[Ultrasonographic screening in healthy 3-month-old children for congenital malformations of the urinary tract]

BACKGROUND AND METHODS We performed renal ultrasonographic screening on 3799 healthy 3-month-old infants, who showed up for the routine health check up in Nobeoka City, for congenital malformations of the urinary tract. RESULTS Urinary tract disorders were suspected in 139 (3.7%). Almost all ultrasonographic abnormalities of these were dissociation of CEC (Central Echo Complex). Thirty-three (24.4%) of the 135, which was 0.9% of the original 3799, were diagnosed as having significant congenital anomalies in urinary tract, such as vesicoureteral reflux (VUR) in 17, hydronephrosis in 10, unilateral renal agenesis in 2, unilateral small kidney in 2 and each case of horseshoe kidney, simple ureterocele, ectopic ureterocele, megaureter and mild dilated ureter. Minor or mild renal pelvis enlargement without the dilatation of calyx was found in 78 cases. Fifty-three of the 78 were followed more than 3 months, and complete or partial reduction of the pelvic enlargement was noted in 39 (74%), while enlarged pelvis remained unchanged in 14. There was no progressive hydronephrosis among these patients during the follow-up. Urinary tract infections were found in 6 cases (5 in VUR and 1 in ectopic ureterocele). Eleven ureters in 9 children of VUR (44%) were cured spontaneously (follow-up period: 3 months-6 months and 2 years). Surgical correction was required in 6 cases, antireflux surgery for VUR in 4, heminephroureterectomy for ectopic ureterocele in 1 and endoscopic incision of ureterocele for simple ureterocele in 1. CONCLUSION Our result indicate that infant ultrasonographic screening is a useful and valuable method of detecting urinary tract malformations.