Primary vesicoureteral reflux detected in neonates with a history of fetal renal pelvis dilatation: a prospective clinical and imaging study.
OBJECTIVE
To assess the clinical outcome and imaging features of neonatal primary vesicoureteral reflux (VUR).


METHODS
We prospectively followed 43 infants with primary VUR identified from among a cohort of 497 infants with fetal renal pelvis dilatation. Postnatal renal ultrasound (US) examinations were performed at 5 days and 1, 3, 6, 12, and 24 months of life. Voiding cystourethrography was performed in the neonatal period and repeated at 12 and 24 months when VUR was persistent. Two radioisotopic examinations, including a 99mTc-MAG3 renogram and a plasma clearance of Cr-51 EDTA, were performed in all children with high-grade reflux.


RESULTS
The incidence of primary VUR in our study group was 9%. Among the 43 patients followed, 11 (26%) had high-grade (IV-V) VUR and 32 (74%) had low-grade VUR. Resolution of reflux occurred in 2 of 11 (18%) patients with high-grade VUR and in 29 of 32 (90.6%) patients with low-grade VUR at age 2 years (P < .001). At age 2 years, 91% of the low-grade refluxing kidneys were normal on US, compared with only 35% of the high-grade refluxing kidneys. Split renal function was within normal range and single-kidney GFR was significantly increased in 13 of the 17 high-grade refluxing kidneys during follow-up. Furthermore, a strong association between dysplasia on US and poor renal function outcome was found.


CONCLUSIONS
In most infants with VUR, the reflux is of low grade and resolves rapidly. In those children with high-grade VUR, spontaneous resolution is rare at age 2 years, but persistent reflux rarely impairs the maturation of renal function.
Department of Perinatal and Pediatric Nephrology, Hôpital Universitaire des Enfants-Reine Fabiola, 15 Avenue J.J. Crocq, 1020 Brussels, Belgium. k.ismaili@yucom.be
Khalid
K
Ismaili
Michelle
M
Hall
Amy
A
Piepsz
Karl M
KM
Wissing
Frank
F
Collier
Claude
C
Schulman
Fred E
FE
Avni
D000892:Anti-Infective Agents, Urinary / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis; D002614:Chelating Agents; D002860:Chromium Radioisotopes / Q000097:blood; D004492:Edetic Acid; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007682:Kidney Pelvis / Q000002:abnormalities* / Q000000981:diagnostic imaging; D008297:Male; D011247:Pregnancy; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D020127:Recovery of Function; D012720:Severity of Illness Index; D017263:Technetium Tc 99m Mertiatide; D014295:Trimethoprim / Q000627:therapeutic use; D016216:Ultrasonography, Prenatal; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D014552:Urinary Tract Infections / Q000209:etiology / Q000517:prevention & control; D014718:Vesico-Ureteral Reflux / Q000150:complications / Q000175:diagnosis* / Q000601:surgery
D000892:Anti-Infective Agents, Urinary; D002614:Chelating Agents; D002860:Chromium Radioisotopes; D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D004492:Edetic Acid; D014295:Trimethoprim