Compensatory kidney growth in children with urinary tract infection and unilateral renal scarring: An epidemiologic study

Abstract

Compensatory renal growth was estimated from repeated urograms over 8 to 15 years in 26 children with urinary tract infection and unilateral renal scarring. These children were derived from an unselected series of 596 patients followed from their first symptomatic urinary tract infection. Renal size was assessed from the renal area, length, and parenchymal thickness. The renal area proved to be a good measure of the compensatory growth of the unscarred kidney as well as of the loss of substance of the scarred kidney. In this series of children, who had been closely supervised from the time of their first infection, unilateral renal scarring was well compensated for by hypertrophy of the contralateral kidney. Thus, the total renal parenchymal area 8 to 15 years after the first investigation was 98 to 99% of the expected normal area. Interestingly, a conspicuous growth spurt was observed at puberty in some of the scarred kidneys, sometimes a decade after the original damage. Prognosis was not influenced by sex, age at onset, or complications such as vesicoureteric reflux and frequent febrile recurrences. Reflux with dilatation was compatible with compensatory renal growth. We conclude that acute febrile pyelonephritis in childhood carries a good prognosis with regard to preservation of renal parenchyma and level of GFR, if diagnosis and treatment are prompt and long-term supervision is provided.