Effect of vesicoureteric reflux on renal growth in children with urinary tract infection

Abstract

Renal growth was studied for periods ranging from 2 to 22 years (average 9·4) in 70 children who presented between 2 weeks and 12 years of age with urinary tract infection and who were found to have vesicoureteric reflux. They were managed on a conservative regimen of continuous prophylaxis and regular, complete voiding. Renal growth over the entire period of observation was normal in relation to the child's growth in height in 100 of the 111 kidneys originally drained by refluxing ureters. During the time that reflux was known to be still present, renal growth was within normal limits in 101 kidneys. Renal growth was impaired in 11 kidneys. Ten of them were exposed to a recurrence of urinary tract infection. The eleventh child had an unproved symptomatic infection. Seven of these kidneys were also already scarred and 4 had gross reflux. In 2 of these children a fresh scar developed, one in a previously normal kidney. Because of the tendency for reflux to disappear, the renal growth during the first 2 years of observation was also analysed. A significant association was found between impaired growth and, independently, infection and renal scarring. No independent association was found between impaired growth and the severity of reflux. Small kidneys tended to grow at the expected rate. If growth was compared in pairs of kidneys with unilateral reflux, no difference in rate could be found if the kidneys were unscarred, but a significant difference was found if the refluxing ureter drained a scarred kidney; this tended to grow slowly, and the unscarred non-refluxing kidney tended to accelerate in growth. The small group of kidneys which grew least well had established severe scarring associated with severe persisting vesicoureteric reflux and each had a further infection during the period of observation, although no rise in plasma creatinine concentration was observed in any of these children. It is in such children that the results of a controlled comparison of medical and surgical management will be of greatest value.