• Childhood Kidney Diseases
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• v.14 no.2
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• pp.203-209
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• 2010

Purpose : It has been a common medical practice to use prophylactic antibiotics to prevent recurrent urinary tract infections (UTI) in high risk situations such as urinary tract obstruction, vesicoureteral reflux, neurogenic bladder, or urinary stones. But sometimes, we meet difficult situation of breakthrough infections (BI) which might cause new or progressive renal scarring. The clinical characteristics of children contracting breakthrough UTI experienced in a single center were studied. Methods : The study was done retrospectively through medical records of 150 pediatric patients who had been cared in pediatric and urologic clinics of Pusan National University Hospital from Jan. 2001 till June 2006 and had prophylactic antibiotics to prevent recurrent UTI. Results : The starting age of prophylactic antibiotics of 150 patient was 1-76 months, and median age was 5 months. The BI developed 61 times in 43 patients (28.7%), 1.5 times per 100 patient-months. The BI occurred more frequently in patients with higher grade of VUR, and in the cases with abnormal DMSA scan. Co-trimoxazole was more effective than 2nd and 3rd generation cephalosporins to prevent UTI. The distribution of causative organisms was more diverse than usual UTI. The causative organisms were sensitive to the antibiotics used for prophylaxis in 29.5%, and resistant in 59.1%. After experience of BI, 40 percents of patients went to the surgical treatment including endoscopic injection of Deflux, 35% to new antibiotics for prophylaxis, 26% remain on the same antibiotics as the previous one. Conclusion : Based on our study results, preexisting renal scar might be one of the factors which should be considered in favor of early surgical interventions of VUR. Poor compliance and wrong selection of antibiotics such as cephalosporins are important underlying causes of breakthrough UTIs.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.178-185
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• 2008

Purpose : Our aim was to investigate the predictive factors for detecting grade III-V vesicoureteral reflux(VUR) in young infants less than 3 months with urinary tract infections (UTI). Methods : Data of infants who underwent ultrasonography and VCUG between January 2004 and September 2007 were reviewed. Age, gender, incidence of bacteremia, C-reactive protein(CRP) and imaging studies were compared between group I(grade III-V VUR) and group II (normal or grade I and II VUR) retrospectively. Sensitivity, specificity, positive and negative predictive values, odds ratio, and likelihood ratio of ultrasonography for high grade VUR were evaluated. Results : Among 54 enrolled infants(41 males, 13 females), 14 infants were group I and 40 infants were group II. In the group I, CRP level was significantly higher(6.11$\pm$5.18 vs. 3.27$\pm$3.45, P=0.025), and there were more ultrasonographic abnormal findings(71.4%, vs. 22.5%, P=0.002) compared with group II. However, ultrasonography was the only significant factor after adjusting with logistic regression(P=0.002). Incidence of bacteremia and abnormal DMSA findings were not significantly different in two groups. Sensitivity, specificity, and odds ratio of ultrasonography was 71.4%, 77.5%, 6.9 respectively. Negative predictive value was 88.6% and negative likelihood ratio was 0.37. Ultrasonography had significant negative likelihood ratio for grade III-V VUR, but missed 4 infants with grade III VUR. Conclusion : We could not find any alternative predictive factors to reduce VCUG in detecting high grade VUR. Therefore, VCUG must be considered in young infants less than 3 months with UTI.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.101-109
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• 2013

Purpose: Pediatric urolithiasis is uncommon in children but is a cause of significant morbidity and damage to the kidney. Although much information on adult urolithiasis is available in the literature, large studies on the pediatric population are still scarce. In this report, we review our experience with pediatric urolithiasis over 22 years at a tertiary referral center. Method: We retrospectively reviewed the records of children with newly diagnosed urolithiasis between January 1991 and May 2013. We assessed the age, sex, family history, initial symptoms, location of stones, underlying cause, stone analysis, treatment, and recurrence among the patients. Results: In total, 137 patients (96 male, 41 female) were assessed. The age range was 0-17 years (mean age, 6.0 years). Forty-three (31%) children were aged <1 year, and 37% (16/43) had a history of intensive care unit (ICU) admission. Thirteen patients (9.5%) had a family history of stones. The most common symptoms at presentation among the patients were gross hematuria (56/137, 41%) and flank or abdominal pain (46/137, 34%). The stones were located in the kidney (85/137, 62%), ureter (29/137, 21%), bladder (2/137, 1.4%), and multiple locations (20/137, 15 %). Congenital abnormalities of the genitourinary (G-U) tract, with or without metabolic abnormality, or urinary tract infection (UTI) was detected in 26 children (19%). Ninety-one patients (66%) underwent metabolic examination, and 38% of these patients exhibited an abnormality. UTI, with or without abnormalities of the G-U tract, or metabolic abnormality was detected in 26 children (19%). Of the 35 stones analyzed, the majority were calcium stones (20/35, 57%), followed by infected stones (5/35, 14%), uric acid stones (4/35, 11%), carbonate apatite stones (3/35, 7%), cystine stones (2/35, 6%), and phosphate stones (1/35, 3%). Five patients (4%) required open procedures, with or without non-open procedures, whereas 77 patients (56%) were managed conservatively; the remaining 55 patients (40%) received some other form of intervention. Eighteen patients (13%) had stone recurrence during the follow-up period. Conclusions: Pediatric urolithiasis is commonly associated with abnormalities of the G-U tract and/or metabolic disorders and/or UTI. Half of the patients will pass their stones spontaneously, and all the techniques of minimally invasive surgery are applicable in the treatment of children with stones. As the recurrence rates are high among this population, long-term follow-up is recommended and the complete clearance of stones is important.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.187-195
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• 1999

Purpose : VUR is state where urine regurge from bladder to ureter and kidney. It is shown in about 1/3 of urinary tract infection patients and it is classified as grade I to V. We compared results from RI VCUG(Radiisotope voiding cystourethrography) and X-ray VCUG which used in diagnosing VUR in children, to evaluate which is better in diagnosing VUR in children. Methods : 41 Patients(19 males, 21 females), who visited Pediatric department, Soonchunhyang university Hospital from peroid of 1991. January to 1998. July for recurrent urinary tract infection or abnormalities in ultrasonogams, were enrolled in the study. The age ranged from 9 months to 17 years and mean age was 5 1/2 years. Both RI VCUG and X-ray VCUG were done and follow-up test of urine culture, renal ultrasonogram and RI VCUG were done every month, every 3 month and every 6 month, respectively to observe the disappearance of VUR and evaluated the prognosis. Results : 24 patients had taken RI VCUG and 17(70.1%) patients showed positive result. 22 patients had taken X-ray VCUG and 9(40.1%) patients showed findings of VUR. 17 patients had taken both tests and 14 patients showed positive result in RI VCUG and 6 of these patients also showed reflux in X-ray VCUG. 3 patients who showed negative in RI VCUG, showed negative also in X-ray VCUG. For prognosis, resolution and scar formation was shown in 8 patients each. Persistent VUR was shown in 6 patients and 2 of these patients VUR was corrected by operation, 1 patient showed decreased renal function, and 1 patient was not follwed up. 8 of 9 patients who showed findings of VUR on DMSA scan formed a scar and 8 patients who showed no findings of VUR didn't form a scar. Urine culture was positive in 17 of 19 patients with VUR. Positive rate in urine culture was higher than that of patients with no VUR who showed positivity in 15 of 21 patients for urine culture. E. coli was most common organism and the period free of UTI was 14 months in VUR patients and it was shorter compared to patients without VUR which was 26 months. Conclusion : In diagnosing VUR in children, the positive rate was higher in RI VCUG than X-ray VCUG. Therefore, in early diagnosis when VUR is suspicious but not shown in X-ray VCUG, RI VCUG should be done and it will help to make accurate diagnosis.