The obstructive diuresis renogram: an appraisal of the significance.

We managed expectantly 23 patients with renal pelvic dilatation and unilaterally obstructive diuresis renograms. Serial renograms showed changes in ipsilateral relative renal function in 8 kidneys (4 deteriorated). Pressure-flow studies demonstrated low pressures on perfusion of 8 kidneys. Eight patients eventually required pyeloplasty, mostly for loin pain. Therefore, serially obstructive diuresis renograms can be associated with preserved renal function, with high pelviocaliceal compliance being a possible explanation.