Prenatal diagnosis of duplex system hydronephrosis: effect on renal salvage

To determine if prenatal identification of significant renal duplication anomalies affects the management of the patient or the clinical outcome.

This is a retrospective review of 79 consecutive children with severe hydronephrosis involving a duplex renal collecting system, identified by either prenatal ultrasound (asymptomatic), or symptoms, most often urinary tract infection, but also including abdominal mass, hematuria, or incontinence. An individualized combination of voiding cystourethrogram, ultrasound, intravenous urogram, and nuclear renal scan was used to assess anatomy and function. Ablation of the involved segment was carried out if no or extremely poor function was identified; a definitive reconstructive procedure was elected in the face of easily measureable function. Outcome was determined clinically and by repeat imaging.

There was no difference in the rate of renal segment salvage between the prenatally and clinically diagnosed groups. Of the cases analyzed, 20/79 were prenatally identified, of which 13/20 (65%) were reconstructed; 59/79 were identified on clinical grounds, of which 34/59 (58%) were reconstructed. One patient in the prenatal salvage group underwent removal of the affected kidney 5 years later. Another, in the clinical salvage group, underwent a successful secondary procedure for closure of a ureteral fistula. All others have shown improved function, drainage, or both in follow-up. No secondary procedures have been required for the ablation group to date. Follow-up ranges from 4 months to 12 years.

Prenatal identification of significant duplex system hydronephrosis does not improve the rate of renal segment salvage, as determined by standard radiographic means, compared to later identification on clinical grounds. The decision for reconstruction versus ablation in significant duplex system hydronephrosis can be made on the basis of function alone.