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Introduction: Hydronephrosis in infancy and childhood is a frequent urinary malformation. We were unable to find any reports concerning rate and causes of hydronephrosis in Iranian children therefore, we decided to evaluate it, in under 12 years old children. Materials and Methods: This was a descriptive study done in a 9-month period starting from Novemger 2004. All children under 12 years old who had visited Amir Kabir hospital of Arak for UTI or FTT were enlisted and an ultrasonography was requested. If hydronephrosis was detected, then a VCUG was performed. For those with normal VCUG results, if hydronephrosis persisted in the follow up sonography, the next step was an IVP or DTPA scan. Results: 65 patients (39 girls and 26 boys) were evaluated for hydronephrosis. 18.5% presented with FTT , 75.4% with UTI and 6.1% with FTT+UTI. The most prevalent causes of hydronephrosis were VUR (40%) and UPJO (23.5%). Grade I hydronephrosis was the most prevalent form (65%), however when VUR was present , it was mostly grades III or IV (27% and 19% respectively). 70% of girls and 31% of boys had VUR and the average age at the time of diagnosis was 2-3 years. Conclusion: Vesicouretero reflux and UPJO are the most prevalent causes of hydronephrosis and must be evaluated in children with hydronephrosis.

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Introduction: Children with reflux who fail prophylaxis management or reflux which do not resolve spontaneously are candidates for sugery. Delay in surgery increases the development of new renal scars. Finding a modal factor for prediction of reflux resolution likelihood can decrease complications of treatments. Regarding that sacral bone anomalies have a direct influence on the final function of urinary and bowel systems, this study is done to investigate the relationship between sacral ratio and reflux. Materials and Methods: This is a case-control study. The case group included 76 children less than 9 years old refered to Vali-e-Asr and Amir Kabir hospital clinics with urinary tract infection and according to voiding cystouretrograply (VCUG) results, children with III, IV and V grade vesicoureteral reflux (VUR) entered the study. The control group included 76 children with previous urinary tract infection and normal VCUG. Sacral ratio in the two groups was measured and was compared by student t, Chi square and Mann Whitney tests. Results: The case group included 24 males and 52 females with average age of 2.7 years old and the control group included 23 males and 53 females with the average age of 3 years. The percent of sacral ratio abnormality were 40% and 23.7% in the case and control groups respectively, which was significantly different (p=0.001). The difference between the mean sacral ratio in case group with the value of 80% and the control group with the value of 84% was not different. The ratio distribution pattern in the two groups was not different. Conclusion: The percent of sacral ratio abnormality in children with vesicoureteral reflux were more than children without reflux.

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Background: Vesicoureteral Reflux (VUR) is the most common urologic anomaly in children. In spite of prescribing prophylactic antibiotics in children with VUR, in some cases breakthrough infection (BTI) occurs while receiving prophylactic antibiotics which may cause pyelonephritis that can ultimately lead in renal scarring.

Materials and Methods: In this discreptive-analytic study, 288 children with primary vesicoureteral reflux under Cotrimoxazole(2mg/kg) treatment have been under supervision for duration of at least one year. Based on the collected data, predictive effect of some factors like gender, mean age of VUR diagnosis, VUR grade, unilateral versus bilateral and presence of abnormal renal scar on the breakthrough infection under prophylactic treatment, were examined.

Results: Breakthrough infection while receiving prophylactic antibiotics was observed among 111(38.54%) patients consisting of 88 girls (79.28%) and 23 boys (20.72%). The moderate to high VUR grades (grade III-V), presence of renal scar and female gender were found to be the important risk factors for BTI. However, no statistically significant relationship between mean age of VUR diagnosis and unilateral versus bilateral VUR with BTI was found.

Conclusion: Results of the current study will help improving parents' and physicians' awareness of the risk factors associated with BTI which may potentially lead to renal damage.