Association between NDUFS1 from urinary extracellular vesicles and decreased differential renal function in children with ureteropelvic junction obstruction.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) is the most common cause of pediatric congenital hydronephrosis, and continuous kidney function monitoring plays a role in guiding the treatment of UPJO. In this study, we aimed to explore the differentially expressed proteins (DEPs) in the urinary extracellular vesicles(uEVs) of children with UPJO and determine potential biomarkers of uEVs proteins that reflect kidney function changes. METHODS: Preoperative urine samples from 6 unilateral UPJO patients were collected and divided into two groups: differential renal function (DRF) ≥ 40% and DRF < 40%.We subsequently used data-independent acquisition (DIA) to identify and quantify uEVs proteins in urine, screened for DEPs between the two groups, and analyzed biofunctional enrichment information. The proteomic data were evaluated by Western blotting and enzyme-linked immunosorbent assay (ELISA) in a new UPJO testing cohort. RESULTS: After one-way ANOVA, a P adj value < 0.05 (P-value corrected by Benjamin-Hochberg) was taken, and the absolute value of the difference multiple was more than 1.5 as the screening basis for obtaining 334 DEPs. After analyzing the enrichment of the DEPs according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment combined with the protein-protein interaction (PPI) network results, we selected nicotinamide adenine dinucleotide-ubiquinone oxidoreductase core subunit S1 (NDUFS1) for further detection. The expression of NDUFS1 in uEVs was significantly lower in patients with DRF < 40% (1.182 ± 0.437 vs. 1.818 ± 0.489, P < 0.05), and the expression level of NDUFS1 was correlated with the DRF in the affected kidney (r = 0.78, P < 0.05). However, the NDUFS1 concentration in intravesical urine was not necessarily related to the change in DRF (r = 0.28, P = 0.24). CONCLUSIONS: Reduced expression of NDUFS1 in uEVs might indicate the decline of DRF in children with UPJO.

Long-term follow-up of congenital hydronephrosis in a single-center study.

OBJECTIVES: Many congenital hydronephroses spontaneously resolve. This study evaluated a long-term follow-up of more than 4 years of patients with congenital hydronephrosis at a single center. METHODS: In total, 215 patients (286 kidneys) with congenital hydronephrosis were included. Hydronephrosis outcomes (resolution, improvement, and persistence) and time-to-outcome were evaluated. RESULTS: Fourteen patients underwent early surgical intervention until the age of 2 years. A total of 189 congenital hydronephrosis cases (66%) showed resolution at a median of 16 months (interquartile range: 7-21 months) and 169 (80%) of 210 kidneys with grade I to II hydronephrosis showed resolution at a median of 14 months (interquartile range: 6-23 months). Of 76 kidneys with grade III to IV hydronephrosis, 24 (32%) showed resolution at a median of 29 months (interquartile range: 24-41 months), and 56 (74%) showed improvement to grade II or less at a median of 12 months (interquartile range: 5-23 months). Of the 76 kidneys with grade III to IV hydronephrosis, five required delayed pyeloplasty at a median of 66 months (interquartile range: 42-89 months). One patient was asymptomatic, with a marked worsening of hydronephrosis and decreased renal function 6 years after the resolution of hydronephrosis. CONCLUSIONS: None of the patients with grade I to II hydronephrosis required surgical treatment, and a shorter follow-up may be sufficient. Grade III to IV severe hydronephrosis should be considered for a longer and more careful follow-up, given the possibility of asymptomatic exacerbation of hydronephrosis.

Contemporary diagnosis and management of pelvi-ureteric junction obstruction.

Pelvi-ureteric junction obstruction (PUJO) is defined as a functionally significant impairment of the flow of urine from the kidney's renal pelvis into the proximal ureter. Symptomatically, the patient may experience flank pain, recurrent infections, stone formation, and impairment of renal function. Although many cases of intrinsic PUJO are diagnosed at birth, a minority of patients may present in adulthood with previously silent disease or develop secondary PUJO to other causes. PUJO is therefore broadly categorised into both primary and secondary PUJO. A wide array of diagnostic scans and tests are available to aid in diagnosing and monitoring patients with PUJO. In patients with compromised renal function or symptomatic PUJO that require intervention, minimally invasive techniques are the 'gold standard' for surgical intervention. This review will detail the endoscopic, laparoscopic, and robotic options available to the urologist practicing in 2021, including the use of autografts and other emerging technologies.

Vascular hitch for paediatric pelvi-ureteric junction obstruction with crossing vessels: institutional analysis and systematic review with meta-analysis.

OBJECTIVE: To compare the outcomes for laparoscopic vascular hitch (VH) and dismembered pyeloplasty in patients with pelvi-ureteric junction obstruction (PUJO) secondary to crossing vessels (CV). PATIENTS AND METHODS: Patients who underwent laparoscopic management of CV at our institution were identified between 2008 and 2020. Baseline characteristics and outcome measures were compared between those who underwent VH and those who underwent dismembered pyeloplasty. Those who underwent VH were selected intraoperatively by identifying CV in the absence of intrinsic obstruction by assessing resolution of hydronephrosis after cranially displacing the CV away from the PUJ, followed by intraoperative fluid bolus and diuretic test. In addition, a systematic search and meta-analysis were performed in June 2020 (International Prospective Register of Systematic Reviews [PROSPERO] ID CRD42020195833). RESULTS: A total of 20 patients underwent VH and 74 dismembered pyeloplasty. On multivariate analysis, VH was associated with: shorter operative time (P = 0.001; odds ratio [OR] 0.455, 95% confidence interval [CI] 0.294-0.705) and length of stay (P = 0.012; OR 0.383, 95% CI 0.183-0.803), lower use of stents (P < 0.001; OR 0.024, 95% CI 0.004-0.141) and opioid administration (P = 0.005; OR 0.157, 95% CI 0.044-0.567). From our literature search, 194 records were identified and 18 records were included (three comparative and 16 non-comparative). Meta-analysis of the comparative studies and our institutional data showed similar success rates (relative risk [RR] 1.77, 95% CI 0.33-9.52) and complication rates (RR 0.75, 95% CI 0.20-2.82). VH was associated with shorter operative time (standardised mean difference [SMD] -1.65, 95% CI -2.58 to -0.72 h) and hospital stay (SMD -1.41, 95% CI -2.36 to -0.47 days). The VH success rates ranged from 87.5% to 100% in the identified studies. Failure of VH was associated with unrecognised concomitant intrinsic obstruction in addition to CV. CONCLUSIONS: A VH, for well-selected patients with CV without concomitant intrinsic obstruction, offers a high success rate with shorter operative times.

Robot-assisted laparoscopic pyeloplasty (RALP) in children with complex pelvi-ureteric junction obstruction (PUJO): results of a multicenter European report.

PURPOSE: This study aimed to report a multi-institutional retrospective case series of outcomes after robot-assisted laparoscopic pyeloplasty (RALP) in pediatric patients with complex pelvi-ureteric junction obstruction (PUJO). METHODS: All patients undergoing complex RALP over the last 5 years were included. RALP was defined complex in the following cases of PUJO: anatomic variations including ectopic, malrotated, horseshoe, or duplex kidney and recurrent PUJO after failed open pyeloplasty. RESULTS: Forty-eight patients underwent complex RALP in four European centers in the study period and included 18 girls and 30 boys with a median age of 8 years (range 5-12). The PUJO was associated with anatomic variations in 35/48 (72.9%), whereas a recurrent PUJO was present in 13/48 (27.1%). A dismembered Anderson-Hynes pyeloplasty was performed in all patients. The median operative time including docking was 178.5 min (range 117-255) and the median anastomotic time was 64.8 min (range 50-76). All patients were discharged on 2nd postoperative day (POD). The median follow-up was 18.2 months (range 14-43). The overall success rate was 95.8% (46/48). Early postoperative complications (< 30th POD) included urinary tract infections (UTIs) and stent-related irritative symptoms in 4/48 (8.3%) [II Clavien], whereas late complications (> 30th POD) included recurrence of PUJO in 2/48 (4.2%), who needed re-operation [IIIb Clavien]. CONCLUSIONS: RALP was safe, feasible, and with good mid-term outcome in complex PUJO. An accurate pre-operative planning, a standardized technique, and an experienced surgical robotic team represented key points to manage successfully such complex cases.

Diagnostic accuracy of an interdisciplinary tertiary center evaluation in children referred for suspected congenital anomalies of the kidney and urinary tract on fetal ultrasound - a retrospective outcome analysis.

BACKGROUND: Fetal ultrasound organ screening has become a standard of care in most high-income countries. This has resulted in increased detection of congenital abnormalities, which may lead to major uncertainty and anxiety in expectant parents, even though many of them are of minor relevance. In order to optimize prenatal counselling, we introduced an interdisciplinary approach for all pregnant women referred to our center by private obstetricians for a co-assessment of suspected relevant fetal abnormalities of the kidney or urinary tract, involving both experienced prenatal ultrasound specialists and a pediatric nephrologist or urologist. METHODS: In a retrospective analysis, we evaluated reports of intrauterine evaluation and postnatal follow-up in order to assess accuracy of explicit intrauterine diagnoses and outcome of hydronephroses according to their severity in this setting. RESULTS: A total of 175 fetuses were examined between 2012 and 2019 and followed postnatally at our Pediatric Nephrology or Urology Department. There was a high concordance (85.9%) between explicit intrauterine and final diagnoses. Resolution rate of hydronephrosis was higher in patients with intrauterine low-grade than high-grade hydronephrosis (61.8% versus 11.9%). An etiological diagnosis was found in 62.5%, 52.0%, and 11.1% of patients with intrauterine bilateral high-grade, unilateral high-grade, and unilateral high-grade with contralateral low-grade hydronephrosis, respectively, but in none of the patients with intrauterine low-grade hydronephrosis. CONCLUSIONS: The results of our study demonstrate that, through interdisciplinary teamwork, intrauterine assessment of the fetal kidneys and urinary tract is highly accurate and allows a good discrimination between relevant and transient/physiological hydronephroses. A higher resolution version of the Graphical abstract is available as Supplementary information.

Utility of Society for Fetal Urology and Anteroposterior Pelvic Diameter Grading Systems for Estimating Time to Resolution of Isolated Hydronephrosis: A Single Center Study.

PURPOSE: We aimed to compare the Society for Fetal Urology and anteroposterior pelvic diameter classification systems in predicting the time to resolution of isolated hydronephrosis. MATERIALS AND METHODS: We retrospectively reviewed isolated hydronephrosis cases prenatally detected and postnatally diagnosed between 1994 and 2018. Other urinary tract anomalies and vesicoureteral reflux were excluded. Baseline grades for both systems were collected. Anteroposterior pelvic diameter was classified as grade 1 to 4 over a scale of 5 mm. Resolution was defined by an anteroposterior pelvic diameter of less than 5 mm with Society for Fetal Urology grade I hydronephrosis. Time to resolution was analyzed using Kaplan-Meier curves. RESULTS: The study population consisted of 831 patients (1,028 renal units). Median followup was 26 months (range 6 to 260), and 559 units (54.3%) reached resolution during a median followup of 9 months (1 to 133). Resolution rates at 48 months were 81.7%, 65.6%, 37.6% and 5.2% for Society for Fetal Urology grades I through IV disease and 80.0%, 41.2%, 13.1% and 2.5% for anteroposterior pelvic diameter grades 1 through 4, respectively. Discrepancies between these grades were present in 481 units (46.8%). Society for Fetal Urology grades II to IV categorized as anteroposterior pelvic diameter grade 1 showed a superior cumulative rate of resolution (84.7%) vs anteroposterior pelvic diameter grades 2 to 4 categorized as Society for Fetal Urology grade I (53.2%, log-rank test p <0.001). CONCLUSIONS: Hydronephrosis cases with anteroposterior pelvic diameter grades 2 to 4 but categorized as Society for Fetal Urology grade I have an inferior cumulative rate of resolution than vice versa. Society for Fetal Urology grades have little influence on resolution when anteroposterior pelvic diameter is less than 10 mm. Therefore, anteroposterior pelvic diameter is more useful in predicting the time to resolution.

Prenatal diagnosis and postnatal outcome of anterior urethral anomalies.

OBJECTIVES: Anterior urethral anomalies (AUA) which present as anterior urethral valve, stenosis or atresia, are a rare cause for congenital urinary tract obstruction. We present our AUA prenatal diagnosis case series. METHODS: Fetuses presenting with prenatal findings suggestive for AUA according to postnatal reported clinical and imaging signs (urinary tract dilatation, dilated bladder, enlarged edematous fetal penis, dilatation of the fetal urethra and diverticula) were followed prospectively. RESULTS: Six fetuses were diagnosed with AUA. Diagnosis was confirmed upon examination of the neonate or the abortus. All cases presented with variable degrees of urinary tract dilatation. Four fetuses who presented with additional congenital anomalies of the kidneys and urinary tract (CAKUT) developed intra-uterine or early postnatal renal failure, while two isolated AUA cases have a normal renal outcome. CONCLUSIONS: AUA is a rare diagnosis. However, high index of suspicion and careful sonographic assessment of the male fetal urethra in cases referred for urinary tract dilatation may enable appropriate parent counseling, optimal prenatal surveillance and timed postnatal urological intervention. As in other lower urinary tract obstructions, future renal function seems to correlate with associated CAKUT, therefore close follow up throughout pregnancy and meticulous sonographic assessment is recommended.

A comparison between short- and long-term D-J stent in Anderson-Hynes pyeloplasty for pelvi-ureteric junction obstruction.

PURPOSE: A double-J (D-J) stent is usually kept in situ during Anderson-Hynes (A-H) pyeloplasty for pelvi-ureteric junction (PUJ) obstruction. The aim of the study is to determine whether early removal of D-J stent is better than long-term stenting. METHODS: In this prospective comparative study, conducted from January 2018 to April 2019 in Chittagong Medical College Hospital, patients with PUJ obstruction, age less than 12 years, were divided into group A (long-term stenting) and group B (short-term stenting) by simple randomization. Main outcome variables were urinary tract infection (UTI), stent colonization, encrustation, renal cortical thickness, differential renal function (DRF), glomerular filtration rate (GFR), and flow rate in DTPA renogram. RESULTS: There were 31 patients in each group. Median age was 5 years (IQR: 2.3 to 7 years) and male to female ratio was 2.1:1. Frequency of post-operative UTI and stent colonization were significantly higher in group A than group B (p < 0.001). All the patients of both groups had similar improvement in renal cortical thickness, DRF, GFR, and flow rate. The study was potentially limited by its small sample size and high median age (5 years). CONCLUSION: Early removal of D-J stent had lower incidence of UTI, stent colonization, encrustation, and stent migration.

Conservative management in congenital severe bilateral hydronephrosis related to uretero-pelvic junction obstruction.

We report our experience in conservative management of patients with prenatal and neonatal diagnosis of severe bilateral ureteropelvic junction obstruction (UPJO), focusing on the actual predictors of renal function impairment or spontaneous resolution. Between 1996 and 2006, 20 patients with bilateral severe hydronephrosis related to UPJO were included in the study. Indications for surgery were an increased hydronephrosis, decreased renal function, onset of symptoms. Conservatively treated patients were followed up for 3 months to 10 years with renal ultrasound, DTPA diuretic, urine culture. At first renal scan, 22 out of 40 renal units had a poor, 10 an intermediary and 8 a good drainage. Pyeloplasty was required in 10 of the 40 kidneys, while 30 out of 40 kidneys were followed conservatively. At the end of follow up, sieric normalized creatinine and estimated glomerular filtration rate were normal in all patients. Our data showed that bilateral severe hydronephrosis related to UPJO can be safely managed in a similar manner of a unilateral case. A poor drainage could be considered a negative predictive factor in the feasibility of a conservative management.

Laparoscopic transposition of lower pole crossing vessels in children with extrinsic pelvi-ureteric junction obstruction: a worthy alternative to dismembered pyeloplasty.

Pelviureteric junction obstruction (PUJO) due to intrinsic or extrinsic causes is a common problem in childhood. Extrinsic compression by a lower pole-crossing blood vessel can present symptomatically in older children. In these cases, laparoscopies Vascular Hitch can represent a valid alternative to pyeloplasty dismembered. We analyzed the data of 4 children affected by extrinsic PUJO treated at our institution with the laparoscopic Vascular Hitch procedure modified by Chapman. Surgical indications included presence of clinical symptoms, worsening of intermittent hydronephrosis, signs of obstruction on the MAG-3 scan, clear or suspected images of polar crossing vessels on CT scan or Uro-MRI. All procedures were completed laparoscopically. No complications occurred. Mean follow-up was 13 months with resolution of symptoms and PUJ obstruction and significant improvement of hydronephrosis in all cases. When blood vessels crossing lower pole represent the pure mechanical cause of UPJ obstruction the laparoscopic Vascular Hitch procedure represents an excellent alternative to dismembered pyeloplasty. It is less technically demanding then pyeloplasty and is associated with a lower complication rate. The main challenge is to intraoperatively ascertain the absence of associated intrinsic stenosis.

Activated Hedgehog-GLI Signaling Causes Congenital Ureteropelvic Junction Obstruction.

Intrinsic ureteropelvic junction obstruction is the most common cause of congenital hydronephrosis, yet the underlying pathogenesis is undefined. Hedgehog proteins control morphogenesis by promoting GLI-dependent transcriptional activation and inhibiting the formation of the GLI3 transcriptional repressor. Hedgehog regulates differentiation and proliferation of ureteric smooth muscle progenitor cells during murine kidney-ureter development. Histopathologic findings of smooth muscle cell hypertrophy and stroma-like cells, consistently observed in obstructing tissue at the time of surgical correction, suggest that Hedgehog signaling is abnormally regulated during the genesis of congenital intrinsic ureteropelvic junction obstruction. Here, we demonstrate that constitutively active Hedgehog signaling in murine intermediate mesoderm-derived renal progenitors results in hydronephrosis and failure to develop a patent pelvic-ureteric junction. Tissue obstructing the ureteropelvic junction was marked as early as E13.5 by an ectopic population of cells expressing Ptch2, a Hedgehog signaling target. Constitutive expression of GLI3 repressor in Ptch1-deficient mice rescued ectopic Ptch2 expression and obstructive hydronephrosis. Whole transcriptome analysis of isolated Ptch2+ cells revealed coexpression of genes characteristic of stromal progenitor cells. Genetic lineage tracing indicated that stromal cells blocking the ureteropelvic junction were derived from intermediate mesoderm-derived renal progenitors and were distinct from the smooth muscle or epithelial lineages. Analysis of obstructive ureteric tissue resected from children with congenital intrinsic ureteropelvic junction obstruction revealed a molecular signature similar to that observed in Ptch1-deficient mice. Together, these results demonstrate a Hedgehog-dependent mechanism underlying mammalian intrinsic ureteropelvic junction obstruction.

Natural course of isolated mild congenital hydronephrosis: A 2-year prospective study at a single center in Japan.

OBJECTIVES: To determine a follow-up plan for mild congenital hydronephrosis in Japanese individuals. METHODS: Neonates at Kansai Medical University Hospital (Hirakata, Osaka, Japan) who were diagnosed with mild congenital hydronephrosis - defined as a Society for Fetal Urology grade 1 or 2 - at 1-month old by abdominal ultrasonography between 2014 and 2016 were enrolled. These patients were encouraged to undergo repeated abdominal ultrasonography for 2 years every 3 months to investigate the course of congenital hydronephrosis. RESULTS: Among 1009 neonates, congenital hydronephrosis was detected in 118 affected renal units of 100 (9.9%) patients. According to the definition of the Society for Fetal Urology, 118 affected renal units were graded as grade 1 in 87 (74%), grade 2 in 30 (25%), grade 3 in one (1%) and grade 4 in 0 units. Among them, 117 affected renal units of mild congenital hydronephrosis comprising grades 1 and 2 were subjected to ultrasonographic evaluation to monitor the natural course. The rates of resolution at 7, 10, 13, 16, 19, 22 and 25 months after birth in Society for Fetal Urology grades 1 and 2 cases were 60% and 8%, 77% and 19%, 90% and 32%, 92% and 40%, 95% and 52%, 96% and 56%, and 99% and 60%, respectively. CONCLUSIONS: Grade 1 congenital hydronephrosis does not need to be followed up, because it mostly shows spontaneous resolution by 2 years of follow up without any complications. However, ultrasonographic examinations at 1-year intervals for grade 2 congenital hydronephrosis are recommended to determine the subsequent follow-up plan of patients.

Early Detection of Ureteropelvic Junction Obstruction Using Signal Analysis and Machine Learning: A Dynamic Solution to a Dynamic Problem.

PURPOSE: We sought to define features that describe the dynamic information in diuresis renograms for the early detection of clinically significant hydronephrosis caused by ureteropelvic junction obstruction. MATERIALS AND METHODS: We studied the diuresis renogram of 55 patients with a mean ± SD age of 75 ± 66 days who had congenital hydronephrosis at initial presentation. Five patients had bilaterally affected kidneys for a total of 60 diuresis renograms. Surgery was performed on 35 kidneys. We extracted 45 features based on curve shape and wavelet analysis from the drainage curves recorded after furosemide administration. The optimal features were selected as the combination that maximized the ROC AUC obtained from a linear support vector machine classifier trained to classify patients as with or without obstruction. Using these optimal features we performed leave 1 out cross validation to estimate the accuracy, sensitivity and specificity of our framework. Results were compared to those obtained using post-diuresis drainage half-time and the percent of clearance after 30 minutes. RESULTS: Our framework had 93% accuracy, including 91% sensitivity and 96% specificity, to predict surgical cases. This was a significant improvement over the same accuracy of 82%, including 71% sensitivity and 96% specificity obtained from half-time and 30-minute clearance using the optimal thresholds of 24.57 minutes and 55.77%, respectively. CONCLUSIONS: Our machine learning framework significantly improved the diagnostic accuracy of clinically significant hydronephrosis compared to half-time and 30-minute clearance. This aids in the clinical decision making process by offering a tool for earlier detection of severe cases and it has the potential to reduce the number of diuresis renograms required for diagnosis.

The molecular biology of pelvi-ureteric junction obstruction.

Over recent years routine ultrasound scanning has identified increasing numbers of neonates as having hydronephrosis and pelvi-ureteric junction obstruction (PUJO). This patient group presents a diagnostic and management challenge for paediatric nephrologists and urologists. In this review we consider the known molecular mechanisms underpinning PUJO and review the potential of utilising this information to develop novel therapeutics and diagnostic biomarkers to improve the care of children with this disorder.

Semaphorin-3A and Netrin-1 predict the development of kidney injury in children with congenital hydronephrosis.

Congenital obstructive nephropathy is amongst the main causes of chronic renal failure in children. Early diagnosis and initiation of the treatment will delay progressive renal tubular atrophy and interstitial fibrosis with the loss of nephrons. The aim of this study was to evaluate whether urinary (u) semaphorin-3A (SEMA-3A) and Netrin-1 may be potential biomarkers in children with congenital hydronephrosis due to ureteropelvic junction obstruction (UPJO). The study consisted of 42 children with severe hydronephrosis who needed surgery and two control groups (Control One: 42 children with mild, non-obstructive hydronephrosis; Control Two: 44 healthy children). All children had normal renal function. Urinary semaphorin-3A and Netrin-1 levels were measured in different groups using immunoenzymatic ELISA commercial kits. Compared with Control One and Control Two groups, the preoperative median uSEMA-3A/creatinine (cr.) and uNetrin-1/cr. levels increased significantly in the children with severe hydronephrosis (p < .01). One month after surgery, uSEMA-3A/cr. and uNetrin-1/cr. levels had decreased significantly in the children with severe hydronephrosis (p < .01), but were still higher than those in both control groups (p < .05). Receiver operator characteristic (ROC) analyses revealed a good diagnostic profile for uSEMA-3A and uNetrin-1 in terms of identifying children with a differential renal function of <40% [area under the curve (AUC) 0.825 and 0.745, respectively]. Our results indicate that increased concentrations of uSEMA-3A and uNetrin-1 are found in urine from children with severe hydronephrosis and that their concentrations are related to the degree of obstruction.

Current State of Fetal Intervention for Lower Urinary Tract Obstruction.

PURPOSE OF THE REVIEW: In this article, we explore the origins of intervention of fetal lower urinary tract obstruction, and we specifically discuss the background and recent outcomes of vesicoamniotic shunt placement and fetal cystoscopy. The article seeks to provide a comprehensive overview of the field while bringing the reader quickly up to speed on the pertinent literature and the critical data that are available to guide decision-making regarding intervention. RECENT FINDINGS: Appropriate patient selection for fetal intervention remains challenging despite advances in prenatal imaging. Both a randomized controlled trial and multiple systematic reviews show evidence of a perinatal survival benefit following fetal intervention but rates of renal morbidity remain very high. Despite 30 years of research, fetal lower urinary tract obstruction remains a difficulty entity to treat. Intervention may lead to survival, but physicians and caregivers must remain alert for the distinct possibility of long-term renal morbidity in survivors.

Pyonephrosis as the first symptom of congenital hydronephrosis in a 6-year old girl.

Pyonephrosis in the course of hydronephrosis usually provides to total or near-total loss of renal function. In adults pyonephrosis usually results from urolithiasis. In children usually congenital urinary tract anomalies are present as contributing factors. CASE REPORT: 6-year old girl was admitted to the hospital because of 2-day history of high fever, abdominal pain, progressive deterioration of general condition and ultrasonographically (US) detected left hydronephrosis. US on admission showed grossly dilated left renal collecting system together with extensive echogenic debris and laboratory tests highly elevated inflammatory markers. Once diagnosis of pyonephrosis was established on the basis of clinical picture and US as well as laboratory tests results, nephrostomy tube was placed percutaneously. Pus culture obtained during placement of nephrostomy showed E.Coli ESBL (-) growth. Intensive antibiotic treatment (Meropenem) was continued for 3 weeks, nephrostomy was removed after 12 days after receiving normal urine. Further evaluation of urinary tract (US and computed tomography urography) showed large hydronephrosis due to ureteropelvic junction obstruction, while dynamic scintigraphy obstructive renogram with grossly diminished left kidney function to 20% of differential renal function. The girl was referred for operative treatment on urgent basis. Intraoperatively long distance utreteropelvic junction stenosis was found and dismembered Anderson- Hynes pyeloplasty was performed. During 2-years follow-up postoperatively US showed gradually decrease of dilatation of left renal collecting system, while dynamic scintigraphy revealed permanent improvement of drainage together with almost normal renal function (up to 45%). No urinary tract infections were noted. CONCLUSIONS: Proper management of pyonephrosis in hydronephrotic kidney due to congenital ureteropelvic junction obstruction enables good final result of treatment.

Associations of Initial Society for Fetal Urology Grades and Urinary Tract Dilatation Risk Groups with Clinical Outcomes in Patients with Isolated Prenatal Hydronephrosis.

PURPOSE: There are limited comparative data on the predictive value of the 2 most commonly used classification systems, that is SFU (Society for Fetal Urology) hydronephrosis grades and urinary tract dilatation risk groups, in regard to the future risk of surgical intervention and the development of febrile urinary tract infection. We explored this topic in infants with isolated hydronephrosis. MATERIALS AND METHODS: After screening 938 patients with prenatal hydronephrosis from 2009 to 2016 we selected 322 patients with ureteropelvic junction obstruction-like hydronephrosis for study. Hydronephrosis grades were prospectively collected at baseline, surgery and last followup. Gender, circumcision status, antibiotic prophylaxis and renal pelvis anteroposterior diameter were captured. The primary outcome was pyeloplasty and the development of febrile urinary tract infection. Comparative analyses between SFU grades/urinary tract dilatation groups and the primary outcome were performed with the Fisher exact and log rank tests. RESULTS: Mean ± SD age at presentation was 3.3 ± 2.6 months and mean followup was 22 ± 19 months. Pyeloplasty was performed in 32% of patients with SFU III/IV vs 31% with urinary tract dilatation 2/3. The rate of febrile urinary tract infection in patients with SFU III/IV was similar to that in those with urinary tract dilatation group 2/3 (8% vs 10%). Children with SFU III/IV showed a significantly higher rate of surgery than those with SFU I/II (32% vs 2%, p <0.01). Similar findings were seen when using urinary tract dilatation groups to compare patients at low risk (1) vs moderate/high risk (2/3). CONCLUSIONS: Both grading systems equally allowed for proper risk stratification and prediction of clinical outcomes based on baseline ultrasound. They correctly separated most infants who underwent surgery or in whom febrile urinary tract infection developed from those who could be treated nonsurgically. Use of the new urinary tract dilatation classification should not affect how families of children with isolated hydronephrosis are counseled regarding surgical intervention and the risk of febrile urinary tract infection.