Ultrasound experience with prenatal genitourinary abnormalities

Successful early pyeloplasty in infants

BACKGROUND

Early pyeloplasty for the treatment of congenital ureteropelvic junction obstruction to maximize nephron salvage is justified only if potential hazards of operating on small infants are avoided.

METHODS

The records were analyzed of all infants who underwent pyeloplasty over a 5-year period. Open pyeloplasty was performed if collecting systems had deteriorated or were demonstrated to be obstructed; it was also performed for severe cases of hydronephrosis. Outcome of surgery in the younger infant (patients <2 months of age) was compared with the older infant group (patients >2 months of age). Preoperative evaluation in case of mild or moderate hydronephrosis was directed toward ruling out a non-obstructed collection system and included voiding cystourethrography, and serial ultrasonography and/or dual isotope diuretic renography. Postoperative assessment consisted of serial ultrasonography and/or nuclear imaging to confirm decompression and relief of obstruction.

RESULTS

A total of 24 pyeloplasties were performed on 22 patients in the younger infant group (two bilateral) and 30 were performed on 27 infants in the older infant group (three bilateral). The only significant differences between the groups were as follows: patients in the younger infant group were likely to present in utero (75%, p = 2.69), whereas those in the older infant group were more likely to present with a urinary tract infection (48%, p = 4.12). During follow-up examination, 23 renal units in the younger infant group and 24 in the older infant group were judged to be stable or improved. Four kidneys were not salvaged after pyeloplasty, one in the younger infant group and three in the older infant group.

CONCLUSIONS

Good results of pyeloplasties performed in the infants in this series support early correction of ureteropelvic junction obstruction in infants.

Hydronephrosis in the neonate and young infant: current concepts

Asymptomatic neonates with urological abnormalities that were discovered antenatally or during screening sonography in the neonatal period differ in a number of important ways from those presenting later with overt clinical signs and symptoms of urological disease. The accumulated experience with these neonates over the past decade has led to important advances in our understanding of the epidemiology, diagnosis, and management of congenital disorders of the urinary tract.

Clinical outcome of fetal uropathy. II. Sensitivity of echography for prenatal detection of obstructive pathology

Among 8,579 neonates born between February 1, 1981 and March 31, 1987, and cleared by prenatal sonography for significant urinary tract abnormality 158 subsequently were hospitalized because of signs or symptoms of urinary tract disease, predominantly urinary tract infection. Evaluation of these 158 patients revealed 24 with vesicoureteral reflux, 7 with duplicated systems (2 of which showed reflux), 1 with the syndrome of Fraley, 1 with pyelectasis and 5 with mild hydronephrosis (3 secondary to reflux and 2 with diethylenetriaminepentaacetic acid renal scans considered to be nonobstructed). There was no incidence of significant obstructive uropathy that had been missed by the previous prenatal sonography and that surfaced subsequently to cause morbidity in this series. The principal disorder of the urinary tract that may fail prenatal investigation is vesicoureteral reflux.

Clinical outcome of fetal uropathy. I. Predictive value of prenatal echography positive for obstructive uropathy

Clinical followup was performed in 73 neonates with a prenatal echographic suspicion of uropathy. Of 42 patients with a prenatal suspicion of unilateral hydronephrosis only 15 had pathological obstruction and 2 had multicystic dysplastic kidneys. Among 10 infants with a prenatal suspicion of bilateral hydronephrosis only 1 had true bilateral obstruction and 2 had unilateral obstruction. In 2 patients hydroureteronephrosis seen on prenatal echography was due to massive bilateral vesicoureteral reflux. In this group there was also a multicystic dysplastic kidney and 1 patient with bilateral cystic dysplasia. There was a prenatal suspicion of cystic disease in 8 infants. Postnatally, diagnosis was multicystic dysplastic kidney in 2 patients and a simple renal cyst in 4. The remaining 2 neonates had obstructive uropathy. Finally, of 13 neonates with a prenatal suspicion of anatomical-echo-structural abnormalities a definitive abnormality could be established in only 8. The predictive value of prenatal echography positive for obstructive uropathy was 34.6%.

Intervention for fetal obstructive uropathy: has it been effective?

The best management of fetal hydronephrosis is controversial. Despite the lack of experimental evidence that prenatal drainage of the obstructed urinary tract substantially improves ultimate renal function, various forms of percutaneous intervention on the fetal bladder and kidney have been used. To evaluate the efficacy of intervention for suspected fetal obstructive uropathy, all published reports of drainage of the fetal urinary tract up to December, 1985, were reviewed. In the 57 reported cases, the most common type of intervention was placement of a vesicoamniotic shunt (37%). Complications occurred in 25 cases (44%), including inadequate shunt drainage or migration (19%), onset of premature labour within 48 h (12%), urinary ascites (7%), and chorioamnionitis (5%). Of 28 fetuses with associated oligohydramnios, only 6 (21%) survived. 2 of these survivors had vesicoamniotic shunts, 2 single or multiple bladder aspirations, 1 an external renal drainage catheter, and 1 in-utero vesicostomy. Because of the high complication rate and lack of evidence of improved survival from in-utero drainage procedures, a prospective, randomised trial is needed to compare survival with and without vesicoamniotic shunt placement.