Nuclear Renal Scan Research Articles

The effect of urinary diversion on kidney function in posterior urethral valves and ureterovesical obstruction.

Posterior urethral valves (PUV) and ureterovesical junction obstruction (UVJO) are common etiologies of lower urinary tract obstruction. The primary objective of therapy is to alleviate the obstruction in the urinary system. Temporary urinary diversion may be necessary in certain situations, such as Urinary tract infection (UTI), sepsis, and unchanging hydronephrosis. This study, aims to assess kidney parameters after urinary diversion (either pyelostomy or ureterostomy) in patients with PUV and UVJO. We conducted a retrospective analysis of all patients diagnosed with PUV or UVJO and treated with urinary diversion following urinary undiversion at our facility between 2015 and 2020. The following variables were collected: demographic details, surgical interventions (type of diversion), serum creatinine throughout follow-up, anterior-posterior diameter of the pelvis (APP), anterior-posterior diameter of the ureter (APU), and sonographic findings of renal parenchymal thickness (PT) as documented by a pediatric radiologist. Additionally, before and after urinary diversion, a Dimercapto succinic acid (DMSA) nuclear renal scan was conducted to assess renal function. We analyzed 67 patients, with a mean follow-up of 38.3months, undergoing either ureterostomy (42 patients) or pyelostomy (25 patients). This included 38 patients with PUV and 29 with UVJO. In PUV patients, significant improvements were observed in APP (MD = 5.56 ± 11.6, p = 0.0194), APU (MD = 5.57 ± 7.28, p < 0.001), and PT (MD = 3.66 ± 2.75, p < 0.001). Similarly, UVJO patients experienced significant improvements in APP (MD = 12.18 ± 18.63, p = 0.005), APU (MD = 7.82 ± 8.98, p = 0.001), and PT (MD = 2.79 ± 3.33, p = 0.001). DMSA scores did not significantly change in either group (p > 0.05). Notably, APP improved more in UVJO patients compared to PUV patients (p = 0.047). Our study suggests that urinary diversion could improve APP, APU, and renal parenchymal thickness in PUV and UVJO patients. The improvement of APP in UVJO patients was greater than in the PUV group. We propose further multi-center studies with longer durations of follow-up and more detailed additional data to support and confirm our results.

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.

New Insights into the Diagnosis, Monitoring, and Management of Antenatal Hydronephrosis, Aiming to Refine Treatment Protocols: A Clinical Study.

Antenatal hydronephrosis (ANH) is a common prenatal finding that requires careful evaluation to determine appropriate management strategies. The variability in outcomes underscores the need for refined diagnostic and monitoring protocols to differentiate between cases necessitating intervention and those likely to resolve spontaneously. A prospective clinical study was conducted involving 150 pregnant women diagnosed with ANH between gestational weeks 18 to 24. Prenatal ultrasounds were performed at regular intervals to monitor renal pelvic dilatation. Postnatal evaluations included renal ultrasound, voiding cystourethrography, and nuclear renal scans to assess renal function and identify associated anomalies. Management decisions were based on standardized criteria including degree of hydronephrosis, presence of associated anomalies, and renal function. Of the 150 cases, 80 (53.3%) resolved spontaneously during the prenatal period, while 70 (46.7%) required postnatal intervention. Among the intervention group, 45 cases (64.3%) required surgical correction for persistent hydronephrosis or associated anomalies, while the remaining 25 cases (35.7%) were managed conservatively with close monitoring. Arbitrarily, the mean anteroposterior renal pelvic diameter (APRPD) in the resolved group was 5.2 mm, compared to 10.6 mm in the intervention group. The median postnatal follow-up duration was 24 months. This study highlights the importance of systematic evaluation and monitoring in managing ANH. While a significant proportion of cases resolve spontaneously, a careful assessment of associated anomalies and renal function is crucial in identifying cases requiring intervention. The arbitrary APRPD values presented underscore the potential for establishing diagnostic thresholds to guide clinical decision-making. Refinement of treatment protocols based on such parameters can improve outcomes and reduce unnecessary interventions in infants with ANH.

Limitations of Parenchymal Volume Analysis for Estimating Split Renal Function and New Baseline Glomerular Filtration Rate After Radical Nephrectomy.

Accurately predicting new baseline glomerular filtration rate (NBGFR) after radical nephrectomy (RN) can improve counseling about RN vs partial nephrectomy. Split renal function (SRF)-based models are optimal, and differential parenchymal volume analysis (PVA) is more accurate than nuclear renal scans (NRS) for this purpose. However, there are minimal data regarding the limitations of PVA. Our objective was to identify patient-/tumor-related factors associated with PVA inaccuracy. Five hundred and ninety-eight RN patients (2006-2021) with preoperative CT/MRI were retrospectively analyzed, with 235 also having NRS. Our SRF-based model to predict NBGFR was: 1.25 × (GlobalGFRPre-RN × SRFContralateral), where GFR indicates glomerular filtration rate, with SRF determined by PVA or NRS, and with 1.25 representing the median renal functional compensation in adults. Accuracy of predicted NBGFR within 15% of observed was evaluated in various patient/tumor cohorts using multivariable logistic regression analysis. PVA and NRS accuracy were 73%/52% overall, and 71%/52% in patients with both studies (n = 235, P < .001), respectively. PVA inaccuracy independently associated with pyelonephritis, hydronephrosis, renal vein thrombosis, and infiltrative features (all P < .03). Ipsilateral hydronephrosis and renal vein thrombosis associated with PVA underprediction, while contralateral hydronephrosis and increased age associated with PVA overprediction (all P < .01). NRS inaccuracy was more common and did not associate with any of these conditions. Even among cohorts where PVA inaccuracy was observed (22% of our patients), there was no significant difference in the accuracies of NRS- and PVA-based predictions. PVA was more accurate for predicting NBGFR after RN than NRS. Inaccuracy of PVA correlated with factors that distort the parenchymal volume/function relationship or alter renal functional compensation. NRS inaccuracy was more common and unpredictable, likely reflecting the inherent inaccuracy of NRS. Awareness of cohorts where PVA is less accurate can help guide clinical decision-making.

Analysis of the Efficacy of Elastography in Comparison with Dynamic Renal Nuclear Scintigraphy in the Evaluation of Unilateral Pelvi–Ureteric Junction Obstruction

IntroductionIn hydronephrosis due to pelviureteric junction obstruction (PUJO), an obstruction to urine flow may lead to increased pelvic pressure, which may cause interstitial fibrosis and renal impairment. Recently, there have been reports on renal pelvic assessment using ultrasound elastography (USE). This study was conducted to see if USE can evaluate PUJO and if it can be correlated to the findings of the dynamic renal nuclear scan. Material and methodsIn this observational study, only patients with unilateral PUJO underwent acoustic radiation force impulse (ARFI) elastography. A rectangular region of interest (ROI) measuring 5 × 10 mm was positioned on the cortex region of the upper, mid, and lower poles of the affected kidney. Three valid measurements were obtained, from which a mean value was calculated. A dynamic renal nuclear scan using Technetium-99m ethylene dicysteine (EC or TC99 m EC) was obtained and split renal function (SRF) was used for comparison. ResultsIn the group of 20 patients, the mean age was 3.37 years. The mean SRF of the affected kidney was 26.65 %, and the corresponding USE value was 0.45 kpa. The Spearman's rho correlation coefficient for SRF and USE was 1 and 0.672, respectively (p = 0.001). Elastography was not feasible if SRF was less than 20 %. ConclusionUSE may be able to comment on the renal functional status of hydronephrosis. If USE is reported as non-feasible, it may suggest that renal function is grossly compromised. It may serve as an alternative diagnostic modality for renal functional evaluation. Level of evidenceLevel II, Prospective Cohort Study.

Extravesical ureteral ectopia from an iliac dystopic hypoplastic left kidney in a girl

Extravesical ureteral ectopia (EUE) is a rare cause of urinary incontinence (UI) in girls. In 80% of cases, ectopia is associated with ureteral duplication. We are reporting a case of a 17-year-old girl with UI by EUE from an iliac dystopic hypoplastic left kidney. The girl received outpatient treatment for UI and left kidney agenesia since the age of 5, when her parents for the first time noticed the UI with background normal urination. The child underwent a complete range of medical tests: CT, cystoscopy, renal nuclear scan, uroflowmetry, ureteral cystometry and profilometry. Although the examination revealed no proof of renal tissue existence on the left side, a pad test with a dye was performed to exclude an EUE. The test gave a positive result, which determined further diagnostic search. Vascular CT was performed and made it possible to visualize a severely hypoplastic left kidney dystopic towards the iliac vessels. Laparoscopic nephrectomy was performed and UI manifestations were corrected. Availability of a wide range of visualisation methods in the urologist's toolkit does not always allow to verify hypoplastic renal dystopia when the kidney is drained by a ureter with an extravesical ectopic orifice. When a reasonable suspicion of an EUE is combined with lack of information about its location and dimensions after visualizing tests, a pad test with a dye appears appropriate prior to a diagnostic laparoscopy in our opinion. Once the UU is confirmed by the dye test results, further diagnostic search using laparoscopic access is justified and can be transformed into a treatment procedure if the kidney is revealed.

Point of care parenchymal volume analyses to estimate split renal function and predict functional outcomes after radical nephrectomy

Accurate prediction of new baseline GFR (NBGFR) after radical nephrectomy (RN) can inform clinical management and patient counseling whenever RN is a strong consideration. Preoperative global GFR, split renal function (SRF), and renal functional compensation (RFC) are fundamentally important for the accurate prediction of NBGFR post-RN. While SRF has traditionally been obtained from nuclear renal scans (NRS), differential parenchymal volume analysis (PVA) via software analysis may be more accurate. A simplified approach to estimate parenchymal volumes and SRF based on length/width/height measurements (LWH) has also been proposed. We compare the accuracies of these three methods for determining SRF, and, by extension, predicting NBGFR after RN. All 235 renal cancer patients managed with RN (2006–2021) with available preoperative CT/MRI and NRS, and relevant functional data were analyzed. PVA was performed on CT/MRI using semi-automated software, and LWH measurements were obtained from CT/MRI images. RFC was presumed to be 25%, and thus: Predicted NBGFR = 1.25 × Global GFRPre-RN × SRFContralateral. Predictive accuracies were assessed by mean squared error (MSE) and correlation coefficients (r). The r values for the LWH/NRS/software-derived PVA approaches were 0.72/0.71/0.86, respectively (p < 0.05). The PVA-based approach also had the most favorable MSE, which were 120/126/65, respectively (p < 0.05). Our data show that software-derived PVA provides more accurate and precise SRF estimations and predictions of NBGFR post-RN than NRS/LWH methods. Furthermore, the LWH approach is equivalent to NRS, precluding the need for NRS in most patients.

MP47-01 LIMITATIONS OF PARENCHYMAL VOLUME ANALYSIS (PVA) FOR ESTIMATING SPLIT RENAL FUNCTION (SRF) &amp; NEW BASELINE GFR (NBGFR) AFTER RADICAL NEPHRECTOMY (RN)

You have accessJournal of UrologyCME1 Apr 2023MP47-01 LIMITATIONS OF PARENCHYMAL VOLUME ANALYSIS (PVA) FOR ESTIMATING SPLIT RENAL FUNCTION (SRF) & NEW BASELINE GFR (NBGFR) AFTER RADICAL NEPHRECTOMY (RN) Kieran Lewis, Carlos Munoz-Lopez, Worapat Attawettayanon, João Pedro Emrich Accioly, Nityam Rathi, Zaeem Lone, Rebecca Campbell, Jihad Kaouk, Georges-Pascal Haber, Mohamad Eltemamy, Venkatesh Krishnamurthi, Robert Abouassaly, Christopher Weight, and Steven Campbell Kieran LewisKieran Lewis More articles by this author , Carlos Munoz-LopezCarlos Munoz-Lopez More articles by this author , Worapat AttawettayanonWorapat Attawettayanon More articles by this author , João Pedro Emrich AcciolyJoão Pedro Emrich Accioly More articles by this author , Nityam RathiNityam Rathi More articles by this author , Zaeem LoneZaeem Lone More articles by this author , Rebecca CampbellRebecca Campbell More articles by this author , Jihad KaoukJihad Kaouk More articles by this author , Georges-Pascal HaberGeorges-Pascal Haber More articles by this author , Mohamad EltemamyMohamad Eltemamy More articles by this author , Venkatesh KrishnamurthiVenkatesh Krishnamurthi More articles by this author , Robert AbouassalyRobert Abouassaly More articles by this author , Christopher WeightChristopher Weight More articles by this author , and Steven CampbellSteven Campbell More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003293.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Accurate prediction of NBGFR after RN can be important for counseling about RN vs. partial nephrectomy in some patients. SRF-based models have been shown to be most accurate for predicting NBGFR after RN, and PVA appears to be superior to nuclear renal scans (NRS) for this purpose. However, data regarding the potential limitations of PVA remain sparse. Our objective was to identify factors associated with PVA inaccuracy. METHODS: 241 RCC patients who underwent RN (2006-2021) with preop. CT/MRI and NRS were included for analysis. Our SRF-based model was: Predicted NBGFR=1.25(Global GFRPre-RN)(SRFContra), with SRF determined by PVA or NRS. Patients were grouped by PVA accuracy: PVAO (PVA over predicted NBGFR by >20%), PVAU (PVA under predicted NBGFR by >20%) and PVAA (PVA accurately predicted NBGFR). Accuracy of NRS was also studied in a similar manner. RESULTS: Six patients (2.5%) were excluded from PVA due to severely altered renal architecture (e.g. PCKD). PVA accurately predicted NBGFR for 83% (196/235) of patients and over/underpredicted NBGFR in 7% and 9%, respectively. NRS only accurately predicted NBGFR for 66% of patients and over/under predicted NBGFR in 22% and 13% of patients, respectively. PVAO had more patients with active/recent hydronephrosis compared to both PVAU /PVAA (29% vs 14% vs 10%, p=0.05). Prior renal infarct (p=0.01) and infiltrative renal mass (IRM) (p=0.002) were associated with PVA inaccuracy in both directions. In contrast, NRS inaccuracy was random and did not associate with hydronephrosis, prior renal infarct, or IRM (all p>0.3). Overall, 30% of patients fell into cohorts where accuracy of PVA was less reliable, but even in these situations PVA was non-inferior to NRS. CONCLUSIONS: PVA accuracy is reduced for IRMs likely due to difficulty distinguishing the true margins of the tumor and, in about 3% of patients, severe disruption of the architecture rendered PVA impossible (e.g. PCKD). Disease processes that distort the volume/function relationship, such as active/recent hydronephrosis, can lead to PVAO, because measured mass may not function optimally. Awareness of cohorts where PVA can be less accurate has clinical utility. However, even in these cohorts, PVA was still non-inferior to NRS, and it remains a cost effective tool for determining SRF/NBGFR. Further study of other processes that can affect the volume/function relationship, such as active or chronic pyelonephritis, or that can affect the degree of renal functional compensation, such as extremes of age, will be required. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e642 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kieran Lewis More articles by this author Carlos Munoz-Lopez More articles by this author Worapat Attawettayanon More articles by this author João Pedro Emrich Accioly More articles by this author Nityam Rathi More articles by this author Zaeem Lone More articles by this author Rebecca Campbell More articles by this author Jihad Kaouk More articles by this author Georges-Pascal Haber More articles by this author Mohamad Eltemamy More articles by this author Venkatesh Krishnamurthi More articles by this author Robert Abouassaly More articles by this author Christopher Weight More articles by this author Steven Campbell More articles by this author Expand All Advertisement PDF downloadLoading ...

PD43-01 LINEAR MEASUREMENTS AT POINT OF CARE TO ESTIMATE SPLIT RENAL FUNCTION AND PREDICT FUNCTIONAL OUTCOMES AFTER RADICAL NEPHRECTOMY

You have accessJournal of UrologyCME1 Apr 2023PD43-01 LINEAR MEASUREMENTS AT POINT OF CARE TO ESTIMATE SPLIT RENAL FUNCTION AND PREDICT FUNCTIONAL OUTCOMES AFTER RADICAL NEPHRECTOMY Nityam Rathi, Kieran Lewis, Worapat Attawettayanon, Carlos Munoz-Lopez, Yosuke Yasuda, Diego Aguilar Palacios, Jianbo Li, Nour Abdallah, Jared Schober, Marshall Strother, Alexander Kutikov, Robert Uzzo, Christopher Weight, Mohamed Eltemamy, Venkatesh Krishnamurthi, Robert Abouassaly, and Steven Campbell Nityam RathiNityam Rathi More articles by this author , Kieran LewisKieran Lewis More articles by this author , Worapat AttawettayanonWorapat Attawettayanon More articles by this author , Carlos Munoz-LopezCarlos Munoz-Lopez More articles by this author , Yosuke YasudaYosuke Yasuda More articles by this author , Diego Aguilar PalaciosDiego Aguilar Palacios More articles by this author , Jianbo LiJianbo Li More articles by this author , Nour AbdallahNour Abdallah More articles by this author , Jared SchoberJared Schober More articles by this author , Marshall StrotherMarshall Strother More articles by this author , Alexander KutikovAlexander Kutikov More articles by this author , Robert UzzoRobert Uzzo More articles by this author , Christopher WeightChristopher Weight More articles by this author , Mohamed EltemamyMohamed Eltemamy More articles by this author , Venkatesh KrishnamurthiVenkatesh Krishnamurthi More articles by this author , Robert AbouassalyRobert Abouassaly More articles by this author , and Steven CampbellSteven Campbell More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003353.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: While radical nephrectomy (RN) is an important consideration for renal tumors with increased complexity and oncologic potential, reduced postoperative new baseline GFR (NBGFR) relative to partial nephrectomy (PN) remains a concern. Thus, accurate predictions of NBGFR after RN can have clinical implications for RCC management, particularly in challenging cases where RN/PN offer distinct merits. Preoperative global GFR, split renal function (SRF), and renal functional compensation (RFC) in the contralateral kidney have been shown to be fundamental parameters for the accurate prediction of NBGFR after RN. While SRF has traditionally been obtained from nuclear renal scans (NRS), recent studies suggest that software-derived differential parenchymal volume analysis (PVA) is more accurate.1 A simplified approach to estimate SRF based on linear length/width/height measurements (LWH) has also been proposed.2 In this study, we compare the accuracies of each of these three methods for determining SRF, and, by extension, predicting NBGFR. METHODS: All 235 RCC patients managed with RN (2006-21) with preoperative CT/MRI, NRS, and preoperative and postoperative GFR data were included. PVA was performed on CT/MRI using a 3D imaging software (Figure 1A-C), and LWH (Figure 1D-G) measurements were obtained using basic tools in the CT/MRI user interface. NBGFR was defined as the GFR 3-12 months after RN, and RFC was approximated at 25% based on prior studies (Predicted NBGFR=1.25×Global GFRPre-RN×SRFContralateral). Predictive accuracies were assessed by correlation coefficients (r) and mean-squared errors. RESULTS: The r values for the LWH-, NRS-, and PVA-based approaches were 0.72, 0.71, and 0.86, respectively (Figure 1H-J). Differences in predictive accuracies of the PVA-based and non-PVA-based approaches were statistically significant. CONCLUSIONS: Software-derived PVA provides the most precise and accurate estimations of SRF, and thus NBGFR after RN, when compared to NRS and LWH methods. Clinically, the PVA-based approach can readily provide accurate predictions of NBGFR in challenging RCC cases where RN is a relevant consideration. Furthermore, the LWH approach, which can also be performed at point of care, is equivalent to NRS, precluding the need for NRS in most patients. Source of Funding: N/A © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1117 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nityam Rathi More articles by this author Kieran Lewis More articles by this author Worapat Attawettayanon More articles by this author Carlos Munoz-Lopez More articles by this author Yosuke Yasuda More articles by this author Diego Aguilar Palacios More articles by this author Jianbo Li More articles by this author Nour Abdallah More articles by this author Jared Schober More articles by this author Marshall Strother More articles by this author Alexander Kutikov More articles by this author Robert Uzzo More articles by this author Christopher Weight More articles by this author Mohamed Eltemamy More articles by this author Venkatesh Krishnamurthi More articles by this author Robert Abouassaly More articles by this author Steven Campbell More articles by this author Expand All Advertisement PDF downloadLoading ...

Optimizing prediction of new-baseline glomerular filtration rate after radical nephrectomy: are algorithms really necessary?

Radical nephrectomy (RN) is an important consideration for the management of localized renal-cell-carcinoma (RCC) whenever the tumor appears aggressive, although reduced renal function is a concern. Split-renal-function (SRF) in the contralateral kidney and postoperative renal functional compensation (RFC) are fundamentally important for the accurate prediction of new baseline GFR (NBGFR) post-RN. SRF can be estimated either from nuclear renal scans (NRS) or from preoperative imaging using parenchymal-volume-analysis (PVA). We compare two SRF-based models for predicting NBGFR after RN with a subjective prediction of NBGFR by an experienced urologic-oncologist. 187 RCC patients managed with RN (2006-16) were included based on the availability of preoperative CT/MRI and NRS, and preoperative/postoperative eGFR. NBGFR was defined as the final GFR 3-12months post-RN. For the SRF-based approaches, SRF was derived from either NRS or PVA, and RFC was estimated at 25% based on previous independent analyses. Thus, the formula (Global GFRPre-RN × SRFcontralateral) × 1.25 was used to predict NBGFR after RN. For subjective-assessment, a blinded, independent urologic oncologist provided NBGFR predictions based on preoperative eGFR, CT/MRI, and clinical/tumor characteristics. Predictive accuracies were assessed by correlation coefficients (r). The r values for subjective-assessment, NRS/SRF-based, and PVA/SRF-based approaches were 0.72/0.72/0.85, respectively (p < 0.05). The PVA/SRF-based model also demonstrated significant improvement across other performance parameters. The PVA/SRF-based model more accurately predicts NBGFR post-RN than NRS/SRF-based and Subjective Estimation. PVA software (Fujifilm-medical-systems) is readily available and affordable and provides accurate SRF estimations from routine preoperative imaging. This novel approach may inform clinical management regarding RN/PN for complex RCC cases.

Robot-assisted versus conventional laparoscopic partial nephrectomy for renal hilar tumors: Parenchymal preservation and functional recovery.

To determine whether robot-assisted laparoscopic partial nephrectomy (RALPN) can benefit patients in terms of functional recovery in the treatment of renal hilar tumors compared to conventional laparoscopic partial nephrectomy (CLPN). Between January 2019 and July 2021, patients with hilar tumors who underwent partial nephrectomy (PN) were acquired at our center and were classified into RALPN and CLPN groups. Ipsilateral parenchymal volume (IPV) and glomerular filtration rate (GFR) were determined independently 3-5 days before and 3 months after PN using contrast-enhanced computed tomography and nuclear renal scans. Pearson correlation was used to determine the link between ipsilateral GFR preservation and IPV preserved. Concurrently, multivariable analysis was employed to determine characteristics associated with functional recovery. A total of 96 patients with hilar tumors were studied, of which 41 received RALPN and 55 received CLPN. Excisional parenchymal volume was 27 and 37 cm3 (p = 0.005) in RALPN and CLPN groups, respectively, and IPV preserved was 77% and 68% (p < 0.001). Furthermore, the ipsilateral GFR preserved was 77.7% and 75.3%, respectively (p = 0.003). On Pearson correlation, ipsilateral GFR preservation was linked with IPV preserved (r = 0.36, p < 0.001). According to a multivariate study, baseline GFR, IPV preserved, and surgical procedures (RALPN vs. CLPN) were significant factors influencing functional recovery. Our study suggests that RALPN, rather than CLPN, can achieve better functional recovery in the treatment of hilar tumors due to its ability to win more IPV preserved. RALPN should be recommended as the first-line treatment for hilar tumors, but randomized controlled trials are required to validate our findings.

PD56-01 IMPROVED PREDICTION OF RENAL FUNCTION AFTER RADICAL NEPHRECTOMY

You have accessJournal of UrologyCME1 May 2022PD56-01 IMPROVED PREDICTION OF RENAL FUNCTION AFTER RADICAL NEPHRECTOMY Nityam Rathi, Yosuke Yasuda, Diego Aguilar Palacios, Yunlin Ye, Jianbo Li, Christopher Weight, Mohammed Eltemamy, Robert Abouassaly, and Steven Campbell Nityam RathiNityam Rathi More articles by this author , Yosuke YasudaYosuke Yasuda More articles by this author , Diego Aguilar PalaciosDiego Aguilar Palacios More articles by this author , Yunlin YeYunlin Ye More articles by this author , Jianbo LiJianbo Li More articles by this author , Christopher WeightChristopher Weight More articles by this author , Mohammed EltemamyMohammed Eltemamy More articles by this author , Robert AbouassalyRobert Abouassaly More articles by this author , and Steven CampbellSteven Campbell More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002636.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Radical nephrectomy (RN) is an important consideration for the surgical management of localized renal cell carcinoma (RCC), particularly in cases of increased oncologic potential. However, reduced renal function after RN is a concern. Preoperative global glomerular filtration rate (GFR) and split renal function (SRF) in the contralateral kidney have been shown to be strong predictors of new baseline GFR (NBGFR) post-RN. Recently, software has been developed to perform parenchymal volume analysis (PVA) on preoperative imaging to determine SRF (FUJIFILM Medical Systems). We compare the abilities of two SRF-based models, using either nuclear renal scan (NRS) or PVA to determine SRF, to predict NBGFR after RN. These SRF-based models were also compared with subjective prediction of NBGFR by an experienced urologic oncologist, because some believe that an expert can predict such outcomes accurately and that predictive models may not be needed in this domain. METHODS: All 187 RCC patients who underwent RN (2006-16) with preoperative CT/MRI, NRS, and preop/postoperative GFR estimations were analyzed. NBGFR was defined as GFR 3-12 months after RN. For the two SRF-based approaches, SRF was derived from either NRS or semi-automated PVA software, and renal functional compensation was estimated at 25% based on previous studies. Thus, the formula (Global GFRPre-RN × SRFcontralateral) x 1.25 was used to predict NBGFR. For the “Subjective Approach”, a blinded, independent urologic oncologist provided predictions of NBGFR based on preoperative CT/MRI, baseline global GFR, tumor features, and patient age/comorbidities. Predictive accuracies were assessed by correlation coefficients (r). RESULTS: The r for the Subjective Assessment, NRS/SRF-based, and PVA/SRF-based approaches were 0.72, 0.72, and 0.85, respectively (Fig. 1). An SRF-based model using PVA to determine SRF performed better than NRS/SRF-based and Subjective approaches (both p < 0.05). CONCLUSIONS: Software-based PVA more accurately predicts NBGFR after RN than NRS and Subjective Assessment. The readily-available, inexpensive PVA software provides a precise and accurate estimation of SRF from routine preoperative CT/MRI. Clinically, this practical and innovative approach can contribute to the assessment of the merits and risks of RN versus partial nephrectomy in complex RCC cases. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e953 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nityam Rathi More articles by this author Yosuke Yasuda More articles by this author Diego Aguilar Palacios More articles by this author Yunlin Ye More articles by this author Jianbo Li More articles by this author Christopher Weight More articles by this author Mohammed Eltemamy More articles by this author Robert Abouassaly More articles by this author Steven Campbell More articles by this author Expand All Advertisement PDF DownloadLoading ...

V84 - Sutureless purely off-clamp robot-assisted partial nephrectomy: Nuclear renal scan findings from a pilot study

V84 - Sutureless purely off-clamp robot-assisted partial nephrectomy: Nuclear renal scan findings from a pilot study

Correlation Between CT Volumetric and Nuclear Renal Scans in Donors with Renal Asymmetry

Correlation Between CT Volumetric and Nuclear Renal Scans in Donors with Renal Asymmetry

What are the Optimal Renal Ultrasound Parameters for Detecting Small Kidney in Young Children?

IntroductionRecent guidelines do not recommend routine screening of vesicoureteral reflux after a first febrile urinary tract infection in children without abnormal findings on ultrasound or atypical/recurrent urinary tract infection. Currently, there are no clear ultrasonographic parameters for detecting abnormalities in renal size, especially in young children. The aim of the present study was to determine an optimal cutoff value for detecting small kidney in children without apparent congenital anomalies except vesicoureteral reflux by retrospective chart review.Patients and MethodsChildren aged ≤3 years who had undergone nuclear renal scans and ultrasound were enrolled. Small kidney was defined as split renal function of <40%. Optimal cutoff values of various ultrasonographic parameters for detecting small kidney were calculated.ResultsOf the 69 children included in the present study, small kidney was identified in 20. There was a significant difference in renal size between each kidney in patients with small kidney, whereas there was no significant difference in those without small kidney. With a ratio of estimated renal area of 74.26%, maximum area under the curve with the highest sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate were obtained. In addition, simple measurement of renal length with a cutoff of 4.97 cm showed high specificity comparable with estimated renal area.ConclusionSmall kidney may be screened by two-dimensional measurement on ultrasonographic examination, even in young children. With the cutoff described, risk stratification or an individualized approach may be possible.

PD12-04 PREDICTING RENAL FUNCTION AFTER RADICAL NEPHRECTOMY: THE IMPORTANCE OF SPLIT RENAL FUNCTION

You have accessJournal of UrologyKidney Cancer: Localized: Surgical Therapy I (PD12)1 Sep 2021PD12-04 PREDICTING RENAL FUNCTION AFTER RADICAL NEPHRECTOMY: THE IMPORTANCE OF SPLIT RENAL FUNCTION Nityam Rathi, Diego Palacios, Hajime Tanaka, Yunlin Ye, Jianbo Li, Robert Abouassaly, and Steven Campbell Nityam RathiNityam Rathi More articles by this author , Diego PalaciosDiego Palacios More articles by this author , Hajime TanakaHajime Tanaka More articles by this author , Yunlin YeYunlin Ye More articles by this author , Jianbo LiJianbo Li More articles by this author , Robert AbouassalyRobert Abouassaly More articles by this author , and Steven CampbellSteven Campbell More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001987.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Accurate prediction of new baseline glomerular filtration rate (NBGFR) after radical nephrectomy (RN) has significant clinical implications for renal cell carcinoma (RCC) management, including decisions about RN versus partial nephrectomy. Current models to predict NBGFR post-RN are complex and omit two important parameters: split renal function (SRF) and renal functional compensation (RFC, also known as compensatory hypertrophy). We propose a simple model to predict NBGFR based solely on preoperative GFR in the contralateral kidney and RFC, and compare its predictive accuracy against a previously published, externally validated non-SRF-based model. METHODS: All 272 RCC patients who underwent RN (2006-16) with preoperative nuclear renal scans and necessary functional data were included. Each patient had estimations of global preoperative and postoperative GFR based on CKD-EPI. NBGFR was defined as GFR 3-12 months after RN. RFC was calculated as percent change in GFR of the preserved kidney after RN. Our SRF-based model was: Predicted NBGFR=Global GFRPre-RN×SRF×RFC, with RFC representing an average for all 272 patients. A recently published non-SRF-based model was also assessed on the same cohort: Predicted NBGFR=35+preoperative GFR (× 0.65) – 18 – age (× 0.25)+3 (if tumor size >7 cm). Alignment between predicted and observed NBGFR was assessed for each model by the correlation coefficient (r) obtained from linear regression analysis. A bootstrapping method was conducted to compare the two r values. RESULTS: Average RFC among the 272 patients was a 24% increase in function at 3-12 months. The correlation coefficients for the SRF-based model and the non-SRF-based model were 0.82 (95% CI: 0.77-0.86) and 0.77 (95% CI: 0.69-0.81), respectively (figure 1). The difference between correlation coefficients was statistically significant (p=0.03). CONCLUSIONS: Incorporation of SRF and RFC generates a simple model to predict NBGFR after RN that can readily be implemented in clinical practice. SRF can be determined at point of care using software that provides differential parenchymal volume analysis, which is more accurate than nuclear renal scans. The SRF-based model demonstrates greater predictive accuracy than the non-SRF-based model. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e204-e204 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nityam Rathi More articles by this author Diego Palacios More articles by this author Hajime Tanaka More articles by this author Yunlin Ye More articles by this author Jianbo Li More articles by this author Robert Abouassaly More articles by this author Steven Campbell More articles by this author Expand All Advertisement Loading ...

The utility of renal sonographic measurements in differentiating children with high grade congenital hydronephrosis

Current grading systems for hydronephrosis include a subjective determination of parenchymal 'thickness' and suffer from poor reliability. Use of more objective ultrasonographic measurements including medullary pyramidal thickness (PT) may be useful in augmenting current grading systems by decreasing subjectivity and enhancing prognostic ability. To evaluate the utility of PT measurements in patients with SFU grades 3 and 4 hydronephrosis, we assessed the: 1) the inter-rater reliability of PT measurements, 2) the correlation between relative renal function on nuclear renal scan and PT, and 3) the pyeloplasty predictive ability of PT alone and in combination with SFU grade and/or other sonographic measurements in multivariate statistical models. We retrospectively reviewed 110 children with SFU grade III and IV hydronephrosis. Most patients presented with a history of prenatally detected hydronephrosis at a median age (IQR) of 1.7 months (0.6-5.2). Sixty-two kidneys were followed without operative intervention while 63 underwent pyeloplasty. Indications for surgery included an obstructive drainage pattern with a T1/2>20min on diuretic renal scan in addition todecreased relative renal function less than 40%, increasing hydronephrosis on serial ultrasounds, and/or a decline in relative renal function >10% onserial renal scans. The median age at the time of pyeloplasty was 5.7 months (2.8-13.7). The median time from initial presentation to final follow-up for all patients was 28 months (18.3-44.6). The PT, APD, and renal length were measured on sonographic images. The inter-rater reliability for SFU grading was only fair whereas it was excellent for PT measurements. Receiver operating characteristic (ROC) curves were generated for inclusive multivariate models for prediction of pyeloplasty with and without SFU grade. PT is a reliable and useful measurement to characterize the hydronephrotic kidney parenchyma and a PT>3mm occurs significantly more frequently in patients with a DRF≥45% (p=0.0056). PT alone was predictive of subsequent pyeloplasty (AUC=0.781). A novel pyeloplasty predictive score (PPS) using only objective measurements including PT, APD, and renal length was more accurate than a PPS that incorporated SFU grade (AUC of 0.885 and 0.866, respectively). Utilization of PT≤3mm as a criterion for 'thinned parenchyma' in the SFU, UTD, and other hydronephrosis grading systems should be considered if confirmed by additional studies.

Girls and renal scarring as risk factors for febrile urinary tract infection after stopping antibiotic prophylaxis in children with vesicoureteral reflux.

To clarify the incidence of and risk factors for febrile urinary tract infection in children with persistent vesicoureteral reflux (VUR) after the discontinuation of continuous antibiotic prophylaxis (CAP), retrospective chart review was performed. Among children with primary VUR at 10years of age or younger at presentation, those who had persistent VUR despite conservative management with CAP and who were subsequently followed after discontinuation of CAP were included. Kaplan-Meier curve and Cox's proportional hazard regression model were used for evaluation of the incidence of and risk factors for febrile urinary tract infection (fUTI) after stopping CAP. Among 144 children (99 boys and 45 girls), fUTI developed in 34. The 5-year fUTI-free rate after discontinuation of CAP was 69.4%. On multivariate analyses, girls (p = 0.008) and abnormalities on nuclear renal scans (p = 0.0019), especially focal defect (p = 0.0471), were significant factors for fUTI. Although the fUTI-free rate was not different between children who had no or 1 risk factor, it was significantly lower in children with 2 risk factors than in those with no or 1 risk factor. The present study revealed that girls and abnormal renal scan, especially focal defect, are risk factors for fUTI. Active surveillance without CAP for persistent VUR seems to be a safe option for children with no or 1 risk factor. Prophylactic surgery or careful conservative follow-up may be an option for girls with abnormal renal scan results if VUR persists under CAP.

Compensatory Changes in Parenchymal Mass and Function after Radical Nephrectomy.

Loss of renal function remains a major limitation of radical nephrectomy. The extent of renal functional compensation by the preserved kidney after radical nephrectomy has not been adequately studied in this elderly population with comorbidities. A total of 273 patients treated with radical nephrectomy without end stage renal disease with available preoperative nuclear renal scans were included in the analysis. Renal functional compensation was defined as percent change in estimated glomerular filtration rate of the preserved kidney after radical nephrectomy. Estimated glomerular filtration rate was calculated by the Chronic Kidney Disease-Epidemiology Collaboration formula up to 5 years postoperatively. Preoperative/postoperative parenchymal volumes of the preserved kidney were measured from cross-sectional imaging. Multiple regression was used to identify predictive factors for renal functional compensation. Median age was 67 years and 67% of the patients were male. Overall 70% had hypertension, 26% diabetes and 37% preexisting chronic kidney disease. Locally advanced (T3a or greater) tumors were found in 53% of cases. Renal functional compensation was observed at 2 weeks (median 10%) and increased during the first 3 months (median 26%) after radical nephrectomy. Functional stability was then observed to 5 years. Renal parenchymal volume increased a median of 10% at 3 to 12 months but in addition, the functional efficiency per unit of parenchymal volume also increased 8% (estimated glomerular filtration rate units/cm3 of parenchyma was 0.236 postoperatively vs 0.208 preoperatively, p=0.004). Age (-0.85, p <0.01), global preoperative estimated glomerular filtration rate (-0.28, p <0.01) and split renal function of the removed kidney (0.61, p <0.01) were independent predictors of renal functional compensation. Percent renal functional compensation after radical nephrectomy is greater in younger patients, when preoperative estimated glomerular filtration rate is lower and when the removed kidney has more robust function. Increases in measurable parenchymal mass and functional efficiency contribute substantially to renal functional compensation.

Split renal function in patients with renal masses: utility of parenchymal volume analysis vs nuclear renal scans.

To evaluate the utility of parenchymal volume analysis (PVA) for estimation of split renal function (SRF) in patients with renal masses. SRF is important for deciding about partial vs radical nephrectomy (PN/RN) and assessing risk for developing severe chronic kidney disease after surgery. For renal donors PVA is routinely used to estimate SRF, but the utility of PVA for the more complex renal mass population remains undefined. All patients (n=374) with renal tumours and a normal contralateral kidney managed with PN (2010-2018), with preoperative/postoperative nuclear renal scans (NRS) and cross-sectional imaging were analysed. Parenchymal volumes were measured by free-hand scripting or software analysis. Concordance between ipsilateral estimated glomerular filtration rate (eGFR) values based on SRF from NRS vs PVA were evaluated by Pearson correlation and Bland-Altman plots. Parallel analysis of all 155 patients managed with RN at our centre (2006-2016) with preoperative NRS and imaging was also performed. For PN, the median age and tumour size were 62years and 3.4cm, respectively. The median preoperative ipsilateral parenchymal volume and eGFR were 181cm3 and 36.9mL/min/1.73m2 , respectively. Parenchymal volumes estimated by free-hand scripting vs software analyses correlated strongly (r=0.98, P<0.001). Preoperative ipsilateral eGFR based on SRF from PVA vs NRS also correlated strongly (r=0.94, P<0.001). Ipsilateral eGFR saved after PN correlated strongly with parenchymal volume preserved (all r >0.60); however, the correlation was much stronger when ipsilateral eGFRs were based on SRF from PVA rather than NRS (z-statistic = 3.15, P=0.002). For RN patients, preoperative eGFR in the contralateral kidney based on SRF from PVA vs NRS also correlated strongly (r=0.87, P<0.001). PVA hasutility for estimation of SRF in patients with renal masses, even though this population is older and more comorbid than renal donors and the tumour can complicate the analysis. PVA can be obtained by software analysis from preoperative cross-sectional imaging and thus readily incorporated into routine clinical practice.