Ureteropelvic Junction Obstruction Research Articles

Comparative Study between Continuous and Interrupted Suturing in Laparoscopic Pyeloplasty

Background: Ureteropelvic junction obstruction (UPJO) is a common cause of symptomatic ureteral obstruction. Dismembered pyeloplasty is the most commonly employed procedure for the repair of UPJO. Both interrupted and continuous suturing is being practiced in laparoscopy. As satisfactory anastomosis determines the success of dismembered pyeloplasty and recovery of renal function, the success rate and the complications associated with the suturing technique need to be evaluated. Objective: To compare the outcome between continuous and interrupted suturing in laparoscopic pyeloplasty. Methods: This hospital-based, quasi-experimental study was done in the Department of Urology, Dhaka Medical College Hospital (DMCH), Dhaka and the National Institute of Kidney Diseases & Urology (NIKDU), Dhaka from July 2022- June 2023. A total of 60 patients were purposively selected for the study. According to the suture method for ureteropelvic anastomosis, patients were divided into two groups: 30 patients (group A) underwent surgery with the continuous suture method, and 30 patients (group B) underwent surgery with the interrupted suture method. Data on suturing time, post-operative drain output, post-operative hospital stay and post-operative complications were collected. Patients were followed up at 01, 03 and 06 months. At 06 months, a DTPA renogram with split GFR was done to evaluate the patients. Results: The mean ages were 30.0 (±8.3) years for Group A and 33.9 (±9.3) years for Group B, with males comprising 56.7% and 63.3% of each group, respectively. Group B had significantly higher mean suturing time, post-operative drain output, and hospital stay compared to Group A (p<0.001). No significant differences in GFR were noted between the groups (p>0.05). Post-operative complications were observed in 10.0% of Group A and 23.3% of Group B (p=0.166). Conclusion: Continuous suturing technique for pyeloplasty is found to have a lower mean suturing time, mean drain output and post-operative hospital stay.

Value of Urine Neutrophil Gelatinase Associated Lipocalin for Prediction of Ureteropelvic Junction Obstruction in Children

Background: Congenital obstructive nephropathy is a significant cause of chronic kidney damage in childhood. Therefore, early diagnosis and management of urinary tract obstruction are necessary to prevent or reduce further renal damage. Various biomarkers have been investigated for the early identification of urinary tract obstruction. Objectives: The aim of this study was to evaluate the excretion of urine neutrophil gelatinase-associated lipocalin (Urine neutrophil gelatinase-associated lipocalin (uNGAL) & uNGAL/Cr) as a useful, sensitive, and non-invasive diagnostic biomarker in children with ureteropelvic junction obstruction (UPJO). Methods: The study cohort consisted of 47 children with obstructive UPJO and 47 healthy children with normal renal ultrasounds. Ultrasonography and 99mTc DTPA radionuclide scans were used for diagnosing UPJO. All affected children had normal renal function based on GFR measurements. Urine neutrophil gelatinase-associated lipocalin was measured using Immunoenzymatic ELISA commercial kits. Results: Urine neutrophil gelatinase-associated lipocalin & uNGAL/Cr levels were significantly higher in children with obstructive UPJO compared to the healthy control group. Additionally, both biomarkers demonstrated acceptable sensitivity and specificity for predicting for predicting UPJO. Conclusions: Based on these results, measuring uNGAL & uNGAL/Cr is suggested for evaluating children with obstructive UPJO.

Electrochemical Detection of Neutrophil Gelatinase-Associated Lipocalin (NGAL) in Simulated Urine Using Au@Si/Ni-Porphyrin Nanocomposite for the Prediction of Kidney Injury

Kidney Injury is multifactorial out of which ureteropelvic junction obstruction is one of the major causes of concern. There are a multitude of methods for monitoring the deterioration of renal function like serum creatinine levels, ultrasound scans, renograms, and nuclear scans like radiolabelled MAG3 and DMSA which require repeat evaluation or sedation during the process. Many of the biomarkers utilized for the assessment of kidney injury are expressed at the later stages. Urine NGAL is a promising biomarker for risk stratification which is reported to be expressed at the onset of ureteropelvic junction obstruction (UPJO) and is a gold standard for the estimation of tubular injury. Urinary NGAL is also reported to be a specific marker for the prediction of hydronephrosis in children who require surgical intervention. The kidney injury cut-off for NGAL in urine is 185ng/mL and 48 ng/mL in the adult and pediatric population groups respectively. Electrochemical detection of NGAL in patient urine is a fast, reliable, non-invasive, accurate, and cost-effective method for monitoring kidney health to segregate patient groups that require surgical intervention.In this study, an electrochemical sensor was designed with Au(150nm) electrodes fabricated using thermal evaporation on a flexible substrate (PET; 250μm) by using Cr(20nm) as the seed layer. The electrode was immobilized with Au@Si core-shell decorated on Ni-porphyrin nanosheets functionalized with anti-NGAL using covalent chemistry. The nanocomposite was synthesized through a bottom-up approach where the Ni-tetrakis(4-carboxyphenyl) porphyrin nanosheets were synthesized using the solvothermal method in an organic phase (DMF) followed by purification and suspension in ethanol medium. The Si nanocrystals were synthesized in a citrate medium with APTMS as the precursor followed by purification via dialysis. The purified Si nanocrystals (60ppm) and Ni-porphyrin nanosheets (880ppm) were treated in chloroauric acid (0.25mM) and the reducing agent trisodium citrate (34mM) to form Au shell. The physicochemical and electronic properties of the synthesized nanocomposite were evaluated through XRD, XPS, microscopic analysis(TEM, SEM), AFM, UV-Vis, FTIR, and Raman spectroscopy. The resultant nanocomposite was purified and linked to anti-NGAL (100μg/mL) through EDC (0.4M)/NHS (0.1M) chemistry. The antibody-nanocomposite was immobilized on the fabricated Au electrodes (working electrode surface area: 0.35mm2) through BSA(1.2mM)/glutaraldehyde (2.5% v/v) crosslinking. The quantitative electrochemical estimation of NGAL antigen spiked in 0.1M PBS (pH=7.2±0.2) and simulated urine was performed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The shelf life of the fabricated sensors was evaluated for 30 days (stored at 4˚ C until use) over the concentration range of 0-5000 ng/mL. The amount of test solution required per measurement for the miniaturized electrodes was 6μL.The sensing mechanism of the electrochemical platform was established through CV by varying the scan rate (0.05 V/s - 2.5 V/s) for 500ng/mL in 0.1M PBS and urine. With increasing scan rate a linear relationship between log ip and log ν was observed. For 0.1M PBS, the process was largely capacitive at various detected potentials (b=0.94 @ 0.5V; b=0.86 @ 0.3V; b=0.85 @ 0.07V). However, in the case of simulated urine, the electrochemical process was diffusion-limited at 0.6V (b=0.49). Therefore, to obtain higher current sensitivity in the diffusion-limited regime, DPV was adopted. With increasing concentration of antigen NGAL, a monotonic decrease in the redox current at 0.6V and 0.45V potential was observed. This signifies that the presence of NGAL antigen leads to the formation of antigen-antibody complex immobilized on the surface of the nanocomposite translating into an increase in the resistance at the electrode surface leading to a decrease in the redox current. The decrease in the current was proportional to the increase in the amount of the test antigen. The sensitivity of the sensor at 0.45V and 0.6V was 2.22 nA/ng mL-1/mm2 and 0.51 nA/ng mL-1/mm2 respectively with the lowest limit of NGAL detection as 12.5ng/mL in simulated urine by using DPV. Similarly, for CV the sensitivity of the sensor at 0.56V was 3.48 nA/ng mL-1/mm2 with 22ng/mL as the limit of detection. The sensor performance was evaluated without the use of nanocomposite (only antibody) as a control for comparison.Therefore, this study is a proof of concept for an effective electrochemical sensor platform design for urinary NGAL detection using a novel nanocomposite. It was established that the use of nanocomposite provides a better surface area to volume ratio through the core-shell nanostructures decorated on the nanosheets translating into higher electrochemical activity. The sensing platform was found to be specific, sensitive, and stable making it a perfect candidate for a point-of-care-testing(POCT) platform. Figure 1

Variable phenotype and genotype of pediatric patients with HNF1B nephropathy.

Hepatocyte nuclear factor 1β (HNF1B) mutations are the most common monogenic cause of congenital anomalies of the kidney and urinary tract (CAKUT). We aimed to investigate clinical and genetic characteristics of patients with HNF1B nephropathy to expand its phenotypic and genetic spectrum. This retrospective cohort study included 16 unrelated pediatric patients (6 females, 10 males) from 13 families with genetically confirmed HNF1B-related nephropathy. Abnormal prenatal kidney abnormalities were present in 13 patients (81.3%). The most common antenatal kidney abnormality was kidney cysts, which were observed in 8 patients (61.5%). Urinary system abnormalities (vesicoureteral reflux (VUR) and ureteropelvic junction obstruction (UPJO)) were present in 4 patients (25%). HNF1B analysis uncovered missense variants in 4 families (30.8%) as the most common genetic abnormality. In addition, 4 novel pathological variations have been defined. During follow-up, hypomagnesemia and hyperuricemia were observed in 7 (43.8%) and 5 patients (31.3%), respectively. None of the patients with a missense variant had hypomagnesemia. However, 7 out of 12 patients (58.3%) with a non-missense variant had hypomagnesemia (p=0.09). None of the patients had an HNF1B score below 8, and the mean score was 15.3±4.4. The mean follow-up period was 7.4±5.0 years. While 100% of patients (n=4) with missense variants were in various stages of CKD (CKD2: 2 patients, CKD3: 2 patients), 25% of those with non-missense variants had CKD (CKD2, 3, and 5; 1 patient, respectively) (p=0.026). Patients with HNF1B-associated disease have concomitant urinary system abnormalities such as VUR or UPJO. Missense variants seem to be the most common pathological variations in HNF1B gene and have higher risk of CKD.

Role of Ultrasonography and Dynamic Renal Scintigraphy Parameters in Decision Making Regarding Performance of Pyeloplasty in Children with Ureteropelvic Junction Obstruction

Role of Ultrasonography and Dynamic Renal Scintigraphy Parameters in Decision Making Regarding Performance of Pyeloplasty in Children with Ureteropelvic Junction Obstruction

Outcomes of robot-assisted laparoscopic pyeloplasty among pediatric patients with complex renal anatomy: A retrospective comparative study

Robot-assisted laparoscopic pyeloplasty (RALP) has been increasingly utilized in the treatment of pediatric ureteropelvic junction obstruction (UPJO) with reported success rates of >95%. Complex renal anatomy can make some cases challenging to reconstruct. To evaluate outcomes of children undergoing RALP with aberrant renal anatomy and compare it to those with simple renal anatomy. An IRB approved prospective registry was queried to retrospectively identify all patients who underwent robotic pyeloplasty at our institution from 2012 to 2022. Patients undergoing re-do pyeloplasty were excluded. Complex anatomy was defined as horseshoe kidney, ectopic/pelvic kidney, duplex collecting system, fully bifid renal pelvis and severe malrotation (≥180°). A comparative analysis of baseline demographics, pre-operative clinical/radiological characteristics, intra and post-operative details, and long-term success was performed between those patients with complex anatomy and those without. Of 405 total robotic pyeloplasty's, 375 patients (378 total pyeloplasty; 353 simple, 22 complex) met inclusion criteria. 27 re-do were excluded from analysis. The complex pyeloplasty cohort included 9 horseshoe kidneys, 8 duplex collecting systems, 3 ectopic/pelvic kidneys and 2 kidneys with severe malrotation. There was no difference in age (58 vs 31 months; p=0.38), procedure time (203 vs 207min; p=0.06), length of stay (1.4 vs 1.3 days; p=0.99), or success (91.6% vs 100%; p=0.24) between the simple and complex groups. Etiology of obstruction differed significantly between groups - high insertion was more common (3.9% vs 18.2%, p=0.02) and intrinsic narrowing was less common (60.1% vs 36.4%, p=0.04) in patients with complex anatomy. A multivariate logistic regression was adjusted for age, gender, etiology of obstruction, preoperative differential renal function and post-operative complications and found no difference in success between complex and simple RALP. The findings showed no significant differences in age, procedure time, length of hospital stay, or success rates between the two groups. Specifically, the success rates were 91.6% for the complex group and 100% for the simple group (p=0.24), indicating comparable efficacy. However, the etiology of obstruction varied significantly, with high ureteral insertion more common in the complex anatomy group (18.2% vs. 3.9%, p=0.02) and intrinsic narrowing less common (36.4% vs. 60.1%, p=0.04). Despite these differences, multivariate logistic regression, adjusted for confounders, confirmed no difference in success rates between the groups. RALP is a safe and efficacious approach in patients with complex anatomy with success rates comparable to index patients. High ureteral insertion does appear to be more common in patients with complex anatomy undergoing pyeloplasty.

Pathological characteristics analysis of children with intermittent and persistent hydronephrosis due to uretero-pelvic junction obstruction.

To analyze from a pathological perspective the differences between intermittent and persistent hydronephrosis in children with uretero-pelvic junction obstruction. 23 children who underwent unilateral dismembered pyeloplasty (Anderson-Hynes operation) for intermittent hydronephrosis from September 2017 to March 2024 were included in the observation group. They were compared with a control group consisting of 23 children with persistent hydronephrosis matched for age, gender, and affected side. All children had the narrowed segment surgically excised during the operation, while other obstructive causes (such as polyps, crossing vessels, or tumor compression) were excluded. The specimens were analyzed for muscle and collagen content using Masson's trichrome staining, and the collagen-to-muscle ratio (CMR) was calculated. The number of Cajal-like cells was quantified with c-kit immunohistochemical staining. For all slides, 10 random fields of view were selected under a 400× optical microscope to record pathological data and calculate mean values. Pathological indicators between the two groups were compared using the T-test and the Chi-square test, with P < 0.05 considered statistically significant. The observation group showed a significant difference in the number of fields with low, medium, and high densities of Cajal-like cells compared to the control group [132 (57.4%) vs. 173 (75.2%); 70 (30.4%) vs. 38 (16.5%); 28(12.2%) vs. 19 (8.3%), P < 0.001]. The uretero-pelvic junction in children with intermittent hydronephrosis had lower collagen content, higher muscle content, and a more regular arrangement. The collagen-muscle ratio was significantly lower than that in children with persistent hydronephrosis [(1.59 ± 0.65) vs. (3.98 ± 1.19), P < 0.001]. Compared with persistent hydronephrosis, the narrowed segment at the uretero-pelvic junction in children with intermittent hydronephrosis has a higher density of Cajal-like cells; lower collagen content, and higher muscle content (lower collagen-muscle ratio).

Determining Split Renal Function in Children With Ureteropelvic Junction Stenosis: Technetium-99m Mercaptoacetyltriglycine (Tc-99m MAG-3) or Technetium-99m Dimercaptosuccinic Acid (Tc-99m DMSA)?

Background Ureteropelvic junction stenosis (UPJS) is the most common cause of clinically significant antenatal hydronephrosis. We compared separate renal function results obtained using technetium-99m-mercaptoacetyltriglycine (Tc-99m MAG-3) and technetium-99m-dimercaptosuccinic acid (Tc-99m DMSA) in pediatric patients with UPJS to evaluate the adequacy of Tc-99m MAG-3 scintigraphy and the necessity of additional Tc-99m DMSA scintigraphy during follow-up. Methodology Patients diagnosed with hydronephrosis in the Pediatric Nephrology Department of Pamukkale University Faculty of Medicine over a period of 10 years (2012-2022) were evaluated retrospectively. Patients who had been diagnosed with UPJS and underwent both Tc-99m MAG-3 and Tc-99m DMSA scintigraphy during follow-up were included in the study. Technetium-99m-labeled MAG-3 and DMSA scans were re-evaluated for all patients by the Department of Nuclear Medicine. Results The study included 52 children with unilateral UPJS (12 girls and 40 boys) with a mean age of 6.34 ± 4.81 years (range: 2.97-9.79 years). Thirty-six patients (69.2%) were diagnosed antenatally. Differential renal function in Tc-99m DMSA was 46.94 ± 10.64 and in Tc-99m MAG-3 was 43.08 ± 11.18; the functions were lower in Tc-99m MAG-3, but the values were within normal limits for both groups (p=0.0001, z=-3.893). When differential renal functions were compared between Tc-99m DMSA and Tc-99m MAG-3 results, a statistically significant positive and strong correlation was found in the kidney with ureteropelvic junction obstruction (UPJO) (p=0.0001, r=0.752). When classifying the Tc-99m MAG-3 and Tc-99m DMSA results in the kidney with UPJO (supranormal, normal, low function) for the determination of differential renal functions, there was a consistency of 76%, and it was correlated (p=0.0001, k=0.456). While two patients had supranormal function and 13 patients had low function in Tc-99m MAG-3, five patients had supranormal function, and eight patients had low function in Tc-99m DMSA. Conclusions Some studies in the literature have reported that Tc-99m MAG-3 causes supranormal function measurements in patients with UPJS; our results showed that Tc-99m DMSA resulted in a higher rate of supranormal values for affected kidneys. We believe that Tc-99m DMSA should not be performed in addition to Tc-99m MAG-3 scintigraphy in the follow-up of every patient with UPJS but can be utilized in select cases, such as patients with surgical indications and those suspected before surgery.

Determination of voiding pressure in infants with normal lower urinary tracts: Exploring the possible effect of sacral development.

To investigate the association between sacral underdevelopment, as defined by subnormal sacral ratio (SR) measurements, with increased maximum detrusor voiding pressure (P det. Max) in infants. In this 2007-2015 retrospective cohort study, the medical records of all infants who underwent a pyeloplasty due to congenital ureteropelvic junction obstruction were added. Their P det. Max was evaluated through the suprapubic catheter utilized for urinary drainage intraoperatively, without imposing any additional risk of urethral catheterization on the infant. SR was calculated via the plain kidney, ureter, and bladder (KUB) radiography film obtained during the voiding cystourethrogram (VCUG) evaluation before the surgery. Participants were categorized into SR < 0.74 or SR ≥ 0.74. P det. Max was subsequently compared between these two groups. A total of 45 patients were included in our analysis. Twenty-eight (62.2%) patients had a (SR < 0.74), while 17 (37.8%) had a (SR ≥ 0.74). P det. Max was shown to be significantly higher in the SR < 0.74 compared to the SR ≥ 0.74 group (167.5 ± 60.8 vs. 55.7 ± 17.9 cmH2O, p < 0.001). After adjusting for age and sex, SR remained a significant contributor to P det. Max (p < 0.001). Physiologic detrusor sphincter dyscoordination (PDSD) rate was significantly higher in the SR < 0.74 versus SR ≥ 0.74 group (100.0% vs. 70.6%, respectively; p = 0.005). Lumbosacral underdevelopment, as indicated by subnormal sacral ratios, is associated with sphincter-detrusor dyscoordination, which causes PDSD and can ultimately result in higher P det. Max in infants.

Minimally invasive versus open pyeloplasty in pediatric population: Comparative retrospective study in tertiary centre.

Ureteropelvic junction obstruction (UPJO) is the most common cause of antenatal hydronephrosis. The incidence is around 1: 750-1500 live births. The standard treatment for (UPJO) is open pyeloplasty (OP) with a high success rate of 90%-95%. In the last 20 years, minimal invasive pyeloplasty (MIP) became an excellent alternative technique to OP which was historically the standard of care. The study participants were male and female patients aged 14 years old or less who had undergone open/minimally invasive pyeloplasty during 2015-2020 and who had at least 1-year follow-up after surgery. The data were collected retrospectively from patients' charts. The patients were categorized into two cohort groups: OP and on the other arm minimally invasive pyeloplasty (robotic/laparoscopic) comparing the outcomes as a 1ry endpoint. 2ry endpoints were hospital stay, duration of surgery, and anteroposterior diameter of renal ultrasound. A total of 133 patients were included in the study. Eighty-four underwent MIP while 49 patients underwent OP. 1ry endpoint was the success rate in both groups. The success rate was 94% (n: 79) and 98% (n: 48) in patients who underwent MIP and OP, respectively. P <0.05 is considered significant. Open and minimally invasive pyeloplasty are comparable in terms of success rate. However, OP was associated with shorter hospital stays and shorter operative times.

Renal Histopathological Changes in Children With Congenital Ureteropelvic Junction Obstruction

Renal histologic changes in congenital ureteropelvic junction obstruction (UPJO), although well documented, are sparsely studied in children. This study aims to establish a histological grading depending on the glomerular and tubulo-interstitial changes in hydronephrotic kidneys and determine correlation with age at surgery and impact on function post-pyeloplasty. A renal cortical wedge biopsy was obtained after pyeloplasty and histological changes were graded from 1 to 4. A total of 47 viable biopsies from 57 children showed grade 1 changes in 10, grade 2 in 7, grade 3 in 27, and grade 4 in 3. Age at surgery, histological grade, and changes in differential renal function (DRF) were statistically analyzed. Younger age, near normal histology, and those with changes in 1 domain had preserved DRF pre-operatively. Renal histology and overall grade showed positive correlation with pre-operative DRF. However, no statistically significant association was noted with age at surgery or change in post-operative DRF.

Objective sonographic measurements of renal pelvic diameter and renal parenchymal thickness can identify renal hypofunction and poor drainage in patients with antenatally detected unilateral ureteropelvic junction obstruction

INTRODUCTIONHydronephrosis grading systems risk stratify patients with potential ureteropelvic junction obstruction, but only some criteria are measured objectively. Most notably, there is no consensus definition of renal parenchymal thinning. OBJECTIVESThe objective of this study was to assess the association between sonographic measures of renal length, renal pelvic diameter, and renal parenchymal thickness and the outcomes of a)renal hypofunction(differential renal function{DRF} <40%) and b)high-risk renal drainage(T1/2 >40 minutes). STUDY DESIGNAn institutional database of patients who had diuretic renograms(DR) for unilateral hydronephrosis was reviewed. Only infants with Society for Fetal Urology(SFU) grades 3/4 hydronephrosis without hydroureter on postnatal sonogram and had a DR within 120 days were included. The following measurement variables were analyzed: anterior posterior renal pelvic diameter(APRPD), renal length(RL), renal parenchymal thickness(PT), minimal renal parenchymal thickness(MPT=shortest distance from mid-pole calyx to parenchymal edge), and renal pyramidal thickness(PyrT). RL, PT, MPT, PyrT measurements were expressed as ratios (hydronephrotic kidney/contralateral kidney). Multivariate logistic regression was performed for each outcome by comparing three separate renal measurement models. Model 1: RLR, APRPD, MPTR; Model 2: RLR, APRPD, PTR, Model 3: RLR, APRPD, PyrTR. Individual performance of variables from the best performing model were assessed via ROC curve analysis. RESULTS196 patients were included (107 with SFU grade 3, 89 with SFU grade 4) hydronephrosis. Median patient age was 29[IQR 16,47.2] days. 10% had hypofunction, and 20% had T1/2 >40 minutes. 90% with hypofunction and 87% with high-risk drainage had SFU4 hydronephrosis. Model 1 exhibited the best performance, but on multivariate analysis, only APRPD and MPTR were independently associated with both outcomes. No other measure of parenchymal thickness reached statistical significance. The odds of hypofunction and high-risk drainage increase 10% per 1mm increase in APRPD(aOR 1.1 [CI 1.03-1.2], p=0.005; aOR 1.1 [CI 1.03-1.2], p=0.003). For every 0.1unit increase in MPTR the odds of hypofunction decrease by 40%(aOR 0.6 [CI 0.4-0.9], p=0.019); and the odds of high-risk drainage decrease by 30%(aOR 0.7 [CI 0.5-0.9], p=0.011). Optimal statistical cut-points of APRPD >16mm and/or MPTR <0.36 identified patients at risk for obstructive parameters on DR. DISCUSSION AND CONCLUSIONOf the sonographic hydronephrosis measurement variables analyzed, only APRPD and MPTR were independently associated with objective definitions of obstruction based on renal function and drainage categories. Patients who maintain APRPD <16mm and/or MPTR >0.36 can potentially be monitored with renal sonograms as there is >90% chance that they will not have DRF<40% or T1/2>40 minutes.

Long-term outcome of retroperitoneoscopic one-trocar-assisted pyeloplasty: a single-center and single-surgeon experience.

The aim of this study was to assess the long-term outcomes of retroperitoneoscopic one-trocar-assisted pyeloplasty (OTAP) for ureteropelvic junction obstruction (UPJO) in children. This retrospective analysis included 70 pediatric cases, all under the age of 5, diagnosed with UPJO and treated with the OTAP technique between May 2011 and June 2013 by a single surgeon. A single 10mm operative scope with a 5mm working channel was utilized to mobilize the ureteropelvic junction (UPJ) and exteriorize it through the trocar insertion site. Subsequently, conventional Anderson-Hynes dismembered pyeloplasty was conducted extracorporeally. Patient's demographics, operative time, hospital stay, complications, and success rate were evaluated. Seventy pediatric patients (65 males and 5 females) underwent OTAP, with ages at the time of operation ranging from 1month to 5years (mean = 22.6 ± 18.6months). The mean operative time was 74.8 ± 15.2min. There was a significant reduction in the mean renal pelvis size from 34.3 ± 8.1mm preoperatively to 13.8 ± 4.7mm postoperatively (p < 0.05). Moreover, the mean differential renal function (DRF) increased from 47.9 ± 9.8% preoperatively to 51.2 ± 5.9% postoperatively (p < 0.05). All patients experienced an uneventful postoperative recovery, with a median hospital stay of 3.4days. The success rate was 95.7%, with a median follow-up time of 75months (range: 6-125months). OTAP is a safe and feasible minimally invasive technique to correct ureteropelvic junction obstruction in children. It could be considered as a treatment of choice for children under the age of 5 as it combines the advantages of open and retroperitoneoscopic pyeloplasty and presents excellent long-term outcomes. NCT06349161 April 4th, 2024, retrospectively registered.

Predicting clinically significant events in children with ureteropelvic junction obstruction

IntroductionUreteropelvic junction obstruction (UPJO) syndrome is one of the most common causes of neonatal hydronephrosis. Management varies from simple monitoring to surgical intervention, with indications differing between institutions. A consensus of 8 societies recently described a new Urinary Tract Dilation (UTD) classification which aims to standardize ultrasound description of hydronephrosis, but which is also supposed to have predictive value in children with hydronephrosis. Our aim was to compare, in a monocentric prospective cohort of children with UPJO, the ability of UTD to predict the occurrence of a clinically significant event within the first year of life, as compared to anteroposterior diameter of the renal pelvis (APD).Study designWe used a preexisting cohort of children followed in a prospective study on UPJO. A pediatric radiologist, blinded to the children's outcome, classified the last antenatal ultrasound and postnatal ultrasound according to the UTD-A and UTD-P classification. He also confirmed the APD-A and APD-P measures. We defined a clinically significant event as being: increased pelvic dilation (&amp;gt;5 mm) and/or the presence of a febrile urinary tract infection (fUTI) and/or impaired renal function on initial nuclear scan (&amp;lt;40%). We performed a ROC-AUC curve and Random Forest (RF) analysis to compare the ability of the APD-A, APD-P, UTD-A and UTD-P scores to predict a clinically significant event.ResultsThe cohort included 28 children. Clinically significant events were noted in 20 out of 28 patients: 13 children presented an increase &amp;gt;5 mm in dilation, 6 presented an episode of fUTI and 9 had impaired function of the affected kidney. APD-A was the most effective individual criterion for predicting the occurrence of a significant clinical event (AUC = 0.867).ConclusionIn our series, for children with UPJO, the most significant marker was prenatal APD &amp;gt;15 mm to predict an increase in dilation &amp;gt;5 mm.

Investigation of reno-protective efficacy of thymoquinone in a unilateral hydronephrosis model

ABSTRACT We aimed to evaluate the effects of the antioxidant thymoquinone on treated and untreated kidneys on histological and oxidative parameters as well as Kidney Injury Molecule (KIM-1) levels in an experimental unilateral ureteropelvic junction obstruction (UPJO) with resultant hydronephrosis (HN) model. In adherence to the Animal research: reporting of in vivo exepriments guidelines, 34 male Wistar rats were randomly divided into four groups which were named accordingly: “CO” (corn oil), “TQ” (thymoquinone and corn oil), “HNCO” (UPJO-HN and corn oil), “HNTQ” (UPJO-HN, thymoquinone and corn oil). Histologically, pelvic epithelial damage, glomerular shrinkage and sclerosis, tubular damage, interstitial edema-inflammation-fibrosis (IEIF), and vascular congestion were assessed. Biochemically, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione reductase (GR) and KIM-1 levels were assessed. Macroscopic HN developed in all obstructed kidneys. Ipsilateral obstructed kidneys deteriorated in all histological parameters. Thymoquinone attenuated glomerular shrinkage and sclerosis alterations but increased vascular congestion. Contralateral non-obstructed kidneys also showed histological deterioration. Thymoquinone had beneficial effects in terms of IEIF presence in contralateral kidneys but it increased vascular congestion. MDA and SOD results were inconclusive. UPJO caused decreased GR levels in the ipsilateral kidneys but not in the contralateral ones. This effect was not ameliorated by thymoquinone treatment. KIM-1 levels were increased in ipsilateral obstructed kidneys with a lower level in HNTQ group than in HNCO. KIM-1 level of the ipsilateral HNTQ group was higher than in both non-obstructed ipsilateral kidney groups. The effect of thymoquinone in ameliorating bilaterally observed histological alterations was limited and controversial. Oxidative damage detected by GR measurements was not prevented by thymoquinone. Thymoquinone partially decreased the damage as evidenced by reduced KIM-1 levels in thymoquinone-treated obstructed kidneys.

#2289 Pregnancy outcomes in patients with congenital abnormality of the urinary tract: experience of a tertiary Portuguese center

Abstract Background and Aims Congenital abnormalities of the urinary tract (CAKUT) represent a broad range of disorders that occur due to abnormal kidney development. Maternal, obstetric, and perinatal outcome in pregnant woman with CAKUT have not been extensively evaluated, although small series report an increased incidence of urinary tract infections (UTI) and obstructive uropathy. Method Retrospective analysis of maternal, obstetric, and perinatal outcomes in pregnant patients with CAKUT (including genetic cystic kidney disease) that were surveilled in our tertiary center by a nephro-obstetric team between 2011 and June 2023. Information was obtained from medical records. Results We evaluated 47 gestations in 41 patients, with mean age of 31 ± 5 years [17-40], 89% were Caucasian, 11% black; 40% were nulliparous, 36% had hypertension (HT) and 42% a previous history of UTI. Regarding CAKUT specificity, 17/41 patients had genetic cystic diseases, 10/41 ureteropelvic junction obstruction (UPJ), 4/41 duplicate collecting system, 5/41 vesicourethral reflux, 2/41 ectopic kidney, 3/41 renal hypoplasia. Genetic testing was done before, during or after pregnancy in 2/4/4 patients, respectively. Teratogenic therapy exposure occurred in 25% of gestations. Most patients were CKD stage 1 (33/41), with 2/4/1/1 with patients in CKD stage 2/3/4/5, respectively. Mean baseline SCr was 0.99 ± 0.8 mg/dL [0.4-4.6] and mean proteinuria was 194 ± 357 mg/g [22-1500]. Renal function (RF) deterioration occurred in 9/47 (19%) women due to pre-eclampsia (PE), pregnancy hyperfiltration (PH) and hydronephrosis in 3/3/3 patients, respectively. Urologic intervention was needed in 2 patients due to hydronephrosis, and one of the patients required transient dialysis. All patients fully recovered RF except for the 1 CKD stage 3 patients that had partial RF recovery. De novo and worsening proteinuria occurred in 7/47 gestations due to PE (3/7) and PH (4/7). De novo or aggravation of HTN occurred in 25% gestations, UTI in 19% and PE in 6% gestations. Regarding fetal outcomes, mean duration of gestation was 38 ± 2 weeks [32-41] and mean birth weight 2910 ± 634 g [1360-4600]. There was 1 miscarriage and 1 medical termination of pregnancy at 17 weeks (neural tube defect). Cesarean was performed in (8/47, 17%) gestations and 10/47 (17%) newborns were admitted to the neonatal care unit (NICU) mainly due to prematurity, sepsis and feeding intolerance. Conclusion Our cohort of CAKUT patients was very heterogenous and only 19.5% had CKD stage 2-5. Still, we found a significant incidence of maternal, obstetric, and perinatal complications, namely HT UTI, PE, and the need for NICU. UPJ obstruction can evolve with RF deterioration and the need for intervention during pregnancy. This study underlines the importance of the management of these patients by a multidisciplinary team.

Risk factors influencing the recurrence of obstruction post-pediatric pyeloplasty: a single-center prospective study

ABSTRACT Background Ureteropelvic junction (UPJ) obstruction is the leading cause of pediatric hydronephrosis. While open pyeloplasty is highly effective, a small proportion of children experience recurrent ureteropelvic junction obstruction (UPJO) necessitating repeat intervention. We aimed to identify potential risk factors for pyeloplasty failure. Methods We prospectively followed 126 children undergoing open Anderson-Hynes pyeloplasty between 2019 and 2021. Demographic, clinical, anatomical, procedural, and postoperative variables were recorded. Patients were monitored for recurrence, defined as worsening hydronephrosis and/or symptoms with diuretic renogram confirmation. Univariate and multivariate analysis identified factors associated with recurrence. Results Median age at pyeloplasty was 17 months, left side was affected in 58% and 73.8% were male. At mean 28.8 months follow-up, UPJO recurred in 9 patients (7%). The only factor significantly associated with recurrence was prolonged postoperative urinary drain leakage, specifically recurrence occurred in 50% (3/6) of cases with prolonged leakage versus 5% (6/120) without (p = 0.005). Conclusions Open pediatric pyeloplasty has a high success rate, yet a minority of patients will experience recurrence necessitating re-intervention. Prolonged urine leakage was the sole predictor of failed repair in our cohort, likely due to inflammation and perianastomotic scarring. Meticulous surgical technique and prompt leak management are vital to optimize pyeloplasty outcomes. Children at higher risk warrant close monitoring to enable early detection and renal salvage.

Robotic-assisted laparoscopic pyeloplasty for the treatment of ureteropelvic junction obstruction - How should success be determined?

Ureteropelvic junction obstruction (UPJO) is characterised by stenosis of the ureteral lumen at the level of the renal pelvis and proximal ureter. At Haukeland University Hospital, robotic-assisted laparoscopic pyeloplasty (RLP) for UPJO has been performed since 2014. The aim of this study was to evaluate the results of the treatment and consider what determines treatment success. Retrospective review was performed of consecutive patients undergoing RLP between 2014-2022. Outcomes of interest included symptom relief, complication rates and renographic findings at follow-up. Treatment success was defined in terms of symptom improvement and/or improvement as well as relief of obstruction on renography. In total, 95 RLPs were performed in 54 women and 41 men, with a mean age of 40 years (IQR: 21-58). Flank pain was the most frequent presenting complaint (n = 81, 85%) followed by infection (n = 33, 35%). More than one indication for surgery was present in 1/3 of the patients. Urodynamic relevant obstruction on renography was found in 62 patients (65%) preoperatively. Mean operative time was 123 minutes (range 60-270). Two patients experienced minor intraoperative complications. At three months follow-up, 91% of patients had symptom relief, and no obstruction on renography was recorded in 64%. There was no significant association between improvement in symptoms and renography findings at follow-up, p = 1. RLP can deliver a high success rate in terms of symptom relief and few complications. There was no association between renography findings and symptom relief at follow-up. Success after surgery should be determined by symptom relief rather than renography findings.

Utility of ultrasound-based scoring system in post-pyeloplasty recovery.

Differentiation of uretero-pelvic junction obstruction (UPJO) from non-obstructive dilatation (NOD) is a major challenge. The aim of this retrospective study is to determine whether pyeloplasty prediction score (PPS) could predict the need for surgery and resolution after surgery. Among patients with antenatally diagnosed hydronephrosis, those who were stable during post-natal follow-up were considered NOD. The UPJO group were the ones who worsened and underwent pyeloplasty based on conventional indications. All patients with UPJO underwent laparoscopic dismembered pyeloplasty. PPS was determined based on three ultrasound parameters obtained retrospectively: Society of Fetal Urology (SFU) grade of hydronephrosis, transverse anteroposterior (APD), and the absolute percentage difference of ipsilateral and contralateral renal lengths. Among 137 patients included (R:L=59:73; M:F 102:35), 96 were conservatively managed (NOD), while 41 patients (29%) needed pyeloplasty (UPJO). Mean PPS was 4.2 (1.2) in the NOD group and it was significantly higher at 10.8 (1.63) in the UPJO group (p=0.001). All patients with PPS>8 needed a pyeloplasty, while two patients with PPS of 7 needed pyeloplasty due to drop in renal function. PPS cutoff value of >8 had a sensitivity 95%, specificity 100% and a likelihood ratio of 20. Post-pyeloplasty PPS resolution was proportional to the duration of follow-up. A PPS cutoff value of 8 or above is associated with the presence of significant UPJO. PPS is also useful in the assessment of hydronephrosis recovery post-pyeloplasty. The limitation of PPS: it can only be applied in the presence of contralateral normal kidney.

Doppler Ultrasound and Resistive Indices in the Diagnosis of Ureteropelvic Junction Obstruction in the Pediatric Population.

Mercapto acetyl tri-glycine renogram (MAG3) scan has been the gold standard assessment of pediatric ureteropelvic junction obstruction (UPJO) but requires intravenous access and radiation exposure. While Doppler ultrasound measurements of resistive indices (RI) of the arcuate arteries have been proposed as an alternative assessment of obstruction, they have not been widely adopted in the pediatric population. We hypothesized that RI of the main renal artery (RA) is more strongly correlated with MAG3 findings than arcuate RI. Pediatric patients with unilateral Society for Fetal Urology grade 3-4 hydronephrosis undergoing concomitant RUS and MAG3 were recruited. Doppler ultrasound peak systolic velocity (PSV); RI of bilateral RA at the origin, middle, and hilum; and RI of the superior, middle, and lower pole arcuate arteries were obtained. MAG3 differential renal function (DRF) and T½ were recorded. Differences in RI measurements (DRI) between the affected and normal kidney were calculated and compared with DRF and T½. 31 patients (median 4.6-month-old) were enrolled. Only RA RI at the origin differed between affected and normal kidneys (p < .001). DRI RA at the origin showed weak evidence for an association with MAG3 DRF < 40% (p .07). DRI was not associated with T½ > 20 minutes. There was weak evidence for an association between RA DRI at the origin and DRF but not with T½. These findings suggest that RA DRI may provide additional data in the evaluation of patients with UPJO to tailor the use of MAG3 and associated risk of radiation exposure to those patients most at risk for concomitant renal function impairment.