• Clinical and Experimental Pediatrics
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• v.45 no.2
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• pp.223-231
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• 2002

Purpose : We review our experience with pyeloplasty for unilateral ureteropelvic junction obstruction of moderate to severe hydronephrosis observed by prenatal ultrasonography to assess the appropriate timing of operation for recovery of renal function and obstruction. Methods : We retrospectively reviewed the records of the total 28 patients who underwent pyeloplasty between 1995 and 2001 at Asan Medical Center. We compared pre and postoperative differentials in renal function and diuretic renogram as measured by technetium-99m-mercaptoacetyl-triglycerine scan and the degree of hydronephrosis by renal ultrasonography. Results : In all 28 patients postoperative follow-up renal ultrasonography revealed significant improvement in hydronephrosis. In 10 poorly functioning hydronephrotic kidneys in which relative renal function function was less than 35%, renal function was improved postoperatively in 3 cases, but not improved in 7 cases. In all 28 patients postoperative follow-up diuretic renogram revealed significant improvement. Conclusion : We believe that the early pyeloplasty should be considered when ultrasonography and diuretic renography suggest obstruction because renal function does not improve significantly after pyeloplasty over preoperative value.

• Childhood Kidney Diseases
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• v.8 no.1
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• pp.91-95
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• 2004

We report a 2-month-old boy who presented with severe hyponatremia and hyperkalemia secondary to ureteropelvic junction(VPJ) obstruction. By prenatal ultrasonography at 19 weeks of gestation, severe hydronephrosis was found which was confirmed postnatally Pyeloplasty was done on the 45th day of life, and fifteen days after pyeloplasty, non-bilious vomiting, decreased activity and dehydration developed. Severe hyponatremia and hyperkalemia were observed, as a result of elevated serum aldosterone and plasma renin activity. The anterior posterior pelvic diameter(APPD) and Society for Fetal Urology(SFU) grade measured showed no interval change before and after pyeloplasty. Pseudohypoaldosteronism was diagnosed, and 2M NaCl was administrated orally for 7 days. The electrolyte imbalance was corrected, and 8 weeks later, the elevated levels of aldosterone and plasma renin activity were normalized. The left hydronephrosis was improved at 5 months of age. We hereby report a transient pseudohypoaldosteronism secondary to UPJ obstruction with a review of the literature.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.33-39
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• 2006

Purpose : Neonatal hydronephrosis is diagnosed with an incidence of 4.5-7% of pregnancies. Recently, early detection of neonatal hydroneprosis with antenatal ultrasonography has be-come possible. But consensus about its management has not been reached, especially concerning surgical intervention. The purpose of this study is to analyze the natural course of neonatal hydronephrosis and to determine the guideline of surgical intervention and follow up study. Methods : Sixty nine hydronephrotic kidneys were confirmed from April 2001 to April 2005. All cases were rechecked by ultrasonography once at least and had a minimum follow-up of 6 months. We classified the patients into 4 groups according to the anterior posterior pelvic diameter(APPD) on perinatal ultrasonography. Ultrasonography to measure the APPD diameter and Society for Fetal Urology(SFU) grade, $^{99m}Tc-MAG3$ scan were done to a set protocol. Pyeloplasty was peformed according to the protocol. Results : Pyeloplasty was not needed in most cases where the APPD was below 10 mm and where the SFU grade were less than grade 3. Many cases with APPD 10 mm above or SFU grade III above had undergone pyeloplasty. We found a correlation between obstruction grade on MAG3 scan and whether surgery was performed or not. Conclusion : If APPD is above 10 mm, SFU grade is above grade 3 or urinary tract obstruction is suspected by MAG3 scan, pyeloplasty must be considered. In cases where APPD is below 10mm and SFU grade is less than grade 3, we can observe the natural course of neonatal hydronephrosis with consecutive follow-up. (J Korean Soc Pediatr Nephrol 2006;10:33-39)

• 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.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.57-64
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• 1999

Purpose: The purpose of this study was to evaluate the accuracy of Tc-99m DTPA diuretic renal scans in children with dilated upper urinary tract. Materials and Methods: We reviewed diuretic renal scans of 14 pediatric patients (age range: 3 days to 4 years) with unilateral hydronephrosis diagnosed by ultrasonography. Diuretic renal scan was done using Tc-99m DTPA and standardized protocol. In 3 neonates, diuretic renal scans were performed within 1 week and 3-7 months after birth. Results: Six patients required Pyeloplasty and eight were managed conservatively. All 6 patients requiring Pyeloplasty were diagnosed as having ureteropelvic junction obstruction in the diuretic renal scan. In these 6 patients, post-operative renal scans at 3-12 months after surgery were converted to nonobstructive pattern in 5 and a nonfunctioning pattern in 1. In 3 patients who underwent diuretic renal scan within 1 week after birth, nonobstructive patterns of initial scan were converted to obstructive patterns in the follow-up scan. However, all patients with nonobstructive diuretic renal scans performed after the neonatal period did well on serial ultrasonography and showed favorable clinical outcome without progression to obstruction. Conclusion: Tc-99m DTPA diuretic renal scan with standardized protocol is useful in assessing suspected ureteropelvic junction obstruction in children as an initial diagnostic or post-operative follow-up modality. Nonobstructive or indeterminate scan results in the neonatal period requires follow-up scan to monitor development of the obstructive pattern.

• Childhood Kidney Diseases
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• v.22 no.1
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• pp.28-31
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• 2018

Ureteropelvic junction obstruction is one of the common causes of hydronephrosis in infancy and childhood. Most cases of ureteropelvic junction obstruction are diagnosed prenatally and are usually asymptomatic. Although less common, older children can experience ureteropelvic junction obstruction that presents with symptoms including flank or abdominal pain. Here, we present the case of a nine-year-old healthy girl who had repeated flank pain and abdominal symptoms, with mild left hydronephrosis, for several months. Computed tomography that was performed during the period of acute flank pain revealed aggravated hydronephrosis on her left kidney, which was secondary to an ureteropelvic junction obstruction. She underwent laparoscopic pyeloplasty, and a crossing vessel that passed the ureteropelvic junction was identified. In addition, we reviewed the current literature of this rare entity.

• Journal of Yeungnam Medical Science
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• v.21 no.1
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• pp.67-73
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• 2004

Background: A ureteropelvic junction (UPJ) obstruction is a congenital anomaly commonly afflicting the pediatric population. However, it occurs more frequently in adults than is generally appreciated. To assess their characteristics, we have here compared and analyzed the clinical manifestations, causes, and outcomes of UPJ obstruction found in children and adults. Materials and Methods: 102 patients (118 renal units) out of 182 patients (218 renal units), with diagnosed UPJ obstruction, were available for follow up. The follow-ups were retrospectively reviewed to determine the presenting symptoms, treatments, and clinical outcomes. Patients who were younger than 18 years of age were assigned to the pediatric group (44 patients), others the adult group (58 patents). Results: The majority of the patients presented with flank pain (pediatric group: 68%, adult group: 76%). The majority of patients underwent a pyeloplasty (pediatric group: 50.9%, adult group: 62.3%). And the major cause of the UPJ obstruction was an intrinsic stenosis (pediatric group: 53%, adult group: 56%). Conclusion: The prevalence of bilateral UPJ obstruction in adults is evidently less prevalent than in pediatrics, and despite the late diagnosis, the surgical outcome is similar. A further investigation of UPJ obstruction will lead us to a more comprehensive understanding of the disease.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.69-74
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• 1994

Authors retrospectively analysed 20 cases of follow-up $^{99m}Tc$-DMSA renal scans to evaluate renal function recovery after treatment in urologic disorders of infants and children. There were 20 cases with both $^{99m}Tc$-DMSA renal scans prior to and after therapy in 15 patients below 9 years old. Among them, 10 patients underwent ureteroneocystostomy under the diagnosis of vesicoureteral reflux, two patients pyeloplasty because of obstructive uropathy and one was treated with antibiotics even diagnosis of UPJ stricture. We have got the quantified uptake rate of $^{99m}Tc$-DMSA renal scan by using the regression equation as "y=0.591x-2.105" (y=the quantified uptake rate, x=the simple uptake rate). The number of kidneys performed proper therapy were 29, and the cases with more increased radiotracer uptake rate in the follow-up $^{99m}Tc$-DMSA renal scans were 20 in number as 69% in frequency. 19 cases with improved renal function on $^{99m}Tc$-DMSA renal scans didn't show any significant difference related to aging or recovery duration after therapy. The $^{99m}Tc$-DMSA renal scans were not useful to evaluate renal function recovery in infants and children, but could be good tests to assess residual renal function prior to or after treatment.