RESUMEN
A prospective study of 502 patients referred for assessment of symptoms of bladder outlet obstruction was performed to determine the value of routine intravenous urography (IVU). The purpose was to establish the rate at which significant occult abnormality in the upper urinary tract is detected with IVU alone; to determine to what extent these abnormalities can be predicted from routine clinical and laboratory evaluation, thus allowing better patient selection for IVU; and to recommend alternative imaging modalities. History, physical examination, and routine laboratory studies constituted the preliminary examination. Abnormalities were found in 23% of patients but significant conditions in only 10%. Occult significant abnormalities that would have been missed without IVU occurred in only 1.5% of patients. Most of these could be detected on an abdominal radiograph. Only one malignancy would have been missed without routine IVU. The authors conclude that IVU in the assessment of prostatism should be limited to patients with positive findings in the clinical work-up. An abdominal radiograph is recommended in the others. Significant cost savings can thus be achieved.