Clinical analysis of the small kidney associated with VUR.

Analysis was performed on the clinical features of children with VUR who had one or two kidneys that were at least -2 SD smaller than normal for age of its renal ratio. The prevalence of the small kidney was 15.6% (97/623 children). Of 107 small kidneys, 87 (82%) were associated with moderate (grade IV) to severe (grade V) reflux and renal scarring was evident on 95 kidneys (88%). About half of the kidneys were diagnosed as scarred atrophy and 40% as congenital hypoplasia. The renal growth after antireflux surgery was evaluated by the change of the renal ratio and it was found that about three-fourths remained small during the pre- and postoperative periods. Accelerated growth was only exceptional.