[Severe primary vesicoureteral reflux in infants. A follow-up of 203 cases]. / El reflujo vesicoureteral primario severo en el primer año de la vida. Revisión de 203 casos.

OBJECTIVE: The aim of our study is to analyze the clinic characteristics and evolution of the primary reflux in infants. METHODS: We studied retrospectively 203 infants in our hospital, diagnosed of severe primary renal reflux. Renal ecography and cyclic mictional cystography were practiced in all cases. DMSA was carried out in 181 patients. RESULTS: Renal reflux was unilateral in the 23% of the patients, and bilateral in the remaining cases; 72% of the renal reflux were grade IV and 28% grade V. The renal injuries affected to male infants and reflux grade V. The renal injury was focal (27%), global (44%) and atrophic (29%). The 79% of the patients had conservative treatment, while 21% had surgical treatment. 100% infants with surgical treatment and 94.2% infants with conservative treatment were recovered (Test of Kaplan-Meier). The 27% of patients developed one or several urinary infections, but progression of old renal injuries or formation of new ones, were exceptional (3 cases): While the time the study lasted none of the patients developed chronic renal failure nor arterial hypertension. CONCLUSIONS: 1) The fetal severe primary reflux of the patients was characterized by the following features: to be bilateral reflux, to affect mainly to male infants and to be associated in 33% of cases with a severe renal injury of congenital origin (renal displasia) most of them unilateral. 2) The natural evolution of the reflux goes to spontaneous recovery, so treatment must be conservative. 3) Some patients underwent urinary infections, but progression or formation of new renal injuries were inusual. None of the patients had terminal renal failure nor hypertension and 4) Risk patients would be male infants with bilateral injuries although these are infrequent.