Renogram Research Articles

A study on comparison of Tc-99m DTPA renal dynamic imaging with Mayo quadratic, Cockcroft-Gault, MDRD, and CKD-EPI formulas for estimation of glomerular filtration rate among South Indian live-related kidney donors

Introduction: Glomerular filtration rate (GFR) is calculated using various prediction equations. These equations are derived from the Western population, and extrapolating to our population subgroups may yield inaccurate results. Objectives: To study the correlation of measured GFR to estimated GFR using four different equations and to analyse how much proximity lies between the GFR calculated by above formulas correlates with DTPA renal scan among South Indian renal donors. Patients and Methods: An observational study was conducted among prospective renal donors undergoing evaluation. Donors underwent a DTPA scan as per protocol. Downloadable calculators calculated the glomerular filtration rate. Results that were descriptive were presented as mean and standard deviation. Correlation and comparisons were made by calculating Pearson’s correlation coefficient and student’s t test respectively. Results: A total of 151 patients were included; 24.5% were males and 75.5% were females. The majority of donors (37.09%) were in the 45-54 years age group. The mean of measured GFR by DTPA was 105.64 mL/min/1.73 m2 whereas estimated GFR was 100.95, 102.34, 109.35, 97.44 mL/min/1.73 m2 in MDRD, CKD-EPI, Mayo, and Cockcroft Gault (CG) formulae respectively with a maximum mean difference for CG of 8.2. Weighted kappa agreement between measured and estimated GFR shows 82.96% agreement with CKD-EPI compared to 78.09% agreement with the MDRD formula. Overall, CKD-EPI performed better in GFR estimation in our study subjects. Conclusion: We found that the CKD-EPI formula performed better in precision, correlation, and accuracy compared to other formulae in GFR estimation among healthy South Indian renal donors. Therefore, the CKD-EPI formula is best suited to pick-up subnormal GFR in clinical practice, as well as in epidemiological studies among the South Asian population.

Correlation between renal sonographic measurements and differential renal function obtained from nuclear renography in children with unilateral hydronephrosis

Children with higher grades of hydronephrosis often undergo mercaptoacetyltriglycine nuclear renography scans (MAG3) to assess differential renal function (DRF) and drainage. Although MAG3 helps identify the potential need for pyeloplasty, its use incurs increased costs, radiation exposure, and stress for children and families. Several studies demonstrate pyramidal thickness (PT)≤3mm as a reliable predictive risk factor for pyeloplasty in children with a history of prenatal hydronephrosis. Our hypothesis was that renal sonographic measurements including PT and parenchymal thickness (ParT) correlate with DRF in children with high-grade unilateral hydronephrosis and may be used to better select the need and frequency of MAG3 scans in children at increased risk for diminished relative renal function. The objective of this project was to determine the correlation between sonographic renal measurements and DRF in patients with unilateral hydronephrosis, we assessed: 1) the correlation between PT, ParT, and the ratio of PT/ParT in hydronephrotic kidneys to DRF, 2) the correlation between the ratio of hydronephrotic PT/contralateral non-hydronephrotic PT and DRF, 3) the correlation between the ratio of hydronephrotic ParT/contralateral non-hydronephrotic ParT and DRF, and 4) the correlation between the ratio of (hydronephrotic PT/ParT)/(contralateral non-hydronephrotic PT/ParT) and DRF. We retrospectively reviewed 71 children with grades 3 or 4 unilateral hydronephrosis. Most patients presented with a history of prenatally detected hydronephrosis at median age (IQR) of 112 days (43-274). Measurements of PT and ParT were completed on 98 renal ultrasounds and DRF was collected from corresponding MAG3 scans. Threshold values were identified visually through scatterplots. Spearman's correlation coefficient and Fisher's p-values were calculated. Ratios of PT and ParT in hydronephrotic kidneys to contralateral non-hydronephrotic kidneys were positively correlated with DRF. Ratios of hydronephrotic PT/non-hydronephrotic PT>0.8 and hydronephrotic ParT/non-hydronephrotic ParT >0.7 occurred more frequently in patients with a DRF >40% (p=0.11 and p=0.001, respectively). A PT>3mm and ParT >5mm occurred significantly more frequently in patients with a DRF >40% (p=0.008 and p=0.006, respectively). Renal sonographic measurements including threshold values of PT>3mm, ParT > 5mm, ratio of hydronephrotic PT/contralateral non-hydronephrotic PT (>0.8), and ratio of hydronephrotic ParT/contralateral non-hydronephrotic ParT (>0.7) are good predictors of DRF >40% in unilateral high-grade hydronephrosis. These identified threshold values have potential utility in determining the need for nuclear renal scans in children with high-grade hydronephrosis.

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.

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.

Can urinary caspase-3 and cytochrome c levels be used as predictive biomarkers in the management of unilateral antenatal hydronephrosis?

We aimed to investigate the urinary caspase-3 and cytochrome c levels in patients with unilateral antenatal hydronephrosis and to determine whether changes in urinary biomarker levels could be useful for both predicting the need for surgical intervention due to ureteropelvic junction obstruction (UPJO) and postoperative surgical success. Sixty-five children with a history of unilateral antenatal hydronephrosis and postnatal anteroposterior diameter ≥ 10mm were included in this prospective case-control study between January 2013 and December 2021. The obstruction group consisted of 33 patients (28 boys, 84.8%) who underwent open dismembered pyeloplasty due to UPJO. The non-obstructive dilatation (NOD) group consisted of 32 patients (27 boys, 84.4%) with stable or improving hydronephrosis and no significant reduction in ipsilateral split renal function during follow-up, whereas 34 healthy children were enrolled in the study as a control group. Urinary urinary caspase-3 and cytochrome c levels using ELISA were measured. The median preoperative urinary caspase-3 level was significantly higher in the obstruction group when compared to the NOD group (4.82ng/mgCr vs. 2.61ng/mgCr, p = 0.013) as well as the control group (4.82ng/mgCr vs. 1.72ng/mgCr, p = 0.002). In the postoperative period, urinary caspase-3 levels significantly decreased compared to preoperative measurements (4.82ng/mgCr vs. 2.51ng/mgCr, p = 0.006) and became similar to the control group (2.51ng/mgCr vs. 1.72ng/mgCr, p = 0.422). On the other hand, no significant differences were observed in urinary cytochrome c levels between the groups. All patients who underwent pyeloplasty achieved postoperative resolution in hydronephrosis and improved drainage on MAG-3, so none of the patients required re-do pyeloplasty. Postoperative decrease in caspase-3 level was found to be compatible with adequate urine drainage on MAG-3 scan. The cut-off value of urinary caspase-3 to predict patients requiring pyeloplasty was found to be 3.31ng/mg creatinine with 63.6% sensitivity, 62.5% specificity (AUC = 0.679). In the multivariable analysis, urinary caspase-3 level (OR: 1.653, p = 0.019), anteroposterior pelvic diameter (OR: 1.401, p = 0.001), and split renal function on MAG-3 (OR: 1.277, p = 0.011) were found to be independent factors in determining patients who require surgery. Based on our preliminary findings, urinary caspase-3 levels could be a useful biomarker not only for predicting the need for surgical intervention but also for determining the postoperative surgical success in children with UPJO.

Comparison of absolute renal uptake by using Tc-99m MAG-3 and Tc-99m DMSA.

The purpose of this study is to compare the value of absolute renal uptake (ARU %) in patients by using Tc-99m MAG-3 and Tc-99m DMSA scan. Absolute renal uptake is calculated using Tc-99m MAG-3 and Tc-99m DMSA in renal scintigraphy, Itoh and Tauex kidney depth methods used, respectively. n = 40 adult patients of both genders were included. All patients underwent Tc-99m MAG-3 and Tc-99m DMSA, respectively. The values of ARU (%) were calculated separately in selected patients n = 40, (left = 17, right = 23 normal functioning kidneys) by MAG-3 and DMSA. Absolute renal uptake (%) of Tc-99m MAG-3 in left kidneys was found to be 15.2 ± 3.4, with spilt renal function 79.2 ± 14.7 and ARU (%) in right kidneys 16.2 ± 3.4 with spilt renal function 77.5 ± 19. Absolute renal uptake of Tc-99m DMSA in left kidneys was 17.5 ± 3.2 and in right kidneys 17.9 ± 4.5 with spilt renal function 81.8 ± 10.7 and 79.3 ± 13.8 for left and right kidney, respectively. Statistical analysis showed strong Pearson correlation. Absolute renal uptake % was found to be more reliable in cases of bilateral compromised kidneys. ARU (%) calculated by Tc-99m MAG-3 solely can be used as predictor of renal function. The use of Tc-99m MAG-3 has more advantages than Tc-99m DMSA alone in renal scintigraphy as dynamic scintigraphy gives less radiation burden to patient, more information regarding renal function, and shorter stay time at hospital in comparison to static renal imaging. SRF % is less reliable than ARU (%).

Renal Phaeohyphomycosis: Aureobasidium Pullulans Infection Caused by Instrument Inoculation in a Healthy Patient - A Case Report

Introduction: Aureobasidium pullulans, ablack yeast-like dematiaceous fungus. Most ofthese infections commonly affect the immunocompromised patients; however, post-instrument inoculation was extremely rare. This is the first report of renal phaeohyphomycosis by A. pullulans after stone surgeries reported worldwide, despite a thorough literature review. Case Report: A 29-year-old immunocompetent native lady, with underlying bilateral grade II renal parenchymal disease, was referred for right staghorn calculi and big left ureteric stone with bilateral hydronephrosis back in 2016. She underwent right percutaneous nephrolithotripsy (PCNL) and left ureteroscopic surgery (URS). Intra-operatively, 90% stone clearance for the right kidney and complete stone clearance was achieved over the left ureteric stone. Blood investigation showed Urea was 8.1 and Creatinine was 200 respectively. There was no growth in Urine C+S sent intraoperatively. Post-operatively, she did a DTPA scan which showed moderate impaired right kidney function (28ml/min-69%) with a non-functioning left kidney (13ml/min-13%). Her condition and renal function had been closely monitored during follow-up in the urology clinic. During follow-up, computed tomography urography (CTU) reassessment in 2018 showed residual right renal stones and resolved left hydronephrosis. Subsequently, she underwent right retrograde intrarenal surgery (RIRS) and ureteric stenting. Intraoperatively, complete stone clearance for the right upper and middle pole; there were a few blackish tubular foreign bodies seen at the right lower pole which were extracted and sent for investigations. Interestingly, the histopathology (HPE) reported as blood clots while the fungal PCR done by the Institute for Medical Research (IMR) showed Aureobasidium pullulans DNA detected. Post-operatively, she completed a one-month course of anti-fungal antibiotic and was discharged home well. Subsequent urine culture was cleared and CTU assessment showed no evidence of stone recurrence or foreign bodies. Discussion and Conclusion: Renal phaeohyphomycosis caused by Aureobadium pollulans secondary to post-instrument inoculation is first reported worldwide in an immunocompetent native lady.

Functional outcome after transperitoneal laparoscopic pyeloplasty at a tertiary care center, Nepal

Introduction: Pyeloplasty is the gold standard surgical treatment for Pelvic-Ureteric Junction Obstruction (PUJO). Laparoscopic pyeloplasty has gained popularity in recent years because it is less invasive, has better cosmesis, and reduces hospital stays with an equivalent success rate compared to open pyeloplasty. This study was designed to find out the success rate of laparoscopic transperitoneal pyeloplasty in cases with unilateral PUJO. Method: This was a retrospective study, which included four years of data on patients who underwent laparoscopic pyeloplasty from 1 Jan 2019 to 31 Dec 2022 in the Department of Urology, Bir Hospital, National Academy of Medical Sciences, Nepal. Ethical approval was obtained. Microsoft Excel was used for descriptive analysis, frequency, and percentage of clinical and demographic data for age, gender, and site. Pre- and post-operative data of differential renal function (DRF) based on the radio-isotope renography and their association were compared using the χ2 test. A p-value of &lt;0.05 was considered statistically significant. Result: Out of 25 cases, renal function improvement was observed in 18(72%), stable in 6(24%), and deteriorated in 1(4%) cases based on DRF analysis. Male to female ratio was 13:12, the mean age was 26 y (8-60 y), and the left side was 14(60%). A mean improvement of DRF of 3.1% was observed in the age group of &gt;30 y, and a mean improvement of DRF of 4.3% was also observed in the cases with DRF ≤30%. Conclusion: The laparoscopic pyeloplasty showed excellent functional outcomes in the majority of the cases with PUJO.

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

BackgroundStandard protocol for post-pyeloplasty monitoring in children and natural course of hydronephrosis resolution have not been well defined. We aimed to analyze critical time intervals and risk factors in the long-term clinical outcomes of children who were operated for ureteropelvic junction obstruction. MethodsFiles of patients who underwent open dismembered pyeloplasty between January 2000 and December 2012 and had a ≥10 years follow-up were retrospectively reviewed. Changes in SFU hydronephrosis grade, pelvis anteroposterior diameter (APD), renal parenchymal thickness, split renal functions (SRF) on MAG-3 scan as well as development of hypertension and proteinuria were noted. Complete resolution was defined as SFU grade 0–1 or APD≤10 mm or ≥50 % APD decrease. ResultsOverall, 223 patients (161 boys, 72.1 %) with a median age of 9 (range 1–185) months underwent unilateral pyeloplasty, whereas 14 patients (13 boys, 92.8 %) with a median age of 4 (range 2–39) months underwent bilateral pyeloplasty. Median follow-up was 13 (range 10–22) years. Complete resolution was observed in 190 patients (85.2 %). None of the cases required re-do pyeloplasty. Regarding unilateral cases, postoperative changes in hydronephrosis reached a plateau at the 60th month. Also, there was no significant difference regarding SRF between the 12th month and the 60th month (p > 0.05). Hypertension developed after a median period of 12 years in 13 (5.4 %) of the patients, while proteinuria developed in four (1.6 %) patients. Bilateral disease (HR: 2.518, p = 0.034) was found to be a significant determinant for development of hypertension and/or proteinuria. ConclusionsOur results indicated that ultrasonographic findings stabilized after the 60th month postoperatively, and SRF remained stable between the postoperative 12th and the 60th months. The risk of developing hypertension and/or proteinuria was 2.5 times greater in bilateral cases. Level of EvidenceLevel II.

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

To assess the incidence of concomitant vesicoureteral reflux (VUR) in unilateral cases of ureteropelvic junction obstruction(UPJO) and to identify factors that predict VUR. Files of 381 pediatric patients who underwent unilateral pyeloplasty between 2000 and 2017 were retrospectively reviewed.A total of 270 patients with available data and ≥5 years of follow-up were eligible for this study.Demographic parameters,preoperative hydronephrosis grade,renal pelvis anteroposterior diameter(APD),renal parenchymal thickness(PT),split renal functions on MAG-3 scan and VUR status were noted.The patients were divided into two groups:Those with concomitant VUR(Group I, n:24, 8.9%) and those without VUR(Group II,n:246, 91.1%). Among 270 patients(205 boys,75.9%) with a median age of 4 months(2-98),197 (72.9%)had antenatal hydronephrosis.Median follow-up was 11 years(5-22).Among 24 patients with concurrent VUR,6(25%) had Grade II VUR,whereas Grade III-V VUR was detected in 18(75%).Of these,12(50%) had ipsilateral VUR,3(12.5%) had contralateral,and 9(37.5%) had bilateral VUR.In a median 137-month follow-up,spontaneous VUR resolution was observed in 6(25%) patients,whereas 15 (62.5%) patients underwent endoscopic subureteral injection and 3(12.5%) patients ureteroneocystostomy,respectively.Preoperative APD[35.5, IQR(27.6-36.0) vs. 26.5 IQR(25.0-35.0), p=0.004] were significantly higher in Group I,whereas Group I had significantly lower PT[3.7, IQR(3.4-6.4) vs. 5.8 IQR(4.4-6.1), p=0.026].Predictive factors for concomitant VUR were presentation with febrile UTI(OR:2.769,p=0.048), PT<3.95 mm(OR:1.367,p=0.043),and APD>28.8 mm (OR:1.035,p=0.001). Our results indicated that concomitant VUR and UPJO might be detected in 1 out of every 11 patients undergoing pyeloplasty,while some type of surgical intervention for VUR was required in 75% of these patients.Thus,VCUG prior to pyeloplasty may be limited in those presenting with febrile UTI,having higher APD and lower PT on preoperative urinary ultrasonography.

Diagnostic value of diuretic ultrasound in evaluating the need for reoperation in children undergoing pyeloplasty

BackgroundPyeloplasty currently stands as the standard treatment for UPJO. Our study aimed to assess the diagnostic value of sonographic parameters following Lasix administration in patients who underwent pyeloplasty to predict the recurrence of obstruction and the need for reoperation.MethodsThe study included 70 children with UPJO who underwent pyeloplasty. Renal ultrasound was performed on patients three to six months after pyeloplasty. Following the Lasix administration, the changes in ultrasound parameters at the 18th and 30th minute were documented. Within two weeks, patients underwent radioisotope renography. Diuretic ultrasound's diagnostic value in predicting the need for reoperation was assessed through a comparison with radioisotope renography.ResultsThe average age of the patients was 3.94 ± 3.52 years. Anteroposterior diameter of the renal pelvis (APD) changes at 18 and 30 min, and the average APD after surgery at 18 and 30 min was significantly higher in patients requiring reoperation. The best cutoff point of APD changes in the 18th minute was 9.50 (sensitivity = 91.7%, specificity = 82.8%). The best cutoff point of APD after surgery in the 18th minute was 25.90 (sensitivity = 91.7%, specificity = 81.0%). The best cutoff points of the resistive index (RI) in the 18th and 30th minutes were reported as 0.70 (sensitivity = 41.7%, specificity = 50.0%) and 0.71 (sensitivity = 41.7%, specificity = 37.9%), respectively.ConclusionsThe assessment of ultrasound findings following pyeloplasty has revealed that changes in APD can serve as a reliable means for assessing the efficacy of the operation.

Measured Glomerular Filtration Rate in Live Related Kidney Donors Three Months Post-Kidney Donation: A Single-Center Experience From Western India.

Background Glomerular filtration rate (GFR) estimation is pivotal in the evaluation of kidney donors. There are various methods available for assessing GFR, but there has been a lack of consensus on the measurement of GFR and the frequency of renal evaluation after kidney donation. Our study aims to analyze the measured GFR (m-GFR) before and three months after kidney donation and note the compensatory abilities of the remnant kidney in live related kidney donors. Methods This prospective observational study was conducted at the Department of Nephrology, Dr. D. Y. Patil Medical College, Hospital & Research Centre,Pune, from April 2021 to December 2022. The study included 30 donors from both genders aged between 23 and 73 years. The measured GFR was calculated using a technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) scan. We analyzed donor characteristics and various parameters that included demography, anthropometry, blood pressure, and serum creatinine and measured GFR(m-GFR) using a Tc-99m DTPA scan, which was compared before and three months after donor nephrectomy. Results Of the 30 donors, 25 (83.3%) were females and five (16.7%) were males. The mean age of donors was 49.23 ± 12.29 years. The mean body mass index (BMI) was noted to be 24.73 ± 5.58 kg/m2, whereas themean body surface area (BSA) was1.59 ± 0.12 m2.In terms of the measured GFR by DTPA scan, pre-donationand post-donation, the average GFR for our population was 103.83 ± 10.07 mL/minute/1.73 m2 and60.47±6.57 mL/minute/1.73 m2, respectively.The mean measured GFR of remnant kidney increased by 9.21 ± 4.39 mL/minute/1.73 m2 in 28 donors, while two donors had a fall in the mean measured GFR by 6.8 ± 1.69 mL/minute/1.73 m2. Conclusions To safeguard donor health, accurate measurement of GFR at various timelines after kidney donation should be consideredas there are various limitations associated with the use ofserum creatinine-based GFR estimating equations for solitary kidneys. However, long-term studies are required to analyze the changes in GFR after nephrectomy and determine the adequacy of compensatory changes in the remnant kidney post-kidney donation.

Supranormal differential renal function on MAG3 scan in children with ureteropelvic junction obstruction – Prevalence and pyeloplasty during follow-up

Children with suspected ureteropelvic junction obstruction (UPJO) may present with a paradoxical ipsilateral supranormal differential renal function (snDRF) on 99mTechnetium mercaptoacetyltriglycine scintigraphy (MAG3 scan). The aim was to investigate the prevalence of snDRF, the risk of pyeloplasty among children with UPJO and snDRF, and to explore the experience of snDRF among international pediatric urologists. A retrospective cohort study of children with suspected unilateral UPJO who underwent MAG3 scan at four hospitals in Sweden between 2005 and 2020. SnDRF was defined as DRF ≥55%. Normal DRF was defined as DRF 45-54%. Primary outcome was risk of pyeloplasty. Indications for pyeloplasty were loss of >10%-points of differential renal function (DRF), ipsilateral DRF <40%, or symptomatic UPJO. Logistic and cox regressions were performed in univariate and multivariable analyses, adjusting for age, gender, year, laterality, antenatal hydronephrosis, anterior-posterior diameter (APD), and kidney size. An international questionnaire regarding the management of snDRF was developed and distributed to pediatric urologists. The prevalence of snDRF was 19%. SnDRF was more common in boys, children with antenatal hydronephrosis, children undergoing their first MAG3 scan at a younger age, and in the left kidney. After further exclusion of 70 children with DRF <45%, a total of 264 were included for longitudinal follow-up of median 6.6 (IQR 2.5-11.5) years. SnDRF was not associated with increased risk of pyeloplasty (adjusted OR 0.98 (95% CI 0.41-2.33), p=0.96, and adjusted HR 1.00 (95% CI 0.53-1.91), p=0.99) or time to pyeloplasty (1.1 years vs. 1.6 years, p=0.40). Among the 79 surveyed pediatric urologists, a majority would not change clinical UPJO-management based on the presence or absence of ipsilateral snDRF. There are only a few studies considering the need of pyeloplasty based on the presence of snDRF and this is the first survey among pediatric urologists on its management. With more included patients than previous studies, this study showed a snDRF prevalence of 19%, congruent with the findings of others. The underlying cause of snDRF is debated, but it cannot solely be explained as an artifact of hydronephrotic kidneys. Further studies on the clinical implications of snDRF are warranted, since DRF influences the decision to operate. A fifth of all children with suspected UPJO presented with ipsilateral snDRF on initial MAG3 scan, and snDRF was not associated with a greater risk of pyeloplasty. Supported by a large group of international pediatric urology colleagues, this study concludes that the same clinical follow-up and management apply, regardless of presence of snDRF.

V01-06 ROBOT-ASSISTED PYELOPLASTY WITH THE NOVEL HUGO TM RAS SYSTEM: SURGICAL SETUP AT A HIGH VOLUME ROBOTIC CENTER

You have accessJournal of UrologyCME1 Apr 2023V01-06 ROBOT-ASSISTED PYELOPLASTY WITH THE NOVEL HUGOTM RAS SYSTEM: SURGICAL SETUP AT A HIGH VOLUME ROBOTIC CENTER Maria Peraire Lores, Carlo Bravi, Marco Paciotti, Luca Sarchi, Luigi Nocera, Adele Piro, Eleonora Balestrazzi, Angelo Mottaran, Federico Piramide, Rui Farinha, Geert De Naeyer, Alexandre Mottrie, and Ruben De Groote Maria Peraire LoresMaria Peraire Lores More articles by this author , Carlo BraviCarlo Bravi More articles by this author , Marco PaciottiMarco Paciotti More articles by this author , Luca SarchiLuca Sarchi More articles by this author , Luigi NoceraLuigi Nocera More articles by this author , Adele PiroAdele Piro More articles by this author , Eleonora BalestrazziEleonora Balestrazzi More articles by this author , Angelo MottaranAngelo Mottaran More articles by this author , Federico PiramideFederico Piramide More articles by this author , Rui FarinhaRui Farinha More articles by this author , Geert De NaeyerGeert De Naeyer More articles by this author , Alexandre MottrieAlexandre Mottrie More articles by this author , and Ruben De GrooteRuben De Groote More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003221.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: New surgical robots with various technical enhancements are gaining popularity in urology and may increase the use of robotics also in non-oncological fields. HUGO RAS system is a robotic platform with independent arm carts and an open console. Here, we presented our first robot-assisted pyeloplasty with HUGO RAS system with the aim to describe technical feasibility and surgical setup of this novel robotic platform for benign kidney surgery. METHODS: A 36-year-old male, without previous abdominal surgeries, was diagnosed with a left pyeloureteral junction stenosis. The CT scan showed a left kidney hydronephrosis with a pelvis diameter of 6 cm with a delayed urinary excretion. The MAG-3 scan showed left and right renal function of 27% and 73%, respectively. A robot-assisted left pyeloplasty was performed through a transperitoneal approach with the HUGO RAS system. With the patient in right lateral decubitus, a 12-mm Airseal trocar was placed 2 cm lateral to the umbilicus, on the left pararectal line. Other two 8-mm robotic ports and an 11-mm optic port were placed under vision in a diamond configuration (Figure 1), all of them 8 cm apart from each other and 2 cm away from bone prominences; lastly, an 8-mm port was placed in the left lower quadrant. In order to optimise working space, three arm carts (corresponding to surgeon’s left hand, optic and forth robotic arm, respectively) were positioned behind the operative bed, whereas one arm cart (i.e. surgeon’s right hand) was placed in front of the patient. RESULTS: The patient was classified as ASA 1 and had a preoperative creatinine of 1.16 mg/dl. Operative and console time were 95 and 70 minutes, respectively. No intraoperative complications occurred, and blood loss was <20 cc. No technical problems, instruments or arms clashes were reported. The patient was discharged the second postoperative day with a creatinine of 1.02 mg/dl. No perioperative complications were reported. CONCLUSIONS: Robot-assisted pyeloplasty using the new HUGO RAS system is safe, feasible and it guarantees optimal perioperative and early functional outcomes. Awaiting study with longer follow-up, our data showed that HUGO RAS might be considered a valuable treatment option for benign kidney surgery, providing relevant information for future adopters of this surgical platform. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e80 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Maria Peraire Lores More articles by this author Carlo Bravi More articles by this author Marco Paciotti More articles by this author Luca Sarchi More articles by this author Luigi Nocera More articles by this author Adele Piro More articles by this author Eleonora Balestrazzi More articles by this author Angelo Mottaran More articles by this author Federico Piramide More articles by this author Rui Farinha More articles by this author Geert De Naeyer More articles by this author Alexandre Mottrie More articles by this author Ruben De Groote More articles by this author Expand All Advertisement PDF downloadLoading ...

V01-10 BILATERAL TESTICULAR VEIN SYNDROME MASQUERADING AS BILATERAL URETEROPELVIC JUNCTION OBSTRUCTION- LESSONS LEARNT

You have accessJournal of UrologyCME1 Apr 2023V01-10 BILATERAL TESTICULAR VEIN SYNDROME MASQUERADING AS BILATERAL URETEROPELVIC JUNCTION OBSTRUCTION- LESSONS LEARNT Ravimohan mavuduru, Shantanu Tyagi, Girdhar Bora, and Shrawan Singh Ravimohan mavuduru Ravimohan mavuduru More articles by this author , Shantanu TyagiShantanu Tyagi More articles by this author , Girdhar BoraGirdhar Bora More articles by this author , and Shrawan SinghShrawan Singh More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003221.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Vascular compression of ureter by aberrant lower polar vessels, retrocaval compression and ovarian vein has been described in the past. Still rarer is the ureteric obstruction with the crossing of testicular vein. We present a case of Bilateral testicular vein syndrome masquerading as Ureteropelvic junction obstruction (UPJO), its intra-operative diagnosis and management. METHODS: Index patient is a 18-year-old male, presented with history of bilateral flank pain since 7 months, colicky in nature, requiring intravenous analgesics. There was no significantly contributing past history. He was evaluated elsewhere with abdominal ultrasonography which was suggestive of bilateral gross hydronephrosis. Non-contrast computed tomography (NCCT), done during an acute episode revealed bilateral gross hydronephrosis with probable site of obstruction at UPJ. Diuretic renography in the form of DTPA Scan consolidated the findings of NCCT revealing bilateral compromised cortical function and obstruction to outflow at UPJ. With the given history and evaluation, patient was diagnosed to have Bilateral UPJO and planned for bilateral robot-assisted pyeloplasty. Intraoperatively, on the left side, at pyelotomy the ureter seemed dilated across UPJ raising questions over pre-operative diagnosis. Consequently distal patency check was undertaken to confirm the site of obstruction. After gentle distal ureteric dissection, extrinsic compression at the site of crossing left testicular vein was found to be the site of actual ureteric obstruction. To relieve this compression, the ureter was super positioned over a posteriorized gonadal vein with a subsequently successful distal patency check. Taking lessons from the left side, we started with distal ureteric dissection and surprisingly found extrinsic compression with right testicular vein on the right side as well. Site of compression was visualised as fibrosed ureteric segment which was excised and ureteroureterostomy was done super positioned over a posteriorized right gonadal vein. RESULTS: The patient had an uneventful post-operative course and bilateral double-J stents were removed at 3 weeks. Follow-up renogram at 3 months documented the resolving bilateral hydronephrosis and unobstructed drainage. CONCLUSIONS: Lessons learned from the given case are- Contrast-enhanced CT imaging could have suggested ureteric compression with gonadal vein pre-operatively, Distal patency check is vital when there is dilatation across PUJ, When in doubt, distal ureteric dissection is a better approach and preservation of ureteric vascularity is of paramount importance. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e82 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ravimohan mavuduru More articles by this author Shantanu Tyagi More articles by this author Girdhar Bora More articles by this author Shrawan Singh More articles by this author Expand All Advertisement PDF downloadLoading ...

Variation in the Expression of Interstitial Cell of Cajal-like Cell (CD117) Across Congenital Pelvic-ureteric Junction Obstruction and its Renal Sonological and Functional Correlation: A Prospective Observational Study.

This study aims to study the variation in the expression of CD117-positive interstitial cells of Cajal-like cells (ICC-LC) across the upper urinary tract region in children presenting with pelvic-ureteric junction obstruction (PUJO) and its association with renal functional and sonological parameters of patients. A prospective observational study was done on 20 children with congenital PUJO who underwent dismembered pyeloplasty. All children underwent renal sonography (anteroposterior pelvic diameter [APPD], pelvicalyceal ratio [P/C ratio], Mid polar renal parenchymal diameter [MPPD]) and functional imaging scan (LLEC scan or DTPA scan). Three specimens were taken intraoperatively from above PUJ, at the level of PUJ, and below PUJ. Those were examined immunohistochemically using CD117 to count ICC-LC using standard criteria. Variation in the expression of CD117-positive ICC-LC was correlated with the abovestated parameters. The number of CD117-positive ICC-LC showed a continuous decreasing trend above downward. P/C ratio and APPD showed a parallel trend with ICC-LC distribution, whereas split renal function (SRF) showed an inverse relationship with the expression of ICC-LC. Children with lesser severity of obstruction (APPD <30 mm and SRF >40%) showed a uniform decreasing trend in the number of CD117-positive ICC-LC across PUJ. Children with more severe obstruction (APPD >30 mm and SRF <40%) showed a decrease in the expression of ICC-LC up to the level of PUJO followed by a sudden relatively increased expression of ICC-LC below the obstruction. The expression of ICC-LC shows a uniformly decreasing trend across obstruction when the severity of obstruction is less. Resurgence in the number of ICC-LC below PUJ in subjects with severe obstruction hints at the emergence of a new pacemaker area below severely blocked PUJ akin to that seen in complete heart block patients and deserves early attention.

The Utility of Radiologic and Symptomatic Surveillance After Minimally-invasive Adult Pyeloplasty

To evaluate different types of failure after minimally-invasive pyeloplasty (MIP) when stratified by initial radiologic study and symptoms after ureteral stent removal. We retrospectively reviewed adults who underwent MIP (1996-2019) at a single academic center. Patients with at least 11 months of follow-up and patients who had a Mag3 scan as their initial postoperative imaging were included. Postprocedure, patients were categorized as having normal, equivocal, or obstructed imaging based on their initial radiologic test. Patients who were obstructed were excluded. Primary outcome was procedural failure, defined as the need for a procedure to treat recurrent obstruction. Secondary outcomes were radiologic failure and symptomatic failure. Groups were compared to assess for statistical significance (P <.05). Overall, 122 patients met inclusion criteria. On initial postoperative imaging, 108 (89%) patients had no obstruction and 14 (11%) had equivocal findings. The procedural failure rate was 6.5% in the unobstructed group and 28.6% in the equivocal group (P=.023). Seven unobstructed patients (6.5%) and 2 equivocal patients (14.3%) eventually experienced radiologic failure (P=.275). Among patients who had no obstruction on initial imaging and remained asymptomatic, only one (0.9%) required a salvage procedure. Recurrent obstruction after pyeloplasty varied based on the outcome of the initial radiologic study. These rates can be used to counsel patients and guide physicians' choice of surveillance schedules. The risk of future failure is very low in asymptomatic patients with normal initial imaging. The utility of routine radiologic surveillance in these patients may be limited.

Deep learning of renal scans in children with antenatal hydronephrosis

Antenatal hydronephrosis (ANH) is one of the most common anomalies identified on prenatal ultrasound, found in up to 4.5% of all pregnancies. Children with ANH are surveilled with repeated renal ultrasound and when there is high suspicion for a ureteropelvic junction obstruction on renal ultrasound, a mercaptuacetyltriglycerine (MAG3) Lasix renal scan is performed to evaluate for obstruction. However, the challenging interpretation of MAG3 renal scans places patients at risk of misdiagnosis. Our objective was to analyze MAG3 renal scans using machine learning to predict renal complications. We hypothesized that our deep learning model would extract features from MAG3 renal scans that can predict renal complications in children with ANH. We performed a case-control study of MAG3 studies drawn from a population of children with ANH concerning for ureteropelvic junction obstruction evaluated at our institution from January 2009 until June of 2021. The outcome was renal complications that occur ≥6 months after an equivocal MAG-3 renal scan. We created two machine learning models: a deep learning model using the radiotracer concentration versus time data from the kidney of interest and a random forest model created using clinical data. The performance of the models was assessed using measures of diagnostic accuracy. We identified 152 eligible patients with available images of which 62 were cases and 90 were controls. The deep learning model predicted future renal complications with an overall accuracy of 73% (95% confidence inteveral [CI] 68-76%) and an AUC of 0.78 (95% CI 0.7, 0.84). The random forest model had an accuracy of 62% (95% CI 60-66%) and an AUC of 0.67 (95% CI. 0 64, 0.72) DISCUSSION: Our deep learning model predicted patients at high risk of developing renal complications following an equivocal renal scan and discriminate those at low risk with moderately high accuracy (73%). The deep learning model outperformed the clinical model built from clinical features classically used by urologists for surgical decision making. Our models have the potential to influence clinical decision making by providing supplemental analytical data from MAG3 scans that would not otherwise be available to urologists. Future multi-institutional retrospective and prospective trials are needed to validate our model.

Anatrophic Nehphrolithotomy: Preservation of Renal Function and Stone Clearance Rate

Aim: To assess the outcomes of anatrophic nephrolithotomy in terms of stone clearance and change in renal function. Study design: Observational study Place and duration of study: Department of Urology Sindh Institute of Urology &amp; Transplantation, Karachi from 1st January 2016 to 31st December 2021. Methodology: Fifty patients who underwent anatrophic nephrolithotomy from were enrolled. Outcomes were measured in terms of stone clearance, change in pre and post procedure eGFR, serum creatinine and differential renal function on renal scan (MAG-3 scan). Results: There were 30 (60%) males and 20 (40%) females with mean age was 5.96±13.09 years. Post-operative serum creatinine and eGFR were compared with pre-operative values and no statistically significant difference observed. Comparison of pre-operative and post-operative 99mTc-mercaptoacetyltriglycine (MAG3) scans revealed statistically significant mild loss of renal function with p-value of0.376. Conclusion: Anatrophic nephrolithotomy can be an alternative for multi tract PCNL when there is huge stone burden as it yields excellent stone clearance, and it can be practiced fearlessly for large staghorn stones because they can become the frequent cause of infections and mortality. Although parenchymal damage after anatrophic nephrolithotomy is of concern, renal dysfunction is usually clinically insignificant. Key words: Anatrophic nephrolithotomy, Staghorn stone, Renal calculi

Initial observational management of hydronephrosis in infants with reduced differential renal function and non-obstructive drainage parameters

Hydronephrosis secondary to ureteropelvic junction (UPJ) obstruction is a common finding in infants with prenatally-diagnosed hydronephrosis and often results in pyeloplasty due to obstructive drainage parameters and/or renal function compromise. However, little is known regarding the natural history of hydronephrosis with reduced differential renal function (DRF) but non-obstructive drainage. We sought to explore our experience with initial observational management of these patients. A retrospective review of our institutional database of all diuretic MAG-3 renal scans obtained between 2000 and 2016 was performed. We included patients with antenatally-detected unilateral hydronephrosis≥SFU grade 2, first MAG-3 scan prior to 18months of age, DRF <40% and post-furosemide half-time (T1/2) <20min. Exclusion criteria were: hydroureter, VUR, solitary kidney, duplication anomalies. Outcomes of interest were a progression of T1/2≥20min and/or further decline in DRF >5%. Of 704 patients with unilateral hydronephrosis, 91 had DRF≤40%, of which 29 (18 boys, 11 girls) met our inclusion criteria and were followed for a mean of 2.8 years (1.4 months-6.6 years). Mean age at first sonogram was 2.3 months. 2 patients had SFU grade 2, 16 had grade 3, and 9 had grade 4 hydronephrosis, and 2 unknown grade. Median half-time on initial MAG-3 scan across all patients was 10min (3-20min). Initial MAG3 scan was performed at a median of 2.3 months of age (0.3-17 months). 22/29 patients had >1 MAG3 scan. Of the 7 remaining, 5 were lost to follow-up and 2 demonstrated improvement in hydronephrosis. Worsening drainage occurred in 10/22(45%), median final T1/2 was 45.5min 8 of these underwent pyeloplasty and 2 were lost to follow up. 4/22 patients (18%) had progressive decline in DRF (mean 8.3%, range 6-10%). 3/4 maintained non-obstructive drainage patterns and stable/improved hydronephrosis, and 1 underwent pyeloplasty. 13/18 remaining patients had stable DRF and 5 had improvement in DRF. 7(39%) of these underwent surgery for worsening drainage (Summary Figure). Overall, 7/29(24%) patientshad sufficient resolution of hydronephrosisto bedischarged from our care, 8(28%) are under continued observation, 9(31%) underwent pyeloplasty, and 5(17%) were lost to follow-up. In the observational group [median follow-up 4.5 years (3.7-6.6 years)], all 8 demonstrated improved non-obstructive drainage (T1/2 <20 minutes) and/or improvement in hydronephrosis. 4/10(40%) with DRF <35% underwent pyeloplasty versus 5/19(26%) with DRF 35-40%(p=0.67). Initial observational management of unilateral hydronephrosis with reduced DRF and nonobstructive drainage is recommended as most kidneys maintain nonobstructive drainage and do not demonstrate further decline in DRF. Even when DRF decreases, the majority remain non-obstructive. Worsening drainage over time more often leads to the decision for pyeloplasty rather than change in DRF.