• Childhood Kidney Diseases
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• v.1 no.1
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• pp.53-59
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• 1997

There have been many recent reports that unilateral renal agenesis and multicystic dysplastic kidneys are accompanied by contralateral vesicoureteral reflux leading to its injury. We grouped the children with unilateral renal agenesis, renal hypoplasia, multicystic dysplastic kidney into abnormal unilateral renal development and investigated whether it was accompanied with contralateral vesicoureteral reflux. We retrospectively reviewed 96 pediatric cases of unilateral renal agenesis, hypoplasia, multicystic dysplastic kidney diagnosed at Shinchon Severance Hospital, Yongdong Severance Hospital from 1987 to 1996 and Ajou University Hospital from 1994 to 1996. Diagnosis was based on radiological findings, renal hypoplasia being defined as small renal size with no apparent renal scarring and no irregularity of the calyceopelvic system on abdominal sonography or intravenous pyelography. Among the 96 cases,48 cases carried out voiding cystourethrography. 58 cases were male(60%) and 38 cases were female(40%). The cases of abnormal unilateral development on the left side were 45(47%) and that on the right side were 51(53%). Although there were diverse reasons leading to diagnosis, the major ones included were prenatal sonography, urinary tract infection, and other congenital anomalies. In cases of unilateral renal agenesis & hypoplasia the leading factors were urinary tract infection & other congenital anomalies and in cases of multicystic dysplastic kidney that was prenatal sonography. There was a chronological gap between the mean age of diagnosis(1.8 year) and voiding cystouerthrography(2.5 year, P < 0.01). 9 of the 18 unilateral renal agenesis cases, 5 of the 11 unilateral renal hypoplasia cases, and 3 of the 19 unilateral multicystic dysplastic kidney cases showed contralateral vesicoureteral reflux. Average reflux grade was above G III.Among the 17 children who had contralateral vesicoureteral reflux, 3 children had chronic renal failure and ureteroneocystostomy was carried out in 6 children. From the above results we conclude that screening voiding cystourethrography should be performed in children with abnormal unilateral renal development for early detection of vesicoureteral reflux in the contralateral kidney.

• Clinical and Experimental Pediatrics
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• v.61 no.1
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• pp.17-23
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• 2018

Purpose: To determine the relationship between vaginal reflux (VR) and urinary tract infection (UTI) in female children aged <36 months. Methods: A single center retrospective study was performed for 191 girls aged <36 months, with a diagnosis of febrile UTI, who underwent a voiding cystourethrography (VCUG) for assessment of vesicoureteral reflux (VUR) at Sanggye Paik Hospital. Fifty-one girls, who underwent VCUG for assessment of congenital hydronephrosis or renal pelvis dilatation, without a UTI, formed the control group. The correlation between the presence and grade of VR and UTI was evaluated. Results: The prevalence rate of VR was higher in the UTI (42.9%) than control (13.7%) group (P<0.05), with a higher VR severity grade in the UTI (mean, 0.64) than control (mean, 0.18) group (P<0.05). On subanalysis with age-matching (UTI group: n=126, age, $5.28{\pm}2.13months$; control group: n=22, age, $4.79{\pm}2.40months$; P=0.33), both VR prevalence (43.65% vs. 18.18%, P<0.05) and grade (0.65 vs. 0.22, P<0.05) remained higher in the UTI than control group. Presence and higher grade of VR were associated with UTI recurrence (P<0.05). VR was correlated to urosepsis (P<0.05). The renal defect rate of patients with VR (VR [+]/VUR [+]) was not different from that of patients without VR (74% vs. 52%, P=0.143) in the VUR group; however, it was higher than that of VR (+)/VUR (-) patients (74% vs. 32%, P=0.001). If a child with VR (+)/VUR (+) is exposed to a UTI, the risk of renal defect increases. Conclusion: Occurrence of VR is associated with UTI recurrence and urosepsis in pediatric female patients.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.136-141
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• 2017

Purpose: This study aimed to investigate clinical and radiological factors that may predict high-grade vesicoureteral reflux (VUR) in patients with febrile urinary tract infection (UTI). Methods: We retrospectively analyzed medical records of 446 patients diagnosed with febrile UTI from March 2008 to February 2017. All patients underwent renal-bladder ultrasonography (RBUS), 99mTc dimercaptosuccinic acid (DMSA) renal scan, and voiding cystourethrography (VCUG), and were divided in to 3 groups: a high-grade VUR group (n=53), a low-grade VUR group (n=28), and a group without VUR (n=365). Results: The recurrence and non-Escherichia coli infection rates in febrile UTI were significantly higher in the high-grade VUR group than in the other two groups (P<0.05). RBUS showed that hydronephrosis and ureter dilatation were more frequent in the high-grade VUR group than in the other groups (P<0.05). In the high-grade VUR group, a renal cortical defect was more likely to appear as multiple defects, and the difference in bilateral renal scan uptake between both kidneys was larger than in the other two groups (P<0.001). Conclusion: Recurrent UTI, non-E. coli UTI, abnormal findings on RBUS such as hydronephrosis and ureter dilatation, and abnormal findings in the DMSA renal scan such as multiple renal cortical defects and greater uptake difference were associated with high-grade VUR. VCUG should be selectively performed when RBUS and/or DMSA renal scan reveal significant abnormalities.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.114-120
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• 2017

Purpose: The aim of this study was to determine the clinical characteristics, frequency of renal abnormalities and benefits of a top-down approach in children with their first febrile urinary tract infection (UTI). Methods: We reviewed 308 patients retrospectively who were admitted to Yeungnam University Hospital and were treated for their first febrile UTI from February 2006 to December 2013. We performed a comparative analysis of laboratory findings and results of imaging techniques including a Tc-99m dimercaptosuccinic acid (DMSA) renal scan. Results: Among the patients, 69% (213/308) were males, and 90% (277/308) had their first UTI episode during infancy. A DMSA renal scan was performed on all patients, and showed positive findings in 60% (184/308) of cases. Laboratory indices of inflammation were significantly higher in the DMSA-positive group (P< 0.05). There was a statistically significant difference in the age distribution between the two groups. In the DMSA-positive group, 165 patients underwent voiding cystourethrography (VCUG), and 58 (35%) cases demonstrated vesicoureteral reflux. In total, 110 patients in the DMSA-positive group, underwent repeat scanning at 6 months; 33 children (30%) demonstrated static scarring, but 77 (70%) had improved completely. The concordance of the ultrasonography (US) and VCUG was low. Older patients had more renal scarring. Conclusion: DMSA is a sensitive method for assessing the severity of inflammation and kidney injury. However, the ability of US to predict renal parenchymal damage was limited. A top-down approach in children with their first febrile UTI showed significant value.

• Childhood Kidney Diseases
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• v.22 no.2
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• pp.47-51
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• 2018

Purpose: Urinary tract infection (UTI) is one of the common infectious diseases in children. Several imaging modalities can be used to confirm the presence of acute pyelonephritis (APN). Among them the 99mTcdimercaptosuccinic acid renal scan (DMSA scan) is used as a gold standard for diagnosis. Ultrasonography technology is evolving. Therefore, in this study, we investigated the sensitivity and specificity of Power Doppler ultrasonography (PDU) compared to the results from the previous study. Methods: There were 260 patients included in this study, aged between 1 and 12 months old. The patients were admitted to the Yeungnam University Medical Center between January 2008 and December 2015. All patients underwent both DMSA scan and PDU within 5days of admission. Voiding cystourethrography (VCUG) was performed in 195 patients with abnormal DMSA scan or PDU. Results: The diagnostic sensitivity of APN using PDU was 45.5% and specificity was 85.5% in 260 patients following detection of a defect on DMSA scan that was defined as APN. The diagnostic sensitivity and specificity of PDU for VUR were 65.5 % and 60.1%, respectively. The diagnostic sensitivity and specificity of DMSA scan for VUR were 95.7% and 14.1%, respectively. Conclusion: PDU has a high specificity but low sensitivity, so there are limitations in using it to replace a DMSA scan for the diagnosis of APN in children. DMSA scan and PDU have different sensitivity and specificity in diagnosis of VUR, respectively. Therefore, we suggest that the sensitivity and specificity of each test can be helpful in diagnosing APN and VUR when used in conjunction.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.262-266
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• 2008

Crossed renal ectopia is a congenital malformation in which both kidneys lie on the same side of the spine, usually side by side longitudinally. More often on the right side. Fusion of the two renal units is eight times more common than nonfusion. Although crossed renal ectopia is uncommon, this unusual entity must be considered in an infant when cystic mass in the abdomen or pelvis paticularly if no kidney can be found on the opposite side. In many cases of crossed fused ectopia with multicystic dysplastic kidney(MCDK), the diagnosis can be strongly suspected from the sonogram, and no other studies may be necessary. However, both intravenous urography and isotope renography is useful to assess the function of the crossed kidney. Crossed renal ectopia and MCDKs are associated with a greater incidence of ureteropelvic junction obstruction and reflux. So, screening voiding cystourethrography should be performed. Very few studies of MCDK in the setting of crossed fused ectopia have been reported. We have experienced a 3-year-old boy with crossed fused renal ectopia with multicystic dysplasia.

• Childhood Kidney Diseases
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• v.24 no.2
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• pp.98-106
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• 2020

Purpose: The aim of this study is to evaluate the clinical utility of late 6-month dimercapto-succinic acid (DMSA) renal scan in predicting vesicoureteral reflux (VUR) and long-lasting renal scars in children with first acute pyelonephritis (APN). Methods: A retrospective case study of children admitted with APN from January 2010 to July 2017 was performed. The study included patients with voiding cystourethrography (VCUG) and acute and late 6-month DMSA scan. We analyzed the clinical, laboratory and imaging findings of patients with and without late cortical defects at 6 months and those with or without VUR. Results: Among 145 children with APN, 50 (34.5%) had cortical defects on the late DMSA renal scan and 60 (41.4%) showed VUR. Thirteen of 38 (34.2%) children undergoing 18-month DMSA renal scan showed a long-lasting renal scars. Compared with children without late cortical defects, patients with late 6-month cortical defects had a higher incidence of VUR and long-lasting renal scars, and relapse of UTI (all P<0.05). In a multivariable analysis, both high-grade VUR and relapse of UTI were independently correlated with the presence of late 6-month cortical defects (P<0.05). Late cortical defects and relapse of UTI were also associated with the presence of VUR (P<0.05). Only the late 6-mo cortical defects was an independent predictor of long-lasting renal scars in children with APN (P<0.05). Conclusion: An abnormal late 6-month DMSA renal scan may be useful in identifying VUR and long-lasting renal scars in children diagnosed with APN.

• International Neurourology Journal
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• v.22 no.4
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• pp.268-274
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• 2018

Purpose: To describe a technique for urodynamic diagnosis of detrusor sphincter dyssynergia (DSD) using urethral pressure measurements and examine potential associations between urethral pressure and bladder physiology among patients with DSD. Methods: Multiple sclerosis (MS) and spinal cord injured (SCI) patients with known DSD diagnosed on videourodynamics (via electromyography or voiding cystourethrography) were retrospectively identified. Data from SCI and MS patients with detrusor overactivity (DO) without DSD were abstracted as control group. Urodynamics tracings were reviewed and urethral pressure DSD was defined based on comparison of DSD and control groups. Results: Seventy-two patients with DSD were identified. Sixty-two (86%) had >20 cm $H_2O$ urethral pressure amplitude during detrusor contraction. By comparison, 5 of 23 (22%) of control group had amplitude of >20 cm $H_2O$ during episode of DO. Mean duration of urethral pressure DSD episode was 66 seconds (range, 10-500 seconds) and mean urethral pressure amplitude was 73 cm $H_2O$ (range, 1-256 cm $H_2O$). Longer (>30 seconds) DSD episodes were significantly associated with male sex (81% vs. 50%, P=0.013) and higher bladder capacity (389 mL vs. 219 mL, P=0.0004). Urethral pressure amplitude measurements during DSD were not associated with significant urodynamic variables or neurologic pathology. Conclusions: Urethral pressure amplitude of >20 cm $H_2O$ during detrusor contraction occurred in 86% of patients with known DSD. Longer DSD episodes were associated with larger bladder capacity. Further studies exploring the relationship between urethral pressure measurements and bladder physiology could phenotype DSD as a measurable variable rather than a categorical observation.

• Urogenital Tract Infection
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• v.13 no.3
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• pp.58-65
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• 2018

Purpose: This study aimed to investigate the relationship between uropathogens of infants with febrile urinary tract infection (UTI) and vesicoureteral reflux (VUR). Materials and Methods: We analyzed 308 infants hospitalized for febrile UTI between January 2010 and December 2015, and assessed the voiding cystourethrography (VCUG). The medical records, including clinical symptoms, laboratory findings, urinalysis, urine culture tests, ultrasound (US), dimercaptosuccinic acid scan, and VCUG, were retrospectively obtained. The incidences of VUR and high-grade VURs (III, IV, and V) were analyzed in 4 groups categorized by uropathogens and renal US findings. Results: The mean age of 308 infants was $3.29{\pm}2.18months$. The male-to-female ratio was 3.46:1. In urine culture tests, 267 infants (86.69%) showed single bacterial uropathogen; Escherichia coli in 241 infants (78.25%) and non-E. coli uropathogens in 26 infants (8.44%). Multiple distinctive microorganisms were identified as causative uropathogens in 41 infants (13.31%). Abnormal findings of US and VCUG were identified in 216 and 64 patients, respectively. In 308 infants, the incidences of VUR and high-grade VUR were not different among the 4 groups. In 239 male infants, the incidences of high-grade VUR were higher in patients with non-E. coli single or multiple uropathogen and with abnormal US findings (p=0.042). Conclusions: In male infants with non-E. coli uropathogen or multiple uropathogens and with abnormal US findings at febrile UTI, there was an increased chance of finding high-grade VURs on subsequent VCUG tests.

• Childhood Kidney Diseases
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• v.26 no.1
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• pp.46-51
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• 2022

Purpose: Delta neutrophil index (DNI) indicates immature granulocytes in peripheral blood and has been confirmed to be effective as a prognostic factor for neonatal sepsis. Also, it has been reported to have diagnostic value in acute pyelonephritis and in predicting vesicoureteral reflux (VUR) in the infant. We conducted the study to verify whether DNI is also helpful in the entire pediatric age group with febrile urinary tract infection (UTI). Methods: Medical records of children hospitalized for febrile UTIs were analyzed retrospectively. All subjects underwent kidney ultrasound and voiding cystourethrography. In the group with and without VUR, we compared sex and age, and the following laboratory values: the white blood cell count, neutrophil, polymorphonuclear leucocyte, eosinophil, hemoglobin, platelet count, C-reactive protein, DNI value, and the finding of ultrasound. Results: A total of 315 patients (163 males and 152 females; range, 0-127 months) were eligible, and 41 patients (13%) had VUR. As a result of univariate analysis, the white blood cell count, neutrophil, DNI, and ultrasonic abnormalities were high in the reflux group, and the hemoglobin and lymphocyte fraction values were low. The value of DNI and the abnormal ultrasound were significantly higher in the reflux group on the multivariate analysis. The area under the curve value of the receiver operating curve was higher in DNI (0.640; 95% confidence interval, 0.536-0.744; P=0.004), and the DNI cutoff value for VUR prediction was 1.85%. Conclusions: We identified that ultrasound findings and DNI values were helpful predictors of VUR in pediatric febrile UTIs.