Diuretic Renogram Research Articles

Robotic Management of Complex Obstructive Megaureter Needing Ureteral Dismembering and/or Tapering in Children: A Single-Center Case Series

Background and Objectives: Robot-assisted extravesical ureteral reimplantation (REVUR) has been described as valuable alternative to open reimplantation in the pediatric population. This study aimed to report the outcome of REVUR in children with complex obstructed megaureter (COM) needing ureteral dismembering and/or tapering. Materials and Methods: The records of patients with COM, who received REVUR with ureteral dismembering and/or tapering over the last 3 years (2021–2024), were retrospectively reviewed. The inclusion criteria for COM included previous surgery, paraureteral diverticula, or ectopic megaureter. Results: A total of 16 patients (15 boys), with a median age of 7.8 years (range 2–16), were treated over the study period. COM was associated with paraureteral diverticula (n = 6), previous failed endoscopic balloon dilation (n = 4), ectopic megaureter (n = 2), and previous bulking agent endoscopic injection causing iatrogenic ureteral obstruction (n = 4). Presentation symptoms included febrile urinary tract infections (n = 8), flank pain (n = 4), hematuria (n = 2), and pseudo-incontinence (n = 2). All surgical procedures were accomplished robotically without conversions or intra-operative complications. Ureteral tapering was performed in 7/16 (43.7%). The median operative time (including robot docking) was 220 min (range 155–290). The median length of stay was 3.8 days (range 3–7). The indwelling double J stent was removed 4–6 weeks postoperatively. Clavien 2 grade complications occurred postoperatively in 2/16 (12.5%). At median follow-up of 34.5 months, all patients were asymptomatic and showed improved hydroureteronephrosis on ultrasound and improved drainage on diuretic renogram. Conclusions: This study demonstrates that robot-assisted extravesical ureteral reimplantation is a safe and effective treatment for primary obstructive megaureter and other complex ureteral anomalies in our patient cohort. The procedure showed low complication rates, high success rates, and favorable long-term outcomes, supporting the feasibility and effectiveness of robotic surgery for these conditions.

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.

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.

Clinical Significance of Hepatobiliary Localization of Tc-99m EC in Diuretic Renography

Abstract Objective Technetium-99m ethylene dicysteine (Tc-99m EC) is a well-established, tubular tracer for diuretic renography. Few occasional cases have been reported in literature regarding visualization of liver, gallbladder (GB), or bowel due to increased hepatobiliary route of excretion of Tc-99m EC on diuretic renography. This study aimed to retrospectively review the incidence of visualization of liver, GB, or bowel and its clinical significance in Tc-99m EC diuretic renography. Materials and Methods Data of all patients who underwent diuretic renography in the department from January 24, 2022 to March 31, 2023 was included in the study. The data was analyzed to assess the incidence of visualization of GB or bowel loops, correlation of the hepatobiliary localization with factors like age of the patient, concentration of 99m TcO4 solution, quality control parameters, presence of renal stone disease, serum creatinine, relative renal function, and effective renal plasma flow. Effect of hepatobiliary localization on scan interpretation and reporting was assessed. Results The retrospective analysis of 437 diuretic renograms revealed the hepatobiliary localization of tracer in 34 patients. Out of these 34 patients, 14 patients had only faint visualization of tracer at 4 hours delayed image. Twenty scans had visualization of both GB and bowel. Out of these 20 scans, GB and bowel were visualized during dynamic imaging in one scan, after initial 20 minutes in two scans and in 2 to 4 hours delayed images in rest of the 17 scans. Two out of 20 patients had increased serum creatinine, 16 patients had either single kidney or relative renal function less than 26%, and 12 patients had renal stone disease. Out of the four patients in whom relative renal function was more than 25%, one patient had raised serum creatinine and three patients had renal stone disease. Interpretation of images was affected only in three patients, in which reporting of the scans required single-photon emission computed tomography imaging and correlation with other imaging modalities. Conclusion Hepatobiliary excretion of Tc-99m EC usually does not usually affect the scan interpretation and quantitative renogram analysis, but reader should be cognizant of the potential pitfalls during scan interpretation. In this study, we reviewed the possible causes of this hepatobiliary clearance and importance of additional views and correlation with other imaging modalities to clarify the suspicion arises for accurate reporting.

Diagnosis and Management of Ureteropelvic Obstruction in Kidney Transplant Recipients and Outcomes of Foley Y-V Pyeloplasty.

To evaluate the etiology and diagnostic tools for ureteropelvic obstruction in kidney transplant recipients, we investigated the short-term and long-term outcomes of Foley Y-V pyeloplasty. We retrospectively reviewed 10 patients who underwent kidney transplant followed by additional interventions to treat obstructive ureteral pathologies between 2016 and 2020. We enrolled 4 patients who had received intervention to treat ureteropelvic obstruction. For these 4 patients, serum creatinine and estimated glomerular filtration rate levels were recorded at baseline, during the symptomatic period, and long-term. In this single center study, we investigated diagnostic tools and management strategies for ureteropelvic obstruction and assessed performance of Foley Y-V nondismembered pyeloplasty in kidney transplant recipients. Among 4 patients, graft function (assessed by serum creatinine and estimated glomerular filtration rate) worsened significantly (P = .03) in the symptomatic period of ureteropelvic obstruction in all patients; however, graft function levels improved rapidly to levels similar to baseline (P = .07) after Y-V pyeloplasty. In addition, no statistically significant difference was detected between baseline and longterm graft functions afterY-V pyeloplasty in follow-up (P = .28). Diagnosis and management of ureteropelvic obstruction in kidney transplant recipients are challenging due to rarity and lack of an ideal management algorithm.There is no specific diagnostic tool to discriminate this pathology from other ureteral pathologies; therefore, a regimen of conventional imaging modalities and diuretic renogram combined with endoscopic evaluation is more reliable. Moreover, nondismembered Foley Y-V pyeloplasty is effective and safe for graft function in the short-term and long-term.

Augmented anastomotic ureteral reconstruction using buccal mucosal graft, initial experience.

To assess the augmented anastomotic ureteral reconstruction using buccal mucosal graft based on omental flap for managing ureteral stricture. This prospective cohort study was conducted on 13 patients with ureteric strictures of different lengths secondary to Bilhalziasis, iatrogenic (post endoscopy) and post inflammatory etiology in upper and mid ureteral segments were treated with buccal mucosal patch grafts and The graft is fixed to the undersurface or the posterior surface of the omentum before doing graft anastomosis to the ureteral walls as to ensure the process of graft take sticky to the principles of tissue transfer. All patients were subjected to full history taking, clinical examination for assessment of pain, lower or upper urinary track symptoms and laboratory investigation (complete blood count, CRP, liver function test and kidney function test (serum urea and creatinine). The mean operative time was 148.85 min and mean hospital stay was 3 days. Mean blood loss was ranged from 20 to 210 ml and Stent was removed after 8-12 weeks. The mean follow up was 13 months, all patients had a non-obstructive RI value <0.7 with a non-obstructed drainage pattern on the diuretic renogram except one patient who had severe postoperative UTI necessitating nephrostomy tube insertion his drainage curve was plateau. BMG ureteroplasty is a valuable option for a carefully selected patient. The fixation of the graft on the back surface of the omentum allows for better anatomical reconstruction without any twisting to the omental pedicle.

Correlation between Doppler sonography and diuretic renogram in the diagnosis and follow-up of infants with unilateral pelvi-ureteric junction obstruction

BackgroundConventionally, diuretic isotope renogram is used to establish and quantify severity of the obstruction in pelvi-ureteric junction obstruction. Doppler ultrasonography too assesses obstruction by evaluating the resistive index (RI) and resistive index ratio (RIR) in the intrarenal vasculature of the kidneys. This study aimed to note correlation between RI, RIR on Doppler ultrasonography and perfusion index (PI) on diuretic isotope renogram in suspect unilateral pelvi-ureteric junction obstruction in infants. A prospective study (2016–2019) in infants with suspect unilateral hydronephrosis, i.e. anteroposterior pelvic diameter (APPD) > 15 mm, divided into Group A (0–6 months) and Group B (6–12 months) based on the age at diagnosis. The RI, RIR and PI were noted at diagnosis, at 3 and 6 months, post-interventions and the correlation assessed.Results37/94 with hydronephrosis were included in the study. 30 among these underwent surgical intervention. A decrease in RI and RIR and increase in PI following surgery were documented at follow-up. Also, the improvement was statistically more significant in the first 3 months following intervention.ConclusionsAn increased RI and RIR and a decreased PI are good indicators of obstruction in unilateral hydronephrosis in infants. The decline in RI with increase in PI following relief of obstruction shows a positive correlation between the two. Doppler sonography may be effective in monitoring unilateral hydronephrosis with unobstructed or equivocal renogram curves and consequently negate the need for repeated nuclear scans.

Comparison of Urinary Biomarkers in Diagnosis of Ureteropelvic Junction Obstruction and Differentiation from Nonobstructive Dilatation.

Differentiation of nonobstructive dilatation (NOD) from ureteropelvic junction obstruction (UPJO) is a challenge in children with antenatally detected hydronephrosis. The aim of this study is to compare the utility of urinary biomarkers: carbohydrate antigen (CA 19-9), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule (KIM) in diagnosing UPJO. A prospective study was conducted after obtaining ethical clearance between 2021 and 2022. Group 1 - control group (n = 30): children with normal antenatal ultrasound with no urinary symptoms. Group 2 - study group (n = 48): children with unilateral hydronephrosis: Group 2a - NOD (n = 24): children stable on ultrasound and diuretic renogram and Group 2b - UPJO (n = 24): children who worsened to Grade 4 hydronephrosis on ultrasound/worsening of differential renal function (10% drop) on renogram who underwent pyeloplasty. Urinary biomarkers NGAL, KIM-1, and CA 19-9 were measured using the enzyme-linked immune absorbent assay method. The urine CA 19-9 level was 128.05 ± 4.08 U/mL in the UPJO group, and this was significantly higher (P = 0.001) than NOD, 70.29 ± 4.41, and controls, 1.91 ± 1.57. The urine NGAL level was 21.41 ± 4.44 pg/mL in UPJO, and this was significantly higher than controls, 2.669 ± 0.513, but not NOD, 24.55 ± 2.67. The urine KIM level was 817 ± 15.84 pg/mL in the UPJO group, and this was significantly higher than controls, 285 ± 8.10, but not NOD, 768.23 ± 15.12. Receiver operating characteristic analysis of CA 19-9 revealed a urine biomarker cutoff of 95 U/mL for diagnosing UPJO (sensitivity 95%; specificity 96%; and area under the curve 0.99). CA 19-9 is a superior marker compared to NGAL and KIM in differentiating UPJO from NOD. Further studies with larger numbers are warranted.

Role of Diuretic Renography and Ultrasonography in Pelvic Ureteric Junction Obstruction among Infants: A Prospective Interventional Study

Introduction: Renography is a non invasive technique routinely used by clinicians to provide information about kidney structure and function. However, its role in the diagnosis of renovascular disease (especially in patients with renal insufficiency), the exclusion of obstruction, and during the follow-up of patients undergoing pyeloplasty is still controversial. Aim: To study the changes in Anteroposterior Pelvic Diameter (APD), cortical thickness, split renal function and T½ post pyeloplasty at three months and to determine the usefulness of these parameters in assessing successful pyeloplasty for Pelvic Ureteric Junction Obstruction (PUJO). Materials and Methods: This prospective non randomised interventional study was conducted in the Department of Nuclear Medicine, PGIMER, Chandigarh, India and Department of Paediatrics, JIPMER, Karaikal, Puducherry, India, from July 2020 to July 2021. A total of 31 infants with persistent postnatal Hydronephrosis (HDN) on Ultrasonography (USG) with no vesicoureteral reflux were included in the study and underwent 99mTc EC renography. The diagnosis of obstruction was determined by visual interpretation, renogram curves, Time to peak (Tmax), and Time from Tmax to T½max parameters. Patients with obstructed patterns in 99mTc EC renography underwent Anderson Hyne’s dismembered pyeloplasty. After three months of surgery, 99mTc EC renography and USG were performed on all enrolled patients. The Chi-square test was used for the comparison of the difference in proportion, and the Student’s t-test was used for the comparison of the mean difference, between two groups. Results: The mean age of enrolled infants was 5.79±3.36 months with a male preponderance (27 males and 4 females). Out of 31 infants, 23 (74%) showed an obstructive pattern of drainage on diuretic renogram and underwent Anderson-Hynes dismembered pyeloplasty. The observed difference in the preoperative renal USG anteroposterior diameter (27.85±14.3 mm) and parenchymal thickness (9.6±3.3 mm) vs postoperative anteroposterior diameter (8±3.19 mm) and parenchymal thickness (15.5±4.19 mm) was statistically significant (p-value=0.001). The follow-up renogram scan conducted at three months showed a significant reduction in clearance half-time (T½). However, there was no statistically significant variation in split renal function at three months after pyeloplasty. Conclusion: Both 99mTc EC renography and USG indicate the likelihood of successful pyeloplasty, and in settings with limited resources, USG may be a viable substitute for early follow-up after pyeloplasty.

Unique presentation of Congenital ureteropelvic junction obstruction in adult

Summary: A 34-year-old female, without comorbidities, presented to the emergency department with sudden right flank pain. Initial workup showed elevated WBC (14.5) and normal creatinine (0.81), but later developed fever spikes and rising CRP (59.50). Gentamicin treatment was initiated. Transferred for a Diuretic Renogram, confirming suboptimal function of the right kidney with obstruction at the renal pelvis/PUJ. Split functions indicated 32% for the right kidney and 68% for the left. Radiological workup included ultrasound, CT KUB with contrast, and CT Urography, revealing right renal acute hydronephrosis without evidence of stones. Management involved symptomatic treatment, but with persistent symptoms, Gentamicin prophylaxis was initiated. The patient was transferred for Renogram, detecting suboptimal right kidney function. A planned stent insertion followed by Robotic-assisted and laparoscopic pyeloplasty was scheduled. Discussion: Uretero Pelvic Junction Obstruction (UPJO) is a partial blockage where the ureter enters the kidney. Congenital UPJO can result from intrinsic narrowing, high ureter insertion, ureteral polyps, or accessory renal artery crossing vessels causing extrinsic compression. Most cases are detected on prenatal ultrasound, while postnatal presentations include UTI, abdominal mass, hematuria, and intermittent flank pain. Diagnosis involves CT urography and diuretic renogram, confirming suboptimal function (

Double J stent combined with pyelostomy tube in pediatric laparoscopic pyeloplasty: a 5-year clinical experience in a single center

ObjectiveTo compare the outcome of using a double J (DJ) stent combined with pyelostomy tube with a DJ stent alone in laparoscopic pyeloplasty (LP) for pediatric ureteropelvic junction obstruction (UPJO).MethodsA retrospective review of all patients with UPJO treated with LP between January 2017 and November 2021 was conducted in our center. According to different postoperative drainage methods patients were divided into a DJ stent group (52 cases) and a DJ stent combined with pyelostomy tube group (combination group, 41 cases). Operative time, bleeding volume, perirenal drainage stent removal time, postoperative hospital stay, postoperative complications, and renal function recovery were compared between the two groups. Renal ultrasound and diuretic renogram (DR) were used for preoperative and postoperative follow-up.ResultsA total of 52 patients were in the DJ stent group and 41 patients in the combination group. The mean hospital stay was 6.46 ± 2.66 days in the DJ stent group and 5.22 ± 1.63 days in the combination group (p < 0.05). Postoperative complications developed in 14 out of 52 patients in the DJ stent group (26.9%), while complications developed in 8 out of 41 patients in the combination group (19.5%) (p > 0.05). Non-catheter-related complications developed in 10/52 patients in the DJ stent group (19.2%) and only 1/41 patients in the combination group (2.4%) (p < 0.05). The renal function and renal cortex thickness in both groups were improved.ConclusionBoth the DJ stent drainage and the DJ stent combined with pyelostomy drainage are safe and effective. We should fully consider the patient’s preoperative and intraoperative conditions and choose appropriate drainage methods. A DJ stent combined with pyelostomy tube can reduce non-catheter related complications, facilitate postoperative recovery, and the hospital stay was significantly shorter than the DJ stent group. However, it is necessary to pay attention to the nursing treatment of the pyelostomy tube and guard against the occurrence of pyelostomy tube shedding.

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.

Predicting obstruction risk using common ultrasonography parameters in paediatric hydronephrosis with machine learning.

To sensitively predict the risk of renal obstruction on diuretic renography using routine reported ultrasonography (US) findings, coupled with machine learning approaches, and determine safe criteria for deferral of diuretic renography. Patients from two institutions with isolated hydronephrosis who underwent a diuretic renogram within 3 months following renal US were included. Age, sex, and routinely reported US findings (laterality, kidney length, anteroposterior diameter, Society for Fetal Urology [SFU] grade) were abstracted. The drainage half-times were collected from renography and stratified as low risk (<20 min, primary outcome), intermediate risk (20-60 min), and high risk of obstruction (>60 min). A random Forest model was trained to classify obstruction risk, here named the 'Artificial intelligence Evaluation of Renogram Obstruction' (AERO). Model performance was determined by measuring area under the receiver-operating-characteristic curve (AUROC) and decision curve analysis. A total of 304 patients met the inclusion criteria, with a median (interquartile range) age of diuretic renogram at 4 (2-7) months. Of all patients, 48 (16%) were low risk, 102 (33%) were intermediate risk, 156 (51%) were high risk of obstruction based on diuretic renogram. The AERO achieved a binary AUROC of 0.84, multi-class AUROC of 0.74 that was superior to the SFU grade, and external validation (n = 64) binary AUROC of 0.76. The most important features for prediction included age, anteroposterior diameter, and SFU grade. We deployed our application in an easy-to-use application (https://sickkidsurology.shinyapps.io/AERO/). At a threshold probability of 30%, the AERO would allow 66 more patients per 1000 to safely avoid a renogram without missing significant obstruction compared to a strategy in which a renogram is routinely performed for SFU Grade ≥3. Coupled with machine learning, routine US findings can improve the criteria to determine in which children with isolated hydronephrosis a diuretic renogram can be safely avoided. Further optimisation and validation are required prior to implementation into clinical practice.

Renal artery aneurism and renal autotransplantation: review of surgical technique, preoperative complementary examinations and postoperative follow-up protocol

Introduction: Renal artery aneurysm (RAA) is a rare pathology; however, its incidental diagnosis is increasingly frequent due to the increasing use of imaging techniques. Complex (hilar) RAAs, dependent on the distal renal artery and its branches, constitute a subset of RAAs that present a therapeutic challenge due to their anatomical location and may require extracorporeal arterial repair and autotransplantation. Material and methods: A bibliographic review is carried out to homogenize the management of this pathology, analyzing the indications for surgical treatment, the recommended surgical technique step by step, as well as post-surgical monitoring. Two clinical cases of RAA treated in our center by hand-assisted laparoscopic nephrectomy, ex vivo bench repair and renal autotransplantation are presented. Results: In both cases, a postoperative Doppler ultrasound of the graft was performed 24 hours later, in which a renal graft was observed in the iliac fossa, of normal size and cortical thickness within normality with normal color Doppler signal, and spectral curves without alterations. Both patients presented oligoanuric acute renal failure (injury) during the immediate postoperative period (first 24 hours) with complete resolution at discharge, which occurred on the 11th and 12th postoperative day, respectively. In both patients a diuretic renogram with MAG3 was performed. In case 1, it was performed the third postoperative month and a slightly ectatic right kidney was observed with less perfusion and parenchymal incorporation of the radiotracer, with a reduction in relative renal function (39.47%) and MAG3 clearance (indeterminate renographic pattern). In this patient, a CT scan with the excretory phase was performed simultaneously, in which a grafted right kidney was seen at the level of the right iliac fossa with good contrast elimination in the excretory phase bilaterally and symmetrically. A small non-perfused area is observed in the upper pole. In the second patient, the renogram was performed on the 14th postoperative day, finding the morphofunctional study of the graft within normal parameters without detecting areas of hypoperfusion. The levels of creatinine and glomerular filtration were, respectively, in the first case: 0.86mg/dl and 90.19ml/min/1.73m2 preoperatively and 0.83mg/dl and 90.96ml/min/ 1.73m2 per postoperative month. In the second case, the values were: preoperatively creatinine of 0.66mg/dl and glomerular filtration rate of 97.96ml/min/1.73m2 and 0.81mg/dl and 89ml/min/1.73m2 one month postoperatively. Conclusion: After reviewing the literature, there is no consensus regarding the imaging techniques to be performed after renal autotransplantation and the optimal time frames for performing these for the evaluation of the postoperative graft. There is also no homogeneity in the imaging techniques to be performed in the preoperative assessment. In our experience, open ex vivo surgical repair of complex distal hilar RAAs has been successful with low morbidity and mortality and an acceptable rate of preservation of renal function.

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

There is paucity of literature in the management of infants with primary obstructive megaureters undergoing upfront primary repair with an extravesical technique of ureteral re implantation (with or without ureteral tailoring). To compare 2 different approaches in the management of infants with unilateral primary obstructive megaureters. This was a retrospective analysis of a prospectively maintained data base between 2005 and 2021. Infants <1 year with unilateral primary obstructive megaureter were included. They were divided into 2 groups: those who underwent an upfront extravesical ureteric reimplantation with or without ureteral tailoring during infancy -Primary Repair (PR), and those who initially underwent a low end cutaneous ureterostomy during infancy followed by take down of ureterostomy and intravesical ureteric reimplantation after 1 year of age -Delayed staged repair (DSR). Children presenting with sepsis, in whom a diversion was imperative, were excluded. All children were followed up annually after their definitive repair with a renal ultrasound, diuretic renogram, estimated glomerular filtration rate and assessment of voiding dysfunction if present. The 1st year and 3rd year follow up details were collated and analysed. Failure was defined as persistent obstructive pattern on renogram with worsening differential renal function or presence of high grade reflux with recurrent breakthrough urinary tract infection; both of which necessitated a redo reimplantation following the definitive surgery. There were 18 infants in Primary repair and 16 infants in Delayed Staged Repair. Urinary tract infections was the commonest presenting symptom amongst both groups i.e. > 50%.The post operative complication rate was 11% in Primary repair and 31% in Delayed Staged Repair. One child in each of the groups (2 girls) required redo reimplantation (5.8%). At the end of the 3rd year follow up (from the definitive repair) there was significant reduction in the hydronephrosis, improvement in the differential renal function with no evidence of obstruction and improvement in the estimated glomerular filtration rate amongst all in both groups which was statistically significant i.e. p<0.05. The success rate was 94.4% in Primary Repair and 93.75% in Delayed Staged Repair. The mean follow up was 9.7 years amongst those undergone Primary Repair and 9 years amongst those undergone Delayed Staged Repair. Primary extravesical ureteral reimplantation may be considered as the preferred line of management of unilateral obstructed megaureters during infancy.

PD37-07 A MACHINE LEARNING TOOL TO DETERMINE OBSTRUCTION IN CHILDREN WITH HYDRONEPHROSIS FROM ROUTINE SONOGRAPHIC FINDINGS

You have accessJournal of UrologyCME1 Apr 2023PD37-07 A MACHINE LEARNING TOOL TO DETERMINE OBSTRUCTION IN CHILDREN WITH HYDRONEPHROSIS FROM ROUTINE SONOGRAPHIC FINDINGS Adree Khondker, Jethro Kwong, Jin Kyu Kim, Michael Chua, Margarita Chancy, Natasha Brownrigg, Joana Santos, Lauren Erdman, Neeta D'Souza, John Weaver, Mandy Rickard, and Armando Lorenzo Adree KhondkerAdree Khondker More articles by this author , Jethro KwongJethro Kwong More articles by this author , Jin Kyu KimJin Kyu Kim More articles by this author , Michael ChuaMichael Chua More articles by this author , Margarita ChancyMargarita Chancy More articles by this author , Natasha BrownriggNatasha Brownrigg More articles by this author , Joana SantosJoana Santos More articles by this author , Lauren ErdmanLauren Erdman More articles by this author , Neeta D'SouzaNeeta D'Souza More articles by this author , John WeaverJohn Weaver More articles by this author , Mandy RickardMandy Rickard More articles by this author , and Armando LorenzoArmando Lorenzo More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003335.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: For children with hydronephrosis (HN), the diuretic renogram is the gold standard in evaluating patients with suspected obstruction. Herein, we aimed to use routinely reported ultrasound findings, along with machine learning approaches, to predict the risk of ureteropelvic junction obstruction (UPJO) in infants with isolated HN. METHODS: We included patients less than 24 months of age at baseline with a renogram within 3 months of an ultrasound. Age, sex, and routinely reported ultrasound findings (laterality, kidney length, anteroposterior diameter [APD], SFU grade) were abstracted. T 1/2 washout periods were collected from renography and stratified as low risk (<20 minutes), unclear risk (20-60 minutes), and high risk of obstruction (>60 minutes). A random forest model was trained to classify obstruction risk, referred to as AI Evaluation of Renogram Obstruction (AERO). Model performance was determined by measuring area under the receiver-operator-characteristic curve (AUROC) and decision curve analysis. RESULTS: A total of 304 patients met inclusion criteria, with a median age of diuretic renogram at 4 months (IQR 2, 7). Of all patients, 48 (16%) were low-risk, 102 (33%) were unclear risk, 156 (51%) were high risk of obstruction based on diuretic renogram. AERO achieved a multi-class AUROC of 0.75 which was superior to logistic regression (Figure 1). The most important features for prediction included age, APD, and SFU grade. We deployed our model in an easy-to-use application (https://sickkidsurology.shinyapps.io/AERO/). At a threshold cutoff of 30%, AERO would allow 137 more patients per 1000 to safely avoid a renogram without missing significant obstruction compared to a strategy in which a renogram is performed for all patients with SFU grade 3 or above. CONCLUSIONS: Routine ultrasound findings can be used to determine if a diuretic renogram can be safely avoided for children with isolated hydronephrosis, thus offering the potential to minimize invasiveness of monitoring and exposure to radiation. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e989 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Adree Khondker More articles by this author Jethro Kwong More articles by this author Jin Kyu Kim More articles by this author Michael Chua More articles by this author Margarita Chancy More articles by this author Natasha Brownrigg More articles by this author Joana Santos More articles by this author Lauren Erdman More articles by this author Neeta D'Souza More articles by this author John Weaver More articles by this author Mandy Rickard More articles by this author Armando Lorenzo More articles by this author Expand All Advertisement PDF downloadLoading ...

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

Mercaptoacetyltriglycine (MAG-3) renogram is one of the gold standard diagnostic tools of ureteropelvic junction obstruction (UPJO); however, there is no widely agreed indications of pyeloplasty based on MAG-3 findings. In this study, we introduce a renogram scoring system that can help improve the prognostic value of MAG-3 renogram and in the decision making of pyeloplasty. We retrospectively reviewed consecutive pyeloplasties for antenatal hydronephrosis from 2010 to 2020. A control group was included of non-operatively managed SFU grade 3 and 4. The initial renal ultrasound and preoperative MAG-3 Lasix renogram were reviewed for differential renal function (DRF), type of renogram curve and tracer washout half-time (T1/2). A ROC curve was used to evaluate the cut-off points that can be associated with obstruction. A multivariate linear regression model was used to assess the best renogram parameter that can predict surgical intervention. We included 188 patients with 209 renal units. The median age for pyeloplasty was 5.4 months. The mercaptoacetyltriglycine-Suspected Obstruction Scoring System (MAG-SOS) was associated with pyeloplasty (AUC=0.97, P<0.001) (FigureA). A score of 5 is 100% specific for obstruction. 78% of units required surgical intervention had a MAG-SOS score of≥5 while all units of the control group had a range of score 0-4. Using the multivariate analysis, the MAG-SOS system showed to the only independent predictor for pyeloplasty (HR=0.03, p<0.001). This study has some limitations. Firstly, the retrospective nature of the cohort; however, all patients were reviewed by one investigator who was blinded to the line of management. This is a single institutional study; therefor, this MAG-SOS should be evaluated by other centers to ensure its efficiency. Lastly, the pyeloplasty decision was taken by 3 different urologists; nevertheless, all of them adopt the same indications which are similar to those of the Society for Pediatric Urology and the Canadian Urological Association guidelines. The MAG-SOS system showed to be a useful tool that can predict pyeloplasty. A score of 5 has 100% specificity for patients having a pyeloplasty performed. Prospective studies are required to confirm the usefulness of this novel tool.

A Cost-effectiveness Model Comparing Urinary Biomarkers with Diuretic Renogram in Diagnosing Ureteropelvic Junction Obstruction in Children.

In this cost-effectiveness model, we compared the cost-effectiveness of commonly used urinary biomarkers with conventional diuretic renogram (DR) in diagnosing ureteropelvic junction obstruction (UPJO). We hypothesized that urinary biomarkers are as effective as DR. We used incremental cost-effectiveness ratio (ICER) as a tool for our cost-effectiveness analysis model. The cost of biomarker assay and renogram were sourced from the same center while the accuracy data of DR and urinary biomarkers from the relevant pubications. As the accuracy of individual biomarker increased, the ICER also got better. As a panel of biomarker was introduced, the ICER went to the negative range suggesting cost saving as well. ICER of most urine biomarkers is currently less expensive and less effective. When a biomarker panel was applied ICER became more expensive and effective. With higher samples, test running cost is likely to go down in future and thus biomarkers are likely become less expensive and more effective. Individual urine biomarkers are currently less expensive and less effective compared to DR in predicting UPJO. In future, biomarker panel is likely to be more cost-effective and reduce the need for invasive renogram thus reducing the radiation exposure.

Correlation of Differential Function and Glomerular Filtration Rate Estimated from Computed Tomography based Renal Volume and Diuretic Renogram in Living Renal Donor

Introduction: In renal transplant, serum creatinine and isotope studies are used for determination of donor glomerular filtration rate (GFR). Studies have shown computed tomography measured renal volume can also be used. Our main objective was to assess the accuracy of volume based estimated GFR (vGFR) with diethylene triamine penta acetic acid (DTPA) measured GFR in living kidney donors. Methods: An observational analytical study was conducted from July 2018 to June 2019 in Department of Urology and Kidney Transplant Surgery and Department of Radiodiagnosis in Tribhuvan University Teaching Hospital where a total of 38 eligible potential donors were evaluated and serum creatinine level, computed tomography with contrast and DTPA renogram were used to measure GFR and differential function. Results: The mean age of the donors were 42.8±10.9 years with 70% of donors being females. Renal volume was not statistically different between male and female donors. There was moderate correlation between volume based and DTPA based GFR (r=0.76) and differential function (r=0.71). Compared to creatinine, volume based GFR estimate showed better correlation to DTPA renogram. There was no significant difference in differential function estimated by DTPA and volume based estimates (p = 0.96). The upper and lower limit of agreement between the volume based and DTPA based differential function was –4.7 and 4.6 respectively. Conclusion: GFR measurement by CT volume overestimates total GFR compared to DTPA renogram but it has better correlation than creatinine based estimates. It can be used to estimate the differential function of the donor kidney.

Efficacy and safety of high-pressure balloon dilatation for primary obstructive megaureter in children: A systematic review

PurposeEndoscopic treatment with high-pressure balloon dilatation (HPBD) has been proposed as a feasible, safe and minimally invasive procedure for primary obstructive megaureter, but the level of evidence is still low. This systematic review aims to evaluate the efficacy and safety of HPBD and its long-term results in paediatric population.MethodsThe review was conducted following the PRISMA guidelines. Systematic research of available literature in the English language from 1995 until June 2022 was conducted through EMBASE, MEDLINE, Cochrane Library and NIH Registry of Clinical Trials. For each relevant study, information was gathered regarding the study design, the inclusion/exclusion criteria, the indications for treatment, the success rate and the complications.ResultsThe final set included 13 studies. Median age of the patients ranged from 4 months to 7 years (full range 15 days-15 years). The indications for HPBD varied in different studies, however most authors included patients with increasing dilation, obstructive patterns found at diuretic renogram scan, decreased renal function or symptoms. All the studies analysed reported a success rate ranging from 69 to 100% for the treatment of POM with HPBD. This approach may avoid surgery in up to 77% of cases and is thought to be a less invasive, definitive and safe treatment for this disorder. The complication rate ranged from 0 to 50% and it was mostly infectious or associated to the stent placement or both.ConclusionHPBD demonstrated to be safe for the treatment of POM in infants, with effective long-term results and can be a definitive treatment in a considerable subset of patients. Nevertheless, the overall level of evidence for HPBD is still low and further comparative studies or randomized clinical trials are needed.