Reflux nephropathy in infancy: A comparison of infants presenting with andwithout urinary tract infection

Purpose: We compared the incidence of renal scarring in infants with high g rade vesicoureteral reflux in those presenting with and without urinary tra ct infection. Materials and Methods: We reviewed the medical records of 81 male and 46 fe male infants (194 renal refluxing units) with a mean age of 4 months who ha d grade TV or V primary vesicoureteral reflux and underwent an anti-reflux procedure between 1984 and 1997. Dimercapto-succinic acid (DMSA) scans and voiding eystourethrography were performed in all cases. Patients were follo wed for 2 to 16 years, including 90% for greater than 3 years. Renal ultras ound and DMSA scan were done at follow up. Results: A total of 97 patients (76%) (148 refluxing renal units) presented clinically with urinary tract infection. The initial DMSA scan demonstrate d renal scarring in 40 of the 106 grade TV (38%) and 28 of the 42 grade V ( 67%) refluxing renal units. There was no scarring on followup in previously normal refluxing renal units. Of the patients 30 (24%) (46 refluxing renal units) were diagnosed before a urinary tract infection developed, 16 under went screening due to vesicoureteral reflux in a sibling and in 10 reflux w as initially suspected due to hydronephrosis on prenatal ultrasound. In the remaining 4 patients vesicoureteral reflux was suspected during abdominal ultrasound to investigate abdominal pain, jaundice, associated hypospadias and fetal alcohol syndrome, respectively. DMSA scan showed evidence of scar ring in 6 of 21 grade IV (29%) and 9 of 25 grade V (36%) refluxing renal un its in this group. Followup revealed scarring in only I previously normal r efluxing renal unit. Conclusions: The incidence of reflux nephropathy in primary grade V vesicou reteral reflux is lower in cases detected by screening and with treatment i t remained lower than in cases of urinary tract infection that presented cl inically. Early treatment of grade V vesicoureteral reflux made possible by screening may prevent renal damage.