[Ureteropelvic junction syndrome. Apropos of 59 cases diagnosed with fetal echography]

We reviewed 59 cases of ureteropelvic junction obstruction diagnosed in 55 fetuses by echographic examination during prenatal period between 1981 and 1987. Postnatal excretory urograms and voiding cysto urethrography were obtained in all patients. Quantitative renal scans with 99 m technetium labeled dimercaptosuccinic acid or 99 m technetium labeled diethylenetriamine penta acetic acid were used in 49 patients and demonstrated a renal impairment in 19 cases (38%). 8 neonates were not operated, 1 required unilateral nephrectomy and 50 were treated by the Anderson-Hynes surgical procedure. 46 (92%) among those 50 obtained a significant improvement of pelvi-caliceal dilatation or excretion; 4 (8%) only a stabilisation. Early recognition of congenital hydronephrosis is now very common. After birth renal scans provided better estimation of renal function than excretory urograms but for the graduation of the obstruction the data did not appear to be always reliable (10% of false negatives in this study). The real problem is to know within which period of time the neonates whose renal function is impaired need surgery. In our study that question cannot be given a definitive answer because of too few post operative renal scans. However, we think, just as literature data tend to prove, that those neonates required early surgery if normal renal function is to be obtained.