5th Joint Meeting of ESPU-SPU - Virtual

S6: OBSTRUCTION & HYDRONEPHROSIS

Moderators: Doug Clayton (USA)

ESPU-SPU Meeting on Thursday 23, September 2021, 17:15 - 18:10


17:15 - 17:18
S6-1 (PP)

★ ACCURATE ESTIMATE OF SPLIT DIFFERENTIAL RENAL FUNCTION USING ULTRASOUND ALONE FOR INFANTS WITH HYDRONEPHROSIS

Mandy RICKARD 1, Lauren ERDMAN 2, Marta SKRETA 2, Daniel T. KEEFE 1, Joana DOS SANTOS 1, Reza VALI 3, Anna GOLDENBERG 1, Michael BRUDNO 2 and Armando J. LORENZO 1
1) The Hospital for Sick Children, Urology, Toronto, CANADA - 2) The Hospital for Sick Children, Centre for Computational Medicine, Toronto, CANADA - 3) The Hospital for Sick Children, Diagnostic Imaging, Toronto, CANADA

PURPOSE

Estimating differential renal function (DRF) requires imaging with nuclear scans. Obtaining DRF from ultrasound (US) images would be beneficial to institutions (by reducing costs) and patients (by avoidance of radiation). Herein we explore applying our existing deep learning architecture to the task of determining DRF from ultrasound images. 

MATERIAL AND METHODS

We used serial imaging from 135 infants with hydronephrosis. Function was classified as “normal” (40-60) or “abnormal” (<40; >60). We trained a convolutional neural network (CNN) with the task of predicting normal or abnormal function from sagittal or transverse renal US images. As input to the model, we took both the left and right kidneys for a given patient and predicted the function for the left kidney, since kidney function is measured in relation to both renal units. To consider information from one view, we tested a CNN with 7 convolutional layers and 2 linear layers. To investigate the predictive gain from using both sagittal and transverse views simultaneously, we used a neural network composed of two identical CNN subnetworks that took in input images from both views to make a prediction.

RESULTS

We were able to predict normal/abnormal renal function in US images with an AUROC 0f 0.776. Including both sagittal and transverse views in the model improved our performance (Table 1). To improve the interpretability of our predictions, we generated heat maps to view areas of interest in US images that our classifier deemed most indicative for predicting function abnormalities.


Model

Training 

(AUROC)

Test

(AUROC)

Sagittal View

0.999

0.668

Transverse View

0.880

0.644

Sag + Trans View

0.992

0.766

CONCLUSIONS

Prediction of normal or abnormal differential function based on US images alone appears to be feasible even without feature-engineering or clinical/patient variables. This technology may allow for closer monitoring and reduce exposure to invasive testing by selecting patients most likely to benefot from a nuclear scan.


17:18 - 17:21
S6-2 (PP)

★ RENAL GLOMERULAR AND TUBULAR FUNCTION IN PATIENTS OPERATED FOR POSTERIOR URETHRAL VALVES

Jukkä HEIKKILÄ 1, Timo JAHNUKAINEN 2, Christer HOLMBERG 2 and Seppo TASKINEN 1
1) Helsinki University Hospital, Paediatric Surgery, Helsinki, FINLAND - 2) Helsinki University Hospital, Paediatric Nephrology, Helsinki, FINLAND

PURPOSE

To evaluate associations between renal glomerular and tubular function and further risk for end stage kidney disease (ESKD) in patients operated for posterior urethral valves (PUV).

MATERIAL AND METHODS

During 1987-1991 63 consecutive patients (median age 11 y (range 2-24)) treated for PUV were enrolled. Glomerular function was estimated by measuring glomerular filtration rate (GFR) and urine albumine excretion. Tubular function was assessed by measuring urine osmolality, electrolyte (Na, K, Ca, Cl, P, Mg) and β-2-microglobulin concentrations. In addition, prevalence of hypertension, serum parathyroid hormone (PTH) and aldosterone values were analyzed. These findings were correlated to GFR and the risk of developing ESKD before November 2018.

RESULTS

Mild, moderate or severe chronic kidney disease (12 (19%), 6 (10%) and 2 (3%) respectively) was observed in 20 (32%) patients. Patients without proteinuria or hypertension had better GFR-values (p<0.01 for both). All the measured variables of tubular function had a significant correlation with GFR (p<0.01 for all, except 0.03 for dU-K). GFR was significantly lower as well as the concentration of all measured electrolytes in urine (p<0.01) in 10 patients developing ESKD during follow-up compared to the others. Urine β-2 - microglobulin and serum PTH and aldosterone values were significantly higher in the patients developing ESKD (p≤0.01). However, only GFR and s-PTH values had a significant association with the speed of developing ESKD (Rho 0.782, p=0.019 and Rho -0.804, p=0.022 respectively).

CONCLUSIONS

In addition to glomerular function, several parameters measuring tubular function may be applicable when assessing the risk of ESKD in PUV patients.


17:21 - 17:27
Discussion
 

17:27 - 17:30
S6-3 (PP)

A PROSPECTIVE INVESTIGATION OF HYDROURETER: AN ANALYSIS FROM THE SOCIETY FOR FETAL UROLOGY HYDRONEPHROSIS REGISTRY

Sarah HOLZMAN 1, Luis BRAGA 2, C. D. Anthony HERNDON 3, Carol DAVIS-DAO 1, Nora KERN 4, Rebecca ZEE 3, Joshua CHAMBERLIN 5, Melissa MCGRATH 2, Kai-Wen CHUANG 1, Heidi STEPHANY 1, Elias WEHBI 1, Anne DUDLEY 6, Valre WELCH 3, Gina LOCKWOOD 7 and Antoine KHOURY 1
1) CHOC Children's and University of California, Irvine, Pediatric Urology, Orange, USA - 2) McMaster University, Pediatric Urology, Hamilton, CANADA - 3) Children's Hospital of Richmond at VCU, Pediatric Urology, Richmond, USA - 4) University of Virginia Health System, Pediatric Urology, Charlottesville, USA - 5) Loma Linda University Children's Hospital and CHOC Children's, Pediatric Urology, Loma Linda, USA - 6) Connecticut Children's Medical Center, Pediatric Urology, Hartford, USA - 7) University of Iowa Hospitals and Clinics, Pediatric Urology, Iowa City, USA

PURPOSE

Current guidelines recommend voiding cystourethrogram (VCUG) for prenatal hydronephrosis (PHN) with hydroureter but do not define the minimum ureteral diameter for hydroureter. We evaluated the definition of clinically significant hydroureter, its association with urinary tract infection (UTI) and whether continuous antibiotic prophylaxis (CAP) impacted UTI risk.

MATERIAL AND METHODS

Patients with PHN from six centers were enrolled into the SFU Hydronephrosis Registry from 2008-2019. Subjects with ureter measurement on ultrasound were included. Subjects with ureterocele, ectopic ureter, neurogenic bladder, posterior urethral valve, horseshoe or solitary kidney, known ureteropelvic junction obstruction, or follow-up <1 month were excluded. Primary outcome was UTI. Analyses were performed using Cox regression.

RESULTS

Of 1280 enrollees, 216 were included. Seventy-six percent were male, ureteral diameter ranged from 1-34 mm, and median follow-up was 2.2 years. Hydroureter of 7mm was a significant cutoff to differentiate subjects at high UTI risk. Subjects with ureters 7mm or greater had three times the risk of UTI adjusting for sex, circumcision, CAP, and hydronephrosis grade (HR=3.3, 95% CI:1.2-9.3), p=0.03). Amongst subjects undergoing VCUG (186/216), 7mm or more identified patients at increased UTI risk controlling for sex, circumcision, reflux and hydronephrosis grade (HR=2.9, 95% CI:1.0-8.4, p=0.04). CAP was strongly protective against UTI (HR=0.26, 95% CI: 0.14-0.48, p<0.0001). In subjects with hydroureter <7mm, 0/24 circumcised males, 1/13 (8%) uncircumcised males and 3/13 (23%) females developed UTI.

CONCLUSIONS

This is the first prospectively collected, multi-center study to show that hydroureter 7mm or more identifies a high UTI risk group who would benefit from further imaging and CAP. In contrast, patients with PHN and hydroureter <7mm may be managed more conservatively.


17:30 - 17:33
S6-4 (PP)

ROLE OF RENAL PARENCHYMA TO HYDRONEPHROSIS AREA RATIO IN PREDICTING OUTCOME AFTER PYELOPLASTY IN CHILDREN WITH URETEROPLEVIC JUNCTION OBSTRUCTION

Ahmed SAKR, Salem KHALIL, Mohamed SELEEM, Emad SALEM and Mohamed SHAWKEY
Zagazig University - Faculty of Medicine, Urology, Zagazig, EGYPT

PURPOSE

To find a correlation between parenchyma to hydronephrosis area ratio (PHAR), other clinical and radiological parameters for prediction of pyeloplasty outcome.

MATERIAL AND METHODS

This Prospective cohort study included children having UPJO and scheduled for open Anderson-Hynes pyeloplasty between April and October 2019. All included patients did an abdominal U/S to assess parenchymal thickness, PHAR, renal echogenicity. PHAR is done preoperatively & postoperatively at 3rd & 6th months. Following the outline of the kidney to obtain the whole surface area of the kidney including the parenchymal (RPA) & the hydronephrosis areas. The following equations were used: RPA= Total renal area - hydronephrosis area. PHAR = Hydronephrosis area / RPA

RESULTS

Thirty cases were enrolled in the study with median age of 9.5 years. Improvement rate after pyeloplasty was 83.3% according to clinical & radiological improvement by U/S & renal isotope scan. Pelvic APD & T½ postoperatively were significantly lower among improved cases, Parenchymal Thickness, GFR and split function postoperatively was significantly higher among improved cases, and PHAR postoperatively was significantly higher among improved cases. Pelvic APD & T ½ postoperatively showed significantly negative correlation with PHAR postoperatively while Parenchymal thickness, Split Function, GFR total pre and postoperatively showed significantly positive correlation with PHAR postoperatively. When a cutoff value for PHAR of 1.89 is assigned to a ROC curve it showed sensitivity 84% specificity 80% for improvement.

CONCLUSIONS

PHAR can be used as a good indicator of success of pyeloplasty & improvement of renal function postoperatively with a positive correlation with renal isotope. The cutoff value of PHAR post-operatively is 1.89 with PHAR above it indicates improvement & can omitting radioisotope scans of those patients.


17:33 - 17:36
S6-5 (PP)

IDENTIFICATION OF URINARY BIOMARKERS IN NEWBORNS WITH PRENATAL UNILATERAL URINARY TRACT DILATATION USING 1H NMR SPECTROSCOPY AND METABOLOMIC ANALYSIS.

Aurelien SCALABRE 1, Yohann CLEMENT 2, Florence GUILLIERE 2, Delphine DEMEDE 3, Pierre MOURIQUAND 4, Pierre LANTERI 5, Benedicte ELENA-HERRMANN 6 and Pierre-Yves MURE 4
1) University Hospital of Saint-Etienne, Pediatric surgery, Saint Etienne, FRANCE - 2) Claude Bernard Lyon 1 University, CNRS, ISA, UMR CNRS n°5280, Villeurbanne, FRANCE - 3) Femme Mere Enfant Hospital, Pediatric surgery, Bron, FRANCE - 4) Femme Mère Enfant Hospital, Pediatric surgery, Bron, FRANCE - 5) Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ISA, UMR CNRS N°5280, Villeurbanne, FRANCE - 6) Univ Grenoble Alpes, CNRS, INSERM, IAB, Grenoble, FRANCE

PURPOSE

The prenatal finding of unilateral Urinary Tract Dilatation (UTD) can be transient or represent a Urinary Flow Impairment (UFI) that would lead to progressive deterioration of renal function. This metabolomic study aims to identify urinary biomarkers that could help to differentiate significant UFI requiring surgical management from transient dilatation at an early stage.

MATERIAL AND METHODS

We prospectively included 70 consecutive newborns prenatally diagnosed with unilateral UTD and 90 healthy newborns as controls. For each one, a urine sample was collected non-invasively within 120 days from birth.  Indications for surgery were recurrent febrile urinary tract infections and/or decrease of relative renal function more than 10% on serial isotope studies and/or increasing anteroposterior intrasinus diameter greater than 20% on serial ultrasounds. After a minimum follow-up of 2 years, patients were classified in 3 groups: simple dilatations, surgery and controls. Analysis of urine was carried out by 1H-Nuclear Magnetic Resonance spectroscopy. Sparse partial-least-squares discriminant analysis (sPLS-DA) was undertaken for classification and variable selection.

RESULTS

After a median follow-up of 39.7 months, 33 patients required surgery and 27 were included in the group of simple dilatations.Specific urinary metabolomics profiles were identified in each group. sPLS-DA provided robust classification, yielding high sensitivity and specificity models capable of discriminating urine samples from controls, simple dilatations and patients who required surgery. Metabolites responsible for these differences were identified.

CONCLUSIONS

Postnatal analysis of urinary metabolome appeared to be a powerful tool for predicting the need for surgery in newborns with prenatally diagnosed unilateral UTD.


17:36 - 17:39
S6-6 (PP)

URINARY EXTRACELLULAR MATRIX PROTEINS AS PREDICTORS OF THE SEVERITY OF URETEROPELVIC JUNCTION OBSTRUCTION IN CHILDREN

Marcos Figueiredo MELLO, Sabrina Thalita REIS, Enzo Yagi KONDO, Katia Ramos Moreira LEITE, Francisco Tibor DÉNES and Roberto Iglesias LOPES
Hospital da Clinicas da Faculdade de Medicina da USP, Urologia, São Paulo, BRAZIL

PURPOSE

Extracellular matrix proteins have been found to be associated with tissue fibrosis in the setting of ureteropelvic junction obstruction (UPJO). The ideal management of UPJO remains debatable. This prospective case-control study aimed to investigate whether urinary levels of extracellular matrix proteins are useful to point out in which children UPJO will need surgical correction.

MATERIAL AND METHODS

51 consecutive children with UPJO were enrolled. Surgery was indicated in the following situations: initial differential renal function <40%, renal function decline over follow-up or symptomatic cases. Urinary matrix metalloproteinases (MMP) 1,2,9,10 and TIMP-1 as well as clinical characteristics (hydronephrosis grade, differential renal function and t1/2) were measured in the following age-matched groups: 26 with surgical UPJO, at initial diagnosis (Group A1) and 6 months postoperatively (Group A2); 25 with non-surgical UPJO (Group B); and 30 controls (Group C). Results were assessed statistically using the unpaired nonparametric Kruskal-Wallis or ANOVA.

RESULTS

Comparing the initial samples, MMP-1 and MMP-10 levels were significantly lower (p=0.015; p=0.048), while MMP-2 and TIMP-1 (p=0.015; p=0.033) were significantly higher in surgical UPJO. The MMP-9 levels were lower in the surgical UPJO, but without significance (p=0.8) (Table 1). Follow-up analysis demonstrated increase of MMP-1, MMP-9 and MMP-10 and decrease of TIMP-1 and MMP-2 (comparison of pre and post pyeloplasty status – group A1 and A2, respectively), but no statistical differences were found.

Table 1

 

Group A1

Group B

Group C

p

TIMP-1

822.50(±872.58)

546.23(±606.32)

433.43(±515.58)

0.033**

MMP-9

309.92(±155.37)

437.00(±380.10)

349.70(±302.86)

0.806**

MMP-1

56.77(±6.45)

57.23(±6.19)

53.40(±3.02)

0.015*

MMP-2

459.31(±89.38)

420.65(±38.79)

416.83(±35.36)

0.015**

MMP-10

48.15(±10.40)

54.31(± 17.42)

75.60(±104.20)

0.048**

* ANOVA   ** Kruskal-Wallis

CONCLUSIONS

Our results showed that urinary MMP-1, MMP-2, MMP-10 and TIMP-1 are able to distinguish patients with UPJO who are designated for pyeloplasty from those under surveillance.


17:39 - 17:51
Discussion
 

17:51 - 17:54
S6-7 (PP)

PROGNOSIS FACTORS FOR SURVIVAL IN FETUSES WITH PRENATALLY DIAGNOSED MEGACYSTIS.

Lucile GRIMAL 1, Tiphaine RAIA-BARJAT 2, Marie-Caroline FAISANT 1, Marie-Noelle VARLET 2, Fabienne PRIEUR 3, Francois VARLET 4 and Aurelien SCALABRE 4
1) Grenoble University Hospital, Gynecology, La Tronche, FRANCE - 2) University Hospital of Saint-Etienne, Gynecology and obstetrics, Saint-Etienne, FRANCE - 3) University Hospital of Saint-Etienne, Genetics, Saint-Etienne, FRANCE - 4) University Hospital of Saint-Etienne, Pediatric surgery, Saint-Etienne, FRANCE

PURPOSE

Fetal megacystis may be associated with a range of different pathologies. This study aims to identify prognosis factors.

MATERIAL AND METHODS

201 pregnant women diagnosed with fetal megacystis in two university hospitals between 2000 and 2018 were identified. 29 were excluded because of missing data. Medical terminations of pregnancy were chosen in 75 cases. Newborns who survived longer than 30 days were classified in the survivor group. In utero fetal death (IUFD) and newborns that died within 30 days from birth constituted the fetal/neonatal deaths group. Demographics and ultrasound data were compared between groups.

RESULTS

Amongst 97 identified cases, 76(78.4%) were included in the survivors group and 21(21.6%) in the fetal/neonatal deaths group (18 IUFD and 3 live birth with survival less than 30 days).

The following factors were significantly more frequent in the fetal/neonatal deaths group: Diagnosis during the first trimester of pregnancy (86% vs 34%, p<0.001), bladder diameter > 15mm (73% vs 15%, p=0.001), oligoamnios (20% vs 0%, p=0.002) and associated malformations (60% vs 8%, p=0.009). After a median follow-up of 4.5 years, the final diagnoses in the survivors group were 36(47%) idiopathic megacystis, 16(21%) posterior urethral valves (PUV), 12(16%) transient megacystis and 2(3%) complex uropathies. 10(13%) megacystis resolved spontaneously before birth. Bladder wall >3mm (p=0.002), bilateral renal pelvis dilation (p=0.001), abnormal renal echogenicity (p=0.03) and posterior urethra dilation (p=0.001) were significantly associated with the diagnosis of PUV.

CONCLUSIONS

This study identified prognosis factors in fetal megacystis, which could prove helpful for prenatal counselling.


17:54 - 17:57
S6-8 (PP)

ANATOMY AND MANAGEMENT OF UPPER MOIETY VASCULAR VARIATION IN CHILDREN WITH DUPLEX KIDNEY

Xing LIU 1, Deying ZHANG 1, Dawei HE 1 and Guanghui WEI 2
1) Children's Hospital of Chongqing Medical University, Urology, Chongqing, CHINA - 2) Children's Hospital of Chongqing Medical University, Urologygy, Chongqing, CHINA

PURPOSE

To describe the upper pole vascular anatomy of duplex kidney and provide our experience with laparoscopic upper pole partial nephrectomy (LUPPN).

MATERIAL AND METHODS

A retrospective study was performed among patients with duplex kidney who underwent computed tomography angiography at one single institution, some of whom were subsequently treated with LUPPN. According to imaging results and intraoperative findings, the arterial supply to the upper moiety of a duplex system was classified based on number and branching pattern.

RESULTS

A total of 84 children were included in the study. Twenty patients (23.8%) were managed conservatively and LUPPN in lateral position was performed in the others. All laparoscopic procedures were successfully completed as planned without conversion. No major intraoperative complications occurred. Of these patients, 68 cases (73.1%) were supplied with one branch of the renal artery. The vascular anatomy of duplex kidney was classified into three patterns according to the variation of arteries. In 71 cases (76.3%), the renal artery separated into two or more arteries near the renal parenchyma, called perihilar arterial branching. Other branching patterns featured accessory renal arteries and branches of the adrenal artery. Gender was not significantly associated with the vascular number (p= 0.19) and the pattern of variation (p= 0.83).

CONCLUSIONS

LUPPN is an effective technique for children with duplex kidney. The upper renal moiety is mainly supplied by one branch of the renal artery and the most common pattern is perihilar arterial branching. Determining vascular variation before surgery might be beneficial to avoid intraoperative hemorrhage and accidental vessel injury.


17:57 - 18:00
S6-9 (PP)

★ DOES BREASTFEEDING REDUCE THE RISK OF UTI IN INFANTS WITH PRENATAL HYDRONEPRHOSIS?

Melissa MCGRATH 1, Rebecca S. ZEE 2, C.D. Anthony HERNDON 2 and Luis H BRAGA 3
1) McMaster University - McMaster Children's Hospital, Surgery, Hamilton, CANADA - 2) Children's Hospital of Richmond at VCU, Department of Surgery, Richmond, USA - 3) McMaster University - McMaster Children's Hospital, Department of Surgery / Urology, Hamilton, CANADA

PURPOSE

The effect of breastfeeding (BF)in preventing urinary tract infections (UTIs)in infants with prenatal hydronephrosis (PHN) has not been properly studied. Herein, we investigate this potential association by reviewing a large PHN database.

MATERIAL AND METHODS

From 2009-20, we prospectively screened 1300 patients with PHN. Infants with BF information missing and other genitourinary anomalies were excluded. Only patients ≤12months old at presentation with grades I-IV SFU HN were included. Demographics, BF history(age BF stopped, % BF), fUTI rates, SFU grades, HN etiology, gender, CAP, and circumcision status were captured. Primary outcome was fUTI rate. Uni and multivariable analyses were conducted.

RESULTS

Of 468 infants, 366 (78%) were male, 213 (58%) were uncircumcised, 251 (54%) had high-grade (III-IV) SFU HN, and 75 (16%) developed fUTI. Overall, 55 (12%) received formula only, 216 (46%) breast milk/formula, and 197 (42%) were breastfed exclusively. 259/413(63%) BF patients were breastfed for ≥6months. BF did not reduce fUTI rates, regardless of the intensity or duration. Lack of CAP (24% vs.6%,p<0.01), having either primary non refluxing megaureter POM or VUR vs. UPJO-like (28%, 35% vs. 9%, p<0.01) and having grade III/IV HN vs I/II (18% vs.13%, p=0.04) were significantly associated with higher fUTI rates. Females and uncircumcised males had a higher risk of fUTI compared to circumcised boys on univariate analysis (17% and 20% vs 10%). On MVA, only lack of CAP, POM and VUR were found to be independent risk factors for fUTI.

CONCLUSIONS

Although a protective effect of BF against infections is widely recognized, such effect was not observed in our PHN cohort. CAP use, POM and VUR were the most important risk factors for fUTI. BF is an intervention with multiple health benefits, however UTI prevention may not be one of them.


18:00 - 18:10
Discussion