The Clinical Characteristics of Infantile Primary Vesicoureteral Reflux and Its Spontaneous Resolution Rate

ABSTRACT

PURPOSE: Childhood primary VUR is generally diagnosed after urinary tract infection, is more prevalent among girls and has a low spontaneous resolution rate in cases of severe VUR. The aim of the present study is to examine the age and gender-related characteristics and the spontaneous resolution rate of infantile primary VUR. METHODS: The medical records of 96 infants with primary VUR, diagnosed after their first UTI, were retrospectively reviewed(1995-2004). The clinical characteristics including gender, the degree of VUR and presence of renal scars were evaluated. The spontaneous resolution rate and contributing factors were also analyzed. RESULTS: Infantile primary VUR was more prevalent in males than females. The percentage of atrophic scarred kidney was significantly higher in males than females(17.2% vs 3.4%)(P<0.05). The cumulative spontaneous resolution rate in 3 years was very high(89.1%), and was not significantly different between gender and among VUR grades. But in the first year, the spontaneous resolution rate of severe refluxing ureters was significantly higher in males than in females(46.2% vs 7.1%)(P<0.05) and the spontaneous resolution rate of refluxing ureters with no scarred kidneys was significantly higher than those associated with atrophic scarred kidneys(76.6% vs 20%)(P<0.05). CONCLUSION: Infantile primary VUR was more prevalent among males and tends to be associated with atrophic scarred kidneys in male infants. The cumulative spontaneous resolution rate in 3 years was very high, even in high-grade VUR and associated atrophic scarred kidneys. In infantile primary VUR, surgery should be withheld even in infants with high-grade VUR with atrophic scarred kidneys.