• Childhood Kidney Diseases
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• v.3 no.1
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• pp.88-94
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• 1999

Purpose : Malformation of urinary tract is among the most common of all congenital anomalies and can progress to irreversible renal damage before diagnosis due to difficulty of early diagnosis. Present study was undertaken to determine the clinical characteristics of urinary tract anomaly and to find out the most appropriate diagnostic and therapeutic measures for children with these anomalies. Methods : During the past 10 years from 1987 to 1998, review of medical records revealed 65 children with congenital anomaly of urinary tract and the following results were obtained. Results : The most common anomalies were ureteropelvic junction obstruction occuring in 26 cases ($36\%$), followed by ureteral duplication in 11 cases, renal agenesis in 10 cases and ureterovesical function obstruction in 7 cases. Complex anomaly of urinary tract was found in 8 cases and anomaly of other systems such as congenital heart disease was detected in 11 cases. The most frequent age group at the time of diagnosis was below 1 year of age constituting 39 cases ($60\%$) and male preponderance was noted as male to female ratio being 2.25:1. Presenting symptoms were urinary tract infection in 25 cases, followed by hematuria, abdominal mass, abdominal pain and voiding difficulty, etc, and in 11 cases, the anomaly was picked up by routine prenatal ultrasonography. Azotemia was noted in 9 cases and the underlying anomaly was obstructive uropathy in 4 out of these 9 cases. Surgical correction was undertaken in 38 cases (most frequently in cases of obstructive uropathy) and in 2 out off cases with obstructive uropathy in whom surgical correction was done, azotemia disappeared during follow up period of 1-5years. No new cases of deteriorating renal function appeared during follow-up period. Conclusion : In spite of high incidence of congenital malformation of urinary tract, early diagnosis is still hampered by nonspecific symptoms and signs. Therefore, in patients with symptoms such as urinary tract infection, abdominal pain and voiding problems, etc, it Is advisable to take various diagnostic tests promptly to pick up any urinary tract anomaly and to apply proper therapy in order to avoid progression to irreversible renal damage. In this regard, prenatal ultrasonography should be utilized more widely as a routine procedure to detect any urinary tract anomalies before birth.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.178-187
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• 2002

Purpose : The detection of hydronephrosis(HN) with antenatal ultrasonography was first reported in the 1970s. Prenatal HN is diagnosed with an incidence of 1:100 to 1:500 on antenatal screening. Recently, the purpose of antenatal screening has changed from simple detection to selection for specific diagnosis-based management. this study is to evaluate the usefulness of antenatal sonography for HN and to investigate the differential causes of HN and their clinical outcomes. Patients and methods : 11,783 live neonates with prenatal ultrasonographic examination at Ajou University School of Medicine, from Sep. 1994 to Aug. 2001 were analyzed. Results and conclusion : Hydronephrosis (>10 mm) was detected in 119 (1.0%) cases antenatally and among these, 91 were proved to have HN postnatally Males were three times more affected than females. Additional imaging studies revealed that ureteropelvic junction obstruction was the most common postnatal diagnosis (47%), followed by multicystic dysplastic kidney, vesicoureteral junction obstruction and vesicoureteral reflux. During 20 months' follow-up(3 to 72 months), 58(48%) renal units showed spontaneous resolution and surgical interventions were necessary in 10 (7.4%) of postnatally confirmed hydronephrotic renal units.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.268-271
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• 2007

Purpose : Premature narrowing of the foramen ovale is rare but serious clinical entity. Prenatal narrowing or obstruction of the foramen ovale shows symptoms such as right heart failure, fetal hydrops, triscupid regurgitation, left heart obstructive disease, and supraventricular tachycardia. This study aimed to assess the prenatal diagnosis and postnatal clinical course of restrictive foramen ovale in utero in otherwise normal heart. Methods : The subjects were five patients diagnosed with restrictive foramen ovale in utero from January 2001 to June 2005 at Chungnam National University Hospital. The diagnostic criteria was defined when the maximum diameter in a 4-chamber view is less than 2.5 mm and there is a continuous doppler velocity at the foramen ovale of more than 0.6m/s. Results : At the time of diagnosis of restrictive foramen ovale, gestation age was 34~37 wks, and chief complaints were fetal arrhythmia(2 cases), pericardial effusion, Ebstein anomaly and subaortic stenosis. Two cases which were diagnosed fetal hydrops and supraventricular tachycardia delivered by emergent cesarian section. Five cases were found to have right heart dilatation on echocardiogram after birth, but right heart dilatation became normalized at day 7 after birth and the clinical courses were not eventful. Conclusion : Identifying an obstructed foramen ovale in the fetus warrants the further search for additional cardiac and extracardiac anomalies, which may alter the prognosis. Delivery should be induced if possible in cases of foramen ovale obstruction with signs of cardiac decompensation.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.60-66
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• 2003

Purpose : Neonatal hydronephrosis has been detected with increasing frequency with the widespread use of prenatal ultrasonography, but the consensus about its postnatal management has not yet been reached, especially about surgical intervention. We attempted to determine the guideline of follow-up study and surgical intervention of hydronephrosis by analyzing clinical outcomes of neonates with hydronephrosis. Materials and Methods : Between 1994 and 2000, 128 hydronephrotic kidneys were postnatally confirmed. Cases associated with other urologic anomalies were excluded and 90 unilateral hydronephrotic kidneys with a minimum follow-up of 12 months were enrolled in this study. We classified the patients into 6 groups according to the anterior posterior pelvic diameter(APPD) at initial ultrasonography(USG) within 1 month after birth. Renal USG and $Tc^{99m}-mercaptoacetyl$ triglycerine(MAG3) scan were done according to a set protocol, and pyeloplasty was performed when indicated according to our protocol. Results : Most cases whose APPD were below 10 mm improved or resolved. Only few cases with APPD above 20 mm showed spontaneous improvement and most(88%) had undergone operation. Those with initial APPD within 10-19 mm showed variable outcomes. When the risk factors for irreversible renal functional deterioration were analyzed, the age at pyeloplasty and pre-operative functional deficit were significant. Conclusion : We concluded that in infants with initial APPD below 10 mm, consideration of surgery is not needed, and in those with initial APPD above 20 mm, early operation is recommended. Our set protocol based on initial USG is useful, but the cut-off value of relative renal function(RRF) for operation might be increased to 40% to improve post operative RRF.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.57-62
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• 2000

Purpose: Unilateral ureteropelvic junction obstruction with high grade of hydronephrosis an obstructed diuretic renogram but good differential renal function were studied to evaluate the natural history of untreated obstruction. Materials and Methods: During the last three years, we encountered 18 kidneys with hydronephrosis detected on prenatal ultrasound. In all these patients other urologic abnormalities were excluded by voiding cystourethrography and other radiological studies. Diuretic renography was initially performed at an age ranging from 2 weeks to 4 weeks. Five had high degree of hydronephrosis and obstructed diuretic renogram despite good relative renal function. Periodic urine examination, ultrasonography and diuretic renogram were done at regular intervals. Results: We have followed 5 neonates with unilateral hydronephrosis and suspected ureteropelvic junction obstruction with noroperative treatment for 15 months. During followup, percentage and relative renal function were maintained in all patients and hydronephrosis improved. Obstructive patterns on diuretic renogram were variable. Conclusions: These findings help to define the natural history of untreated good functioning hydronephrotic kidneys. Many newborn kidneys with severe hydronephrosis are not obstructed despite even high grade of hydronephrosis and obstructed diuretic renogram.

• Journal of radiological science and technology
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• v.40 no.2
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• pp.213-218
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• 2017

Recently, as the number of high-risk pregnancies increases, the use of new techniques such as Doppler, which have higher acoustic power than in the past, has been increasingly used in prenatal diagnosis and guidelines have been set up by various organizations to prevent excessive exposure. Therefore, in this study, we tried to investigate the temperature change of the body surface for each test mode according to the long time ultrasound examination and to examine the exposure time which is not influenced by the thermal effect. B mode, C mode, and PD mode according to time, and the temperature difference between exposed and unexposed sites were compared. As a result, the B mode showed a significant difference in the temperature change from 10 minutes, 50 minutes after exposed, 20 minutes from the C mode, and 30 minutes from the PD mode (p<0.01). In all three modes, the temperature difference was different (p<0.000), and PD mode was the most sensitive to temperature change. Also, it was found that the temperature rise time was shortened with the increase of the ultrasonic exposure time. Therefore, it is recommended that ultrasonography to observe the embryo or fetus should be used only for diagnostic purposes, avoiding excessive test time.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.64-70
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• 2006

Purpose : The natural courses of prenatally diagnosed hydronephrosis(HN) are diverse. Our purpose was to determine if the findings of renal ultrasonography(USG) in patients with prenatal HN at 1 month of age can predict the 1 year follow-up results and determine the guideline of follow-up study. Methods : Among 462 hydronephrotic patients registered between 1996 and 2004, 153 unilateral hydronephrotic renal units were enrolled in this study, bilateral HN, vesicoureteral reflux and other associated anomaly were excluded. These were classified into four groups respectively, according to anterior posterior pelvic diameter(APPD) or Society for Fetal Urology(SFU) grading by USG findings at 1 month after birth. Renal USG and $Tc^{99m}$-mercaptoacetyl triglycerine(MAG3) scan were done according to a set protocol. Results : Most cases improved or remained stationary. No one underwent an operation SFU grade 1,2 groups and only one case of SFU grade 3 group was operated. Thirty two cases(64 percent) were operated on among the 50 cases of SFU grade 4 group. 0/2(0 percent), 5/11(45.5 percent), 11/17(64.7 percent) and 16/20(80 percent) were operated on in each group with APPD <10, 10-19, 20-29, >30 mm, and the operation risk is higher as the APPD is increased. Conclusion : In group with SFU grade below 3 and APPD below 10 mm, we can delay the follow-up study beyond existing set protocol. Operations are recommended immediately if diuretic renogram show the obstructive pattern or decreased renal function in SFU grade 4 group with APPD over 10 mm.

• Childhood Kidney Diseases
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• v.11 no.1
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• pp.65-73
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• 2007

Purpose : Voiding cystourethrography(VCUG) is a commonly performed diagnostic procedure in children with urinary tract infections. Recently, with the widespread use of prenatal ultrasonography, VCUG is performed as part of the postnatal radiological evaluation of asymptomatic infants with prenatally detected hydronephrosis. The procedure is relatively simple but it involves discomfort and some complications. We studied post procedural symptoms and complications in children who underwent VCUG. Methods : This study reviewed 259 patients who underwent VCUG in our hospital between October 2005 and September 2006. We did a chart review and a telephone interview with the patients' parents about symptoms and complications associated with VCUG. Results : Among 269 children, 217 patients(80.7%) were under 2 years of age and 5 patients (1.9%) were over 8 years of age. Their mean age was $13.1{\pm}22.9$ months. After VCUG, dysuria was found in 49 patients presented with dysuria, and irritability in 36 patients with irritability. Other complications were hematuria, fever, frequency, bladder rupture and urinary tract infection. Mean symptoms duration was $1.4{\pm}0.7$ days. There was no significant relationship between prophylactic antibiotics use and complication rate associated with VCUG. Conclusion : Our study demonstrated that 32.7% of patients showed complications including bladder rupture and urinary tract infection after VCUG. We also found that prophylactic antibiotics use did not prevent urinary tract infection nor decrease the rate of complications associated with VCUG. Therefore, we suggest that the procedure must be done carefully and aseptically, and we should closely observe the children who undergo VCUG for development of possible complications.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.42-50
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• 2010

Purpose : The clinical characteristics and associated anomalies in children with solitary kidney (SK) were analyzed retrospectively. Methods : Total 38 children diagnosed to have SK at our hospital between December 1989 and December 2009 were recruited, and the clinical records including imaging studies were retrospectively reviewed. SK was defined as unilateral renal agenesis by imaging studies only, and patients with regression of unilateral dysplastic kidney were excluded. Results : Among total 38 patients, 12 were male. The median age at the diagnosis of SK was 6.5 months (at birth-13 years). SK was detected by prenatal ultrasonography in 14 patients and during work-up for renal or urinary tract diseases in 13 (including urinary tract infection in 7). In 10 patients, SK was detected incidentally. Anomalies in the SK were noted in 17 patients including vesicoureteral reflux in 11. Other anomalies in the genitourinary tract were present in 16 patients, and multi-organ-involving syndromes or chromosomal anomalies were detected in 9. The mean duration of follow-up was 9 years (9 months-20 years). Two patients developed chronic renal failure during follow-up, and the median serum creatinine concentration of the remaining 36 at their last follow-up was 0.6 mg/dL. Conclusion : SK may be isolated and clinically asymptomatic; it is frequently accompanied by other anomalies in genitourinary tract and other organs, some of which can induce progressive renal dysfunction. Early recognition of associated anomalies with SK and regular follow-up is recommended to reduce long-term risk.