Anterior-posterior Renal Pelvic Diameter Research Articles

Single-port-plus-one robot-assisted laparoscopic modified Lich-Gregoir direct nipple ureteral extravesical reimplantation in children with a primary obstructive megaureter.

To introduce a new technique of single-port-plus-one robotic laparoscopic-modified Lich-Gregoir direct nipple ureteral extravesical reimplantation and ascertain its validity in the treatment of pediatric primary obstructive megaureter. Between January 2021 and November 2021, we retrospectively analyzed the clinical data of 12 children with primary obstructive megaureter who were admitted to the Department of Pediatric Surgery of Fujian Provincial Hospital. All 12 children were treated with single-port-plus-one robotic laparoscopic Lich-Gregoir direct nipple ureteral extravesical reimplantation. Five of them were female and seven were male, including nine cases were simple obstructive type, while the remaining three cases were obstructive with reflux type. The mean age of the children was 17.33 ± 6.99 (10-36) months and the mean follow-up time was 14.16 ± 1.75 (12-17) months. Changes in preoperative and first-year postoperative parameters were compared. The mean operative time for all 12 children was 123.58 ± 10.85 (110-145) min, with a mean internal operative time of 101.42 ± 0.85 (90-120) min, a mean operative bleeding time of 2.42 ± 0.67 (2-4) ml, and a mean hematuria duration of 16.08 ± 1.44 (14-19) h. The mean indwelling catheterization time was 2.25 ± 0.45 (2-3) days and the mean hospitalization time was 3.83 ± 0.39 (3-4) days. At the postoperative first year, the ureteral diameter, calyceal diameter, and anterior-posterior renal pelvic diameter were found to be significantly smaller than at the preoperative period (18.83 ± 3.21 mm vs. 6.83 ± 1.27 mm, 13.99 ± 3.58 mm vs. 3.5 ± 2.90 mm, and 34.92 ± 4.25 mm vs. 10.08 ± 1.88 mm, P < 0.001). There was a significant increase in renal cortical thickness and the percentage of differential renal function (3.63 ± 1.66 mm vs. 5.67 ± 1.88 mm, 33.75 ± 2.77 mm vs. 37.50 ± 1.31 mm, P < 0.001). The resolution rate of obstruction was 100% and no child developed DeNovo vesicoureteral reflux. The technique of modified Lich-Gregoir direct nipple ureteral extravesical reimplantation can help maintain the physiological direction of the ureter and at the same time enhance the effectiveness of antirefluxing in robotic surgery. The design of a single-port-plus-one wound can produce a cosmetic appearance by concentrating and hiding the wound around the umbilicus. This modified reimplantation procedure has the potential to become a promising technique in the robot-assisted treatment of primary obstructive megaureter.

Laparoscopic strategies in complex upper urinary tract obstruction

We enumerate the various laparoscopic strategies to resolve upper urinary tract (UUT) obstruction in the context of variations in anatomy and report their outcomes. Retrospective review of primary laparoscopic UUT reconstructions performed between May 2012 and May 2021. Anomalies included: malrotated kidney (MRK), horseshoe kidney (HSK), duplex kidney (DK), pure intrarenal pelvis (IRP) and mid-ureteric stenosis (MUS). Success was defined by postoperative resolution of symptoms, improvement of anterior-posterior renal pelvic diameter (APD) on US and drainage on Mag3. Complications were categorised by Clavien-Dindo grading. Outcomes compared using the student's t-test with P<0.05 considered statistically significant. Of the 214 laparoscopic primary UUT reconstructions, 37 (17.2%) were: 13-MRK, 12-HSK, 4-DK, 4-IRP and 4-MUS. Median age at surgery was 5-years (range 0.3-15). Dismembered pyeloplasty: 8; pyeloplasty with renal sinus dissection: 8; neo-PUJ anastomosis: 8; primary ureterocalycostomy: 7; pyeloureterostomy: 2; and uretero-ureterostomy: 4. Median follow-up was 43-months (range 8-108) with a success rate of 94.5% (35/37). Complete resolution of symptoms in 20/21 patients; improvement of hydronephrosis on US in 35/37 patients (median pre-operative APD 27mm vs. median postoperative APD 8mm) [P<0.001]; improvement of drainage on diuretic renogram in 32/34 kidneys and stable/improved DRF in 34/35 kidneys (median preoperative DRF - 45% vs. median postoperative DRF - 47%) [P>0.05]. Postoperative complications managed medically (II Clavien) included urinary tract infections - 2 patients (5%), stent-related symptoms in 2 (5%) and umbilical port site collection in 1 patient (3%). Recurrent pelvi-ureteric junction obstruction PUJO occurred in one patient (3%) requiring redo surgery (IIIb Clavien), renal stones in 1 (3%) which resolved with ESWL (IIIb Clavien); in 1 (3%) patient with a HSK there was complete loss of ipsilateral kidney function but this was managed conservatively up to date (I Clavien). Laparoscopic transperitoneal approach allows the prompt recognition of in-situ anatomical variants. UUT obstruction in such settings calls for a variety of strategies with excellent outcomes.

Decreased percent change in renal pelvis diameter on diuretic functional magnetic resonance urography following administration of furosemide may help characterize unilateral uretero-pelvic junction obstruction

A well-established definition of obstruction in the setting of congenital hydronephrosis is lacking. Multiple imaging modalities and radiographic characteristics or parameters have been described to help confirm the diagnosis of ureteropelvic junction obstruction (UPJO). We sought to evaluate the change in anterior-posterior renal pelvic diameter (APRPD) following furosemide administration in patients with unilateral hydronephrosis and confirmed UPJO on functional magnetic resonance urography (fMRU) who underwent pyeloplasty. There were 49 patients who met inclusion criteria (11 females, 38 males; average age 2.2 years, SD 3.4 years) from February 2006 to September 2020, diagnosed with unilateral hydronephrosis (SFU Grade 3-4) who underwent fMRU prior to pyeloplasty for confirmed UPJO. 29 of the included patients also underwent a post-pyeloplasty fMRU. A weight-adjusted dose of 1mg/kg of furosemide (max 20mg/kg) was administered intravenously. Two board-certified pediatric radiologists measured the APRPD of the obstructed and non-dilated kidneys prior to pyeloplasty and APRPD of the hydronephrotic kidneys on the post-pyeloplasty follow up fMRUs. Measurements were performed on images prior to and approximately 30min following furosemide injection. The average APRPD before furosemide injection in the obstructed kidney prior to pyeloplasty was 26.3mm (SD 9.0mm) compared to the non-dilated (not obstructed) kidney measurement of 5.1mm (SD 3.6mm) (p<0.001). Following administration of furosemide, the average APRPD was 31.4mm (SD 8.8mm) in the obstructed kidney, and 7.8mm (SD 4.1mm) in the non-dilated kidney (p<0.001). After pyeloplasty, the pre-furosemide APRPD measurement was 17.8mm (SD 11mm), which was significantly less compared to the pre-pyeloplasty APRPD (p<0.001). The post-pyeloplasty, post-furosemide APRPD measurement was 25.8mm (SD 12mm), also significantly less compared to the pre-pyeloplasty measurement (p=0.02). The changes in APRPD in the obstructed kidney prior to pyeloplasty was 5.1mm (SD 3.5mm) and after pyeloplasty was 8mm (SD 4.6mm) (p=0.002). Change in APRPD in the non-dilated kidney was 2.7mm (SD 2.3mm). Percent APRPD change in the obstructed kidney was 22.9% (SD 18.5%), which was significantly less than 33.3% (SD 22.1%) in the post-pyeloplasty kidney (p=0.028) and 82.8% (SD 87.9%) in the non-dilated kidney (p<0.001). A relatively smaller change in APRPD on fMRU following administration of furosemide in the setting of UPJO may serve as another predictive characteristic of obstructed kidneys.

MP70-15 PRIMARY VESICOURETERAL REFLUX IN A MODERN COHORT: WHAT ARE THE RISK FACTORS FOR URINARY TRACT INFECTIONS?

You have accessJournal of UrologyCME1 Apr 2023MP70-15 PRIMARY VESICOURETERAL REFLUX IN A MODERN COHORT: WHAT ARE THE RISK FACTORS FOR URINARY TRACT INFECTIONS? Daniel Wilkinson, Matthew Buell, Kai Wen Cheng, Cayde Ritchie, Levi Miles, Jocelyn Huang, Ala’a Farkouh, David Chamberlin, and Joshua Chamberlin Daniel WilkinsonDaniel Wilkinson More articles by this author , Matthew BuellMatthew Buell More articles by this author , Kai Wen ChengKai Wen Cheng More articles by this author , Cayde RitchieCayde Ritchie More articles by this author , Levi MilesLevi Miles More articles by this author , Jocelyn HuangJocelyn Huang More articles by this author , Ala’a FarkouhAla’a Farkouh More articles by this author , David ChamberlinDavid Chamberlin More articles by this author , and Joshua ChamberlinJoshua Chamberlin More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003338.15AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Children with vesicoureteral reflux (VUR) are known to be at increased risk of urinary tract infection (UTI). With a trend towards observational management of children with VUR, untreated VUR and subsequent UTI can lead to significant morbidity. The purpose of this study was to identify risk factors for development of UTI in a modern cohort of children with primary VUR. METHODS: We performed a review of a prospectively maintained clinical database of children with primary VUR at a single children’s hospital from July 2013 to June 2022. Children were included if they were diagnosed with primary VUR by voiding cystourethrography between the ages of 1 day to 18 years. Patients with secondary VUR were excluded. Demographic and clinical data were collected. The primary endpoint was development of a UTI defined by pyuria (>6 WBC/hpf or positive leukocyte esterase) on urinalysis and single-organism urine culture greater than 50,000 CFU/mL. Low-grade (LG) VUR was defined as International VUR grades 1-3 and high-grade (HG) VUR was defined as International VUR grades 4 and 5. Dilated ureter was defined as any ureteral dilation greater than 2 mm. Data were analyzed by performing univariate and multivariate Cox proportional hazards regressions as well as Chi Square tests. RESULTS: A total of 242 children had primary VUR, 116 (47.9%) male and 126 (52.1%) female. UTI occurred in 42 (17.3%) children with primary VUR, with an average follow-up time of 20.1 months [IQR of 6.2 - 45.0]. Female sex (HR: 2.39, 95% CI 1.22 - 4.67, p=0.011) and younger age at presentation of VUR (HR-1: 1.01, 95% CI 1.00 - 1.02, p=0.015) were found to be independent risk factors on multivariate analysis. Univariate analysis showed increased UTI rates in dilated ureter (14.6% non-dilated vs 30.5% dilated, p=0.024), HG VUR grade (13.2% in LG vs 23.7% in HG, p=0.038), and renal pelvis anterior-posterior diameter (APD) (16.9% ≤ 15 mm, 31.9% >15 mm p=0.032). Circumcision, degree of phimosis, constipation, voiding dysfunction, SFU grade of hydronephrosis, and prior febrile UTI were not found to be independent risk factors. CONCLUSIONS: Risk factors for UTI in children with primary VUR include female sex, age younger than 50 days old, dilated ureter, HG VUR, and hydronephrosis with APD greater than 15 mm. Treatment may be individualized to treat these higher risk patients. Further multi-institutional study of patients with primary VUR may help to further elucidate risk factors for UTI and improve the management of these patients. Source of Funding: none © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1009 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daniel Wilkinson More articles by this author Matthew Buell More articles by this author Kai Wen Cheng More articles by this author Cayde Ritchie More articles by this author Levi Miles More articles by this author Jocelyn Huang More articles by this author Ala’a Farkouh More articles by this author David Chamberlin More articles by this author Joshua Chamberlin More articles by this author Expand All Advertisement PDF downloadLoading ...

Application of the postnatal urinary tract dilation classification system to predict the need for surgical intervention among neonates and young infants.

The aim of this study was to validate the postnatal urinary tract dilation (UTD) classification system by correlating it with the need for surgical intervention. Young infants who underwent ultrasound (US) examinations for prenatal hydronephrosis were retrospectively identified. The kidney units (KUs; right, left, or bilateral) were graded from UTD P0 (very low risk) to P3 (high risk) based on seven US criteria from the UTD system. Surgery-free survival curves were constructed using the Kaplan-Meier method. Univariable and multivariable Cox proportional-hazards regression analysis clustered by patients was performed. Interobserver agreement was analyzed using the weighted kappa coefficient. In total, 504 KUs from 336 patients (mean age, 18.3±15.9 days; range, 1 to 94 days; males, n=276) were included, with a median follow-up of 24.2 months. Fifty-eight KUs underwent surgical intervention. Significant differences were observed among the Kaplan-Meier curves stratified into UTD groups (P<0.001). The presence of anterior-posterior renal pelvic diameter ≥15 mm (hazard ratio [HR], 8.602; 95% confidence interval [CI], 1.558 to 43.065), peripheral calyceal dilation (HR, 8.190; 95% CI, 1.558 to 43.065), ureteral dilation (HR, 2.619; 95% CI, 1.274 to 5.380), parenchymal thickness abnormality (HR, 3.371; 95% CI, 1.574 to 7.223), bladder abnormality (HR, 12.209; 95% CI, 3.616 to 41.225) were significantly associated with the occurrence of surgery. The interobserver agreement was moderate to almost perfect agreement for US features (κ=0.564-0.898) and substantial for final UTD grades (κ=0.716). The UTD classification system is reliable and appropriately stratifies the risk of surgical intervention.

Ureteral reimplantation for pediatric vesicoureteral reflux and primary obstructive megaureter: Transvesicoscopic cohen vs. Politano-Leadbetter approaches

Transvesicoscopic approaches for ureteral reimplantation (UR) are effective surgical techniques with which to resolve vesicoureteral reflux (VUR) or primary obstructive megaureter (POM) in pediatric patients. However, the effectiveness of different UR surgical methods for these two diseases is still unclear. To compare the effects of Cohen's cross-trigonal and Politano-Leadbetter techniques in children in need of UR. A retrospective chart review was performed for consecutive patients who underwent UR at our institution between May 2018 and November 2019, including those treated for vesicoureteral reflux (VUR) or primary obstructive megaureter (POM). Patients who underwent Cohen's technique included in Group C, and those who underwent the Politano-Leadbetter technique were included in Group P. Patient characteristics, perioperative parameters, and short-term postoperative outcomes were compared. Forty-six patients who underwent unilateral UR were included in the analysis. At presentation, those in Group P (N=22, 12 diagnosed with VUR and 10 with POM) did not differ from those in Group C (N=24, 12 diagnosed with VUR and 12 with POM) with respect to age, sex, disease type or severity. For VUR patients, reflux was clinically resolved for all patients in both groups; however, only a 75% resolution rate was observed in Group C, with 3 patients experiencing persistent low-grade, clinically insignificant reflux, while a 100% resolution rate was found in Group P (P>0.05). Among POM patients, the obstruction was resolved for all those in Group P and for 90% of those in Group C; this difference was also not statistically significant (P>0.05). At the 1-year follow-up, the ureteral diameter (P<0.05) and anterior-posterior renal pelvic diameter (APRPD) (P<0.05) of Group P were significantly reduced, and differential renal function (DRF) (P<0.05) was slightly improved compared with that in Group C in both VUR and POM patients. Politano-Leadbetter and Cohen are both reliable techniques for UR in children with VUR or POM, and the short-term outcomes of these methods in solving reflux and obstruction are comparable. Besides traditional Cohen's technique, Politano-Leadbetter's technique maybe a potential choice for ureteral reimplantation in children.

Integrated Ultrasound With Urodynamics Illustrates Effect of Bladder Volume on Upper Tract Dilation: Should we Trust Surveillance Ultrasounds?

ObjectiveTo evaluate if ultrasound during urodynamics (uUS) will show that traditional ultrasound (tUS) routinely underestimates the potential magnitude of upper tract dilation (UTD). MethodsProspective pilot study of 10 consecutive patients ≥ 5 years of age undergoing same day uUS and tUS. Using randomized images, the study pediatric radiologist determined anterior-posterior renal pelvic diameter (APD), bladder volume, vesicoureteral reflux (VUR) and UTD grades. A single pediatric urologist determined urodynamic bladder capacity and assigned either hostile, intermediate, abnormal but safe, or normal national spina bifida patient registry classification (NSBPR). ResultsBladder volume on tUS was significantly smaller than final bladder volume on uUS (180 vs 363 ml: P<.001). On average, patient reported maximum catheterized/voided volumes were also 82 ml greater than final bladder capacity on uUS. UTD was upgraded in 25% of kidneys and APD increased by 0.6 cm on uUS over that seen on tUS (P=.001). Units with VUR had greater increases in APD (1.2 P=.007 vs. 0.3 cm P=0.06). Changes in APD stratified by NSBPR revealed average increases of up to 1.3 cm. ConclusionDespite instructions to the contrary, patients come for tUS with a relatively empty bladder as compared to either their urodynamic or patient-reported capacity. This translates to a significant underestimation of UTD with tUS, most notably in those with VUR. Alternatives to traditional protocols include insisting patients wait until their bladder is truly full for tUS, retrograde filling their bladder, or performing uUS. Accurate assessment of UTD severity may help guide long term management.

Early outcome findings of treatment for transperitoneal laparoscopy-assisted pyeloplasty

BackgroundWe retrospectively analyzed the initial results of laparoscopic pyeloplasty, among pediatric patients undergoing the procedure by transperitoneal access.MethodsWe retrospectively reviewed the medical records of patients who were operated with transperitoneal laparoscopy-assisted pyeloplasty at our institution between 2015 and 2020.ResultsThe mean age of the 51 patients (M/F = 36/15) was 59 ± 49.8 months. The mean preoperative renal pelvis anterior–posterior diameter was 32.9 ± 13.4 mm, and the relative renal function was 42 ± 12.1% on the operation side. Forty-three (84.3%) patients had no excretion on MAG3 examination preop. The number of patients with no excretion decreased to 10 (19.7%) after surgery. One of them underwent a successful endopyelotomy; eight of them underwent a successful laparoscopic re-pyeloplasty. There was nothing to do in only one patient whose DRF decreased to 11%. The mean anterior posterior diameter decreased significantly to 16.7 ± 11.2 mm after surgery (p < 0.001).ConclusionPreoperative increased renal pelvis anterior–posterior diameter detected in our study was found to be a risk factor in the failure of transperitoneal laparoscopy-assisted pyeloplasty procedure.

Evaluation of pediatric hydronephrosis using deep learning quantification of fluid-to-kidney-area ratio by ultrasonography.

Hydronephrosis is the dilation of the pelvicalyceal system due to the urine flow obstruction in one or both kidneys. Conventionally, renal pelvis anterior-posterior diameter (APD) was used for quantifying hydronephrosis in medical images (e.g., ultrasound, CT, and functional MRI). Our study aimed to automatically detect and quantify the fluid and kidney areas on ultrasonography, using a deep learning approach. An attention-Unet was used to segment the kidney and the dilated pelvicalyceal system with fluid. The gold standard for diagnosing hydronephrosis was the APD >1.0cm. For semi-quantification, we proposed a fluid-to-kidney-area ratio measurement, i.e., [Formula: see text], as a deep learning-derived biomarker. Dice coefficient, confusion matrix, ROC curve, and Z-test were used to evaluate the model performance. Linear regression was applied to obtain the fluid-to-kidney-area ratio cutoff for detecting hydronephrosis. For regional kidney segmentation, the Dice coefficients were 0.92 and 0.83 for the kidney and dilated pelvicalyceal system, respectively. The sensitivity and specificity of detecting dilated pelvicalyceal system were 0.99 and 0.83, respectively. The linear equation was fluid-to-kidney-area ratio = (0.213 ± 0.004) × APD (in cm) for 95% confidence interval on the slope with R2=0.87. The fluid-to-kidney-area ratio cutoff for detecting hydronephrosis was 0.213. The sensitivity and specificity for detecting hydronephrosis were 0.90 and 0.80, respectively. Our study confirmed the feasibility of deep learning characterization of the kidney and fluid, showing an automatic pediatric hydronephrosis detection.

Unilateral Üreteropelvik Bileşke Obstrüksiyonu Nedeniyle Opere Edilen Pediatrik Hastaların Dinamik Renal Sintigrafi Sonuçları: İpsilateral Diferansiye Renal Fonksiyonun Yüksek Ölçümüne Yeni Yaklaşım

Objective: The aim of this study was to scintigraphically investigate the preoperative and postoperative renal functions of patients operated due to ureteropelvic junction obstruction, discuss the factors affecting the indication of surgery and emphasize the important points to consider during scintigraphic examination. Method: We retrospectively analyzed pediatric cases who underwent pyeloplasty due to ureteropelvic junction obstruction. Patients operated for primary ureteropelvic junction obstruction whose preoperative and postoperative dynamic scintigraphy results could be obtained were included in the study. The patients were divided into two groups as those with &lt;50% and ≥50% ipsilateral differentiated renal function. The difference between the groups was considered statistically significant when p&lt;0.05. Results: The median ages of 36 cases in &lt;50% DRF group and 24 cases in ≥50% DRF group were 7.7 months and 8.5 months, respectively. The mean ipsilateral differentiated renal function values of the main groups were significantly different from each other both in the preoperative and postoperative periods. The changes within the two main groups were also analyzed, yielding significant differences. Ipsilateral differentiated renal function changes on a general, group and subgroup basis, and preoperative ultrasound findings of the ipsilateral kidney in subgroups were revealed. Conclusion: Increased hydronephrosis degree and renal pelvis anterior-posterior diameter are closely related to overestimated ipsilateral kidney function. For deciding on surgery in patients with ureteral obstruction, scintigraphic examinations make sense with the help of US and the clinical condition of the patient.

The Change in the Renal Pelvis Anterior-Posterior Diameter Between Prevoiding and Postvoiding Status, and Its Correlation With Vesicoureteral Reflux.

In this study, our aim was to evaluate the significance of the change in renal pelvis anterior-posterior diameter (RPAPD) before and after micturition between vesicoureteral reflux (VUR)-positive and -negative patients to whom had voiding cystourethrography (VCUG) was performed.In this study, 69 children, age ranging from 0 to 12 years, were included. Before the VCUG imaging, the RPAPD was measured first with a full bladder and then after urination via ultrasound (US). The differences between in RPAPD measurements were noted and values compared made among VUR-positive and -negative children. Data distribution was inhomogeneous, and the Wilcoxon Sign Rank test was utilized instead of Student t test. There was no statistically significant difference in prevoiding and postvoiding RPAPD in VUR (+) and VUR (-) patients (P = 0.672). There was no statistically significant relation between VUR and the presence of hydronephrosis (P = 0.126). Vesicoureteral reflux is more common in patients with urinary tract infections (UTI) (P = 0.001). There was no statistically significant relationship between prevoiding and postvoiding RPAPD change and VUR diagnosis (P = 0,164).Ultrasound is the modality of choice for urinary system evaluation. Diagnosis of hydronephrosis via US is not sufficient in predicting VUR; however, indirect findings may reveal the diagnosis. A decrease in RPAPD in postvoiding US evaluation may not rule out the VUR diagnosis for this reason further imaging modalities, such as VCUG, should be taken into consideration for the patients with clinical suspicion.

The different elements of the Urinary Tract Dilation (UTD) Classification System and their capacity to predict findings on mercaptoacetyltriglycine (MAG3) diuretic renography

The UTD Classification System risk stratifies postnatal UTD into three groups: low risk (UTD P1), intermediate risk (UTD P2), and high risk (UTD P3). In the original consensus document, a functional scan is not recommended for UTD P1 and is left to the discretion of the clinician for UTD P2 and P3. This study aims to understand which patients with postnatal urinary tract dilation would benefit from a functional study. We investigated how different elements of the UTD classification system predict differential renal function (DRF) and diuretic half-life (T½) on MAG3 scan in infants undergoing evaluation for prenatally detected UTD. This is a multicenter retrospective chart review of infants 6 months of age or younger evaluated for prenatal UTD, correlating their first MAG3 scan and first postnatal renal ultrasound (RUS). Multivariable logistic regression was used to find UTD elements predictive of DRF<40% and/or T½>20min. A total of 517 patients met study criteria. Median age at time of RUS and MAG3 renal scan was 48 days (IGR 31-81) and 63 days (IQR 45-98), respectively. DRF<40% was found in 6% of kidneys with UTD P2 and 35% of kidneys with UTD P3. T½>20min was found in 31% of kidneys with UTD P2 and 79% of kidneys with UTD P3. An abnormal ureter (OR 2.7, 95% CI 1.2-6.0) and parenchymal thinning (OR 16, 95% CI 5.8-41.4) were significant at predicting DRF<40%. Parenchymal thinning (OR 3.0, 95% CI 1.5-6.1) also predicted T½>20min, as did each cm increase in the anterior-posterior renal pelvic diameter (APRPD) (OR 4.8, 95% CI 3.0-7.7). The UTD system discriminates well and correlates with the likelihood of finding adverse features on diuretic renography. Patients in the UTD P3 high-risk category had a significantly higher incidence of decreased differential renal function and delayed drainage than those in UTD P1 and P2. Of the individual components of the UTD Classification system, the presence of parenchymal thinning was the most important factor in predicting both decreased differential renal function and delayed drainage. Given the high incidence of poor function and delayed drainage seen in the UTD P3 group, we believe a functional study should be recommended in the evaluation of these patients. Our findings support leaving the performance of a functional study at the discretion of the physician for UTD P2.

The course of alterations in ureteral jet dynamics following kidney transplantation: a prospective observational cohort study.

To prospectively investigate the alterations and normal ranges of ureteral jet dynamics after double-J-stent (DJS) removal in patients who underwent renal transplantation (RTx). Patients who underwent RTx were prospectively evaluated between November 2017 and June 2018. After RTx, Doppler ultrasonography (D-US) was performed on all patients after DJS removal. Renal artery resistive index (RA-Ri), renal pelvis anterior-posterior diameter (RP-APD), pelvicalyceal system dilation (PCSD), and ureteral jet flow dynamics (maximum and average velocity; JETmax and JETave) were measured by D-US. Also, patients' demographics, estimated glomerular filtration rate (eGFR) levels, and acute rejection were investigated in the study. Patients were assessed two different times by D-US, about 6 and 12 weeks after DJS removal, and the two different measurements were compared with the Wilcoxon test and Chi-square test. A total of 25 patients were evaluated in the study. Nonobstructive PCSD rate (12% vs 8%), JETave (18.8 vs 12.9 cm/sec), and JETmax (29.2 vs 20 cm/sec) levels were significantly decreased (p values are 0.01, 0.010 and 0.014, respectively). In addition, monophasic and square pattern rates were significantly observed to increase over time (p=0.035); however, ureteral jet patterns were correlated between the two different D-US measurements (R=0.225, p=0.032). After RTx, dilation rate and ureteral jet flow velocities were significantly decreased, and monophasic and square JETpattern rates were significantly increased over time. Ureteral jet dynamics can provide useful information about the follow-up of peristaltic activity in the pelvic-ureteric system.

Early detection of congenital anomalies of the kidney and urinary tract: cross-sectional results of a community-based screening and referral study in China

ObjectiveTo establish an effective screening model of congenital anomalies of the kidney and urinary tract (CAKUT) using ultrasound among neonates in Shanghai, China.DesignCross-sectional study.SettingA three-level screening model for CAKUT in...

Severe fetal hydronephrosis: the added value of associated congenital anomalies of the kidneys and urinary tract (CAKUT) in the prediction of postnatal outcome.

The aim of this study was to focus on fetuses diagnosed with severe hydronephrosis and correlate prenatal sonographic characteristics with postnatal outcome. Cases presenting prenatally with severe hydronephrosis (anterior-posterior renal pelvic diameter >15mm) were collected retrospectively over a period of 11years and divided into 2 groups: (1) isolated hydronephrosis and (2) those associated with congenital anomalies of the kidney and urinary tract (CAKUT). A total of 83 fetuses comprised the study group: 35 fetuses had isolated severe hydronephrosis and 48 had associated CAKUT. The mean anterior-posterior renal pelvic diameter was 22.6±8.5mm (range 15.0-66.0mm). The CAKUT group was associated with a significantly increased incidence of postnatal need for surgery (17.6% vs 44.2%, P=.014), dysplastic kidney (0% vs 14%, P=.023), and total abnormal outcome (52.9% vs 86%, P=.001) in comparison with isolated severe prenatal hydronephrosis. Severe fetal hydronephrosis has a wide postnatal clinical spectrum, which is mainly influenced by the presence of associated sonographic CAKUT findings. These clinical data have biological relevance: a genetic or environmental defect that influences multiple renal developmental processes leads to hydronephrosis but also to concomitant malformations (CAKUT) and critically influences renal prognosis. A more selective abnormal developmental process that results in isolated enlarged pelvis even to a severe extent has less influence on renal prognosis.

MRI-based reference range for the renal pelvis anterior-posterior diameter in children ages 0-19 years.

To determine the mean and normal range of anteroposterior diameter (APD) of the renal pelves in children. Patients aged 0-19 years with normal spinal MRIs were identified after institutional review board approval. Those with dilating uropathy or abdominal surgery/radiation were excluded. The maximum APD was measured. A mixed linear model was fit to determine the relationship between APD and age, adjusted for bladder distention. The left and right kidneys were treated independently. 283 left and 285 right renal units were included. For the left, a 3.5% increase in APD per year was predicted (p < 0.0001), with the average APD for infants and 18-year olds with non-distended bladders being 2.5 mm (95th percentile: 7.2 mm) and 4.6 mm (13.4 mm), respectively. For the right, a 3.9% increase in APD per year was predicted (p < 0.0001), with the average APD for infants and 18-year olds with non-distended bladders being 2.8 mm (8.4 mm) and 5.5 mm (16.6 mm), respectively. Compared with a non-distended bladder, a distended bladder increased the predicted APD between 23% (right) and 38% (left) (p = 0.01 and p < 0.0001, respectively). The mean and normal ranges of APD measured by MRI in children are provided. APD increases with age and bladder distension and is greater on the left. Advances in knowledge: This article establishes normative ranges for APD, a critical component of genitourinary tract evaluation, and does so using the most precise imaging modality for this condition.

Sonographic Renal Parenchymal Measurements for the Evaluation and Management of Ureteropelvic Junction Obstruction in Children.

To correlate sonographic renal parenchymal measurements among patients with ureteropelvic junction obstruction (UPJO) labeled society of fetal urology (SFU) hydronephrosis grades 1-4 and to examine whether sonographic renal parenchymal measurements could be used to differentiate conservative vs. surgical management. Retrospective chart review and sonographic renal parenchymal measurements (renal length, medullary pyramid thickness, and renal parenchymal thickness) were performed in patients with SFU grades 1-4 hydronephrosis secondary to UPJO managed between 2009 and 2014. Exclusion criteria included other concomitant genitourinary pathology or incomplete follow-up. Anterior-posterior renal pelvic diameter (APRPD) and radionuclide renography were also evaluated when available. One hundred four patients with UPJO underwent 244 renal and bladder ultrasound (1,464 sonographic renal parenchymal measurements in 488 kidneys). Medullary pyramid thickness and renal parenchymal thickness progressively decreased from SFU grades 1-4 (p < 0.05). A similar trend was appreciated when comparing SFU grades 1 and 2 vs. 3 and 4, as well as SFU grades 3 vs. 4 (p < 0.05). SFU grade 3 and 4 patients who underwent pyeloplasty had longer renal length in comparison to those who were managed conservatively (p < 0.02). This is the first study that evaluates these objective, quantifiable sonographic renal parenchymal measurements in children with unilateral UPJO. These sonographic renal parenchymal measurements correlate closely with worsening of hydronephrosis graded by the SFU and APRPD classification systems. Prospective studies are needed to elucidate the role of sonographic renal parenchymal measurements in the management of children with UPJO.

Multidisciplinary consensus on the classification of prenatal and postnatal urinary tract dilation (UTD classification system)

ObjectiveUrinary tract (UT) dilation is sonographically identified in 1–2% of fetuses and reflects a spectrum of possible uropathies. There is significant variability in the clinical management of individuals with prenatal UT dilation that stems from a paucity of evidence-based information correlating the severity of prenatal UT dilation to postnatal urological pathologies. The lack of correlation between prenatal and postnatal US findings and final urologic diagnosis has been problematic, in large measure because of a lack of consensus and uniformity in defining and classifying UT dilation. Consequently, there is a need for a unified classification system with an accepted standard terminology for the diagnosis and management of prenatal and postnatal UT dilation. MethodsA consensus meeting was convened on March 14–15, 2014, in Linthicum, Maryland, USA to propose: 1) a unified description of UT dilation that could be applied both prenatally and postnatally; and 2) a standardized scheme for the perinatal evaluation of these patients based on sonographic criteria (i.e. the classification system). The participating societies included American College of Radiology, the American Institute of Ultrasound in Medicine, the American Society of Pediatric Nephrology, the Society for Fetal Urology, the Society for Maternal-Fetal Medicine, the Society for Pediatric Urology, the Society for Pediatric Radiology and the Society of Radiologists in Ultrasounds. ResultsThe recommendations proposed in this consensus statement are based on a detailed analysis of the current literature and expert opinion representing common clinical practice. The proposed UTD Classification System (and hence the severity of the UT dilation) is based on six categories in US findings: 1) anterior-posterior renal pelvic diameter (APRPD); 2) calyceal dilation; 3) renal parenchymal thickness; 4) renal parenchymal appearance; 5) bladder abnormalities; and 6) ureteral abnormalities. The classification system is stratified based on gestational age and whether the UT dilation is detected prenatally or postnatally. The panel also proposed a follow-up scheme based on the UTD classification. ConclusionThe proposed grading classification system will require extensive evaluation to assess its utility in predicting clinical outcomes. Currently, the grading system is correlated with the risk of postnatal uropathies. Future research will help to further refine the classification system to one that correlates with other clinical outcomes such as the need for surgical intervention or renal function.

Editorial Board

Urinary tract (UT) dilation is sonographically identified in 1–2% of fetuses and reflects a spectrum of possible uropathies. There is significant variability in the clinical management of individuals with prenatal UT dilation that stems from a paucity of evidence-based information correlating the severity of prenatal UT dilation to postnatal urological pathologies. The lack of correlation between prenatal and postnatal US findings and final urologic diagnosis has been problematic, in large measure because of a lack of consensus and uniformity in defining and classifying UT dilation. Consequently, there is a need for a unified classification system with an accepted standard terminology for the diagnosis and management of prenatal and postnatal UT dilation.A consensus meeting was convened on March 14–15, 2014, in Linthicum, Maryland, USA to propose: 1) a unified description of UT dilation that could be applied both prenatally and postnatally; and 2) a standardized scheme for the perinatal evaluation of these patients based on sonographic criteria (i.e. the classification system). The participating societies included American College of Radiology, the American Institute of Ultrasound in Medicine, the American Society of Pediatric Nephrology, the Society for Fetal Urology, the Society for Maternal-Fetal Medicine, the Society for Pediatric Urology, the Society for Pediatric Radiology and the Society of Radiologists in Ultrasounds.The recommendations proposed in this consensus statement are based on a detailed analysis of the current literature and expert opinion representing common clinical practice. The proposed UTD Classification System (and hence the severity of the UT dilation) is based on six categories in US findings: 1) anterior-posterior renal pelvic diameter (APRPD); 2) calyceal dilation; 3) renal parenchymal thickness; 4) renal parenchymal appearance; 5) bladder abnormalities; and 6) ureteral abnormalities. The classification system is stratified based on gestational age and whether the UT dilation is detected prenatally or postnatally. The panel also proposed a follow-up scheme based on the UTD classification.The proposed grading classification system will require extensive evaluation to assess its utility in predicting clinical outcomes. Currently, the grading system is correlated with the risk of postnatal uropathies. Future research will help to further refine the classification system to one that correlates with other clinical outcomes such as the need for surgical intervention or renal function.