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

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Practical Prediction of New Baseline Renal Function After Partial Nephrectomy.

BACKGROUND: Partial nephrectomy (PN) is generally preferred for localized renal masses due to strong functional outcomes. Accurate prediction of new baseline glomerular filtration rate (NBGFR) after PN may facilitate preoperative counseling because NBGFR may affect long-term survival, particularly for patients with preoperative chronic kidney disease. Methods for predicting parenchymal volume preservation, and by extension NBGFR, have been proposed, including those based on contact surface area (CSA) or direct measurement of tissue likely to be excised/devascularized during PN. We previously reported that presuming 89% of global GFR preservation (the median value saved from previous, independent analyses) is as accurate as the more subjective/labor-intensive CSA and direct measurement approaches. More recently, several promising complex/multivariable predictive algorithms have been published, which typically include tumor, patient, and surgical factors. In this study, we compare our conceptually simple approach (NBGFRPost-PN = 0.90 × GFRPre-PN) with these sophisticated algorithms, presuming that an even 90% of the global GFR is saved with each PN. PATIENTS AND METHODS: A total of 631 patients with bilateral kidneys who underwent PN at Cleveland Clinic (2012-2014) for localized renal masses with available preoperative/postoperative GFR were analyzed. NBGFR was defined as the final GFR 3-12 months post-PN. Predictive accuracies were assessed from correlation coefficients (r) and mean squared errors (MSE). RESULTS: Our conceptually simple approach based on uniform 90% functional preservation had equivalent r values when compared with complex, multivariable models, and had the lowest degree of error when predicting NBGFR post-PN. CONCLUSIONS: Our simple formula performs equally well as complex algorithms when predicting NBGFR after PN. Strong anchoring by preoperative GFR and minimal functional loss (≈ 10%) with the typical PN likely account for these observations. This formula is practical and can facilitate counseling about expected postoperative functional outcomes after PN.

Thermal Ablation Versus Partial Nephrectomy for cT1 Renal Mass in a Solitary Kidney: A Matched Cohort Comparative Analysis.

BACKGROUND: Nephron-sparing approaches are preferred for renal mass in a solitary kidney (RMSK), with partial nephrectomy (PN) generally prioritized. Thermal ablation (TA) also is an option for small renal masses in this setting; however, comparative functional/survival outcomes are not well-defined. METHODS: A retrospective study of 504 patients (1975-2022) with cT1 RMSK managed with PN (n = 409)/TA (n = 95) with necessary data for analysis was performed. Propensity score was used for matching patients, including age, preoperative glomerular filtration rate (GFR), tumor diameter, R.E.N.A.L. ((R)adius (tumor size as maximal diameter), (E)xophytic/endophytic properties of tumor, (N)earness of tumor deepest portion to collecting system or sinus, (A)nterior (a)/posterior (p) descriptor, and (L)ocation relative to polar lines), and comorbidities. Functional outcomes were compared, and Kaplan-Meier was used to analyze survival. RESULTS: The matched cohort included 132 patients (TA = 66/PN = 66), with median tumor diameter of 2.4 cm, R.E.N.A.L. of 6, and preoperative GFR of 52 ml/min/1.73 m2. Acute kidney injury occurred in 11%/61% in the TA/PN cohorts, respectively (p < 0.01). After recovery, median GFR preserved was 89%/83% for TA/PN, respectively (p = 0.02), and 5-year dialysis-free survival was 96% in both cohorts. Median follow-up was 53 months. Five-year recurrence-free survival (RFS) was 62%/86% in the TA/PN cohorts, respectively (p < 0.01). Five-year local recurrence (LR)-free survival was 74%/95% in the TA/PN cohorts, respectively (p < 0.01). Five-year cancer-specific survival (CSS) was 96%/98% in the TA/PN cohorts, respectively (p = 0.7). Local recurrence was observed in nine of 36 (25%) and five of 30 (17%) patients managed with laparoscopic versus percutaneous TA, respectively. For TA with LR (n = 14), nine patients presented with multifocality and/or cT1b tumors. Twelve LR were managed with salvage TA, and seven remained cancer-free, while five developed systemic recurrence, three with concomitant LR. CONCLUSIONS: Functional outcomes for TA for RMSK were improved compared with PN. Local recurrence was more common after TA and often was associated with the laparoscopic approach, multifocality, and large tumor size. Improved patient selection and greater experience with TA should improve outcomes. Salvage of LR was not always possible. Partial nephrectomy remains the reference standard for RMSK.

PADRES: a phase 2 clinical trial of neoadjuvant axitinib for complex partial nephrectomy.

OBJECTIVE: To report the results of PADRES (Prior Axitinib as a Determinant of Outcome of Renal Surgery, NCT03438708), a study investigating neoadjuvant axitinib for tumours of high complexity with imperative indication for partial nephrectomy (PN). METHODS: We conducted a single-arm phase II clinical trial of localized (cT1b-cT3M0) clear-cell renal cell carcinoma (RCC) patients with imperative indications for nephron preservation, where PN is a high-risk procedure due to complexity (RENAL score 10-12). Axitinib 5 mg was administered twice daily for 8 weeks with repeat imaging at completion, followed by surgery. The primary outcome was successful completion of planned PN following axitinib treatment. Secondary objectives included changes in tumour diameter, RENAL nephrometry score, renal function and Response Evaluation Criteria in Solid Tumours (RECIST) v1.1, and surgical complications. RESULTS: Twenty-seven patients were enrolled (median age 69 years). Prior to therapy, twenty patients (74.0%) had ≥ clinical T3a staged tumours. Axitinib resulted in reductions in tumour diameter (7.5 vs 6.2 cm; P < 0.001) and RENAL score (11 vs 10; P < 0.001). Nine patients (33.3%) had partial response based on RECIST and nine (33.3%) were clinically downstaged. PN was performed in twenty patients (74.0%); twenty-five patients (96.2%) had negative margins. Six patients (22.2%) had Clavien III-IV complications. The median change in estimated glomerular filtration rate (preoperative to last follow-up) was 8.5 mL/min/1.73 m2 . CONCLUSION: Neoadjuvant axitnib resulted in reductions in tumour size and complexity, enabling safe and feasible PN and functional preservation in patients with complex renal masses and imperative indication.

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.

Body morphometry may predict parastomal hernia following radical cystectomy with ileal conduit.

OBJECTIVE: To investigate whether preoperative body morphometry analysis can identify patients at risk of parastomal hernia (PH), which is a common complication after radical cystectomy (RC). PATIENTS AND METHODS: All patients who underwent RC between 2010 and 2020 with available cross-sectional imaging preoperatively and at 1 and 2 years postoperatively were included. Skeletal muscle mass and total fat mass (FM) were determined from preoperative axial computed tomography images obtained at the level of the L3 vertebral body using Aquarius Intuition software. Sarcopenia and obesity were assigned based on consensus definitions of skeletal muscle index (SMI) and FM index (FMI). PH were graded using both the Moreno-Matias and European Hernia Society criteria. Binary logistic regression and recursive partitioning were used to identify patients at risk of PH. The Kaplan-Meier method with log-rank and Cox proportional hazards models included clinical and image-based parameters to identify predictors of PH-free survival. RESULTS: A total of 367 patients were included in the final analysis, with 159 (43%) developing a PH. When utilising binary logistic regression, high FMI (odds ratio [OR] 1.63, P < 0.001) and low SMI (OR 0.96, P = 0.039) were primary drivers of risk of PH. A simplified model that only relied upon FMI, SMI, and preoperative albumin improved the classification of patients at risk of PH. On Kaplan-Meier analysis, patients who were obese or obese and sarcopenic had significantly worse PH-free survival (P < 0.001). CONCLUSION: Body morphometry analysis identified FMI and SMI to be the most consistent predictors of PH after RC.

Every decade counts: a narrative review of functional recovery after partial nephrectomy.

OBJECTIVE: To provide a narrative review of the major advances regarding ischaemia and functional recovery after partial nephrectomy (PN), along with the ongoing controversies. METHODS: Key articles reflecting major advances regarding ischaemia and functional recovery after PN were identified. Special emphasis was placed on contributions that changed perspectives about surgical management. Priority was also placed on randomized trials of off-clamp vs on-clamp cohorts. RESULTS: A decade ago, 'Every minute counts' was published, showing strong correlations between duration of ischaemia and development of acute kidney injury (AKI) and chronic kidney disease after clamped PN. This reinforced perspectives that ischaemia was the main modifiable factor that could be addressed to improve functional outcomes and helped spur efforts towards reduced or zero ischaemia PN. These approaches were associated with strong functional recovery and some peri-operative risk, although they were generally safe in experienced hands. Further research demonstrated that, when parenchymal volume changes were incorporated into the analyses, ischaemia lost statistical significance, and percent parenchymal volume saved proved to be the main determinant. Cold ischaemia was confirmed to be highly protective, and limited warm ischaemia also proved to be safe. The reconstructive phase of PN, with avoidance of parenchymal devascularization, appears to be most important for functional outcomes. Randomized trials of on-clamp vs off-clamp PN have shown minimal impact of ischaemia on functional recovery. CONCLUSIONS: The past decade has witnessed great progress regarding functional recovery after PN, with many lessons learned. However, there are still unanswered questions, including: What is the threshold of warm ischaemia at which irreversible ischaemic injury begins to develop? Are some cohorts at increased risk for AKI or irreversible ischaemic injury? and Which patients should be prioritized for zero-ischaemia PN?

Parenchymal volume analysis to assess longitudinal functional decline following partial nephrectomy.

OBJECTIVE: To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN). PATIENTS AND METHODS: Of 1140 patients managed with PN (2012-2014), 349 (31%) had imaging/serum creatinine levels pre-PN, 1-12 months post-PN (new baseline), and >3 years later necessary for inclusion. Parenchymal-volume analysis was used to determine split renal function. Patients were grouped as having significant renal comorbidity (CohortSRC : diabetes mellitus with insulin-dependence or end-organ damage, refractory hypertension, or severe pre-existing chronic kidney disease) vs not having significant renal comorbidity (CohortNoSRC ) preoperatively. Multivariable regression was used to identify predictors of annual ipsilateral parenchymal atrophy and functional decline relative to new baseline values post-PN, after the kidney had healed. RESULTS: The median follow-up was 6.3 years with 87/226/36 patients having cold/warm/zero ischaemia. The median cold/warm ischaemia times were 32/22 min. Overall, the median tumour size was 3.0 cm. The preoperative glomerular filtration rate (GFR) and new baseline GFR (NBGFR) were 81 and 71 mL/min/1.73 m2 , respectively. After establishment of the NBGFR, the median loss of global and ipsilateral function was 0.7 and 0.4 mL/min/1.73 m2 /year, respectively, consistent with the natural ageing process. Overall, the median ipsilateral parenchymal atrophy was 1.2 cm3 /year and accounted for a median of 53% of the annual functional decline. Significant renal comorbidity, age, and warm ischaemia were independently associated with ipsilateral parenchymal atrophy (all P < 0.01). Significant renal comorbidity and ipsilateral parenchymal atrophy were independently associated with annual ipsilateral functional decline (both P < 0.01). Annual median ipsilateral parenchymal atrophy and functional decline were both significantly increased for CohortSRC compared to CohortNoSRC (2.8 vs 0.9 cm3 , P < 0.01 and 0.90 vs 0.30 mL/min/1.73 m2 /year, P < 0.01, respectively). CONCLUSIONS: Longitudinal renal function following PN generally follows the normal ageing process. Significant renal comorbidities, age, warm ischaemia, and ipsilateral parenchymal atrophy were the most important predictors of ipsilateral functional decline following establishment of NBGFR.

Functional recovery after partial nephrectomy: next generation analysis.

OBJECTIVES: To provide a more rigorous assessment of factors affecting functional recovery after partial nephrectomy (PN) using novel tools that allow for analysis of more patients and improved accuracy for assessment of parenchymal volume loss, thereby revealing the potential impact of secondary factors such as ischaemia. PATIENTS AND METHODS: Of 1140 patients managed with PN (2012-2014), 670 (59%) had imaging and serum creatinine levels measured before and after PN necessary for inclusion. Recovery from ischaemia was defined as the ipsilateral glomerular filtration rate (GFR) saved normalised by parenchymal volume saved. Acute kidney injury was assessed through Spectrum Score, which quantifies the degree of acute ipsilateral renal dysfunction due to exposure to ischaemia that would otherwise be masked by the contralateral kidney. Multivariable regression was used to identify predictors of Spectrum Score and Recovery from Ischaemia. RESULTS: In all, 409/189/72 patients had warm/cold/zero ischaemia, respectively, with median (interquartile range [IQR]) ischaemia times for cold and warm ischaemia of 30 (25-42) and 22 (18-28) min, respectively. The median (IQR) global preoperative GFR and new baseline GFR (NBGFR) were 78 (63-92) and 69 (54-81) mL/min/1.73 m2 , respectively. The median (IQR) ipsilateral preoperative GFR and NBGFR were 40 (33-47) and 31 (24-38) mL/min/1.73 m2 , respectively. Functional recovery correlated strongly with parenchymal volume preserved (r = 0.83, P < 0.01). The median (IQR) decline in ipsilateral GFR associated with PN was 7.8 (4.5-12) mL/min/1.73 m2 with loss of parenchyma accounting for 81% of this loss. The median (IQR) recovery from ischaemia was similar across the cold/warm/zero ischaemia groups at 96% (90%-102%), 95% (89%-101%), and 97% (91%-102%), respectively. Independent predictors of Spectrum Score were ischaemia time, tumour complexity, and preoperative global GFR. Independent predictors of recovery from ischaemia were insulin-dependent diabetes mellitus, refractory hypertension, warm ischaemia, and Spectrum Score. CONCLUSIONS: The main determinant of functional recovery after PN is parenchymal volume preservation. A more robust and rigorous evaluation allowed us to identify secondary factors including comorbidities, increased tumour complexity, and ischaemia-related factors that are also independently associated with impaired recovery, although altogether these were much less impactful.

Prognostic impact of the radiological infiltrative feature of primary renal tumor in metastatic renal cell carcinoma.

OBJECTIVES: Recent studies suggest that the radiological infiltrative feature (r-IF) of renal tumors is strongly correlated with poor oncologic outcomes in locally advanced renal cell carcinoma (RCC). This study investigated the prognostic impact of r-IF of primary renal tumors in metastatic RCC (mRCC) in comparison with International Metastatic RCC Database Consortium (IMDC) risk model. METHODS: We retrospectively analyzed 91 patients with previously untreated mRCC. Dynamic computed tomography of the primary renal tumor was reviewed to assess r-IF, defined as a focally/extensively ill-defined tumor interface with normal renal parenchyma. RESULTS: The median age was 67 years, and 69 patients (76%) were men. Prior nephrectomy was performed in 47 patients (52%). The median size of the primary renal tumor was 6.7 cm, and 50 patients (55%) presented with cT3-4 stage. Overall, 25 (28%)/52 (57%)/14 (15%) patients were classified into IMDC favorable/intermediate/poor-risk groups, respectively. An image review identified r-IFs in the primary renal tumor in 40 patients (44%). The incidences of r-IFs were 28%/46%/64% in IMDC favorable/intermediate/poor-risk groups, respectively. During a median follow-up of 2.6 years, 31 patients (34%) died of RCC. On multivariable analysis, r-IF and IMDC intermediate-poor risks were independently associated with poor cancer-specific survival (CSS). Two-year CSS were 64%/87% in patients with/without r-IF, respectively. C-index was improved from 0.73 to 0.81 by adding r-IF to the IMDC risk factors. CONCLUSIONS: R-IF of the primary renal tumor was an independent risk factor for poor CSS in patients with mRCC, which may improve the prognostic accuracy when combined with the IMDC risk model.

Neocapsular reconstruction for challenging partial nephrectomy: A feasibility study in a porcine model and recent clinical experience.

OBJECTIVES: Multifocal renal masses and large central-endophytic tumors can be challenging for partial nephrectomy (PN) due to the paucity of capsule remaining after tumor removal. Our objective was to develop a neocapsule to provide tamponade and test its feasibility/safety in a porcine model. METHODS: Eight live pigs (50-70 kg) underwent unclamped open right flank PN. Renal defects were 1 cm deep and had moderate ongoing venous bleeding. A 6 × 9 inch sheet of Nu-knit® was used for neocapsular reconstruction with Fibrillar™ packing to provide modest tamponade and preclude ongoing bleeding. Blood chemistry and hemoglobin (Hb) levels were drawn preoperatively and postoperative Days 3/5/8. On postoperative Day 8, euthanasia was performed, and both kidneys were inspected and analyzed for histologic changes. RESULTS: PN defects ranged from 1 × 1 × 1 cm to 4 × 2 × 1 cm; four pigs had PN performed in both poles and four in one pole. Neocapsular reconstruction was successful (n = 8), with no perioperative complications. Median baseline Hb was 10.4 g/dL, and median Hb postoperative Days 3/5/8 were 10.0/10.8/10.6 g/dL, respectively. Median baseline serum creatinine (SCr) was 1.9 mg/dL, and median SCr postoperative Days 3/5/8 were 1.5/1.4/1.5 mg/dL, respectively. At sacrifice, no significant hematomas were observed. Other than adjacent to the PN site, there were no significant histologic changes in the parenchyma for operative kidneys versus controls. Based on our experience, we recently performed neocapsular reconstruction safely/effectively after extensive PN for multifocal tumors and for an allograft with difficult-to-manage subcapsular hematoma. CONCLUSIONS: Neocapsular reconstruction after PN or capsular trauma appears feasible and safe and may be considered to reduce the risk of perioperative bleeding. However, further study will be needed to confirm the utility/efficacy of this approach.

Low grade oncocytic tumors of the kidney: a clinically relevant approach for the workup and accurate diagnosis.

Renal oncocytoma and chromophobe renal cell carcinoma were accepted as unique renal tumors in the late 1990s. Since their formal description, criteria for diagnosis have evolved and additional distinct tumor subtypes originally considered as one these two entities are now recognized. The last two decades have witnessed unprecedented interest in the spectrum of low grade oncocytic renal neoplasms in three specific areas: (1) histologic characterization of tumors with overlapping morphologic features between oncocytoma and chromophobe renal cell carcinoma; (2) description of potentially unique entities within this spectrum, such as eosinophilic vacuolated tumor and low-grade oncocytic tumor; and (3) better appreciation of the association between a subset of low grade oncocytic tumors and hereditary renal neoplasia. While this important work has been academically rewarding, the proposal of several histologic entities with overlapping morphologic and immunophenotypic features (which may require esoteric adjunctive immunohistochemical and/or molecular techniques for confirmation) has created frustration in the diagnostic pathology and urology community as information evolves regarding classification within this spectrum of renal neoplasia. Pathologists, including genitourinary subspecialists, are often uncertain as to the "best practice" diagnostic approach to such tumors. In this review, we present a practical clinically relevant algorithmic approach to classifying tumors within the low grade oncocytic family of renal neoplasia, including a proposal for compressing terminology for evolving categories where appropriate without sacrificing prognostic relevance.

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.

Evaluation of Urinalysis-Based Screening for Urothelial Carcinoma in Patients With Lynch Syndrome.

BACKGROUND: Approximately 5% to 10% of patients with Lynch syndrome develop urothelial carcinoma. Current screening recommendations vary and are based on expert opinion. Practices need to be evaluated for clinical effectiveness. Our program utilizes urinalysis as a screening test, followed by additional evaluation of microscopic hematuria. OBJECTIVE: This study aimed to determine the clinical utility of a urinalysis-based screening approach for urothelial cancers in patients with Lynch syndrome. DESIGN: This is a retrospective review of a prospectively maintained cohort. SETTING: Patients with Lynch syndrome were managed at a tertiary referral center. PATIENTS: All patients with a Lynch syndrome diagnosis who had a screening urinalysis done as part of our institutional screening protocol (N = 204) were included. MAIN OUTCOME MEASURES: A single-institution hereditary colorectal cancer syndrome registry was queried for patients with Lynch syndrome who had been screened for urothelial carcinomas by urinalysis. Demographics, genotype, family history of urothelial carcinoma, urinalysis results, and subsequent screenings and final diagnosis were gathered for patients between 2008 and 2017. RESULTS: Two hundred four asymptomatic patients underwent screening by urinalysis. Nineteen patients (9.3%) had microscopic hematuria and were further evaluated with urine cytology, imaging, cystoscopy, and/or Urology consultation. None of the 19 patients with microscopic hematuria had urothelial carcinoma. During the same study period, 5 of 204 (2.4%) patients with Lynch syndrome were diagnosed with urothelial cancer, and all presented with symptoms between screening intervals. LIMITATIONS: This is a retrospective study, and not all patients underwent the same secondary evaluation. CONCLUSIONS: No urothelial carcinomas were detected by screening urinalysis in our cohort of asymptomatic patients with Lynch syndrome. False-positive testing led to extensive, mostly uninformative, workups. If urothelial cancer screening is to continue, more effective screening approaches need to be identified. See Video Abstract at http://links.lww.com/DCR/B702. EVALUACIN DEL CRIBADO BASADO EN ANLISIS DE ORINA PARA CARCINOMA UROTELIAL EN PACIENTES CON SNDROME DE LYNCH: ANTECEDENTES:Aproximadamente el 5-10% de los pacientes con síndrome de Lynch desarrollan carcinoma urotelial. Las recomendaciones actuales de detección varían y se basan en la opinión de expertos. Las prácticas deben evaluarse para determinar su eficacia clínica. Nuestro programa utiliza el análisis de orina como prueba de detección, seguido de una evaluación adicional con hematuria microscópica.OBJETIVO:Determinar la utilidad clínica desde un enfoque de cribado basado en análisis de orina, para cánceres uroteliales en pacientes con síndrome de Lynch.DISEÑO:Revisión retrospectiva de una cohorte mantenida prospectivamente.ENTORNO CLINICO:Pacientes con síndrome de Lynch atendidos en un centro de referencia terciario.PACIENTES:Criterios de inclusión fueron todos los pacientes con diagnóstico de síndrome de Lynch realizándoles un análisis de orina de detección como parte de nuestro protocolo de detección institucional (N = 204).PRINCIPALES MEDIDAS DE VALORACION:Solicitando un registro de síndrome de cáncer colorrectal hereditario de una sola institución para pacientes con síndrome de Lynch previamente evaluados para carcinomas uroteliales mediante análisis de orina. Se recopilaron para los pacientes entre 2008 y 2017, datos demográficos, genotipo, antecedentes familiares de carcinoma urotelial, resultados del análisis de orina, posteriores exámenes de detección posteriores y diagnóstico final.RESULTADOS:Doscientos cuatro pacientes asintomáticos fueron sometidos a cribado mediante análisis de orina. Diecinueve pacientes (9,3%) tenían hematuria microscópica y fueron investigados más a fondo con citología de orina, imágenes, cistoscopia y / o consulta de urología. Ninguno de los 19 pacientes con hematuria microscópica tenían carcinoma urotelial. Durante el mismo período de estudio, 5 de 204 (2,4%) pacientes con síndrome de Lynch fueron diagnosticados con cáncer urotelial y todos presentaron presentando síntomas entre los intervalos de detección.LIMITACIONES:Estudio retrospectivo y no todos los pacientes sometidos a la misma evaluación secundaria.CONCLUSIONES:No se detectaron carcinomas uroteliales mediante análisis de orina de detección en nuestra cohorte de pacientes asintomáticos con síndrome de Lynch. Las pruebas de falsos positivos. Condujeron a estudios exhaustivos y en su mayoría poco informativos. Si se desea continuar con la detección del cáncer de urotelio, es necesario identificar enfoques de detección más efectivos. Consulte Video Resumen en http://links.lww.com/DCR/B702.

New Baseline Renal Function after Radical or Partial Nephrectomy: A Simple and Accurate Predictive Model.

PURPOSE: Preoperative estimation of new baseline glomerular filtration rate after partial nephrectomy or radical nephrectomy for renal cell carcinoma has important clinical implications. However, current predictive models are either complex or lack external validity. We aimed to develop and validate a simple equation to estimate postoperative new baseline glomerular filtration rate. MATERIALS AND METHODS: For development and internal validation of the equation, a cohort of 7,860 patients with renal cell carcinoma undergoing partial nephrectomy/radical nephrectomy (2005-2015) at the Veterans Affairs National Health System was analyzed. Based on preliminary analysis of 94,327 first-year postoperative glomerular filtration rate measurements, new baseline glomerular filtration rate was defined as the final glomerular filtration rate within 3 to 12 months after surgery. Multivariable linear regression analyses were applied to develop the equation using two-thirds of the renal cell carcinoma Veterans Administration cohort. The simplest model with the highest coefficient of determination (R2) was selected and tested. This model was then internally validated in the remaining third of the renal cell carcinoma Veterans Administration cohort. Correlation/bias/accuracy/precision of equation were examined. For external validation, a similar cohort of 3,012 patients with renal cell carcinoma from an outside tertiary care center (renal cell carcinoma-Cleveland Clinic) was independently analyzed. RESULTS: New baseline glomerular filtration rate (in ml/minute/1.73 m2) can be estimated with the following simplified equation: new baseline glomerular filtration rate = 35 + preoperative glomerular filtration rate (× 0.65) - 18 (if radical nephrectomy) - age (× 0.25) + 3 (if tumor size >7 cm) - 2 (if diabetes). Correlation/bias/accuracy/precision were 0.82/0.00/83/-7.5-8.4 and 0.82/-0.52/82/-8.6-8.0 in the internal/external validation cohorts, respectively. Additionally, the area under the curve (95% confidence interval) to discriminate postoperative new baseline glomerular filtration rate ≥45 ml/minute/1.73 m2 from receiver operating characteristic analyses were 0.90 (0.88, 0.91) and 0.90 (0.89, 0.91) in the internal/external validation cohorts, respectively. CONCLUSIONS: Our study provides a validated equation to accurately predict postoperative new baseline glomerular filtration rate in patients being considered for radical nephrectomy or partial nephrectomy that can be easily implemented in daily clinical practice.

Renal Mass and Localized Renal Cancer: Evaluation, Management, and Follow-up: AUA Guideline: Part II.

PURPOSE: This AUA Guideline focuses on active surveillance (AS) and follow-up after intervention for adult patients with clinically-localized renal masses suspicious for cancer, including solid enhancing tumors and Bosniak 3/4 complex cystic lesions. MATERIALS AND METHODS: In January 2021, the Renal Mass and Localized Renal Cancer guideline underwent additional amendment based on a current literature-search. This literature search retrieved additional studies published between July 2016 to October 2020 using the same Key Questions and search criteria from the Renal Mass and Localized Renal Cancer guideline. When sufficient evidence existed, the body of evidence was assigned strength-rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (table 1[Table: see text]). RESULTS: AS with potential delayed intervention should be considered for patients with solid, enhancing renal masses <2cm or Bosniak 3-4 lesions that are predominantly-cystic. Shared decision-making about AS should consider risks of intervention/competing mortality versus the potential oncologic benefits of intervention. Recommendations for renal mass biopsy and considerations for periodic clinical/imaging-based surveillance are discussed. After intervention, risk-based surveillance protocols are defined incorporating clinical/laboratory evaluation and abdominal/chest imaging designed to detect local/systemic recurrences and possible treatment-related sequelae, such as progressive renal-insufficiency. CONCLUSION: AS is a potential management strategy for some patients with clinically-localized renal masses that requires careful risk-assessment, shared decision-making and periodic-reassessment. Follow-up after intervention is designed to identify local/systemic recurrences and potential treatment-related sequelae. A risk-based approach should be prioritized with selective use of laboratory/imaging resources.

Renal Mass and Localized Renal Cancer: Evaluation, Management, and Follow-Up: AUA Guideline: Part I.

PURPOSE: This AUA Guideline focuses on evaluation/counseling/management of adult patients with clinically-localized renal masses suspicious for cancer, including solid-enhancing tumors and Bosniak 3/4 complex-cystic lesions. MATERIALS/METHODS: The Renal Mass and Localized Renal Cancer guideline underwent an update literature review which resulted in the 2021 amendment. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (table 1[Table: see text]). RESULTS: Great progress has been made regarding the evaluation/management of clinically-localized renal masses. These guidelines provide updated, evidence-based recommendations regarding evaluation/counseling including the evolving role of renal-mass-biopsy (RMB). Given great variability of clinical/oncologic/functional characteristics, index patients are not utilized and the panel advocates individualized counseling/management. Options for intervention (partial-nephrectomy (PN), radical-nephrectomy (RN), and thermal-ablation (TA)) are reviewed including recent data about comparative-effectiveness/potential morbidities. Oncologic issues are prioritized while recognizing the importance of functional-outcomes for survivorship. Granular criteria for RN are provided to help reduce overutilization of RN while also avoiding imprudent PN. Priority for PN is recommended for clinical T1a lesions, along with selective utilization of TA, which has good efficacy for tumors≤3.0 cm. Recommendations for genetic-counseling have been revised and considerations for adjuvant-therapies are addressed. Active-surveillance and follow-up after intervention are discussed in an adjunctive article. CONCLUSION: Several factors require consideration during counseling/management of patients with clinically-localized renal masses including general health/comorbidities, oncologic-considerations, functional-consequences, and relative efficacy/potential morbidities of various management-strategies.

The effect of partial nephrectomy on blood pressure in patients with solitary kidney.

PURPOSE: To determine the effect of partial nephrectomy (PN) in the solitary kidney on systolic and diastolic blood pressures (SBP and DBP, respectively), and use of antihypertensive medications. METHODS: We performed a retrospective cohort study of solitary kidney patients who underwent PN for kidney cancer from 1999-2015. Primary outcomes evaluated were blood pressure (BP) and antihypertensive medication changes from baseline up to 5 years postoperatively. Using a multivariable mixed-effects model to account for repeated measurements, we evaluated the effect of PN on the outcome measurements while controlling for baseline patient, pathologic, and perioperative characteristics. RESULTS: 292 patients who underwent PN on solitary kidneys met inclusion criteria (median [range] age, 63 [24-84] years; 179 men [61%]). SBP decreased immediately postoperatively (- 1.7 mmHg [- 2.6, - 0.7], p < 0.001), and further decreased by 0.04 mmHg per year (p = 0.01) postoperatively, for a total change of - 1.9 [- 3.9, 0.2] mmHg at 5 years (p = 0.01). DBP decreased immediately postoperatively (- 2.2 mmHg [- 2.7, - 1.7], p < 0.001), and then rebounded by 0.37 mmHg per year (p = 0.003) postoperatively, for a total change of - 0.4 [- 1.5, 0.7] mmHg at 5 years (p = 0.003). Antihypertensive medication use increased at 5 years (0.35 more medications per patient, p < 0.001). CONCLUSIONS: Our results suggest a minimal change in BP after PN, although patients increased antihypertensive medication use. This data suggests damage to renal parenchyma or hilar nerves during PN did not significantly impact BP regulation in our cohort.

Infiltrative Renal Malignancies: Imaging Features, Prognostic Implications, and Mimics.

Infiltrative renal malignancies are a subset of renal masses that are morphologically characterized by a poorly defined interface with the renal parenchyma. Infiltrative renal malignancies are less common but more aggressive than more typical renal malignancies and carry an overall worse prognosis. Although an infiltrative renal process often represents a malignant neoplasm, infiltrative masses include a wide spectrum of diseases including primary renal cortical, medullary, and pelvic tumors; lymphoproliferative processes; metastases; and various infectious, inflammatory, immune-mediated, and vascular mimics. The imaging features of these masses are often nonspecific, but with the appropriate history, laboratory results, and clinical context, the radiologist can help narrow the diagnosis and guide further treatment. An invited commentary by Lee is available online.Online supplemental material is available for this article. ©RSNA, 2021.

Infiltrative tumor interface with normal renal parenchyma in locally advanced renal cell carcinoma: Clinical relevance and pathological implications.

OBJECTIVES: Locally advanced renal cell carcinoma is considered clinically aggressive, despite heterogeneity in survival outcomes. We investigated the clinical relevance and pathological implications of infiltrative tumor interface with normal renal parenchyma on preoperative imaging in locally advanced renal cell carcinoma. METHODS: A total of 77 patients with locally advanced renal cell carcinoma (≥pT3a Nany M0) who underwent radical or partial nephrectomy (2008-2018) were analyzed. Preoperative dynamic computed tomography images were reviewed to assess radiological infiltrative features. A radiological infiltrative feature was defined as an ill-defined tumor interface with normal renal parenchyma. The tumor interfaces were analyzed histologically and compared with radiological findings. RESULTS: The median tumor size was 6.4 cm. Lymphadenopathy was observed in four patients (5.2%). Clear cell renal cell carcinoma was diagnosed in 66 patients (86%) and Fuhrman grade was 3-4 in 38 patients (49%). A total of 30 patients (39%) showed radiological infiltrative features, which were significantly associated with larger tumor size and higher clinical T stage. The specificity and sensitivity of radiological infiltrative features in predicting pathological renal parenchymal infiltration were 90 and 64%, respectively. During a median follow-up period of 3.8 years, 27 patients (35%) developed cancer recurrences, and six patients (7.8%) died of renal cell carcinoma. Multivariable analysis showed that the presence of radiological infiltrative features was an independent risk factor for cancer recurrence. Cancer recurrence and cancer-specific mortality were significantly stratified by the presence or absence of radiological infiltrative features (P < 0.001 and P = 0.02, respectively). CONCLUSIONS: Locally advanced renal cell carcinoma can show radiological infiltrative features preoperatively, which are significantly associated with unfavorable prognosis. Radiological infiltrative features on preoperative imaging correspond with a high specificity to pathological renal parenchymal infiltration.