Primary megaureter detected by prenatal ultrasonography: conservative management and prolonged follow-up.

With the widespread use of obstetric echography the incidence of fetal hydronephrosis has been reported more frequently. Consequently, many uropathies have been detected in asymptomatic neonates. The authors report their experience with prenatally detected primary non-refluxing megaureter. Newborns with fetal hydronephrosis were investigated by ultrasonography and micturating cystourethrogram after the beginning of chemoprophylaxis. If primary megaureter was identified, after 1 month the children underwent 99tm-DMSA, diuretic 99tm-DTPA, and intravenous urography. Eight infants with primary megaureter (bilateral in 3 cases) were identified, for a total of 11 renal units for study. All children were submitted to non-operative management. We performed ultrasonography and diuretic 99tm-DTPA during follow-up, which lasted on average 75 months. The mean cross-sectional diameter of the dilated ureter was 13.6 mm during neonatal period, and reached 8.4 mm at the end of follow-up. The renal function and the diuretic renogram remained stable throughout follow-up. Two neonates presented transitory hypertension. Our results support the notion that conservative management is safe for primary megaureter detected in asymptomatic neonates, with most cases showing spontaneous regression during a prolonged follow-up.

Features of primary vesicoureteric reflux detected by investigation of foetal hydronephrosis.

Primary vesicoureteric reflux (VUR) diagnosed on investigation of foetal hydronephrosis accounts for many antenatally detected uropathies. In order to study foetal VUR and its consequences, newborns with foetal hydronephrosis were investigated by ultrasound, micturating cystourethrogram and 99mTechnetium-dimercapto-succinic acid (DMSA), after beginning of chemoprophylaxis. Twenty-eight infants with VUR (bilateral in 15 cases) were identified giving a total 43 renal units for study. There was a predominance of males (86%), moderate/severe reflux (84%) and renal damage (51%). Presence of renal damage was correlated with the severity of reflux. VUR should be investigated in cases of foetal hydronephrosis and our results support that renal damage is frequently congenital and not secondary to urinary tract infection.

[Fetal hydronephrosis: postnatal management and follow up]. / Hidronefrose fetal: abordagem pós-natal e seguimento.

OBJECTIVE: Fetal hydronephrosis is being detected with increasing frequency and probably this observation will increase as the quality of ultrasound equipment improves. This study evaluated etiology and postnatal clinical outcomes of prenatally detected hydronephrosis. METHODS: In a period of 13 years 148 infants were referred with fetal hydronephrosis. The initial evaluation, after prophylaxis, included ultrasound and voiding cystography. Sequential evaluation was determined by initial findings. RESULTS: Postnatal predominant diagnosis were pelviureteric junction obstruction (24%) and hydronephrosis without obstruction (18%). Follow up median was 38.7 months. Renal function deteriorated in 13 (8.8%) children and 11 (7.4%) died during follow up. Bad prognosis was associated with urethral obstruction. CONCLUSIONS: Fetal hydronephrosis is a clue of urinary tract anomalies. Urinary tract infections and delay in postnatal diagnosis must be prevented in children with this uropathy.

Multicystic dysplastic kidney detected by fetal sonography: conservative management and follow-up.

The most common cystic lesion recognized antenatally is multicystic dysplastic kidney (MCDK). Recently, conservative management without nephrectomy has been advocated. The purpose of this study was to report our experience in the conservative management of unilateral MCDK. Between 1989 and 1997, 20 children with MCDK detected by prenatal ultrasonography (US) were prospectively followed. At birth, US confirmed the prenatal findings in all cases. All patients were submitted to radioisotope scans and a micturating cystogram. Follow-up US examinations were performed annually. Mean age at diagnosis during the prenatal period was 31 weeks of gestation (range 24-38). Median follow-up time was 33 months (range 7-91). Follow-up US was performed in 19 children; 13 (68%) showed partial involution, 4 (21%) complete involution, and 2 (11%) an increase in unit size. The mean age at complete or partial involution of the lesion was 18 months. No children developed hypertension or tumors, and all maintained normal growth. In conclusion, the natural history of MCDK is usually benign, and serial US examinations show that affected kidneys frequently show involution with time.