (2), or other (4). All but two renal units had been previously treated with traditional stents. Eight out of 20 (40%) patients required further intervention for their MUO. Mean time to failure for the metallic stents was 7.4 months (222 days). Two patients required conversion to percutaneous drainage. Five patients required change to traditional stents (3) or removal of metallic stents. At the last follow-up, sixteen patients had died. Fourteen of the sixteen patients died with functioning metallic stents in place, although one patient who initially had bilateral metallic stent placements had a left stent removed due to migration. Of the remaining four living patients, two have functioning metallic stents at a mean follow-up of 42 months.

MUO remains a difficult clinical problem in a group of patients with a high mortality. While metallic stents ultimately have a failure rate similar to that of traditional stents, the mean time to failure is longer. Therefore, metallic stents may benefit patients with MUO, because the longer dwell time may eliminate the need for more frequent stent changes or further interventions.