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We sought to automate R.E.N.A.L. (for radius, exophytic/endophytic, nearness of tumor to collecting system, anterior/posterior, location relative to polar line) nephrometry scoring of preoperative computerized tomography scans and create an artificial intelligence-generated score (AI-score). Subsequently, we aimed to evaluate its ability to predict meaningful oncologic and perioperative outcomes as compared to expert human-generated nephrometry scores (H-scores).A total of 300 patients with preoperative computerized tomography were identified from a cohort of 544 consecutive patients undergoing surgical extirpation for suspected renal cancer at a single institution. A deep neural network approach was used to automatically segment kidneys and tumors, and geometric algorithms were developed to estimate components of R.E.N.A.L. nephrometry score. Tumors were independently scored by medical personnel blinded to AI-scores. AI- and H-score agreement was assessed using Lin's concordance correlation and their predictive abilities for both oncologic and perioperative outcomes were assessed using areas under the curve.Median age was 60 years (IQE 51-68), and 40% were female. Median tumor size was 4.2 cm and 91.3% had malignant tumors, including 27%, 37% and 24% with high stage, grade and necrosis, respectively. There was significant agreement between H-scores and AI-scores (Lin's ⍴=0.59). Both AI- and H-scores similarly predicted meaningful oncologic outcomes (p0.001) including presence of malignancy, necrosis, and high-grade and -stage disease (p0.003). They also predicted surgical approach (p0.004) and specific perioperative outcomes (p0.05).Fully automated AI-generated R.E.N.A.L. scores are comparable to human-generated R.E.N.A.L. scores and predict a wide variety of meaningful patient-centered outcomes. This unambiguous artificial intelligence-based scoring is intended to facilitate wider adoption of the R.E.N.A.L. score.

OBJECTIVE To analyze predictors, extent and functional implications associated with renal parenchymal volume replacement (PVR) by renal cell carcinoma (RCC) prior to intervention. This phenomenon is well-recognized yet not adequately studied, and, if severe, can influence management. MATERIALS AND METHODS A retrospective review was performed of partial nephrectomy (PN) and radical nephrectomy (RN) patients with available preoperative nuclear-renal-scan and imaging demonstrating solitary RCC with normal contralateral kidney. Normal renal parenchymal volume of each kidney was measured by free-hand scripting from preoperative axial images. Primary endpoint was percent PVR which was estimated assuming that the contralateral-kidney serves as a control: PVR = (volume contralateral kidney - volume ipsilateral kidney) normalized by volume contralateral kidney. Multivariable linear-regression analysis assessed factors associated with preoperative PVR. Further analysis evaluated the functional effect of PVR prior to surgery. RESULTS 146 PN and 136 RN patients with necessary studies were analyzed. For RN, the median PVR was 15% and a quarter of patients had PVR ≥27%. In contrast, PVR was negligible in PN patients for whom median preoperative parenchymal volumes were nearly identical in the ipsilateral/contralateral kidneys (179/180cc, respectively). PVR inversely correlated with preoperative renal function in the ipsilateral kidney (P

Background Recent publications have reported an association between increased renal cancer-specific mortality (CSM) and reduced renal function “below safety limits,” and advocated for partial nephrectomy (PN) even for potentially aggressive/complex tumors. We hypothesize that this association may be related to confounding factors rather than a consequence of functional differences. Objective To assess whether there is an independent association between preoperative estimated glomerular filtration rate (eGFR) or new baseline eGFR (NB-GFR) and CSM in patients undergoing PN or radical nephrectomy (RN). Design, setting, and participants A single-center retrospective review was performed. All clinically and pathologically confirmed T1-T3a/N0/M0 renal cancer patients undergoing PN/RN (1999–2008, n = 1605) with adequate functional/oncological data were included. Outcome measurements and statistical analysis The primary endpoint was CSM. Secondary endpoints were cancer recurrence (CR) and all-cause mortality (ACM). Cox regression analyses investigated endpoints and predictive factors. Results and limitations The median age was 60 yr and 64% of patients were male. Comorbidities included hypertension (60%), cardiovascular disease (19%), diabetes (21%), and chronic kidney disease (22%). PN was performed in 954 patients (59%). The median preoperative eGFR and NB-GFR were 80 and 60 ml/min/1.73 m2, respectively. Median tumor diameter was 3.6 cm (interquartile range [IQR] = 2.4, 5.5); 70% of tumors were clear cell and 40% were of high grade. Pathology revealed pT1–2/N0/M0 and pT3a/N0/M0 in 81% and 19%, respectively. The median follow-up among survivors was 11.5 yr (IQR = 4, 14). Cancer-specific survival, recurrence-free survival, and overall survival were 94%, 88%, and 73% at 10 yr, respectively. On multivariable analysis, increased age (hazard ratio [HR] = 1.03, p = 0.04), increased tumor size (HR = 1.24, p 0.1), while an increased preoperative eGFR was associated with reduced hazard of ACM (HR = 0.87, p Conclusions Our data do not support oncological protection of greater preservation of renal function and confirm that unfavorable oncological outcomes for localized RCC are mostly associated with aggressive tumor characteristics. Patient summary We did not find an association between greater preservation of renal function and oncological outcomes for kidney cancer.

Purpose:Preoperative estimation of new baseline glomerular filtration rate after partial nephrectomy or radical nephrectomy for renal cell carcinoma has important clinical implications. However, cu...

693 Background: The American Urologic Association (AUA) recommends estimation of the postoperative glomerular filtration rate (GFR) in patients with a renal mass to help decide between partial nephrectomy (PN) or radical nephrectomy (RN). If postoperative GFR2, a PN should be prioritized. Most existing methods to predict postoperative GFR are rarely implemented in the clinical setting due to complexity. Previously validated models based on clinical equations or kidney volumes from hand-segmented or semi-automated segmentations are quite accurate but have seen limited uptake in clinical practice. We hypothesize that we could develop an artificial intelligence (AI)-GFR prediction that would be calculated automatically on a preoperative computed tomography (CT) scan and predict a postoperative GFR as accurately as a validated clinical model. Methods: 300 patients undergoing PN or RN for renal tumor from the 2021Kidney and Kidney Tumor Segmentation Challenge(KiTS21) were analyzed. We excluded 7 patients having bilateral tumors. Preoperative GFR was the closest recorded value preoperatively and postoperative GFR≥90 days postoperatively. Split-renal-function (SRF) was determined in a fully automated way from preoperative imaging and our previously developed deep learning segmentation model. We programmed the algorithm to estimate postoperative GFR as 1.24×preoperative GFR×contralateral SRF for RN; and as 89% of the preoperative GFR for PN. We compared AI-predicted GFR to a validated clinical model (GFR=35+preoperative GFR(x0.65)-18(if radical nephrectomy)-age(x0.25)+3(if tumor size >7 cm)-2 (if diabetes)). We compared the AI and clinical model estimations of GFR to the measured postoperative GFR using correlation coefficients (R) and compared the ability of AI models to predict a postoperative GFR2, the AI and clinical models performed similarly (AUC of 0.89 and 0.9, respectively). Conclusions: Our study demonstrates the feasibility of a fully automated prediction of postoperative GFR based on CT imaging and baseline GFR with comparable predictive accuracy to existing validated clinical prediction models. These AI-generated predictions can be implemented for decision-making, with no clinical details, clinician time, or measurements needed.

Purpose: Preoperative assessment of T3a renal-cell-carcinoma (RCC) in absence of main renal vein involvement or lymph node enlargement is challenging but has potential implications for counseling and prognosis. Materials and Methods: A retrospective review of 1129 cT1-T3aN0M0 RCC patients managed with partial/radical nephrectomy (PN/RN) in our institution (2012-2014) was performed. Exclusion criteria included radiological evidence of main renal vein involvement or substantial lymphadenopathy. Eleven radiological findings suggestive of aggressive tumor biology or invasive phenotype based on prior literature were assessed for correlation with pT3a status. These included perinephric-findings (stranding, enhancing-nodule, collateral-vessels, or irregular-perinephric-tumor-contour), findings within the sinus (stranding, collecting-system invasion, branch-vein enlargement, or irregular-tumor-sinus-border [ITSB]), and tumor-necrosis, infiltrative-features, and tumor-size. Radiological assessment was blinded to final pathology. Sensitivity/specificity and logistic-regression analyses assessed the performance of each imaging-finding for detecting pT3a tumors. Results: Median tumor-size was 4.0cm and R.E.N.A.L. was 8. Median follow-up was 53 months (IQR:28-64). pT3a tumors were found in 281 patients (25%) and strongly correlated with local and systemic recurrence (p

OBJECTIVES 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. PATIENTS AND METHODS 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. RESULTS For PN, the median age and tumour size were 62 years and 3.4 cm, respectively. The median preoperative ipsilateral parenchymal volume and eGFR were 181 cm3 and 36.9 mL/min/1.73 m2 , respectively. Parenchymal volumes estimated by free-hand scripting vs software analyses correlated strongly (r = 0.98, P 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

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)...

INTRODUCTION AND OBJECTIVE:The crude rates and time of progression to end stage renal disease (ESRD) after radical nephrectomy (RN) has not been well defined, particularly in patients with risk fac...

INTRODUCTION AND OBJECTIVE:Partial nephrectomy (PN) is prioritized over radical nephrectomy (RN) in patients with CKD whenever feasible. However, we hypothesized that some patients with severe CKD ...

INTRODUCTION AND OBJECTIVE:Preoperative estimation of new baseline glomerular filtration rate (GFR) after renal surgery for RCC has important clinical implications. Here we develop and externally v...

INTRODUCTION AND OBJECTIVE:A recent publication in European Urology reported an association between reduced renal function following nephrectomy and increased cancer-specific mortality (CSM) in kid...

To evaluate indications/outcomes for open partial nephrectomy (OPN) when non-flank approaches are required, with comparison to patients managed with the flank approach. Outcomes with a non-flank approach are presumed less favorable yet there have been no previous reports on this topic. 2747 OPNs were performed (1999–2015) and 76 (2.8%) required a non-flank approach. We also reviewed all traditional flank OPNs performed during odd years in this timeframe yielding 1467 patients for comparison. Overall, median tumor size was 3.5 cm and 274 patients (18%) had a solitary kidney. Non-flank patients were younger, and tumor size and clinical/pathologic stage were significantly increased for this cohort, but the groups were otherwise comparable. Indications for non-flank OPN included large tumor size/locally advanced disease (n = 21), need for simultaneous surgery (n = 25), previous flank incision or failed thermoablation (n = 13), or congenital/vascular abnormalities (n = 9). The most common non-flank approach was anterior subcostal (n = 39, 51%). Operative times, estimated blood loss, positive margins, and functional decline were all modestly increased for non-flank patients. Intraoperative and genitourinary complications were more common in non-flank patients (p

Renal cancer surgery can adversely impact long-term function and survival. We evaluated predictors of chronic kidney disease 5 years and nonrenal cancer mortality 10 years after renal cancer surgery.We analyzed the records of 4,283 patients who underwent renal cancer surgery from 1997 to 2008. Radical and partial nephrectomy were performed in 46% and 54% of patients, respectively. Cumulative probability ordinal modeling was used to predict chronic kidney disease status 5 years after surgery and multivariable logistic regression was used to predict nonrenal cancer mortality at 10 years. Relevant patient, tumor and functional covariates were incorporated, including the preoperative glomerular filtration rate (A), the new baseline glomerular filtration rate after surgery (B) and the glomerular filtration rate loss related to surgery (C), that is C = A - B. In contrast, partial or radical nephrectomy was not used in the models due to concerns about strong selection bias associated with the choice of procedure.Multivariable modeling established the preoperative glomerular filtration rate and the glomerular filtration rate loss related to surgery as the most important predictors of the development of chronic kidney disease (Spearman ρ = 0.78). Age, gender and race had secondary roles. Significant predictors of 10-year nonrenal cancer mortality were the preoperative glomerular filtration rate, the new baseline glomerular filtration rate, age, diabetes and heart disease (all p0.05). Multivariable modeling established age and the preoperative glomerular filtration rate as the most important predictors of 10-year nonrenal cancer mortality (c-index 0.71) while the glomerular filtration rate loss related to surgery only changed absolute mortality estimates 1% to 3%.Glomerular filtration rate loss related to renal cancer surgery, whether due to partial or radical nephrectomy, influences the risk of chronic kidney disease but it may have less impact on survival. In contrast, age and the preoperative glomerular filtration rate, which reflects general health status, are more robust predictors of nonrenal cancer mortality, at least in patients with good preoperative function or mild chronic kidney disease.

To evaluate whether excised parenchymal mass (EPM) during partial nephrectomy (PN) correlates with functional decline and can serve as a surrogate for functional outcomes.All 215 patients managed with PN for unifocal renal mass with necessary studies to determine EPM and percent glomerular filtration rate (GFR) and parenchymal mass preserved (both global and specific to the operated kidney) were analyzed. EPM was estimated from the pathologic specimen by subtracting the tumor mass from the specimen mass, with both calculated using the elliptical formula. Vascularized parenchymal mass preserved was measured from computed tomography scans obtained2 months prior and 3-12 months after surgery. All functional analyses were required to be within the same time frames, and patients with a contralateral kidney were also required to have nuclear renal scans.The median tumor size was 3.5 cm and the median R.E.N.A.L. was 7. Warm and cold ischemia were utilized in 123 and 92 patients, respectively (median ischemia time = 23 minutes). The median global GFR preserved was 89%, the median total parenchymal mass preserved was 93%, and the median estimated EPM was 16 cmOur data suggest that parenchymal mass preserved with standard PN by experienced surgeons associates strongly with function preserved, whereas EPM fails to correlate with functional outcomes. Further study of the functional impact of EPM in other circumstances will be required, such as enucleation or PN performed by less-experienced surgeons.

Partial nephrectomy is prioritized over radical nephrectomy in patients with chronic kidney disease whenever feasible. However, we hypothesized that some patients with severe chronic kidney disease might rapidly progress to end stage renal disease, in which case the morbidity that can be associated with partial nephrectomy would not be justified.A retrospective review of all 62 patients with stage IV chronic kidney disease undergoing partial nephrectomy at our institution (1999-2015) was performed. We analyzed preoperative/intraoperative factors and postoperative outcomes. Survival-analyses evaluated factors associated with time-to-progression to end stage renal disease the primary end point.Median age was 67 years, 71% of patients were male, and 84% Caucasian. Comorbidities included hypertension (94%), cardiovascular disease (53%) and diabetes (32%). Median preoperative estimated glomerular filtration rate was 23 ml/minute/1.73 mOur data suggest that some patients with stage IV chronic kidney disease undergoing partial nephrectomy have substantial comorbidities and nonaggressive pathology, and are at risk for unfavorable perioperative outcomes and rapid-progression to end stage renal disease. Renal mass biopsy should be strongly considered to improve patient-selection. Alternate strategies (active surveillance or radical nephrectomy) may be more appropriate, particularly when partial nephrectomy is high complexity or when the patient is African American, or preoperative glomerular filtration rate is less than 25 ml/minute/1.73 m

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/cmPercent 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.

INTRODUCTION AND OBJECTIVES:Replacement of healthy renal parenchyma by renal cell carcinoma (RCC) can contribute to preexisting CKD and thus complicate management. However the magnitude and factors associated with this phenomenon have not been described.METHODS:A retrospective review was performed of all radical nephrectomies (RN) performed at our center from 2006-2016. 155 patients with available nuclear renal scan and imaging demonstrating a single RCC tumor with normal contralateral kidney were included for analysis. Healthy renal parenchyma of each kidney and tumor volumes were measured by free-hand scripting from axial images at 3 mm intervals. Parenchymal volume discordance (volume ipsilateral kidney – volume contralateral kidney) was calculated assuming that the volume of the contralateral kidney serves as a control to assess replacement of healthy parenchyma by RCC. Split renal function was used as an internal control for volumetric measures. Multiple regression was used to identify preoperative a...

INTRODUCTION AND OBJECTIVES:Loss of renal function remains a major limitation of radical nephrectomy (RN) for renal cell carcinoma (RCC). RCC patients tend to be older and have significant comorbid...

INTRODUCTION AND OBJECTIVES:Percent parenchymal mass preserved (PPMP) is the primary determinant of functional outcomes after partial nephrectomy (PN). Accurate methods for predicting PPMP based on...

Background Acute ischemic injury in the operated kidney after partial nephrectomy (PN) is often masked by a functional contralateral kidney; however, there is no practical method to assess this and its prognostic significance has not been defined. Objective We propose a spectrum score to reflect the degree of ischemic insult in the ipsilateral kidney and study its relationship to subsequent functional recovery. Design, setting, and participants From 2007 to 2014, 243 patients with a functional contralateral kidney underwent PN with necessary studies for detailed analysis of function and parenchymal mass before and after surgery in the ipsilateral kidney. Based on split function and percent parenchymal mass preserved in the ipsilateral kidney, we determined: serum creatinine (SCr) ideal-peak : expected peak SCr presuming no ischemic injury; and SCr worstcase-peak : expected peak SCr presuming temporary complete nonfunction of the ipsilateral kidney. The acute ipsilateral renal dysfunction spectrum score was defined: (observed peak SCr – SCr ideal-peak )/(SCr worstcase-peak – SCr ideal-peak ). Subsequent functional recovery was defined: (percent function preserved)/(percent mass saved). Intervention PN. Outcome measurements and statistical analysis Factors associated with spectrum score and relationship between spectrum score and subsequent functional recovery were evaluated by linear regression. Results and limitations Median duration of warm ischemia ( n =152) was 21min (interquartile range [IQR] = 15–27) and hypothermia ( n =91) 26min (IQR=23–30). Median parenchymal mass preservation was 83% (IQR=74–91%). Warm ischemia and longer ischemia duration associated with higher spectrum score (both p 75% quartiles) had decreased functional recovery (98%, 94%, 90%, and 89%, respectively, p p p =0.3–0.7). Conclusions Acute ipsilateral renal dysfunction spectrum score unmasks the degree of ischemic insult in the operated kidney after PN and associates with functional recovery. While increased spectrum score associates with suboptimal recovery, even patients with a high spectrum score reached 89–90% recovery. Patient summary Acute functional decline after partial nephrectomy is difficult to evaluate in patients with two kidneys, but a proposed spectrum score can be used to evaluate this. Increased spectrum score reflects increased ischemia and may impact the functional recovery of the kidney.

The percent of preserved parenchymal mass is the primary determinant of functional outcomes after partial nephrectomy. Accurate methods to predict the percent of preserved parenchymal mass based on preoperative imaging could facilitate patient counseling.We evaluated the records of 428 patients who had undergone partial nephrectomy and the studies necessary to assess preserved ipsilateral parenchymal mass and function. Preoperative and postoperative ipsilateral parenchymal volumes were measured from contrast enhanced computerized tomography less than 2 months before and 3 to 12 months after partial nephrectomy and the actual percent of preserved parenchymal mass was determined. The ipsilateral percent of preserved parenchymal mass and the final global glomerular filtration rate were estimated based on preoperative imaging using subjective estimation, quantitative estimation, or estimation derived from the contact surface area or the R.E.N.A.L. (radius, exophytic/endophytic, nearness of tumor to collecting system or sinus, anterior/posterior and location relative to polar lines) score.Median tumor diameter was 3.5 cm, median contact surface area was 24 cmCurrently available methods to estimate the percent of preserved parenchymal mass have important limitations. The final global glomerular filtration rate, which is the most important functional outcome, could be predicted fairly accurately by all tested methods. However, none of them were better than simply presuming that 89% of function would be saved due to strong anchoring to the preoperative glomerular filtration rate.

Acute kidney injury often leads to chronic kidney disease in the general population. The long-term functional impact of acute kidney injury observed after partial nephrectomy has not been adequately studied.From 2004 to 2014 necessary studies for analysis were available for 90 solitary kidneys managed by partial nephrectomy. Functional data at 4 time points included preoperative serum creatinine, peak postoperative serum creatinine, new baseline serum creatinine 3 to 12 months postoperatively and long-term followup serum creatinine more than 12 months postoperatively. Adjusted acute kidney injury was defined by the ratio, observed peak postoperative serum creatinine/projected postoperative serum creatinine adjusted for parenchymal mass loss to reveal the true effect of ischemia. The long-term change in renal function (the long-term functional change ratio) was defined as the most recent glomerular filtration rate/the new baseline glomerular filtration rate. The relationship between the grade of the adjusted acute kidney injury and the long-term functional change was assessed by Spearman correlation analysis and multivariable regression.Median patient age was 64 years and median followup was 45 months. Median parenchymal mass preservation was 80%. Adjusted acute kidney injury occurred in 42% of patients, including grade 1 injury in 20 (22%) and grade 2/3 in 18 (20%). On univariable analysis the degree of the adjusted acute kidney injury did not correlate with the long-term glomerular filtration rate change (p = 0.55). On multivariable analysis adjusted acute kidney injury was not associated with a long-term functional change (p0.05) while diabetes and warm ischemia were modestly associated with a long-term functional decline (each p0.05).Acute kidney injury after partial nephrectomy was not a significant or independent predictor of long-term functional decline in our institutional cohort. A prospective study with larger sample sizes and longer followup is required to evaluate factors associated with long-term nephron stability.

Background Tumor enucleation (TE) optimizes parenchymal preservation and could yield better function than standard partial nephrectomy (SPN), although data on this are conflicting. Objective To compare functional outcomes for TE and SPN strategies. Design, setting, and participants Patients managed with partial nephrectomy (PN) with necessary data for analysis of preservation of ipsilateral parenchymal mass (IPM) and global glomerular filtration rate (GFR) from two centers were included. All studies were required Intervention Partial nephrectomy. Outcome measurements and statistical analysis Vascularized IPM was estimated from contrast-enhanced CT scans preoperatively and postoperatively. Serum creatinine-based estimates of global GFR were also obtained in the same timeframes. Univariable and multivariable linear regression evaluated factors associated with new-baseline global GFR. Results/limitations Analysis included 71 TE and 373 SPN cases. The median preoperative global GFR was comparable for TE and SPN (75 vs 78ml/min/1.73m 2 ; p =0.6). The median tumor size was 3.0cm for TE and 3.3cm for SPN ( p =0.03). The median RENAL score was 7 in both cohorts. For TE, warm ischemia and zero ischemia were used in 51% and 49% of cases, respectively. For SPN, warm ischemia and cold ischemia were used in 72% and 28% of patients, respectively. Capsular closure was performed in 46% of TE and 100% of SPN cases ( p 0.001). Positive margins were found in 8.5% of TE and 4.8% of SPN patients ( p =0.2). The median vascularized IPM preserved was 95% (interquartile range [IQR] 91–100%) for TE and 84% (IQR 76–92%) for SPN ( p 0.001). The median global GFR preserved was 101%(IQR 93–111%) and 89% (IQR 81–96%) for TE and SPN, respectively ( p 0.001). On multivariable analysis, resection strategy, preoperative GFR, and vascularized IPM preserved were all significantly associated ( p Conclusions Our analysis suggests that TE has potential for maximum IPM preservation compared to SPN and may provide optimized functional recovery. Further investigation will be required to evaluate the clinical significance of these findings. Patient summary Tumor enucleation for kidney cancer involves dissection along the tumor capsule and optimally preserves normal kidney tissue, which may lead to better functional recovery. The importance of this approach in various clinical settings will require further investigation.

667 Background: Validation and implementation of quality indicators (QIs) for oncological surgical care is imperative in national health care systems. However, QIs must be adjusted for significant case-mix variations among hospitals and to capture disparate patient outcomes. Here, we explore and validate a compound quality score (CQS) as a metric for hospital-level quality of care in kidney cancer patients. Methods: Kidney cancer patients (n = 8233) treated at the VA (2005-2015) were identified. Two previously described and validated process QIs were explored: the proportion of patients with a) T1a tumors undergoing partial nephrectomy; and b) T1-T2 tumors undergoing minimally invasive radical nephrectomy. Demographics, comorbidity, tumor characteristics and treatment year were used for case-mix adjustment using indirect standardization / multivariable regression models. The predicted vs observed ratio of cases was calculated to generate each QI score. CQS represents the sum of both QIs scores. Ninety-six hospitals were benchmarked by CQS and patient-level outcomes were regressed on CQS levels to assess for length of stay (LOS), 30 days complications/readmission, 90 days overall mortality and total cost of surgical admission. Results: CQS identified 25, 33 and 38 hospitals with higher, lower and average performance, respectively. Total CQS score was independently associated with LOS [β = -0.04, p< 0.01, predicted LOS 0.84 days shorter for CQS = 2 vs. CQS = -2], 30 days surgical complications [OR = 0.88, p < 0.01] or 30 days medical complications [OR = 0.93, p < 0.01] and total cost of surgical admission [β = -0.014, p< 0.01, predicted 12% lower cost for CQS = 2 vs. CQS = -2]. No association was found between CQS and 30 day readmissions or 90 days mortality (all p>0.05), although low event rates were observed (8.9% and 1.7%, respectively). Conclusions : Variability in quality of surgical care at a hospital-level can be captured with the CQS among kidney cancer patients. CQS is associated with length of stay, post-operative complications and total cost of surgical admission. Quality indicators should be used to identify, audit and implement quality improvement strategies across health systems.

Background: Proteinuria is included in the Kidney Disease: Improving Global Outcomes (KDIGO) risk stratification for chronic kidney disease (CKD) in the general population. However, the importance of proteinuria in patients with renal cancer has not been adequately studied. Objective: To evaluate the prognostic impact of preoperative proteinuria on overall survival (OS) and renal function stability (RFS) for patients managed with renal cancer surgery. Design, setting, and participants: From 1999 to 2008, 977 patients who underwent renal cancer surgery had preoperative data recorded for the glomerular filtration rate (GFR) estimated using the CKD Epidemiology Collaboration equation (G1 � 90, G2 60–89, G3a 45–59, G3b 30–44, G4 15–29, and G5

Background Proteinuria is included in the Kidney Disease: Improving Global Outcomes (KDIGO) risk stratification for chronic kidney disease (CKD) in the general population. However, the importance of proteinuria in patients with renal cancer has not been adequately studied. Objective To evaluate the prognostic impact of preoperative proteinuria on overall survival (OS) and renal function stability (RFS) for patients managed with renal cancer surgery. Design, setting, and participants From 1999 to 2008, 977 patients who underwent renal cancer surgery had preoperative data recorded for the glomerular filtration rate (GFR) estimated using the CKD Epidemiology Collaboration equation (G1 ≥90, G2 60–89, G3a 45–59, G3b 30–44, G4 15–29, and G5 2 ) and proteinuria status according to a dipstick assay (A NEG , negative or trace protein; A POS , ≥30mg/dl). Median follow-up was 8.7 yr (range 7.0–10.7). Intervention Renal cancer surgery. Outcome measurements and statistical analysis OS and RFS (avoidance of a decline in GFR of ≥50% and of dialysis) were analyzed using the Kaplan-Meier method. We performed multivariable Cox regression to evaluate independent predictors for both outcomes. Results and limitations The 326 patients (33%) with A POS proteinuria status had compromised 5-yr OS compared with A NEG patients (65% vs 77%; p p p p Conclusions Proteinuria appears to be a significant and independent predictor of OS and RFS in patients undergoing renal cancer surgery, particularly for certain cohorts, and should be sensibly incorporated into routine management. Further studies, ideally prospective, are required to evaluate the importance of the degree of proteinuria. The generalizability of our findings will also require further investigation. Patient summary Protein in the urine (proteinuria) is a sign of kidney damage, and kidney cancer patients with proteinuria have worse outcomes after surgery. Assessment of proteinuria should be routinely included in the preoperative evaluation of patients with kidney cancer.

In this issue of European Urology, Capitanio and colleagues [1] present a multicenter analysis of functional outcomes after renal cancer surgery with a special focus on the incidence of end-stage renal disease (ESRD). The study population comprised 2027 patients with a clinical T1 renal mass treated with partial nephrectomy (PN; n = 1334) or radical nephrectomy (RN; n = 693) between 1984 and 2010, with mean follow-up of 72 mo. Patients with preexisting chronic kidney disease (CKD) were excluded, and ESRD was defined as development of estimated glomerular filtration rate (GFR) of 15 ml/min/1.73 m 2 . ESRD was observed in 1.5% and 2.5% of PN patients at 5- and 10-yr follow-up, respectively, very similar to the rates of 1.9% and 2.7% after RN at the same time points. However, relevant comorbidities that can impact renal function were more prevalent in the PN cohort, and when multivariable analysis was applied to control for these potential confounders, PN was associated with a substantially lower risk of ESRD (hazard ratio [HR] 0.4, 95% confidence interval [CI] 0.2–0.8; p = 0.02). The authors conclude that ‘‘PN independently protects against ESRD and consequent need for dialysis’’. The authors should be congratulated for making a substantial contribution to the debate regarding the merits of PN relative to RN [2], and their findings are certainly in alignment with common sense. However, a discerning reader might want to ask some important questions. First, what is the quality of evidence and does it really suggest cause/effect as the authors imply? Even more pertinent, what is the relevance of such findings to long-term survival for the population as a whole? To address these issues, let us first look at the statistical analysis presented by the authors in Supplementary Table 1, in which univariable and multivariable results are outlined. It is not clear why some factors that were significant in univariable analysis, such as the Charlson comorbidity index (p = 0.01), were not included in the multivariable analysis, while other factors that were not even close to statistical significance in univariable analysis, such as treatment type (PN vs RN, p = 0.5), were carried forward. In reality, the statistical analysis is somewhat complex, and is described in the table as a ‘‘reduced model after backward stepwise’’. When the statistical manipulations required to elucidate the advantages of a given treatment are this obscure, one wonders about the true degree of the effect. Beyond this we must recognize the more fundamental