[Chronological age for the spontaneous resolution of vesicoureteral reflux]

Vesicoureteral reflux (VUR) may have medical management, which implies prophylactic antibiotic therapy, control with serial urine cultures and imaging tests, such as annual voiding cystourethrogram (VCUG) or direct isotopic cystogram (DIC); or it may be surgical, when medical treatment fails, due to recurrent UTI or renal damage. We analyze the chronological age of the patient at which VUR resolve spontaneously, so that we know when we should have a more precise control with VCUG, avoiding a traumatic test and irradiation, but also avoiding to give prophylactic antibiotic without real need. We aim to associate age of resolution with VUR grade and side, and patient's gender.

Retrospective study of patients with VUR under control at the Hospital Clinico of the Catholic University of Chile between 1996 and 2004.

patients with the diagnosis of VUR grades I, II, and III obtained by VCUG, and spontaneous resolution of VUR on control VCUG or DIC, with no urological surgery, without bladder dysfunction or other urinary tract disorders. 156 patients were included.

73.5% are females, with a mean age at the time of resolution of 52.7 +/- 36 months. 74.3% of the patients had unilateral VUR. There were not statistically significant differences in the age of resolution between unilateral or bilateral VUR, or between different grades. There is a statistically significant difference in the age of resolution comparing gender (p < 0.0001), resolving between 12 and 17 months before in males.

VUR improves earlier in males than females, without differences between unilateral-bilateral, or VUR grade I, II and III. The control VCUG or DIC should be indicated in relation to the most probable chronological age of resolution, generally around 4 years of age, and not once a year, so avoiding irradiation and trauma, with a special consideration to the child gender.