Ultrasound grading of hydronephrosis: introduction to the system used by the Society for Fetal Urology

What to Expect on the Long-term Follow-up of Pediatric Pyeloplasty: Critical Time Intervals and Risk Factors

BACKGROUND

Standard protocol for post-pyeloplasty monitoring in children and natural course of hydronephrosis resolution have not been well defined. We aimed to analyze critical time intervals and risk factors in the long-term clinical outcomes of children who were operated for ureteropelvic junction obstruction.

METHODS

Files of patients who underwent open dismembered pyeloplasty between January 2000 and December 2012 and had a ≥10 years follow-up were retrospectively reviewed. Changes in SFU hydronephrosis grade, pelvis anteroposterior diameter (APD), renal parenchymal thickness, split renal functions (SRF) on MAG-3 scan as well as development of hypertension and proteinuria were noted. Complete resolution was defined as SFU grade 0-1 or APD≤10 mm or ≥50 % APD decrease.

RESULTS

Overall, 223 patients (161 boys, 72.1 %) with a median age of 9 (range 1-185) months underwent unilateral pyeloplasty, whereas 14 patients (13 boys, 92.8 %) with a median age of 4 (range 2-39) months underwent bilateral pyeloplasty. Median follow-up was 13 (range 10-22) years. Complete resolution was observed in 190 patients (85.2 %). None of the cases required re-do pyeloplasty. Regarding unilateral cases, postoperative changes in hydronephrosis reached a plateau at the 60th month. Also, there was no significant difference regarding SRF between the 12th month and the 60th month (p > 0.05). Hypertension developed after a median period of 12 years in 13 (5.4 %) of the patients, while proteinuria developed in four (1.6 %) patients. Bilateral disease (HR: 2.518, p = 0.034) was found to be a significant determinant for development of hypertension and/or proteinuria.

CONCLUSIONS

Our results indicated that ultrasonographic findings stabilized after the 60th month postoperatively, and SRF remained stable between the postoperative 12th and the 60th months. The risk of developing hypertension and/or proteinuria was 2.5 times greater in bilateral cases.

LEVEL OF EVIDENCE

Level II.

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.

Risk factors of early infectious complications after ureterorenoscopy for stone disease: a prospective study

PURPOSE

To prospectively evaluate the rate and associated risk factors of early infectious complications after ureterorenoscopy for urolithiasis.

METHODS

After ethical committee approval, 400 therapeutic retrograde ureterorenoscopy procedures between August 3, 2020 and November 24, 2021 were included for analysis in a single-center study. Postoperative infection was defined as an afebrile urinary tract infection, fever (≥ 38 °C) with pyuria (≥ 300 WBC/μL) or proven urinary pathogen, and urosepsis. The primary outcome was the rate of infectious complications after ureterorenoscopy. Secondary outcomes were the perioperative factors that increased the risk of infectious complications within 30 days of surgery using univariate and multivariate logistic regression analysis.

RESULTS

Twenty-nine of four hundred (7.3%) patients developed an infectious complication within 30 days after ureterorenoscopy. Ten (2.5%) patients developed an afebrile urinary tract infection, eight (2.0%) developed fever with pyuria, five (1.3%) febrile urinary tract infection, and six (1.5%) urosepsis. On univariate analysis, preoperative stent-type JFil® pigtail suture stent was significantly associated with the dependent variable (p < 0.001). On multivariate logistic regression analysis, older age (OR 1.035; 95% CI 1.006-1.070; p = 0.02) was found to be significantly associated with developing a postoperative infectious complication.

CONCLUSIONS

A 7.3% rate of postoperative infectious complications and 1.5% urosepsis rate were observed after therapeutic ureterorenoscopy, without the need of intensive care admission. The only significant risk factors were preoperative stent type (JFil® pigtail suture stent) on univariate analysis, and older age on multivariate logistic regression analysis. Further multicentric prospective observational data are needed in this field.

Comparison of safety and efficacy of tubeless vs. conventional mini percutaneous nephrolithotomy in patients with Escherichia coli bacteriuria

To evaluate the safety and efficacy of tubeless percutaneous nephrolithotomy (PCNL) in patients with Escherichia coli (E. coli) bacteriuria. We conducted a retrospective review of 84 patients with E. coli bacteriuria who underwent PCNL. Patients were divided into two groups according to whether a nephrostomy tube is placed at the end of the procedure. Preoperative clinical data, surgical outcomes, and postoperative complications were compared. Then, regression analysis of factors predicting success rate of PCNL in patients with E. coli bacteriuria was performed. After PCNL, residual fragments ≤ 4 mm were considered as success. At baseline, the two groups were similar with regard to age, gender, BMI, underlying disease, hydronephrosis, stone characteristics, and urinalysis. Postoperative fever occurred in 1 patient (3.8%) in the tubeless PCNL group, and in 5 patients (8.6%) in the conventional PCNL group (p > 0.05). There were no significant differences in terms of successful rate, decrease in hemoglobin, pain scores, blood transfusion, and hospitalization expenses. However, the tubeless PCNL group had significantly shorter operative time (60 vs. 70 min, p = 0.033), indwelling time of catheter (2 vs. 4 days, p < 0.001), and hospital stays (3 vs. 5 days, p < 0.001) than the conventional PCNL group. In the analysis of factors predicting success, the stone diameter, stone burden, and operative time were associated with success rate of PCNL. It is safe and effective to perform tubeless PCNL in patients with E. coli bacteriuria. Compared to conventional PCNL, tubeless PCNL accelerates patient recovery and shortens hospital stays.

Area of hydronephrosis is a useful predictive factor of impacted ureteral stones

Ureteroscopic lithotripsy for impacted stones is challenging, but it is important to predict impacted stones preoperatively. Hydronephrosis, which is evaluated by a grading system, is often apparent in impacted stones. However, the currently used grading system is a qualitative evaluation. We, therefore, focused on a quantitative evaluation: the area of hydronephrosis. The aim of this study was to investigate whether the area of hydronephrosis could predict impacted stones more accurately than Society for Fetal Urology grade. We retrospectively identified 160 patients who underwent ureteroscopic lithotripsy for ureteral stones at our hospital between January 2014 and April 2022. Impacted stones were defined as stones fixed to the ureteral wall that could not be moved by means of ureteroscopic manipulation or water pressure. Of the 160 patients, 54 (33.8%) had impacted stones. Comparing patient characteristics, there were significant differences in stone size, ureteral wall thickness, Society for Fetal Urology grade, renal pelvic width and area of hydronephrosis (all P < 0.01). Receiver operating characteristic analysis showed that area of hydronephrosis was the more significant predictive value (area under the curve 0.781) compared with Society for Fetal Urology grade (area under the curve 0.676, P < 0.01). Multivariate analysis revealed that significant independent predictive factors of impacted stones were thicker ureteral wall thickness and larger area of hydronephrosis (both P < 0.01). The area of hydronephrosis and ureteral wall thickness were significant predictors of impacted stones in patients undergoing ureteroscopic lithotripsy for ureteral stones. These factors may be useful for selecting the treatment and preoperative settings.

A machine learning algorithm predicting risk of dilating VUR among infants with hydronephrosis using UTD classification

BACKGROUNDS

Urinary Tract Dilation (UTD) classification has been designed to be a more objective grading system to evaluate antenatal and post-natal UTD. Due to unclear association between UTD classifications to specific anomalies such as vesico-ureteral reflux (VUR), management recommendations tend to be subjective.

OBJECTIVE

We sought to develop a model to reliably predict VUR from early post-natal ultrasound.

STUDY DESIGN

Radiology records from single institution were reviewed to identify infants aged 0-90 days undergoing early ultrasound for antenatal UTD. Medical records were reviewed to confirm diagnosis of VUR. Primary outcome defined as dilating (≥Gr3) VUR. Exclusion criteria include major congenital urologic anomalies (bilateral renal agenesis, horseshoe kidney, cross fused ectopia, exstrophy) as well as patients without VCUG. Data were split into training/testing sets by 4:1 ratio. Machine learning (ML) algorithm hyperparameters were tuned by the validation set.

RESULTS

In total, 280 patients (540 renal units) were included in the study (73 % male). Median (IQR) age at ultrasound was 27 (18-38) days. 66 renal units were found to have ≥ grade 3 VUR. The final model included gender, ureteral dilation, parenchymal appearance, parenchymal thickness, central calyceal dilation. The model predicted VUR with AUC at 0.81(0.73-0.88) on out-of-sample testing data. Model is shown in the figure.

DISCUSSION

We developed a ML model that can predict dilating VUR among patients with hydronephrosis in early ultrasound. The study is limited by the retrospective and single institutional nature of data source. This is one of the first studies demonstrating high performance for future diagnosis prediction in early hydronephrosis cohort.

CONCLUSIONS

By predicting dilating VUR, our predictive model using machine learning algorithm provides promising performance to facilitate individualized management of children with prenatal hydronephrosis, and identify those most likely to benefit from VCUG. This would allow more selective use of this test, increasing the yield while also minimizing overutilization.

Utility of F-15 diuretic MAG3 renography in assessment of paediatric hydronephrosis

INTRODUCTION

Diuretic renography is crucial in evaluation of paediatric hydronephrosis. Furosemide is conventionally given 15-20 min after radiolabelled tracer (F+15/F+20 protocol), however this is equivocal in around 15% of patients. Giving furosemide 15 min prior to tracer (F-15 MAG3 protocol) has been suggested as an additional tool in the investigation of patients with suspected upper urinary tract obstruction. However, the role of this method in assessment and management of paediatric hydronephrosis is not widely reported.

OBJECTIVE

To investigate utility of F-15 renograms in children with hydronephrosis being assessed for Pelvi-Ureteric Junction Obstruction (PUJO).

STUDY DESIGN

Retrospective review of patients <16 years old undergoing F-15 MAG3 renogram between 2018 and 2021 in our tertiary paediatric surgical centre. Data collected included patient demographics, mode of presentation, investigations, management and outcomes.

RESULTS

Eighteen patients were included. Median age at F-15 renogram was 7.3 years. Eleven patients presented with antenatal hydronephrosis, 5 with symptoms in childhood and 2 with incidental hydronephrosis on trauma imaging. Fourteen patients were symptomatic. Ten had a prior non-obstructed F+20 renogram but persisting symptoms suggestive of PUJO. Seven had previous equivocal F+20 renograms. One symptomatic patient directly underwent an F-15 renogram. A conclusive result was obtained in 16/18 (89%); 11 patients had obstructed curves and 5 non-obstructed. Two asymptomatic patients' scans were inconclusive. All symptomatic patients had conclusive scans. Of 11 patients with an obstructed F-15, 9 have undergone pyeloplasty to date. All have had post-operative resolution in symptoms and static or improved post-operative ultrasound. One patient with an inconclusive scan underwent pyeloplasty due to persisting hydronephrosis and parent preference. Three patients with non-obstructed F-15 renograms have been discharged. One symptomatic patient with a non-obstructive F-15 had a ureteric stent inserted due to persistent flank pain; 1 continues under surveillance.

DISCUSSION

It is known that conventional F+20 MAG3 renograms can give equivocal results. Published experience suggests that F-15 renograms are conclusive in the majority of patients. Routine primary use is, however, discouraged as they can 'over diagnose' obstruction and limit the study of tracer transit under physiological flow rates. This study indicates that the F-15 renogram is a useful adjunct in the assessment of patients with symptoms suggestive of PUJO who have previously had an equivocal or a non-obstructed F+20 renogram.

CONCLUSION

F-15 renogram was conclusive in 89% of patients. We recommend using F-15 renograms to aid surgical decision-making in children with equivocal F+20 renograms, especially in the presence of symptoms.

Diagnostic Accuracy of Point-of-Care Gram Stains in Obstructive Pyelonephritis due to Ureteral Stones

Background

The diagnostic utility of point-of-care (POC) Gram stains for obstructive pyelonephritis with hydronephrosis is not well established. The current study aimed to assess the diagnostic accuracy of urine Gram stains in patients with obstructive pyelonephritis due to ureteral stones.

Methods

A retrospective observational study was conducted on patients with obstructive pyelonephritis admitted to our hospital between January 2011 and December 2021. The diagnostic accuracy of Gram stains was evaluated based on the severity of hydronephrosis, including Gram stains performed by both trained physicians and microbiological technicians.

Results

After analyzing 210 patients, POC Gram stains of bladder urine presented a sensitivity, specificity, positive predictive value, and negative predictive value of 86.8%, 81.8%, 93.7%, and 66.7%, respectively, for gram-negative rods and 65.7%, 83.4%, 48.9%, and 91.0%, respectively, for gram-positive cocci. The agreement between POC Gram stains and urine culture was good for gram-negative rods, with a kappa (κ) coefficient of 0.637 and agreement rate of 85.6%, and moderate for gram-positive cocci, with a κ coefficient of 0.435 and agreement rate of 80%. The agreement between POC Gram stains and bladder urine culture results for gram-negative rods was higher in the mild hydronephrosis group (κ coefficient = 0.677) than in the severe hydronephrosis group (κ coefficient = 0.466). Discrepancies in Gram stain results between physicians and technicians were observed in 21 of 180 cases (11.7%).

Conclusions

POC Gram stains for gram-negative rods may be a useful diagnostic tool for obstructive pyelonephritis, particularly in cases of mild hydronephrosis.

Is the Mayo Adhesive Probability Score Predictive in Patients Undergoing Percutaneous Nephrolithotomy?

Introduction: Mayo Adhesive Probability (MAP) score was developed as a means to predict the presence of adherent perinephric fat. Our aim was to determine the predictive value of the MAP score on surgical outcomes in patients undergoing standard adult percutaneous nephrolithotomy (PCNL). Materials and Methods: We retrospectively analyzed the data from 130 renal units that underwent PCNL between January 2022 and 2023. MAP scores 0-2 were classified as low, whereas MAP scores 3-5 were classified as high. The impact of the MAP score on perioperative and postoperative outcomes was studied. All statistical analyses were performed using SPSS 24.0 for Windows. Results: The median age of the patients at the time of surgery was 48 (21) years, with a female-to-male ratio of 1:1.82. The median MAP score was 2 (2), with 43.8% of patients falling into the high MAP score group. Advanced age, hypertension history, low estimated glomerular filtration rate (eGFR) levels, and low renal parenchymal thickness were significantly higher in the high MAP score group (P = .010, P = .004, P = .001, and P = .005, respectively). Female patients had a significantly higher MAP score of 0 (P = .021). Operation time, postoperative hematocrit decrease, blood transfusion rate, postoperative fever rate, hospitalization, and stone-free rates were comparable between the low and high MAP score groups (P = .535, P = .209, P = .313, P = .289, P = .281, and P = .264, respectively). Gender and eGFR levels were shown to be significant predictors of a MAP ≥3 (P = .004 and P = .003, respectively). Conclusion: The present study showed that the MAP score groups had similar perioperative and postoperative results. Low eGFR levels and the male gender were associated with MAP score ≥3. To determine the predictive MAP score value for PCNL outcomes, more prospective studies are needed.

A narrative review on the application of artificial intelligence in renal ultrasound

Kidney disease is a serious public health problem and various kidney diseases could progress to end-stage renal disease. The many complications of end-stage renal disease. have a significant impact on the physical and mental health of patients. Ultrasound can be the test of choice for evaluating the kidney and perirenal tissue as it is real-time, available and non-radioactive. To overcome substantial interobserver variability in renal ultrasound interpretation, artificial intelligence (AI) has the potential to be a new method to help radiologists make clinical decisions. This review introduces the applications of AI in renal ultrasound, including automatic segmentation of the kidney, measurement of the renal volume, prediction of the kidney function, diagnosis of the kidney diseases. The advantages and disadvantages of the applications will also be presented clinicians to conduct research. Additionally, the challenges and future perspectives of AI are discussed.

Stratifying Antenatal Hydronephrosis: Predicting High-Grade VUR Using Ultrasound and Scintigraphy

(1) Background: Antenatal hydronephrosis (AHN), detected in approximately one percent of prenatal ultrasounds, is caused by vesicoureteral reflux (VUR) in 15-21% of cases, a condition with significant risks such as urinary tract infections and renal scarring. Our study addresses the diagnostic challenges of VUR in AHN. Utilizing renal ultrasonography and scintigraphy, we developed a novel scoring system that accurately predicts high-grade VUR, optimizing diagnostic precision while minimizing the need for more invasive methods like voiding cystourethrogram (VCUG); (2) Methods: This retrospective study re-analyzed renal ultrasonography, scintigraphy, and VCUG images from infants admitted between 2003 and 2013, excluding cases with complex urinary anomalies; (3) Results: Our analysis included 124 patients (75% male), of whom 11% had high-grade VUR. The multivariate analysis identified visible ureter, reduced renal length, and decreased differential renal function (DRF) as primary predictors. Consequently, we established a three-tier risk score, classifying patients into low, intermediate, and high-risk groups for high-grade VUR, with corresponding prevalences of 2.3%, 22.2%, and 75.0%. The scoring system demonstrated 86% sensitivity and 79% specificity; (4) Conclusions: Our scoring system, focusing on objective parameters of the visible ureter, renal length, and DRF, effectively identifies high-grade VUR in AHN patients. This method enhances diagnostics in ANH by reducing reliance on VCUG and facilitating more tailored and less invasive patient care.

Predictors of surgical intervention for antenatally detected ureteropelvic junction obstruction (UPJO): A prospective multivariate analysis

OBJECTIVE

We aimed to identify clinical and radiological predictors of the need for surgical intervention in infants with antenatally detected UPJO.

MATERIAL AND METHODS

We prospectively followed infants born with antenatally diagnosed ureteropelvic junction obstruction (UPJO) presented at our outpatient clinics for evidence of obstructive injury with a standard protocol with ultrasonography and renal scintigraphy. Indications for surgery included progression of hydronephrosis on serial examinations, initial differential renal function (DFR) ⩽35% or >5% loss in sequential studies, and febrile urinary tract infection (UTI). Univariate and multivariate analyses were utilized to define the predictors for surgical intervention, while the appropriate cut-off value of the initial Anteroposterior diameter (APD) was determined using the receiver operator curve analysis.

RESULTS

Univariate analysis revealed a significant association between surgery, the initial APD, cortical thickness, Society for Fetal Urology grade, UTD risk group, initial DRF, and febrile UTI (p-value < 0.05). No significant association between surgery and sex or side of the affected kidney (p-value 0.91 and 0.38, respectively). On multivariate analysis, the initial APD, initial DRF, obstructed renographic curve, and febrile UTI (p-value < 0.05) were the only independent predictors for surgical intervention. An initial APD of 23 mm can predict surgical requirement, with a specificity of 95% and sensitivity of 70%.

CONCLUSION

For antenatally diagnosed UPJO, the APD value (at the age of 1 week), DFR value (at the age of 6-8 weeks), and febrile UTI during follow-up are significant and independent predictors of the need for surgical intervention. APD, when used with a cut-off value of 23 mm, is associated with high specificity and sensitivity for predicting surgical need.

The urological evaluation and management of neurogenic bladder in children and adolescents-what every pediatric nephrologist needs to know

Neurogenic bladder (NGB) is an encompassing term that includes multiple causes of bladder dysfunction linked to a congenital or acquired neurological condition that adversely impacts the innervation of the lower urinary tract. Multiple static or progressive conditions can be associated with NGB in pediatric and adolescent patients. Currently, spinal dysraphism (i.e., spina bifida) is one of the most common etiologies, which occurs in 3-4 per 10,000 live births in developed nations. Abnormal bladder dynamics can lead to kidney damage secondary to high pressures or recurrent infections, as well as urinary incontinence. The current management paradigm centers on a proactive approach to preserving kidney function and achieving continence through behavioral, pharmacological, and surgical means. This educational review highlights the key components of urological management to maximize collaboration with pediatric nephrologists.

Fetal urinary tract dilation: What to tell the parents

Urinary tract dilation (UTD), which refers to the abnormal dilation of the urinary collection system, is the most common finding on prenatal ultrasound and presents with varying severity, presentation, etiology, and prognosis. Prenatal classification and risk stratification aim to prevent postnatal complications, such as urinary tract infections and further kidney dysfunction. Parents expecting a child with UTD should be counseled by a multidisciplinary team consisting of maternal-fetal medicine specialists, and pediatric urology and nephrology providers. This review summarizes the key points in the diagnostic evaluation and management during the prenatal and initial postnatal period, focusing on the information that should be provided to future parents. We address frequently asked parental questions and concerns that our multidisciplinary clinical practice faces.

Voiding Cystourethrogram Before Pyeloplasty: To Do or Not To Do?

OBJECTIVE

To assess the incidence of concomitant vesicoureteral reflux (VUR) in unilateral cases of ureteropelvic junction obstruction (UPJO) and to identify factors that predict VUR.

METHODS

Files of 381 pediatric patients who underwent unilateral pyeloplasty between 2000 and 2017 were retrospectively reviewed. A total of 270 patients with available data and ≥5 years of follow-up were eligible for this study. Demographic parameters, preoperative hydronephrosis grade, renal pelvis anteroposterior diameter (APD), renal parenchymal thickness (PT), split renal functions on MAG-3 scan and VUR status were noted. The patients were divided into two groups: those with concomitant VUR (group I, n: 24, 8.9%) and those without VUR (group II, n: 246, 91.1%).

RESULTS

Among 270 patients (205 boys, 75.9%) with a median age of 4 months (2-98), 197 (72.9%) had antenatal hydronephrosis. Median follow-up was 11 years (5-22). Among 24 patients with concurrent VUR, 6 (25%) had grade II VUR, whereas grade III-V VUR was detected in 18 (75%). Of these, 12 (50%) had ipsilateral VUR, 3 (12.5%) had contralateral, and 9 (37.5%) had bilateral VUR. In a median 137-month follow-up, spontaneous VUR resolution was observed in 6 (25%) patients, whereas 15 (62.5%) patients underwent endoscopic subureteral injection and 3 (12.5%) patients ureteroneocystostomy, respectively. Preoperative APD [35.5, (Inter Quantile Range) IQR (27.6-36.0) vs 26.5 IQR (25.0-35.0), P = .004] were significantly higher in group I, whereas group I had significantly lower PT [3.7, IQR (3.4-6.4) vs 5.8 IQR (4.4-6.1), P = .026]. Predictive factors for concomitant VUR were presentation with febrile UTI (odds ratio (OR): 2.769, P = .048), PT <3.95 mm (OR: 1.367, P = .043), and APD >28.8 mm (OR: 1.035, P = .001).

CONCLUSION

Our results indicated that concomitant VUR and UPJO might be detected in 1 out of every 11 patients undergoing pyeloplasty, while some type of surgical intervention for VUR was required in 75% of these patients. Thus, voiding cystourethrogram prior to pyeloplasty may be limited in those presenting with febrile urinary tract infection, having higher APD and lower PT on preoperative urinary ultrasonography.

The Toronto nomogram: A Bayesian meta-regression derived prenatal ultrasound index to predict lower urinary tract obstruction and prune belly syndrome

INTRODUCTION

A nomogram for predicting the diagnosis of lower urinary tract obstruction (LUTO) based on an antenatal ultrasound index generated from a Bayesian Meta-regression analysis has been in development and noted with superior diagnostic accuracy compared to the keyhole sign (KHS). We aim to assess the accuracy of the nomogram in expanded diagnostic utilization to predict LUTO.

METHODOLOGY

The validation of the nomogram for expanded diagnostic utilization was based on data from a prospective institutional antenatal clinic database between January 2020 and June 2022. Diagnostic accuracy indices were determined for confirmed postnatal diagnosis of LUTO or prune belly syndrome (PBS). Receiver operating characteristics (ROC) curves were generated to compare the area under the curve (AUC) of the nomogram versus KHS.

RESULTS

Based on 84 male fetuses with antenatal ultrasound of moderate-severe hydronephrosis (PUV n = 15, PBS n = 4), the KHS had 26.3% (95%CI 9.1-51.2) sensitivity and 100% (95%CI 94.4%-100%) specificity, with 14 false-negatives. The nomogram showed a 84.2 (95%CI 60.4%-96.6%) sensitivity and 95.4 (95%CI 87.1%-99%) specificity with three false-positives. The nomogram also had a superior AUC compared to KHS (0.98 vs. 0.63).

CONCLUSION

The nomogram can be used as a valuable tool to trigger further postnatal screening and provide individualized risk assessments to families during prenatal counseling.

The role of circumcision in preventing urinary tract infections in children with antenatal hydronephrosis: Systematic review and meta-analysis

INTRODUCTION

Circumcision has been reported to reduce the risk of urinary tract infections (UTIs) in boys with antenatal hydronephrosis (HN). Our aim was to compare the incidence of UTIs in circumcised vs. uncircumcised boys with antenatal HN by conducting a systematic review and meta-analysis.

STUDY DESIGN

A comprehensive search was performed until December 2022. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed measures included: UTIs, continuous antibiotic prophylaxis (CAP) use, renal outcomes, and circumcision complications. Odds ratios (OR) and mean difference with 95% confidence interval (CI) were extrapolated from available data. Random-effects meta-analysis were performed.

RESULTS

Twenty-three studies describing 9093 boys with antenatal HN were identified, including 4677 uncircumcised and 4416 circumcised boys. Overall effect estimates demonstrate that circumcised boys have significantly reduced odds of developing any UTI [OR 0.26, 95%CI 0.21, 0.32; p < 0.001]]. In addition, there a significantly reduced odds of developing UTI when circumcised and on CAP [OR 0.19, 95% CI 0.13, 0.30; p < 0.001]. When stratifying by etiology, circumcision reduced the odds of UTI in boys with isolated HN [OR 0.33, 95% CI 0.16, 0.68; p = 0.003], vesicoureteral reflux [OR 0.23, 95% CI 0.13, 0.42; P < 0.00001], or with posterior urethral valves [OR 0.29, 95% CI 0.13, 0.64; p = 0.002].

DISCUSSION

Circumcision reduces the incidence of UTIs in boys with antenatal HN. This review is limited by the varied definitions of UTIs and inconsistent reporting on HN etiology, renal outcomes, and circumcision complications.

CONCLUSIONS

Circumcision should be considered in boys with antenatal HN to prevent the risk of developing UTI. Further research is warranted to individualize the prophylactic role of circumcision for patients with HN.

Determination of tissue tracer transit of Technetium-99m-mercaptoacetyltriglycine diuretic renography in infants with suspected ureteropelvic junction obstruction - A multicenter prospective observational study

INTRODUCTION

There is an ongoing controversy regarding management of ureteropelvic junction obstruction in infants, with a shift towards a non-operative approach. However, precise predictors of outcome are lacking. Recent studies postulated a high prognostic value of Technetium-99m-mercaptoacetyltriglycine tissue tracer transit with regard to the development of an impaired differential renal function and its potential improvement following pyeloplasty.

OBJECTIVE

To evaluate the prognostic value of Technetium-99m-mercaptoacetyltriglycine tissue tracer transit for the occurrence of changes in differential renal function in infants with suspected unilateral ureteropelvic junction obstruction in a prospective observational multicenter study.

STUDY DESIGN

Infants below 3 months of age with a unilateral isolated hydronephrosis ≥ grade 3 received ultrasound and Technetium-99m-mercaptoacetyltriglycine diuretic renography at two different time points (timepoint 1 and timepoint 2). Data were analyzed at local centers and at the study center and were collected in an internet-based database system. Tissue tracer transit was determined for each diuretic renography, inter-observer variation for tissue tracer transit and standard parameters for judgement of differential renal function development were assessed.

RESULTS

Thirty-seven patients were analyzed. Median age was 11 weeks (7-15) at timepoint 1 and 26 weeks (19-33) at timepoint 2. A delayed tissue tracer transit at timepoint 1 was not associated with deterioration of differential renal function at timepoint 2 in both, locally (10/37 cases) and centrally (4/37) analyzed cases. However, sensitivity and specificity were poor. The intraclass correlation coefficient comparing local and central findings of tissue tracer transit and renal drainage demonstrated poor or fair agreement. Analysis of standard parameters for differential renal function development revealed a prognostic value only for the dichotomized anteroposterior renal pelvic diameter (APD, p = 0.03, 95%-CI 1.2-22.2).

DISCUSSION

Regarding the primary endpoint of our study, we could not confirm the hypothesis that delayed tissue tracer transit reliably predicts a subsequent decline in differential renal function in the cohort of patients studied. Whether the low age of the patients, technical problems in the correct assessment of tissue tracer transit by the investigator in early infancy, the study design, or the parameter itself played a role is debated.

CONCLUSION

In the presented setting tissue tracer transit was not useful as a predictive parameter for deterioration of differential renal function in infants with suspected unilateral ureteropelvic junction obstruction. Sensitivity and specificity of tissue tracer transit were not sufficient for risk stratification. Improved utility of tissue tracer transit as a marker might be achieved using a different study setting.

What is the safe and effective dilator number during access in PCNL? Three-shot dilation versus classical sequential Amplatz dilation

BACKGROUND

Although PCNL has been used for a long time to treat nephrolithiasis, there is still contradictory information concerning the use of the dilation method. In this study, we aimed to compare conventional sequential Amplatz dilatation (SAD) using ten dilators and a method using three dilators (12, 20, and 30 Fr), which we named "three-shot dilatation" (3SD), in terms of fluoroscopy time (FT), operation time, bleeding and stone-free rates.

METHODS

The study included patients who underwent PCNL with the SAD and 3SD methods. A different surgeon with extensive endourology experience applied each technique. One of the surgeons operated on the patients using the SAD method with ten dilators, and the other surgeon performed the operations using the 3SD method involving three Amplatz dilators (12, 20, and 30 Fr).

RESULTS

A total of 283 patients, 138 in the 3SD group and 145 in the SAD group, were included in the study. The mean age of the patients was 47.32 ± 13.71 years. There was no statistically significant difference between the two groups regarding preoperative characteristics (p > 0.05). The FTs of access 2, total access, and total operation were significantly shorter in the 3SD group (p = 0.0001). The decrease in hemoglobin was statistically significant in the 3SD group compared to the SAD group (p = 0.022), while the blood transfusion requirements of the groups were similar (p = 0.176). There was no statistically significant difference between the two groups regarding stone-free rates (p = 0.973). In four patients in the SAD group, re-access was necessary due to the loss of passage due to the guide wire slipping out of its place.

CONCLUSION

Intraoperative FT can be shortened using the described 3SD method without compromising surgical safety. However, this method can be used as an intermediate step in the transition to one-shot dilation by surgeons experienced in performing SAD.

Our experience of operated pediatric ureteropelvic junction obstruction patients

AIMS

Ureteropelvic junction obstruction (UPJO) may originate from extrinsic or intrinsic causes in children. The aim of this study is to present preoperative and postoperative data of our patients operated for UPJO.

METHODS

A total of 64 patients who underwent open pyeloplasty were investigated retrospectively. They were evaluated in terms of demographically, clinics, hydronephrosis, differential renal functions (DRFs), half-time tracer clearance (½TC), and histopathologic results. Patients' numerical results were stated as mean ± standard deviation (SD).

RESULTS

Male gender was more prevalent (n = 47, 73.4%) and mean age at surgery was 46.87 months. UPJO was located at the left side in 56.3% (n = 36), and at the right side in 39.1% (n = 25) of patients. It was bilateral in 4.7% (n = 3). Hydronephrosis was found antenatally in 68.8% (n = 44) of patients. The mean preoperative DRF was 49.7% (21-78%) and mean postoperative DRF was 49.2% (20-56%). Mean renal scintigraphic t1/2 was >20 min for all patients. The mean AP diameter was 21.58 mm (10-62 mm). Muscular hypertrophy was the most common pathological finding, mean length of excised segment was 10.26 mm (3-40 mm). Crossing vessel (CV) was detected in 17.18% (n = 11). The CV was statistically associated with increased age of operation, left side, and female gender. Statistically significant hydronephrosis was found in non-CV patients. Re-operation was required in seven patients (7.8%).

CONCLUSIONS

Intrinsic pathologies are more seen in the etiology of UPJO patients with antenatal diagnosis and this group needs operation at an earlier age. However, CV is found more commonly in patients who are diagnosed and operated at older ages.

Pilot study of machine learning in the task of distinguishing high and low-grade pediatric hydronephrosis on ultrasound

PURPOSE

Hydronephrosis is a common pediatric urological condition, characterized by dilation of the renal collecting system. Accurate identification of the severity of hydronephrosis is crucial in clinical management, as high-grade hydronephrosis can cause significant damage to the kidney. In this pilot study, we demonstrate the feasibility of machine learning in differentiating between high and low-grade hydronephrosis in pediatric patients.

MATERIALS AND METHODS

We retrospectively reviewed 592 images from 90 unique patients ages 0-8 years diagnosed with hydronephrosis at the University of Chicago's Pediatric Urology Clinic. The study included 74 high-grade hydronephrosis (145 images) and 227 low-grade hydronephrosis (447 images). Patients were excluded if they had less than 2 studies prior to surgical intervention or had structural abnormalities. We developed a radiomic-based artificial intelligence algorithm incorporating computerized texture analysis and machine learning (support-vector machine) to yield a predictor of hydronephrosis grade.

RESULTS

Receiver operating characteristic analysis of the classifier output yielded an area under the curve value of 0.86 (95% CI 0.81-0.92) in the task of distinguishing between low and high-grade hydronephrosis using a five-fold cross-validation by kidney. In addition, a Mann-Kendall trend test between computer output and clinical hydronephrosis grade yielded a statistically significant upward trend (p<0.001).

CONCLUSIONS

Our findings demonstrate the potential of machine learning in the differentiation between low and high-grade hydronephrosis. Further studies are warranted to validate our findings and their generalizability for use in clinical practice as a means to predict clinical outcomes and the resolution of hydronephrosis.

Non-surgical management in children with non-refluxing primary megaureter: a systematic review and meta-analysis

BACKGROUND

Children with non-refluxing primary megaureter are mostly managed by a watchful approach with close follow-up and serial imaging.

OBJECTIVES

This systematic review and meta-analysis aimed to determine whether there is sufficient evidence to support the current non-surgical management strategy in these patients.

DATA SOURCES

A comprehensive search including electronic literature databases, clinical trial registries, and conference proceedings was performed.

DATA SYNTHESIS METHODS

Outcomes were estimated as pooled prevalence. If meta-analytical calculations were not appropriate, outcomes were provided in a descriptive manner.

RESULTS

Data from 8 studies (290 patients/354 renal units) were included. For the primary outcome, differential renal function estimated by functional imaging, meta-analysis was impossible due to reported data not being precise. Pooled prevalence for secondary surgery was 13% (95% confidence interval: 8-19%) and for resolution 61% (95% confidence interval: 42-78%). The risk of bias was moderate or high in most studies.

LIMITATIONS

This analysis was limited by the low number of eligible studies with few participants and high clinical heterogeneity, and the poor quality of the available data.

CONCLUSIONS

The low pooled prevalence of secondary surgical intervention and high pooled prevalence of resolution may support the current non-surgical management in children with non-refluxing primary megaureter. However, these results should be interpreted cautiously due to the limited available body of evidence. Future studies should overcome existing limitations of imaging methods by using standardized, comparable criteria and report outcome parameters in a quantitative manner. This would allow more sufficient data synthesis to provide evidence-based recommendations for clinical decision-making and counseling.

SYSTEMATIC REVIEW REGISTRATION

The protocol was registered on PROSPERO under CRD42019134502.

[Report template from the German Society of Urology and the German Radiological Society for standardized, structured reporting of native computed tomography scans in the diagnosis of urinary stones]

Standardized structured radiological reporting (SSRB) has been promoted in recent years. The aims of SSRB include that reports be complete, clear, understandable, and stringent. Repetitions or superfluous content should be avoided. In addition, there are advantages in the presentation of chronological sequences, tracking and correlations with structured findings from other disciplines and also the use of artificial intelligence (AI)-based methods. The development of the presented template for SSRB of native computed tomography for urinary stones followed the "process for the creation of quality-assured and consensus-based report templates as well as subsequent continuous quality control and updating" proposed by the German Radiological Society (DRG). This includes several stages of drafts, consensus meetings and further developments. The final version was published on the DRG website ( www.befundung.drg.de ). The template will be checked annually by the steering group and adjusted as necessary. The template contains 6 organ domains (e.g., right kidney) for which entries can be made for a total of 21 different items, mostly with selection windows. If "no evidence of stones" is selected for an organ in the first query, the query automatically jumps to the next organ, so that the processing can be processed very quickly despite the potentially high total number of individual queries for all organs. The German, European, and North American Radiological Societies perceive the establishment of a standardized structured diagnosis of tomographic imaging methods not only in oncological radiology as one of the current central tasks. With the present template for the description of computed tomographic findings for urinary stone diagnostics, we are presenting the first version of a urological template. Further templates for urological diseases are to follow.

Antenatally detected urinary tract dilatation: long-term outcome

This review provides updated knowledge on the long-term outcomes among children with antenatally diagnosed urinary tract dilatation (UTD), previously often referred to as antenatal hydronephrosis. Different definitions of UTD exist, which makes comparison between studies and generalized conclusions difficult. Roughly, one-third of antenatally diagnosed UTD, defined as a renal pelvis anterior posterior diameter (APD) of ≥ 4 mm in the second trimester and/or ≥ 7 mm in the third trimester, will resolve before birth, another third will resolve within the first years of life, and in the remaining cases, UTD will persist or a congenital abnormality (CAKUT) will be diagnosed postnatally. The risk of a postnatal CAKUT diagnosis increases with the degree of prenatal and postnatal dilatation, except for vesicoureteral reflux (VUR), which cannot be predicted from the degree of UTD. Urinary tract infections (UTIs) occur in 7-14% of children with UTD during the first years of life. The risk of UTI is higher in children with traditional risk factors for UTI, such as dilated VUR, hydroureteronephrosis, female gender, and intact foreskin. Continuous antibiotic prophylaxis may be considered in selected patients during the first years of life. In long-term follow-ups, permanent kidney damage is diagnosed in approximately 40% of children with moderate or severe UTD, but hypertension, proteinuria, and/or reduced eGFR are uncommon (0-5%). In children with mild UTD, the long-term outcome is excellent, and these children should not be subjected to unnecessary examinations and/or follow-up.

Primary repair vs Delayed staged repair in infants with primary obstructive megaureters and their long term outcomes - A single centre experience

BACKGROUND

There is paucity of literature in the management of infants with primary obstructive megaureters undergoing upfront primary repair with an extravesical technique of ureteral re implantation (with or without ureteral tailoring).

OBJECTIVE

To compare 2 different approaches in the management of infants with unilateral primary obstructive megaureters.

STUDY DESIGN

This was a retrospective analysis of a prospectively maintained data base between 2005 and 2021. Infants <1 year with unilateral primary obstructive megaureter were included. They were divided into 2 groups: those who underwent an upfront extravesical ureteric reimplantation with or without ureteral tailoring during infancy -Primary Repair (PR), and those who initially underwent a low end cutaneous ureterostomy during infancy followed by take down of ureterostomy and intravesical ureteric reimplantation after 1 year of age -Delayed staged repair (DSR). Children presenting with sepsis, in whom a diversion was imperative, were excluded. All children were followed up annually after their definitive repair with a renal ultrasound, diuretic renogram, estimated glomerular filtration rate and assessment of voiding dysfunction if present. The 1st year and 3rd year follow up details were collated and analysed. Failure was defined as persistent obstructive pattern on renogram with worsening differential renal function or presence of high grade reflux with recurrent breakthrough urinary tract infection; both of which necessitated a redo reimplantation following the definitive surgery.

RESULTS

There were 18 infants in Primary repair and 16 infants in Delayed Staged Repair. Urinary tract infections was the commonest presenting symptom amongst both groups i.e. > 50%.The post operative complication rate was 11% in Primary repair and 31% in Delayed Staged Repair. One child in each of the groups (2 girls) required redo reimplantation (5.8%). At the end of the 3rd year follow up (from the definitive repair) there was significant reduction in the hydronephrosis, improvement in the differential renal function with no evidence of obstruction and improvement in the estimated glomerular filtration rate amongst all in both groups which was statistically significant i.e. p < 0.05. The success rate was 94.4% in Primary Repair and 93.75% in Delayed Staged Repair. The mean follow up was 9.7 years amongst those undergone Primary Repair and 9 years amongst those undergone Delayed Staged Repair.

DISCUSSION AND CONCLUSION

Primary extravesical ureteral reimplantation may be considered as the preferred line of management of unilateral obstructed megaureters during infancy.

The application of artificial technology in pediatric pyeloplasty the efficacy analysis of robotic-assisted laparoscopic pyeloplasty in the treatment of ureteropelvic junction obstruction

Objective

To investigate the clinical effect of the da Vinci robotic-assisted laparoscopic pyeloureteroplasty (RALP) in treating pediatric ureteropelvic junction obstruction (UPJO).

Methods

We retrospectively analyzed clinical data from 32 children with UPJO who suffered from RALP in our hospital from October 2020 to February 2023, compared with those treated with common laparoscopy at the same time. After the establishment of the robotic arm, a mesenteric approach was performed after entering the abdominal cavity to focus on the lesion site. The dilated renal pelvis was then cut and the stenotic ureter was removed; the anastomosis and the incision were sutured by layer.

Results

A total of 62 children (44 boys and 20 girls) with a median age of 14 months (ranging from 3 to 38 months) were included. All 62 cases had hydronephrosis caused by unilateral UPJO, and the surgery was successfully completed without conversion to open. All intraoperative blood losses amounted to less than 10 ml. In the RALP group, the average operative duration was 131.28 min (ranging from 108 to 180 min). The average catheter time was 3.66 days (ranging from 2 to 7 days). The average hematuria time was 3.84 days (ranging from 2 to 6 days). The average postoperative hospital stay was 7.8 days (ranging from 6 to 12 days). The average hospitalization costs were 59,048.31 yuan (ranging from 50,484 to 69,977 yuan). The double-J tube was removed 1 month after surgery. Only one patient suffered from complications, developing a urinary tract infection 4 weeks after surgery, and was cured with the administration of oral cefaclor anti-inflammatory drugs for 3 days. All patients were followed up for 2-28 months, with a median follow-up time of 12 months. The thickness of the renal cortex was increased after surgery [(1.95 ± 0.24) vs. (4.82 ± 0.50)] cm, and the isotope renograms revealed a definite recovery of the split renal function [(28.32 ± 1.95) vs. (37.01 ± 2.71)]%.

Conclusion

The robotic-assisted laparoscopic pyeloureteroplasty (RALP) in the treatment of children with upper ureteral obstruction has overall clinical efficiency. With technological advancements and an increased number of experienced surgeons, robotic surgery may become a new trend in surgery.

Posterior urethral valve in thai boys

BACKGROUND

Posterior urethral valve (PUV) is the most common congenital bladder outlet obstruction in boys, causing renal damage beginning in utero. There are scarce data from Thailand regarding the long-term outcomes of PUV in boys, thus the aim of this study was to examine the presentation, clinical course, complications, outcomes and renal survival in PUV boys.

METHODS

We reviewed the medical records of PUV boys treated at the Pediatric Nephrology Clinic, Prince of Songkla University, Thailand, over a 30-year-period.

RESULTS

Seventy-seven PUV boys were identified, with a median age at diagnosis of 4.8 months. The most common presentations were urinary tract infection (UTI), poor urine stream and urinary dribbling in 26 (33.8%), 19 (24.7%) and 11 (14.3%) boys, respectively. Renal ultrasound results in 70 boys showed 8 (11.4%) unilateral and 56 (80%) bilateral hydronephroses. Of 72 voiding cystourethrograms, 18 (25.0%) showed unilateral and 22 (30.6%) bilateral vesicoureteral refluxes. 99mTc dimercaptosuccinic acid renal scans in 30 boys showed 12 (40%) unilateral and 8 (26.7%) bilateral renal damage. Fifty-nine (76.6%) boys had 149 UTIs; 42 (54.4%) had recurrent UTI. Forty-eight boys had valve ablation at the median age of 30.3 months. 22 boys (28.6%) developed chronic kidney disease (CKD) at a median age of 15.0 years.

CONCLUSION

Of 77 PUV Thai boys, UTI was the most common presentation. Recurrence of UTI and CKD was the most common consequence. Lifelong follow-up for renal and bladder functions is essential for all PUV patients.

Assessment of lower urinary tract function in pediatrics using ultrasonography

Ultrasound imaging is a less invasive imaging modality without radiation exposure and is available for repeated tests. It is the gold standard examination for diagnosing and managing disorders of the urinary tract, including lower urinary tract dysfunction (LUTD) in pediatric urology. Ultrasound imaging is effective for screening underlying diseases and determining treatment strategies. Ultrasound examination at the bedside should focus on post-voided residual urine (PVR), bladder wall thickening, renal morphology, and rectal diameter. Since PVR must be tested immediately after voiding, examining infants who cannot complain of the urge to void is difficult. PVR measurement combined with a 4-h voiding observation or alarm system activated by urine is recommended for these infants. Early diagnosis is important because LUTD is associated with the risk of morbid residual urine and high voiding pressure, which can result in renal deterioration, urinary leakage, and febrile urinary tract infection.

Kidney Ultrasonography After First Febrile Urinary Tract Infection in Children: A Systematic Review and Meta-analysis

Importance

Controversy exists on the clinical utility of kidney ultrasonography after first febrile urinary tract infection (UTI), and clinical practice guideline recommendations vary.

Objective

To determine the prevalence of urinary tract abnormalities detected on kidney ultrasonography after the first febrile UTI in children.

Data Sources

The MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Central Register of Controlled Trials databases were searched for articles published from January 1, 2000, to September 20, 2022.

Study Selection

Studies of children with first febrile UTI reporting kidney ultrasonography findings.

Data Extraction and Synthesis

Two reviewers independently screened titles, abstracts, and full texts for eligibility. Study characteristics and outcomes were extracted from each article. Data on the prevalence of kidney ultrasonography abnormalities were pooled using a random-effects model.

Main Outcomes and Measures

The primary outcome was prevalence of urinary tract abnormalities and clinically important abnormalities (those that changed clinical management) detected on kidney ultrasonography. Secondary outcomes included the urinary tract abnormalities detected, surgical intervention, health care utilization, and parent-reported outcomes.

Results

Twenty-nine studies were included, with a total of 9170 children. Of the 27 studies that reported participant sex, the median percentage of males was 60% (range, 11%-80%). The prevalence of abnormalities detected on renal ultrasonography was 22.1% (95% CI, 16.8-27.9; I2 = 98%; 29 studies, all ages) and 21.9% (95% CI, 14.7-30.1; I2 = 98%; 15 studies, age <24 months). The prevalence of clinically important abnormalities was 3.1% (95% CI, 0.3-8.1; I2 = 96%; 8 studies, all ages) and 4.5% (95% CI, 0.5-12.0; I2 = 97%; 5 studies, age <24 months). Study recruitment bias was associated with a higher prevalence of abnormalities. The most common findings detected were hydronephrosis, pelviectasis, and dilated ureter. Urinary tract obstruction was identified in 0.4% (95% CI, 0.1-0.8; I2 = 59%; 12 studies), and surgical intervention occurred in 1.4% (95% CI, 0.5-2.7; I2 = 85%; 13 studies). One study reported health care utilization. No study reported parent-reported outcomes.

Conclusions and Relevance

Results suggest that 1 in 4 to 5 children with first febrile UTI will have a urinary tract abnormality detected on kidney ultrasonography and 1 in 32 will have an abnormality that changes clinical management. Given the considerable study heterogeneity and lack of comprehensive outcome measurement, well-designed prospective longitudinal studies are needed to fully evaluate the clinical utility of kidney ultrasonography after first febrile UTI.

Ureteropelvic Junction Obstruction/Hydronephrosis

Congenital hydronephrosis can be classified and managed based on the Urinary Tract Dilation consensus scoring system. Ureteropelvic junction obstruction is one of the most common causes of hydronephrosis in the pediatric population. Although most cases can be managed conservatively with follow-up and serial imaging, some patients need surgical repair because of renal function deterioration, infections, or symptoms. Additional research to create predictive algorithms or develop noninvasive biomarkers for renal deterioration is necessary to better identify surgical candidates. The robotic-assisted approach for pyeloplasty is becoming increasingly widespread and associated with shorter hospital stay, high success rates, and low complication rates.

Association of the Hydronephrosis Severity Score With Likelihood of Pyeloplasty: A Large Prospective Database Analysis

OBJECTIVE

To apply and reproduce this scoring system in our prenatal hydronephrosis population with ureteropelvic junction obstruction (UPJO)-like hydronephrosis (HN), specifically looking at determining better HHS cutoffs that would allow for stratification into three risk categories: spontaneous HN resolution, observation, and surgery.

METHODS

A prospectively collected prenatal hydronephrosis database was reviewed to extract UPJO-like HN patients. Children with vesicoureteral reflux, primary megaureter, bilateral HN, and other associated anomalies were excluded. Only patients who had an ultrasound and mercaptoacetyltriglycine renal scan at a minimum of 2-time points were included. Hydronephrosis Severity Score was calculated at the initial, interim, and last follow-up clinic visits. Scores were analyzed regarding its usefulness to determine which patients would have been more likely to undergo pyeloplasty.

RESULTS

Of 167 patients, 131 (78%) were male, 119 (71%) had left UPJO-like, and 113 (67%) had a pyeloplasty. The median age at baseline was 2months (interquartile range 1-4). According to initial (first clinic visit) Hydronephrosis Severity Score, 5/36 (14%) patients with a 0-4 score, 93/116 (80%) with a 5-8 score, and 15/15 (100%) with a 9-12 score underwent pyeloplasty, respectively (P < .01).

CONCLUSION

The proposed HHS system for UPJO-like HN patients is reproducible, however, cut-off values need to be reassessed to accurately reflect true risk categories, as the purpose of this system is to differentiate those who have HN severe enough to require intervention from those who can be managed nonsurgically. Changing risk groups to mild (0-3), moderate (4-6), and severe (7-12) allowed for better discrimination between patients who underwent surgical intervention from those who did not in our dataset.

The natural course of incidental ureteral polyp during ureteroscopic surgery: KSER research

BACKGROUND

The natural course of polypoid lesions in the ureter during ureteroscopic stone surgery was not yet clarified.

METHODS

Patient data were collected prospectively from six teaching hospitals between 2019 and 2021. Patients with polypoid lesions in the ureter distal to ureteral stones were included during ureteroscopy. Computed tomography was performed on all enrolled patients three months after the procedure. Follow-up ureteroscopy was performed only if the patient consented, due to the need for general anesthesia and ethical considerations.

RESULTS

Among the 35 patients who were followed up, 14 had fibroepithelial polyps and 21 had inflammatory polyps. Twenty of the followed-up patients underwent ureteroscopy, and nine of them had fibroepithelial polyps. Although fibroepithelial polyps did not disappear in the follow-up ureteroscopy (p = 0.002), the rate of postoperative hydronephrosis was not higher in the fibroepithelial group than in the inflammatory group. Postoperative ureteral stricture and moderate-to-severe hydronephrosis were found to be closely related to the number of resected polyps, regardless of the type of polyp (p = 0.014 and 0.006, respectively).

CONCLUSION

Fibroepithelial polyps in the ureter may persist after treatment of adjacent ureter stones. However, conservative management may be preferable to active removal of ureteral polyps because fibroepithelial polyps may not contribute to clinically significant hydronephrosis after surgery, and inflammatory polyps disappear spontaneously. Hasty resections of polyps may increase the risk of ureteral stricture.

Can we improve the usefulness of the diuretic renogram in the diagnosis of ureteropelvic junction obstruction (UPJO) in children? Introduction of mercaptoacetyltriglycine-suspected obstruction scoring system (MAG-SOS)

INTRODUCTION

Mercaptoacetyltriglycine (MAG-3) renogram is one of the gold standard diagnostic tools of ureteropelvic junction obstruction (UPJO); however, there is no widely agreed indications of pyeloplasty based on MAG-3 findings. In this study, we introduce a renogram scoring system that can help improve the prognostic value of MAG-3 renogram and in the decision making of pyeloplasty.

PATIENTS AND METHODS

We retrospectively reviewed consecutive pyeloplasties for antenatal hydronephrosis from 2010 to 2020. A control group was included of non-operatively managed SFU grade 3 and 4. The initial renal ultrasound and preoperative MAG-3 Lasix renogram were reviewed for differential renal function (DRF), type of renogram curve and tracer washout half-time (T1/2). A ROC curve was used to evaluate the cut-off points that can be associated with obstruction. A multivariate linear regression model was used to assess the best renogram parameter that can predict surgical intervention.

RESULTS

We included 188 patients with 209 renal units. The median age for pyeloplasty was 5.4 months. The mercaptoacetyltriglycine-Suspected Obstruction Scoring System (MAG-SOS) was associated with pyeloplasty (AUC = 0.97, P < 0.001) (Figure A). A score of 5 is 100% specific for obstruction. 78% of units required surgical intervention had a MAG-SOS score of≥5 while all units of the control group had a range of score 0-4. Using the multivariate analysis, the MAG-SOS system showed to the only independent predictor for pyeloplasty (HR = 0.03, p < 0.001).

DISCUSSION

This study has some limitations. Firstly, the retrospective nature of the cohort; however, all patients were reviewed by one investigator who was blinded to the line of management. This is a single institutional study; therefor, this MAG-SOS should be evaluated by other centers to ensure its efficiency. Lastly, the pyeloplasty decision was taken by 3 different urologists; nevertheless, all of them adopt the same indications which are similar to those of the Society for Pediatric Urology and the Canadian Urological Association guidelines.

CONCLUSION

The MAG-SOS system showed to be a useful tool that can predict pyeloplasty. A score of 5 has 100% specificity for patients having a pyeloplasty performed. Prospective studies are required to confirm the usefulness of this novel tool.

Robot-assisted Laparoscopic Pyeloplasty: Experience of a Single Pediatric Institution, Including Long-term and Safety Outcomes

OBJECTIVE

To evaluate the efficacy and safety of robot-assisted laparoscopic pyeloplasty (RALP) and describe the short and long-term outcomes of pediatric RALP.

METHODS

We retrospectively reviewed all patients ..±21 years old who underwent primary RALP from 7/2007 through 12/2019. Patients were excluded from postoperative analysis if follow-up data after stent removal was not available. The primary outcome was surgical success, defined as radiographic improvement of hydronephrosis without need for reoperation. Secondary outcomes were time to reoperation and 90-day complication rate.

RESULTS

A total of 356 patients underwent primary repair of ureteropelvic junction obstruction during the study period; 29.ßpatients were limited to intraoperative data due to lack of follow-up imaging. Radiographic improvement at latest follow-up was seen in 308/327 (94.2%). Ten of 327 patients (3.1%) underwent reoperation: 7 were identified within 1 year of RALP and 3 were identified over 1 year after RALP. The median time to reoperation was 13.0 months (IQR 9.3-21.7). We defined long-term as>3 years after pyeloplasty. Over one-third (122/327, 37.3%) of the cohort had>3 years of follow-up, none of whom developed evidence of recurrent obstruction requiring reoperation beyond 3 years. Complications occurred within 90 days of surgery in 20/327 (6.1%).

CONCLUSION

This largest single-institution series confirms short- and long-term surgical effectiveness and safety of RALP. Our data also indicate that most patients who needed reoperation were identified within 1 year, and reoperation more than 3 years after RALP is rare.

External validation of the current scoring systems and derivation of a novel scoring system to predict stone free rates after retrograde intrarenal surgery in patients with cumulative stone diameter of 2-4 cm

OBJECTIVE

Our primary aim is to perform the external validation of the current scoring systems in predicting stone-free status (SFS) after retrograde intrarenal surgery (RIRS) for renal stones 2-4 cm and develop a novel scoring system by re-examining possible predictive factors related to SFS.

METHODS

Patients who underwent RIRS due to renal stones with a cumulative stone diameter of 2-4 cm between January 2017 and March 2021 were retrospectively screened. Residual stones ≤2 mm were defined as clinically insignificant, and these cases were considered to have SFS. Possible predictive factors related to SFS were examined using the multivariate logistic regression analysis. A nomogram and a scoring system were developed using independent predictive variables. The prediction ability of the previous and the new scoring system were evaluated with the ROC analysis.

RESULTS

The existing scoring systems were found to be insufficient in predicting SFS (AUC < 0.660 for all). The independent predictors of SFS were identified as stone surface area (OR: 0.991, p < 0.001), stone density (OR: 0.998, p < 0.001), number of stones (OR: 0.365, p = 0.033), and stone localization (p = 0.037). Using these predictive markers, a new scoring system with a score ranging between 4 and 15 was developed. The AUC value for this scoring system was 0.802 (0.734-0.870).

CONCLUSION

The RUSS, S-ReSC and R.I.R.S. scoring systems and Ito's nomogram failed to predict SFS in stones >2 cm. The SFS predictive ability of our new scoring system was higher in >2 cm stones compared to the other scoring systems.

Long term results of non-refluxing ureteral reimplantation in the pediatric population

PURPOSE

To evaluate the long-term results of UR and to determine the difference between patients with VUR and OMU in terms of re-obstruction rate, complications associated with pregnancy, and de novo reflux.

METHODS

Two-site retrospective study with 69 patients (36 females and 33 males) with a mean age of 5 ± 3.4 years. Fifty-nine (85.5%) underwent UR due to VUR and 10 (14.5%) due to OMU. Mean length of surgery and hospitalization was 90 ± 29.2 min and 9 ± 2.4 days, respectively.

RESULTS

Eight (13.5%) patients with VUR suffered from febrile UTI with a mean of 2.1 ± 1.3 events. In the OMU group, 1 (10%) patient suffered from febrile UTI. None of the patients showed recurrence, obstruction or de novo VUR. Two patients (20%) with OMU suffered from CKD. In the VUR group, 3 (5.1%) patients suffered from CKD. Three women suffered from UTIs during pregnancy. Mean follow-up was 17.5 ± 4.6 years.

CONCLUSIONS

Successful UR is associated with a decreased rate of febrile UTI in patients with VUR. Patients with OMU maintained and improved renal function in the long term. None demonstrated technical failures in the long term. Patients who presented with bilateral VUR are more prone to developing major complications.

Postoperative hydronephrosis following ureteral reimplantation: Clinical significance and importance of surgical technique and experience

BACKGROUND

Though common, postoperative hydronephrosis (POHN) following ureteroneocystostomy raises concern for an underlying obstruction. We aimed to determine the clinical significance of POHN following open (OUR) or robotic (RALUR) ureteral reimplantation.

METHODS

We retrospectively reviewed pediatric patients who underwent ureteral reimplantation for vesicoureteral reflux (VUR) from 2008 to 2019 by a single surgeon. Baseline characteristics, operative outcomes, and trends in POHN were assessed. POHN was defined as new onset hydronephrosis or exacerbation of pre existing hydronephrosis. Renal ultrasounds were performed 1, 4, and 12 months postoperatively. Voiding cystourethrograms were performed 4 months postoperatively. Surgical experience for RALUR cases was defined as number of ureters operated over time.

RESULTS

Altogether, 93 patients (127 ureters) underwent RALUR and 19 patients (26 ureters) underwent OUR. POHN was found in 27.6% and 30.8% of ureters after RALUR and OUR, respectively. Rate and time to POHN resolution for RALUR (91.4%, 112 days) and OUR (75%, 211 days) were statistically similar. Odds of POHN after RALUR were directly related with preoperative VUR grade (Range OR: 2.82[2.26-3.52]) and surgical experience (Range OR: 8.88[7.16-11.02]). Surgical experience was inversely related with odds of VUR recurrence (Range OR: 0.41[0.32-0.54]). Rates of VUR resolution were comparable for OUR and RALUR patients. No patient required additional intervention for POHN.

CONCLUSIONS

Incidence and resolution rate of POHN after OUR and RALUR were similar. Higher VUR grades were associated with increased odds of POHN after RALUR. Increasing RALUR experience improved VUR resolution rate but increased odds of POHN. Surgical success rates were similar for RALUR and OUR.

LEVEL OF EVIDENCE

II.

Evaluation of renal oxygenation by near-infrared spectroscopy during endoscopic injection of bulking agents in children with vesicoureteral reflux

BACKGROUND

Near infrared spectroscopy (NIRS) is the measuring of regional tissue oxygenation (rSO2) by interpreting oxyhemoglobin and deoxyhemoglobin signals that come back by transmitting near infrared light to tissues. The effect of endourological interventions on renal perfusion in children is largely unknown.

AIMS

To evaluate the effects of endoscopic injection of bulking agents (EIBA) for vesicoureteral reflux (VUR) on renal oxygenation (RO) using renal NIRS monitoring, which shows renal perfusion and oxygenation changes.

STUDY DESIGN

Case-control study.

METHODS

Group I had bilateral inguinal surgery, Group II cystoscopy, and Group III, EIBA for VUR with 30 patients in each group. During the operation, vital signs, peripheral oxygen saturation, end-tidal carbon dioxide, and renal regional oxygen saturation index (rSO2) values by bilateral renal NIRS monitoring were recorded. NIRS values before induction (T0) to postoperative (Tend) were determined. A 20% or more reduction in renal rSO2 (%20↓rSO2) was considered significant. Group III was also evaluated as subgroup III-A (not having "%20↓rSO2") and subgroup III-B ("%20↓rSO2").

RESULTS

The rSO2 decrease was observed in the first 5 min for both sides in group III. The most significant drop was at T30 for the right kidney and a significant decrease in rSO2, 20% or more, was observed in 6 renal units of 4 patients having higher SFU grading and renal scar in group III.

CONCLUSION

EIBA may transitionally impair renal oxygenation. Higher SFU grading and renal scar may increase the risk of renal hypoxia during EIBA.

A nomogram for predicting postoperative urosepsis following retrograde intrarenal surgery in upper urinary calculi patients with negative preoperative urine culture

Retrograde intrarenal surgery (RIRS) is one of the main surgical methods for upper urinary calculi, but severe complications of infection may occur after surgery. This study aimed to establish and validate a preoperative nomogram for predicting postoperative urosepsis following retrograde intrarenal surgery to treat upper urinary calculus in patients with a negative preoperative urine culture. We retrospectively recruited 1767 patients with negative preoperative urine cultures who underwent retrograde intrarenal surgery to treat upper urinary calculi from January 2017 to April 2022. The independent risk factors for urosepsis include a solitary kidney, positive urine nitrite, operative time ≥ 75 min, history of recurrent urinary tract infections, and history of diabetes were identified by univariate analysis and multivariate binary logistic regression analysis, which construct a nomogram. The receiver operating characteristic curve of the nomogram for predicting urosepsis was 0.887 in the training cohort and 0.864 in the validation cohort, respectively. The calibration curve and decision curve analysis demonstrated great consistency and clinical utility of the nomogram. Therefore, the nomogram combining preoperative independent risk factors can predict the probability of a postoperative urosepsis following retrograde intrarenal surgery in patients with a negative preoperative urine culture, which could help urologists take preventive measures in advance after surgery to avoid more serious complications of infection.

Laparoscopic ureteroneocystostomy and round ligament bladder hitching for ureteral stenosis in parametrial deep endometriosis: Our tips for a tension-free anastomosis

OBJECTIVE

To investigate the feasibility and the efficacy of laparoscopic ureteroneocystostomy with round ligament bladder hitching.

METHODS

This is a monocentric retrospective study. Enrolled patients affected by deep endometriosis underwent laparoscopic nerve-sparing parametrectomy and monolateral ureteroneocystostomy with bladder suspension to the round ligament. Perioperative and postoperative outcomes were collected, as well as urinary and pain symptoms before and after surgery.

RESULTS

Laparoscopic ureteroneocystostomy with round ligament bladder hitching was performed in nine women. The most frequent postoperative complication was post-voiding urinary retention (22.2%). No ureteral fistula or stenosis of the anastomosis was reported.

CONCLUSION

In selected cases of ureteral resection and reimplantation, performing a round ligament bladder hitching allowed us to overcome the ureteral gap. This is a safe and feasible procedure to ensure stability of the anastomosis and avoid the possible disadvantages of the "standard" psoas hitch procedure.

Imaging characteristics predicting elevated detrusor pressures in patients with spina bifida

PURPOSE

Patients with spina bifida require urologic follow up with assessments of bladder and renal function. The ideal screening protocol for bladder compliance remains controversial. This study assessed associations between bladder end filling pressure (EFP) and detrusor leak point pressure (DLPP) on urodynamic studies (UDS) and findings from renal bladder ultrasounds (RBUS) and voiding cystourethrograms (VCUG).

METHODS

Pediatric spina bifida patients who underwent RBUS and/or VCUG within six months of UDS at a single institution from 2015 to 2021 were retrospectively reviewed. Demographics, VCUG and RBUS results, and UDS EFP and DLPP were recorded. Multiple linear regression analyses and Pearson chi-square tests were conducted to correlate RBUS and VCUG findings with DLPP/EFP.

RESULTS

129 patients were included. In adjusted analyses, moderate to severe hydronephrosis on RBUS was significantly associated with elevations in mean DLPP/EFP (p = 0.006). Patients with round bladders had significantly lower mean DLPP/EFP than patients with elongated or conical bladders (p < 0.0001). The presence of trabeculations was associated with increased mean DLPP/EFP (p < 0.0001) and increases in severity of trabeculations were associated with higher DLPP/EFP (p < 0.0001). The presence of vesicoureteral reflux (VUR) on VCUG was not associated with significant differences in mean DLPP/EFP (p = 0.20).

CONCLUSIONS

Abnormal bladder shape and trabeculations on VCUGs in spina bifida patients had significant associations with increased mean bladder pressures on UDS. Assessment of bladder shape and contour by VCUG may be a valuable screening tool in conjunction with routine RBUS in determining the need for further assessment of bladder pressures in patients with spina bifida.

Robot-assisted laparoscopic ileal ureter replacement with extracorporeal ileal segment preparation for long ureteral strictures: a case series

BACKGROUND

Complete intracorporal robotic ileal ureteric replacement is challenging. We aimed to present the surgical technique of robotic ileal ureter replacement with extracorporeal ileal segment preparation for long ureteral strictures.

METHODS

From March 2019 to March 2021, 18 patients underwent robotic ileal ureter replacement with extracorporeal ileal segment preparation by one experienced surgeon. The demographic, perioperative, and follow-up data were recorded. Success was defined as the resolution of the presenting symptom, a stable estimated glomerular filtration rate and unobstructive drainage on imaging examination.

RESULTS

All 18 surgeries were successfully completed without conversion. The median length of the intestinal tube used was 20 (12-30) cm. The median operative time was 248 (170-450) min, the median estimated blood loss was 50 (10-200) ml, and the median postoperative hospital stay was 7 (5-27) days. At a median follow-up of 16 (13-28) months, all patients were symptom-free. No or mild hydronephrosis was confirmed in 17 patients; 1 patient had moderate hydronephrosis without peristalsis of the ileal ureter. The renal function was stable in all patients. The overall success rate was 100%. Postoperative complications, including 4 cases of urinary infections (Grade I), 1 case of an incision hernia (Grade I), 4 cases of kidney stone formation (Grade I), 6 cases of metabolic acidosis (Grade I), 4 cases of incomplete ileus (Grade II), and 1 case of an incision infection (Grade IIIb).

CONCLUSIONS

Robot-assisted laparoscopic ileal ureter replacement with extracorporeal ileal segment preparation is safe, feasible, and effective for the treatment of long ureteral strictures, especially in high-volume tertiary referral centers with extensive robotic surgery experience capable of managing severe peri-operative complications.

Evaluation, management, and analysis of demographic and radiological characteristics of patients with renal colic at a tertiary hospital in Somalia

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Renal Colic is a common emergenbcy care complaint worldwide–but its epidemiology and strategies for evaluation and treatment have been little reported in Africa.

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To date, there have been no studies regarding epidemiologic and radiological findings of renal colic in the emergency centre reported from Somalia.

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Ultrasound can be the initial investigation of choice because it is safe, cheap, and may help guide for diagnosis and need for further imaging.

Background

Renal colic is a common emergency centre (EC) complaint worldwide, but its epidemiology and strategies for evaluation and treatment have been little reported in Africa. To the best of our knowledge, this is the first study aimed at evaluating the radiological investigations, management, and analysis of demographic characteristics of patients with urinary system stones who visited the EC.

Method

A 3-year retrospective study of a total of 435 patients with acute renal colic who underwent radiologic investigations was included in this study. The overall positive stone rate, stone location, size, and hydronephrosis grade were assessed. The sensitivity and specificity of ultrasound were evaluated using patients with both an ultrasound and a non-contrast CT (NCCT).

Results

The mean age of the patients was 34.7years; males accounted for 71.3% (n = 310), while females were 28.7% (n = 125). Urolithiasis was found in 63.4% of the cases, 71.3% of males and 28.7% of the females had a stone diagnosis (P < 0001). There was no statistically significant association between age and stone diagnosis (P > 0.05). The sensitivity and specificity of USG were 86.1% and 94%, respectively. Seventy-two percent of the cases had ureteral stones (29% in proximal, 25% in UVJ, 9% in mid, and 9% in distal ureter), followed by 28% having renal stones (19% calyces and 9% in renal pelvis). The mean size of the stone was 5.9±1.8, half of the cases harbour stone size <5mm, followed by 30% in 5mm-1cm.

Conclusion

Due to the scarcity of well-equipped tertiary care hospitals and the low socioeconomic status of the patients living in Sub-Saharan Africa, Ultrasound can be the initial investigation of choice because it is safe, cheap, and may help guide diagnosis and the need for further imaging. However, NCCT remains the gold standard diagnosis of choice for acute flank pain.

Importance of the hounsfield unit value measured by computed tomography in the differentiation of hydronephrosis and pyonephrosis

Background

Acute or chronic obstruction of the urinary tract can be due to a lot of different causes. Patients with pyonephrosis usually complain of a triad of fever, loin pain and elevated white blood cell count in cases of acute obstruction; and they may also have hypotension in severe cases of the disease. These patients have to be treated with appropriate decompression, or they may develop septic shock. The urgency of the need for treatment greatly depends on the differentiation between hydronephrosis and pyonephrosis.

There is a lack of reliable clinical prognosticators of pyonephrosis in patients with obstructive hydronephrosis. Hounsfield unit (HU) measurement is considered as an adequate predictor of pyonephrosis and may aid in the diagnosis and management of this disease that may be fatal.

The use of HU values in differentiation between pyonephrosis from hydronephrosis depends on the fact that the pyonephrotic fluid contains infected material, urine, cellular particles and microorganisms, which when combined can increase the HU values on a computed tomography (CT) study.

This study was done to assess the diagnostic value of the HU measured CT in differentiation between hydronephrosis and pyonephrosis.

Results

Thirty-nine patients were included in this study. All patients had loin pain and were diagnosed with pelvicalyceal dilatation by ultrasonographic examination. They then underwent non-contrast CT examination.

Using CT scan, the degree of PC dilatation was significantly higher among hydronephrosis group as hydronephrosis group had 63.1% severe dilatation of PCs versus 30.8% in pyonephrosis group with p value 0.0001.

Pelvic wall thickness > 2 mm was reported in 10 (76.9%) patients of pyonephrosis group versus in three (7.9%) patients among hydronephrosis group with p value 0.0001.

The mean Hounsfield units were significantly higher among pyonephrosis group compared to hydronephrosis group (16 ± 5.2 versus 1.7 ± 5.5) with p value 0.0001.

Sensitivity analysis showed that Hounsfield units can significantly diagnose pyonephrosis using the cutoff point 6.2 units, with sensitivity 92.3%, specificity 93.3%, area under the curve (AUC) 96.9% and p value 0.0001.

Conclusions

Measuring HU in a NCECT scan of the kidney might be helpful for differentiating between hydronephrosis and pyonephrosis especially upon considering 6.2 HU as a cutoff point.

The sequence of intervention determines the risk of early postoperative acute kidney injury in infants with bilateral ureteropelvic junction obstruction

INTRODUCTION AND OBJECTIVES

The management of bilateral ureteropelvic junction obstruction (UPJO) is greatly debated. We aim to identify the risk of early postoperative acute kidney injury (AKI) in relation to the sequence of intervention in children with bilateral UPJO managed in a sequential manner.

METHODS

A single center database was retrospectively reviewed for children ≤2 years who underwent bilateral pyeloplasty. According to the differential renal function on the preoperative renograms, patients were categorized into group A: pyeloplasty on the poorer functioning kidney first and group B: pyeloplasty on the better functioning side first. Serum creatinine and eGFR, using the modified Schwartz formula, were evaluated at four time points (I): before the first intervention (II): within 48 h of the first intervention (III): before the second intervention and (IV): within 48 h of the second intervention. Preoperative and postoperative values were compared. The incidence of early postoperative AKI in both groups was defined according to the Acute Kidney Injury Network (AKIN) criteria.

RESULTS

The study comprised 46 children treated by staged pyeloplasty, 28 of them underwent pyeloplasty on the poorer functioning side first. Baseline serum creatinine and eGFR were not significantly different between both groups. Patients who underwent pyeloplasty on the poorer functioning side first, had a significant decline of eGFR after the first intervention (p = 0.006). Conversely, no significant eGFR changes were observed after the first or second interventions in the other group (figure). Overall, 64.3% and 33.3% of patients developed some degrees of AKI when intervention was started on the poorer and better functioning renal units, respectively (p = 0.04).

DISCUSSION

Bilaterality is seen in approximately ¼ of patients with UPJO. Oftentimes, both renal units are asymmetrically affected with little data to guide surgeons on the optimal sequence of intervention. Following pyeloplasty, 52.2% of the evaluated children with bilateral UPJO had early postoperative AKI, mostly of low stage. Our data suggest that intervening first on the better functioning side allows for better recovery of the renal functional reserve and lowers the risk of postoperative AKI.

CONCLUSION

In children with bilateral UPJO, starting intervention on the poorer functioning kidney is associated with increased risk of postoperative AKI. Long-term prospective studies are needed to confirm our findings.

Clues for the early loss of renal function in congenital hydronephrosis: Analysis of renal pelvis collagen ratio, diuresis renography and upper urinary tract morphology

INTRODUCTION

Diagnosing real urinary obstruction and surgical decision making for the operative correction of urinary obstruction, are still problematic in congenital hydronephrosis (CH). Compliance of the renal pelvis is one of the important defense mechanisms of renal parenchyma against urinary obstruction. We observed early loss of function in some cases of CH with low and moderate anteroposterior diameter of the renal pelvis (APDRP).

OBJECTIVE

To evaluate structural properties of the renal pelvic tissue of patients with CH and the relation of these structural properties with renal function and Anteroposterior diameter of the renal pelvis.

STUDY DESIGN

Ureteropelvic junction (UPJ) excised during UPJ obstruction operations from 2013 to 2019 were evaluated histopathologically. The patients were divided into the two groups according to initial renal function, i.e. group with initial preoperative differential renal function (DRF) less than 35% and group with initial DRF greater than 35%. The percentage of collagen to whole tissue area were analyzed using image processing program. The relationship between DRF and tissue collagen ratio, SFU and APDRP was evaluated.

RESULTS

There were 5 patients in the DRF <35% group and 16 patients in the DRF >35% group. However, APDRP's of the DRF <35% group were also significantly lower than the DRF >35% group. The collagen distribution in the muscle layer was more prominent in the DRF <35% group. Proportionally, percentage of collagen stained surface was significantly higher in DRF <35% group.

DISCUSSION

There are numerous histopathological studies evaluating the cause of UPJ obstruction. Besides these studies that are oriented to etiology, there are many studies comparing the histopathological changes at UPJ with surgical outcome and prognosis. In the present study, we found that renal pelvis collagen ratio was significantly increased in patients with lower APDRP and with severe renal function loss. This increase in the collagen content in the renal pelvis have been shown to affect the compliance negatively and decrease APDRP, which leads to a faster loss of renal function. Thus, pelvic structural changes accompanying UPJ obstruction may aggravate urinary obstructive process.

CONCLUSION

Increased renal pelvis collagen ratio negatively affects the expansion of the renal pelvis, which is one of the protective mechanisms of the renal parenchyma, and may be one of the triggering mechanisms of early loss of renal function.

Urinary tract obstruction: Ultrasound-guided intervention

Introduction

Urinary tract obstruction (UTO) is a common clinical problem of which there are many potential causes. The aim of this feature article is to explore the role of ultrasound in diagnosing UTO, during guided interventional procedures and the potential procedural complications.Topic description and discussion: Ultrasound is an integral imaging modality throughout the management pathway of a patient with UTO and is often utilised as a first-line test in diagnosis and treatment. Percutaneous nephrostomy is an interventional technique, usually performed by radiologists or interventional sonographers, as either a short- or long-term management strategy. It can either be used in isolation or to gain access to the renal collecting system prior to more complex interventional or surgical techniques. Ultrasound-guided interventional techniques to relieve UTO can be employed in a number of clinical scenarios each with their own indications, contraindications and complications.

Conclusion

Ultrasound plays a unique role in the planning and active stages of intervention with the provision of dynamic imaging which is crucial for providing safe and effective patient management.