Effect of emergent nephrostomy on long-term total and split renal function in patients with upper urinary tract obstruction due to pelvic malignant tumors.

PURPOSE: This study aimed to investigate the impact of nephrostomies on the outcome of total renal function (TRF) and split renal function (SRF) in patients with malignant pelvic tumors associated with upper urinary tract obstruction (UUTO). METHODS: Patients with pelvic tumors suffering severe unilateral hydronephrosis treated at our hospital from 2000 to 2022 were included. Data for nephrostomy placement, short- and long-term renal function, and radiological and nuclear imaging studies were collected. The TRF and SRF of patients who underwent nephrostomy were compared to those who did not. RESULTS: Seven patients were included (rhabdomyosarcoma: 5, ovarian germ cell tumor: 1, malignant rhabdoid tumor: 1). Nephrostomies were placed in four, which were successfully managed without severe infections. Estimated glomerular filtration rate (eGFR) was significantly improved at the end of treatment in patients with nephrostomy. In contrast, eGFR in patients who did not undergo nephrostomy was not improved. Nuclear imaging studies (renograms or renal scintigrams) revealed impaired SRF of the affected kidney compared to the contralateral kidney, even in patients whose eGFR was within normal levels. Notably, SRF showed a trend to improve over time in one patient treated with nephrostomy. CONCLUSION: Nephrostomy for UUTO caused by pelvic tumors may improve renal outcome.

Does Age Influence the Functional Recovery after Infant Pyeloplasty?

Purpose: The purpose was to study the correlation between age at surgery and functional recovery after infant pyeloplasty. Materials and Methods: All infants who underwent pyeloplasty were analyzed retrospectively in this multicenter study. Anteroposterior diameter (APD) >2 cm, split renal function (SRF) <40%, and Society of Fetal Urology (SFU) grade 3-4 were surgical indications. Based on the age at pyeloplasty, they were divided into Group 1 (1-3 months) and Group 2 (4-12 months). APD and SRF were compared before and after surgery in both groups. The fractional recoverable function (post-SRF-pre-SRF)/(50-pre-SRF) ×100 was correlated with age. Results: Fifty-one infants underwent pyeloplasty (mean age: 1.6 months - Group 1 and 7.2 months - Group 2). The mean APD decreased from 3 cm to 1.2 cm in Group 1 while 2.8 cm to 2 cm in Group 2 (P = 0.001). The mean SRF increased from 32.28% to 42.81% in Group 1 while 31%-34.18% in Group 2. SRF recovery was significantly higher in Group 1 compared to Group 2 (P = 0.001). Regression analysis showed a weak negative correlation (r = -0.2792) between age at surgery and renal function improvement. Conclusion: Functional recovery after pyeloplasty is better when done earlier (1-3 months), as this gives the growing kidney the best opportunity to recover.

Parenchymal volume preservation during partial nephrectomy: improved methodology to assess impact and predictive factors.

OBJECTIVE: To rigorously evaluate the impact of the percentage of parenchymal volume preserved (PPVP) and how well the preserved parenchyma recovers from ischaemia (Recischaemia) on functional outcomes after partial nephrectomy (PN) using an accurate and objective software-based methodology for estimating parenchymal volumes and split renal function (SRF). A secondary objective was to assess potential predictors of the PPVP. PATIENTS AND METHODS: A total of 894 PN patients with available studies (2011-2014) were evaluated. The PPVP was measured from cross-sectional imaging at ≤3 months before and 3-12 months after PN using semi-automated software. Pearson correlation evaluated relationships between continuous variables. Multivariable linear regression evaluated predictors of ipsilateral glomerular filtration rate (GFR) preserved and the PPVP. Relative-importance analysis was used to evaluate the impact of the PPVP on ipsilateral GFR preserved. Recischaemia was defined as the percentage of ipsilateral GFR preserved normalised by the PPVP. RESULTS: The median tumour size and R.E.N.A.L. nephrometry score were 3.4 cm and 7, respectively. In all, 49 patients (5.5%) had a solitary kidney. In all, 538 (60%)/251 (28%)/104 (12%) patients were managed with warm/cold/zero ischaemia, respectively. The median pre/post ipsilateral GFRs were 40/31 mL/min/1.73 m2, and the median (interquartile range [IQR]) percentage of ipsilateral GFR preserved was 80% (71-88%). The median pre/post ipsilateral parenchymal volumes were 181/149 mL, and the median (IQR) PPVP was 84% (76-92%). In all, 330 patients (37%) had a PPVP of <80%, while only 34 (4%) had a Recischaemia of <80%. The percentage of ipsilateral GFR preserved correlated strongly with the PPVP (r = 0.83, P < 0.01) and loss of parenchymal volume accounted for 80% of the loss of ipsilateral GFR. Multivariable analysis confirmed that the PPVP was the strongest predictor of ipsilateral GFR preserved. Greater tumour size and endophytic and nearness properties of the R.E.N.A.L. nephrometry score were associated with a reduced PPVP (all P ≤ 0.01). Solitary kidney and cold ischaemia were associated with an increased PPVP (all P < 0.05). CONCLUSIONS: A reduced PPVP predominates regarding functional decline after PN, although a low Recischaemia can also contribute. Tumour-related factors strongly influence the PPVP, while surgical efforts can improve the PPVP as observed for patients with solitary kidneys.

Predicting new-baseline glomerular filtration rate (NBGFR) after donor nephrectomy: validation of a split renal function (SRF)-based formula.

BACKGROUND: Accurate prediction of post-donor nephrectomy (DN) glomerular filtration rate is potentially useful for evaluating and counselling living kidney donors. Currently, there are limited tools to evaluate post-operative new-baseline glomerular filtration rate (NBGFR) in kidney donors. We aim to validate a conceptually simple formula based on split renal function (SRF) previously developed for radical nephrectomy patients. METHODS: Eighty-three consecutive patients who underwent DN from 2010 to 2016 were included. Pre-operative CT imaging and functional data including pre-DN baseline Global GFR (108.2 ± 13.2 mL/min/1.73m2) were included. Observed NBGFR was defined as the latest eGFR 3-12 months post-DN. SRF, defined as volume of the contralateral non-resected kidney normalised by total volume of kidneys, was determined from pre-operative cross-sectional imaging (49.2 ± 2.36%). The equation derived from Rathi et al. is as detailed: Predicted NBGFR = 1.24 × (Global GFR Pre-DN) x (SRF). RESULTS: The relationship between predicted NBGFR (66.0 ± 8.29 mL/min/1.73m2) and observed NBGFR (74.9 ± 16.4 mL/min/1.73m2) was assessed by evaluating correlation coefficients, bias, precision, accuracy, and concordance. The new SRF-based formula for NBGFR prediction correlated strongly with observed post-operative NBGFR (Pearson's r = 0.729) demonstrating minimal bias (median difference = 7.190 mL/min/1.73m2) with good accuracy (96.4% within ± 30%, 62.7% within ± 15%) and precision (IQR of bias = - 0.094 to 16.227). CONCLUSION: The SRF-based formula was also able to accurately discriminate all but one patient to an NBGFR of > 45 mL/min/1.73m2. We utilised the newly developed SRF-based formula for predicting NBGFR in a living kidney donor population. Counselling of donor post-operative renal outcomes may then be optimised pre-operatively.

Computed Tomography Renal Volumetry Better Predicts Postoperative Donor Renal Function in Live Kidney Donor Transplantation than Renal Scintigraphy: A Comparative Study.

INTRODUCTION AND OBJECTIVES: Both computed tomography (CT) and renal scintigraphy (RS) have been used to assess vascular anatomy, renal status, and split renal function (SRF). In this study, we used a recently developed software that facilitates renal volumetric evaluations to compare RS and automated CT volumetry for assessing residual renal function and, thus, estimating postoperative renal function after donor nephrectomy. METHODS: Fifty-one cases of donor nephrectomy were analyzed. Residual renal function was estimated based on RS and CT volumetry. The correlation between the postoperative estimated glomerular filtration rate (eGFR) and expected SRF, measured using RS and three types of CT volumetry data (ellipsoid, thin-slice, and 5-mm slice data), was determined. RESULTS: The correlation coefficient between actual eGFR and expected SRF was significantly associated at each time point and modality (p < 0.0001). At any time point, the difference in correlation coefficient between RS and 5-mm volumetry was significant (p value: 0.003-0.018), whereas the differences in correlation coefficients between RS and the triaxial volume calculation, and the triaxial volume calculation and 5-mm volumetry, were generally statistically insignificant. CONCLUSIONS: Expected SRF was estimated more accurately by CT volumetric calculations (especially 5-mm slice-based volumetry) than RS.

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

INTRODUCTION: In 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 METHODS: In 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. RESULTS: In 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 %. CONCLUSION: USE 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 EVIDENCE: Level II, Prospective Cohort Study.

Non-invasive estimation of split renal function from routine 68Ga-SSR-PET/CT scans.

Objective: Patients with impaired kidney function are at elevated risk for nephrotoxicity and hematotoxicity from peptide receptor radionuclide therapy (PPRT) for advanced neuroendocrine tumors. Somatostatin receptor (SSR)-PET/CT imaging is the method of choice to identify sufficient SSR expression as a prerequisite for PRRT. Therefore, our study aimed to explore whether split renal function could be evaluated using imaging data from routine SSR-PET/CT prior to PRRT. Methods: In total, 25 consecutive patients who underwent SSR-PET/CT (Siemens Biograph mCT®) before PRRT between June 2019 and December 2020 were enrolled in this retrospective study. PET acquisition in the caudocranial direction started at 20 ± 0.5 min after an i.v. injection of 173 ± 20 MBq [68Ga]Ga-ha DOTATATE, and the kidneys were scanned at 32 ± 0.5 min p.i. The renal parenchyma was segmented semi-automatically using an SUV-based isocontour (SUV between 5 and 15). Multiple parameters including SUVmean of renal parenchyma and blood pool, as well as parenchyma volume, were extracted, and accumulation index (ACI: renal parenchyma volume/SUVmean) and total kidney accumulation (TKA: SUVmean x renal parenchyma volume) were calculated. All data were correlated with the reference standard tubular extraction rate (TER-MAG) from [99mTc]Tc-MAG3 scintigraphy and glomerular filtration rate (GFRCDK - EPI). Results: SUVmean of the parenchymal tracer retention showed a negative correlation with TERMAG (r: -0.519, p < 0.001) and GFRCDK - EPI (r: -0.555, p < 0.001) at 32 min p.i. The herein-introduced ACI revealed a significant correlation (p < 0.05) with the total tubular function (r: 0.482), glomerular renal function (r: 0.461), split renal function (r: 0.916), and absolute single-sided renal function (r: 0.549). The mean difference between the split renal function determined by renal scintigraphy and ACI was 1.8 ± 4.2 % points. Conclusion: This pilot study indicates that static [68Ga]Ga-ha DOTATATE PET-scans at 32 min p.i. may be used to estimate both split renal function and absolute renal function using the herein proposed "Accumulation Index" (ACI).

Renal function damage in children with duplex kidneys.

PURPOSE: To evaluate renal function damage in children with duplex kidneys. METHODS: A total of 355 duplex kidneys, 110 urinary tract infection (UTI) kidneys without abnormalities, and 104 kidneys with primary unilateral vesicoureteral reflux (VUR) were reviewed. Clinical data including age at diagnosis, body weight, history of UTI, ureteroceles, ectopic ureteral opening, VUR grade, serum creatinine level, cystatin C level, renal scarring, split renal function in dimercaptosuccinic acid scans, and effective renal plasma flow (ERPF) were analyzed. RESULTS: Duplex kidneys had a higher grade of VUR and renal scarring. Split renal function in unilateral duplex kidneys (45.58 ± 12.85%) was much lower than that in contralateral duplex kidneys (56.33 ± 11.90%) and controls (50.00 ± 11.38%) (P < 0.001 and P = 0.014, respectively). Both left and right split renal functions in bilateral duplex kidneys were similar to those ipsilateral to the controls (P = 0.906 and P = 0.932, respectively). However, the total ERPFs in the left, right, and bilateral duplex kidneys were significantly lower than that in the control group (P = 0.003, P = 0.001, and P = 0.003, respectively). The total ERPFs in the left and right unilateral duplex kidneys were similar. ERPF in unilateral duplex kidneys (106.70 ± 48.05 mL/min/m2) was significantly lower than that in contralateral duplex kidneys (150.18 ± 49.01 mL/min/m2) or those ipsilateral to controls (145.98 ± 41.16 mL/min/m2) (P < 0.001 and P < 0.001, respectively). CONCLUSION: Duplex kidneys are usually accompanied by a higher grade of VUR, more severe renal scarring, and renal function impairment. Split renal function in duplex kidneys often declines significantly. Notably, the evaluation of split renal function in bilateral duplex kidneys should be performed cautiously.

CT volumetry performs better than nuclear renography in predicting estimated renal function one year after living donation.

The evaluation of split renal function (SRF) is a critical issue in living kidney donations and can be evaluated using nuclear renography (NR) or computerized tomography (CT), with unclear comparative advantages. We conducted this retrospective study in 193 donors to examine the correlation of SRF assessed by NR and CT volumetry and compared their ability to predict remaining donor renal function at 1 year, through multiple approaches. A weak correlation between imaging techniques for evaluating the percentage of the remaining kidney volume was found in the global cohort, with an R2 = 0.15. However, the Bland-Altman plot showed an acceptable agreement (95% of the difference between techniques falling within - 8.51 to 6.11%). The predicted and observed eGFR one year after donation were calculated using the CKD-EPI, and CG/BSA equations. CT volume showed a better correlation than NR for both formulas (adjusted R2 of 0.42. and 0.61 vs 0.37 and 0.61 for CKD-EPI and CG/ BSA equations, respectively). In non-nested modeling tests, CT volumetry was significantly superior to NR for both equations. CT volumetry performed better than NR in predicting the estimated renal function of living donors at 1-year, independently from the eGFR equation.

Whole ureter replacement with Yang-Monti principle: successful treatment of challenging conditions.

BACKGROUND: No clear consensus has been reached on the reconstruction of long-segment or total ureter discontinuation. Here we present our experience using the Yang-Monti technique in total ureter reconstruction. METHODS: This study was a single-center retrospective study of patients who underwent Yang-Monti ileal whole ureter reconstruction (from the ureteropelvic junction[UPJ] to the ureterovesical junction). Data were collected on patients' baseline characteristics, stricture etiology, the time interval between insult and surgical repair, pre/postoperative serum creatinine, estimated glomerular filtration rate (eGFR), split renal function, complications during admission and follow-ups, and the indwelling durations of JJ tubes and nephrostomy tubes, if presented. RESULTS: Seven patients underwent Yang-Monti ileal ureter reconstruction in 2010-2020 at our hospital. One of the patients underwent single-session bilateral ureter repair. Radiation therapy-related fibrosis and degloving injury were the most common etiologies for ureter injury. The median interval between ureter insult and operation was 8 months. The median follow-up was 36.7 months. The average operation time was 11.4 h, and the average blood loss was 273 ml. Postoperatively, no significant differences were found in serum creatinine, eGFR, or split renal function. As for postoperative complications, two patients experienced ileus and were treated conservatively. One patient had UPJ stenosis, which resolved after re-anastomosis surgery 11 months later. Metabolic acidosis or electrolyte imbalance was not reported. CONCLUSION: We found that ileal replacement of total ureteral loss using the Yang-Monti principle is effective and durable. This is the largest cohort study conducted with more than 2 years of follow-up.

Case Report: Endovascular Treatment of Chronic Atherosclerotic Renal Artery Total Occlusions with Failed Medical Therapy.

Background: Current guidelines generally no longer support revascularization for chronic renal artery occlusive diseases because results from randomized controlled trials favor medical therapy over angioplasty. However, increasing reports indicate that patients with renal artery occlusion (RAO) can benefit from revascularization under certain circumstances. Case summary: Here, we present a patient with renal artery stenosis (RAS) who does not have refractory hypertension or fit any clinical trial inclusion criteria by far. Medical therapy failed to prevent the progression of RAS in this patient, leading to total occlusion of his right renal artery. This patient had progressive renal insufficiency but recovered renal function after endovascular treatment. Conclusion: This case demonstrates that angioplasty can be beneficial in selected RAO patients, especially those with residual renal function and collateral perfusion.

Renal scars in children with febrile urinary tract infection - Looking for associated factors.

INTRODUCTION: Febrile urinary tract infection (UTI) is a common childhood infection related to renal scarring and potentially long-term complications like chronic kidney disease. It would be of great benefit to find a correlation between easy-accessible factors in the acute phase of a febrile UTI and the development of renal scar formation and/or decreased renal function in order to identify children at risk of future complications. OBJECTIVE: The aim of this study was to identify factors associated with the development of decreased split renal function (DSRF) and/or permanent renal scar formation in children with febrile UTI. STUDY DESIGN: The medical records of 212 Children aged 0 months to 15 years with febrile UTI admitted to The Pediatric Department of Lillebaelt Hospital, Kolding from January 2011 to September 2014 were systematically reviewed. We analyzed clinical, laboratory, and radiologic findings. Statistical analysis was performed to identify factors associated with renal scar formation and DSRF on nuclear imaging at 6 months follow-up. RESULTS: A total of 113 medical records were eligible for further analysis, 99 girls and 14 boys, 34 patients younger than 12 months. In total 30 patients (26.5%) had an abnormal follow-up imaging (DSRF less than 45% and/or renal scarring). Nine patients (8%) had renal scarring. Four patients (3.5%) had renal scarring only, 21 patients (18.6%) had DSRF only, and five patients (4.4%) had both renal scarring and DSRF. Patients with renal scar formation on follow-up imaging had significantly higher C-reactive protein (CRP) than patients with no scarring (p < 0.01). CRP and absolute neutrophil count (ANC) was significantly higher in patients with abnormal follow-up imaging (p < 0.01 and p = 0.010), and these patients more often had positive nitrite in urine dipstick compared to patients with normal kidneys on follow-up (p = 0.048). Temperature above 38.5 °C and CRP >50 mg/L in combination were also associated with a higher risk of abnormal follow-up imaging (p = 0.016). DISCUSSION: This study contributes with further knowledge to the ongoing debate regarding renal scarring but also reveals the possibility of associated factors for the development of DSRF following a febrile UTI in children. However, due to the retrospective design as well as the small number of events in our study definite conclusions on whether the above-mentioned factors are indeed prognostic for the development of renal scarring or DSRF following a febrile UTI can not be drawn.

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

INTRODUCTION: 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. METHODS: 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 3-12 months 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). RESULTS: 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. CONCLUSIONS: 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.

Split Renal Function Is Fundamentally Important for Predicting Functional Recovery After Radical Nephrectomy.

While partial nephrectomy (PN) is generally preferred for localized renal cell carcinoma (RCC), radical nephrectomy (RN) is occasionally required. A new-baseline glomerular filtration rate (NBGFR) >45 ml/min/1.73 m2 after kidney cancer surgery is associated with strong survival outcomes. If NBGFR after RN will be above this threshold and the tumor has increased oncologic potential, RN may be a relevant consideration. Predicting NBGFR, defined as the GFR at 3-12 mo after RN, has been challenging owing to omission of two important parameters: split renal function (SRF) and renal function compensation (RFC). Our objective was to evaluate a simple SRF-based model in comparison to five published non-SRF-based models using data from a retrospective cohort of 445 RN patients. SRF was obtained via readily available semiautomated software (FUJIFILM Medical Systems) that provides differential parenchymal volume analysis on the basis of preoperative imaging. Our conceptually simple and clinically implementable SRF-based model more accurately predicts NBGFR after RN than five published non-SRF-based models (all p < 0.01). The SRF-based model also improved prediction of the clinically relevant threshold of NBGFR >45 ml/min/1.73 m2 (all p < 0.05). Patient summary: We validated a novel approach for more accurate prediction of kidney function after removal of one kidney. Our approach can be used in clinical and practice and will help in making decisions on full or partial removal of a kidney for kidney cancer.

Comparison of 2D planar and 3D volumetric methods for estimation of split renal function by 99mTc-DMSA scintigraphy.

PURPOSE: Split renal function (SRF) can be measured by using several methods in 99mTc-DMSA scintigraphy. Geometric mean (GM) based methods derived from planar images(2D) have been used for several years, besides; 3D-methods were also reported as an option for assessment of SRF. The purpose of this study to compare 2D and 3D methods for calculation of SRF in pediatric and adult patients. METHODS: We evaluated 212 patients, underwent both planar and SPECT 99mTc-DMSA scintigraphy.2D-SRFs were calculated by GM without background correction (SRFnobcg), GM with background correction in crescent formation from lower lateral borders (SRFcres), and GM with background correction in circumferential formation, including the whole kidney surroundings (SRFcirc). In 3D settings, SRF was measured with SPECT (SRFspect). Paired t-test was used to compare the mean SRFs of each group. Bland-Altman method was used as an agreement method for each method. Analyses were performed based on left kidney SRFs. RESULTS: In comparison of 2D and 3D methods, SRFspect was significantly different from SRFnobcg and SRFcres (p=<0.001) but not from SRFcirc (p = 0.155) in all patients. Similar results were found for patients with high creatinine level, SRFcirc and SRFspect were not significantly different (p = 0.317), while significant differences were found between SRFspect and SRFnobcg/SRFcres (p=<0.001).On the other hand, all 2D-methods showed statistical differences (p=<0.001-0.026) from 3D-method in pediatric patients. Bland-Altman-plot demonstrated that SRFcirc underestimated the poor functioning kidneys. CONCLUSION: SRFcirc can be used in measurement of SRF in adult patients with normal functioning kidneys in busy clinics. However, SRFspect provides more accurate results and suggested particularly for pediatric patients and poor functioning kidneys.

Comparison of surgical outcomes and split renal function between laparoscopic and robot-assisted partial nephrectomy: a propensity score-matched analysis.

PURPOSE: The objective of this study was to compare perioperative outcomes and total and split renal function between laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN). Predictive risk factors of preservation of operated renal function were also assessed. METHODS: We retrospectively analyzed 173 patients who underwent LPN (n = 84) or RAPN (n = 89) between 2010 and 2020. After propensity score matching (1:1), perioperative outcomes and total and split renal function were assessed. Logistic regression analysis was used to evaluate predictive risk factors of preservation of operated renal function. Trifecta criteria were defined as negative surgical margins, warm ischemia time (WIT) < 25 min, and no complications more than Clavien-Dindo grade II within 4 weeks after surgery. Split renal function was evaluated by mercaptoacetyltriglycine renal scan. RESULTS: After propensity score matching, 42 patients were allocated to each group. RAPN was associated with significantly shorter WIT (RAPN vs LPN: 12 vs 22 min; p < 0.0001) and higher trifecta achievement rate (93.3 vs 64.2%; p < 0.0001). Other perioperative outcomes and total and split renal function were not significantly different between LPN and RAPN. The R.E.N.A.L. nephrometry score (RNS) was a predictive risk factor of preservation of operated renal function in the multivariable logistic regression analysis (odds ratio 1.68, 95% confidence interval 1.29-2.20, p < 0.0001). CONCLUSIONS: RAPN improved WIT and trifecta achievement rate, but it did not improve the preservation of operated renal function, for which RNS was found to be a strong predictive risk factor.

Predicting GFR after radical nephrectomy: the importance of split renal function.

PURPOSE: To evaluate a conceptually simple model to predict new-baseline-glomerular-filtration-rate (NBGFR) after radical nephrectomy (RN) based on split-renal-function (SRF) and renal-functional-compensation (RFC), and to compare its predictive accuracy against a validated non-SRF-based model. RN should only be considered when the tumor has increased oncologic potential and/or when there is concern about perioperative morbidity with PN due to increased tumor complexity. In these circumstances, accurate prediction of NBGFR after RN can be important, with a threshold NBGFR > 45 ml/min/1.73m2 correlating with improved overall survival. METHODS: 236 RCC patients who underwent RN (2010-2012) with preoperative imaging (CT/MRI) and relevant functional data were included. NBGFR was defined as GFR 3-12 months post-RN. SRF was determined using semi-automated software that provides differential parenchymal-volume-analysis (PVA) from preoperative imaging. Our SRF-based model was: Predicted NBGFR = 1.24 (× Global GFRPre-RN) (× SRFContralateral), with 1.24 representing the mean RFC estimate from independent analyses. A non-SRF-based model was also assessed: Predicted NBGFR = 17 + preoperative GFR (× 0.65)-age (× 0.25) + 3 (if tumor > 7 cm)-2 (if diabetes). Alignment between predicted/observed NBGFR was assessed by comparing correlation coefficients and area-under-the-curve (AUC) analyses. RESULTS: The correlation-coefficients (r) were 0.87/0.72 for SRF-based/non-SRF-based models, respectively (p = 0.005). For prediction of NBGFR > 45 ml/min/1.73m2, the SRF-based/non-SRF-based models provided AUC of 0.94/0.87, respectively (p = 0.044). CONCLUSION: Previous non-SRF-based models to predict NBGFR post-RN are complex and omit two important parameters: SRF and RFC. Our proposed model prioritizes these parameters and provides a conceptually simple, accurate, and clinically implementable approach to predict NBGFR post-RN. SRF can be easily obtained using PVA software that is affordable, readily available (FUJIFILM-Medical-Systems), and more accurate than nuclear-renal-scans. The SRF-based model demonstrates greater predictive-accuracy than a non-SRF-based model, including the clinically-important predictive-threshold of NBGFR > 45 ml/min/1.73m2.

Contrast-enhanced MRI for simultaneous evaluation of renal morphology and split renal function in living kidney donor candidates.

PURPOSE: The evaluation process of potential living kidney donors focusses on renal anatomy and split renal function. This study aimed to evaluate a magnetic resonance imaging (MRI)-based approach for simultaneous evaluation of both and its impact on clinical decision making. METHOD: Over a 3-year period, 65 potential living kidney donors were consecutively enrolled. The MRI protocol was extended by MR-nephrography to measure split renal function. Standard DTPA-scintigraphy was used for functional comparison. RESULTS: Split renal function showed no systematic bias between the two methods (mean difference 0.3%, p = 0.08). Both methods would have yielded the same clinical decision for donor nephrectomy in 75% of the patients. In 25 % of the patients, one method indicated a relevant side difference while the other did not, and a different clinical decision could have been made based on split renal function alone. CONCLUSIONS: MRI proved eligible for comprehensive living kidney donor evaluation and non-inferior to scintigraphy for determining split renal function. In clinical decision making, these two methods would have resulted in the same side for donor nephrectomy in a large proportion of potential donors. Whether MRN will be implemented in clinical practice depends on transplant centre infrastructure and policy.

Determination of split renal function in voluntary renal donors by multidetector computed tomography and nuclear renography: How well do they correlate?

BACKGROUND: The use of computed tomography (CT) for estimation of split renal function (SRF) has been reported previously. However, most of these studies have small samples, and many do not account for the renal attenuation at CT. OBJECTIVE: The aim of this study was to compare multidetector computed tomography (MDCT) volumetry-attenuation-based SRF with that obtained via Tc99m-diethylenetriaminepentaacetic acid (DTPA) renal scintigraphy in voluntary renal donors. METHODS: Between January 2017 and January 2020, 526 voluntary renal donors were enrolled prospectively. All donors underwent contrast CT and DTPA scan before surgery. The semiautomatic region of interest (ROI) tool was applied slice by slice on axial CT images acquired in the arterial phase. The renal contour was drawn semiautomatically with mouse clicks around the renal parenchyma, and the renal volume was ascertained. Using renal volume and attenuation, SRF was determined and compared with results obtained at DTPA imaging. RESULTS: The mean age was 44.91 ± 10.97 years (mean ± s.d.). There was no significant difference in SRF based on DTPA and MDCT volumetry for the left kidney (49.18% ± 3.40% vs. 49.15% ± 3.38%, p = 0.540) and for the right kidney (50.82% ± 3.40% vs. 50.86% ± 3.39%, p = 0.358). A very good correlation was observed between the two methods for the left kidney (r = 0.953, p = 0.000) and the right kidney (r = 0.955, p = 0.000). On simple linear regression analysis, 90.8% of DTPA SRF values for the left kidney and 91.3% of DTPA SRF values for the right kidney could be predicted correctly using the corresponding MDCT SRF values. CONCLUSION: MDCT volumetry-attenuation-derived estimation of SRF for living renal donors could be an alternative to renal scintigraphy-based SRF estimation.

Short-term outcomes of pyeloplasty vs. nephrectomy in adult patients with ureteropelvic junction obstruction and differential renal function ≤15.

OBJECTIVES: To compare symptom resolution and short-term renal function after pyeloplasty or nephrectomy in adults with ureteropelvic junction obstruction (UPJO) in poorly functioning renal units (PFRU). METHODS: Retrospective analysis of adult patients with UPJO and differential renal function (DRF) ≤ 15% who underwent laparoscopic pyeloplasty or nephrectomy. Primary endpoints included symptom resolution and estimated glomerular filtration rate (eGFR) at 12 months. Surgical complications were compared between groups. A secondary analysis was performed comparing baseline and postoperative DRF to evaluate the PFRU recovery potential after pyeloplasty. RESULTS: Sixty-three patients were included; 19 underwent pyeloplasty and 44 underwent nephrectomy. The mean age of the cohort was 39.5 ± 13.8 years. Nephrectomy was associated with significantly higher intra-operative blood loss (p = 0.02). Operative time and length of hospital stay were not significantly different between groups. There were three complications in the nephrectomy group, and none in the pyeloplasty group (p = 0.34). Symptom resolution rates were equivalent between groups (73% vs. 76%; p = 0.78). The eGFR variation was not statistically different after pyeloplasty or nephrectomy (+6.2 vs. +0.1 mL/min/1.73m2, respectively; p = 0.18). Patients undergoing pyeloplasty had no significant change in the mean DRF (baseline 9.5 vs. 10%; p = 0.99). CONCLUSION: Pyeloplasty can be considered for selected patients with UPJO in PFRU as an organ-sparing alternative to nephrectomy. Although there was no significant gain in mean DRF, pyeloplasty prevented further functional loss and relieved symptoms in most cases in the short-term with at least the same complication rates of nephrectomy.