Purpose: The increasing number of ultrasonographically detected asymptomatic, renal dilations have caused a lot of explorations to be performed in these patients. The Society of Fetal Urology proposed a four grades classification of echographic renal dilations and renographic studies are recommended in grades II to IV. However we have observed that grade II dilations don't evolve to obstruction. The aim of this work is to evaluate the obstruction rate in this group of patients, and the necessity or not of practising diuretic renography.
Material and methods: We studied 42 children diagnosed of grade II renal dilation during a 1.5 year period. Left side was more frequently affected, 23 cases, 7 cases were bilateral what means 49 affected renal units. There was a male predominance (69%). Mean age at diagnosis was 2 months (0 to 36 months). Seventy nine per cent were prenatally diagnosed.
Results: The MAG-3 renal scan showed 48 unobstructed renal units and 1 obstructed. The F-15 variant was made in 15 cases by a doubtful curve or retarded elimination. The patient with obstructive curve presented an 15 mm renal pelvic diameter echographically measured and the intravenous urography showed a higher dilation being operating on. The mean time follow up was 23.5 months (13 to 53 months) without any change.
Conclusion: Grade II pielocalicial dilations with renal pelvis lesser than 15 mm can be echographically controlled without renal scan. It should be performed only if renal dilation increases.