Role of the diuresis renogram in the study of the pelviureteric junction.

A consecutive series of 29 patients (33 pelviureteric units) with urographic signs of altered passage through the pelviureteric junction underwent diuresis renography performed by means of an intravenous injection of 99mTc-diethylenetriamine pentaacetic acid/kg body weight followed by intravenous administration of frusemide. Anderson-Hynes pyeloplasty was performed in 19 pelviureteric units with a modest or almost absent fall in the renographic curve after diuretic injection; 2 other symptomatic patients, in whom a moderate fall of the same curve was found also underwent surgery. Complete normalization of the renogram was observed in 17 of 21 operated patients. Severe functional deficit and polymegacalicosis were evident in 3 and 1 patient, respectively, with unchanged postoperative renograms. During follow-up (6 months to 2 years) diuresis renography remained unaltered in non-operated units. Our experience indicates how the diuresis renogram not only gives functional confirmation of a pelviureteric junction obstruction, but is also helpful in resolving situations in which there is a discrepancy between symptoms and urographic signs. Furthermore it provides an accurate method for evaluating the results of pyeloplasty. However, the use of this investigation is not, in our opinion, indicated in the presence of severe functional deficit of the kidney or pyelectasis.