Takayuki Matsui

Renal Growth and Progression of Reflux Nephropathy in Children with Vesicoureteral Reflux

We analyzed renal growth and development of renal scars in 754 children with primary and 169 with secondary vesicoureteral reflux. The incidence of a small kidney was 15.5 per cent in the primary and 24.1 per cent in the secondary groups. About three-fourths of the small kidneys remained small from the first examination through followup. Catch-up renal growth was only exceptional. New scars or progression of previous scarring was observed in 7.4 and 30 per cent of the primary and secondary groups, respectively. Factors that promote formation of new scars are high grade vesicoureteral reflux, recurrent urinary tract infections and abnormal bladder function that results in high pressure reflux. We emphasized the importance of precise examination of the lower urinary tract. An early antireflux operation should be performed on children with severe reflux or recurrent urinary tract infections.

Vesicoureteral reflux in infants under one year old Follow-up study and consideration on development of renal scarring

In an attempt to clarify reflux nephropathy (RN), 67 infants aged under one year with vesicoureteral reflux (VUR) were retrospectively classified into two groups, non-surgical and surgical. They were evaluated on VUR grading, VUR spontaneous cessation rate, and incidence of scarring. As a whole, spontaneous cessation rate was 61 percent. The cessation rate was higher for infants with lower VUR grading. The average age at cessation was 2.5 years. Some patients showed no scarring at presentation despite severe VUR. However, most cases of renal scarrings at the time of presentation belonged to grade IV or V. Scarring advanced in 3 kidneys of the non-surgical group and in 13 kidneys of the surgical group. Of these 16 kidneys, 7 were rated as grade IV and 9 as grade V. An association between development of scarring and recurrent urinary tract infections was suggested.

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.