• 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.

• Childhood Kidney Diseases
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• v.4 no.2
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• pp.170-174
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• 2000

Ureteropelvic junction obstruction and duplicated collecting system are common urologic anomalies in upper urinary system, but they seldom occur in combination. These obstruction can occur in both partial or complete duplicated collecting system. Complete duplication of the ureter may be asymptomatic or recognized when complications develop as a result of reflux into the lower pole ureter or obstruction of the upper pole with an ectopic ureterocele. It is difficult to choose an optimal therapy due to the high variability in function, degree of obsturction, damage and potential fir regeneration in growing kidney. We report our experience of successful surgical interventions in the ureteropelvic junction obstruction of the lower pole with complete duplicated collecting system.

• Childhood Kidney Diseases
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• v.28 no.1
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• pp.1-7
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• 2024

Antenatally diagnosed urinary tract dilatation (UTD), previously referred to as antenatal hydronephrosis, is the most commonly detected abnormality by prenatal ultrasonography. Several grading systems have been developed for the classification of antenatal UTD using prenatal and postnatal ultrasonography. UTD comprises a wide variety of congenital abnormalities of the kidney and urinary tract ranging from transient UTD to more significant abnormalities such as vesicoureteral reflux, ureteropelvic junction obstruction, ureterocele, ureterovesical junction obstruction, posterior urethral valves, and non-refluxing megaureter. Optimizing the evaluation of antenatally detected UTD is essential to recognize children with important disorders while avoiding excessive investigations. Conservative approach with close follow-up is increasingly accepted as an appropriate treatment option for patients with asymptomatic vesicoureteral reflux and ureteropelvic junction obstruction in recent years. However, predicting permanent kidney damage in an unselected group of children with antenatal UTD is still challenging. The management and follow-up of children with UTD should be individualized based on recommendations from a pediatric nephrologist, a pediatric urologist, or both. Future research directed at predicting long-term outcomes of children diagnosed with UTD from mild findings to severe disease is needed to refine management for those at higher risk of kidney disease progression.

• 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.

• 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.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.

• Neonatal Medicine
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• v.18 no.2
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• pp.379-382
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• 2011

Spontaneous intraperitoneal extravasation of urine is rare. Perirenal urinoma may develop when obstruction to urinary flow creates sufficient back pressure to produce extravasation of urine. Urinary ascites most commonly indicate a disruption to the integrity of the urinary tract. We report a case of urinary ascites with urinoma resulting from an ureteropelvic junction obstruction in a neonate.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.239-247
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• 1993

Differentiating the various causes of hydronephrosis from that of obstruction can be very difficult. The decision-making process for those instances of urinary tract dilatation that require surgical correction and those that do not is based in part on the findings of diuresis renography. The methodology for performing this test has differed among nuclear medicine practitioners and the surgical findings are occasionally discrepant from the diuretic renogram interpretation. Consequently we made an automatic computer software program that calculates the slope of the response curve. The quantitative indices, such as the injection and response t1/2 by linear-fitting and monoexponential-fitting, were compared with the visual assessment of the diuretic cinerenography and clinical outcome in 50 children (62 kidneys) with ureteropelvic junction obstruction. Pooled diuresis renogram data indicated that: (1) Visual evaluation of the diuretic cinerenography is a sensitive (87%, 54/62) tool to differentiate obstruction in suspected ureteropelvic junction obstruction. (2) The cut-off value (maximum washout t1/2 with non-obstruction) of injection and response t1/2 by linear-fitting were 40 min. (3) The sensitivity and specificity using injection and response t1/2 by linear-fitting for obstruction were 89%(23/26) and 100%(30/30), respectively. (4) Response t1/2 as well as injection t1/2 by monoexponential-fitting do not stratify children with possible ureteropelivic junction obstruction. In conclusion, quantitative assessment of diuretic renography as well as visual assessment of diuretic cinerenography correlate well with surgical and clinical outcome of suspected ureteropelvic junction obstruction.

• 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.2 no.2
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• pp.161-168
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• 1998

Purpose : Lots of congenital anomalies of urinary tract including hydronephrosis are detected in fetus and neworn by popular use of prenatal ultrasonography. But there are little data available in Korea about natural course of hydronephrosis diagnosed antenatally by ultrasonography. So we intended to help management of these patients by analizing the follow up data of the neonates with hydronephrosis diagnosed antenatally. Methods : We evaluated 22 patients with neonatal hydronephrosis(33 renal units) who were diagnosed prenatally and confirmed postnatally. Especially patients with suspected ureteropelvic junction obstruction were followed regulary with renal ultrasonography and diuretic renography for 8-24 months. Results : 1) The etiologies of neonatal hydronephrosis diagnosed prenatally were suspected ureteropelvic junction obstruction($69.9\%$), vesicoureteral reflux($15.1\%$), primary megaureter($3.0\%$), double ureter with ureterocele($3.0\%$), ureteral stricture($3.0\%$), multicystic dysplastic kidney(3.0$\%$), and ureterovesical junction obstruction(3.0$\%$). 2) The follow up results of 23 renal units of suspected ureteropelvic junction obsruction: Except 4 renal units with palpable abdominal mass, of the remained 19 renal units, 14 units($73.6\%$) were improved spontaneously, 3 units($15.7\%$) remained stable, only2 units($10.5\%$) were aggravated. Conclusion : We concluded that in most cases of hydronephrosis there is no need for immediate surgery, and that nonoperative approach, using serial ultrasonography and diuretic renogram, is safe management of neonatal hydronephrosis diagnosed anteratally.