Stent placement for the diagnosis of upper tract obstruction

The aim of this study was to evaluate the effectiveness of ureteral stent placement in diagnosing ureteropelvic junction (UPJ) obstruction in patients with negative or equivocal radiographic/nuclear studies and to assess relief of symptoms following definitive surgical procedures to relieve the obstruction. Patients undergoing ureteral stent placements performed by two attending urologists over an 18-month period were reviewed. All patients with equivocal or negative radiographic evaluations for ureteral obstruction in whom the stent was placed for diagnostic purposes were selected. Preoperative and postoperative information was obtained from the medical record or by telephone interview. Five patients were found who had equivocal radiographic studies along with symptoms of flank pain and who underwent diagnostic stent placement. All patients were female (average age 40 years, range 20-52). All had pain relief following stent placement and, on this basis, underwent an operative procedure to remove the presumed ureteral obstruction. Three underwent Acucise endopyelotomy, one had laparoscopic resection of the right ovarian vein, and one underwent nephrectomy. The average preoperative creatinine level was 0.9 mg/dL (range 0.8-1.0), and the average postoperative creatinine level was 1.0 mg/dL (range 0.9-1.1). All patients had relief of flank pain at a mean of 17 months following the surgical procedure. Relief of pain following stent placement in patients with clinical suspicion of ureteral obstruction portends a favorable outcome from procedures to relieve the presumed obstruction. In unusual cases where ureteral obstruction is suspected despite negative or equivocal radiographic findings, diagnostic stent placement appears to be useful.