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Objective: To rigorously evaluate the impact of the percentage of parenchymal volume preserved (PPVP) and how well the preserved parenchyma recovers from ischaemia (Rec ischaemia ) 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. Rec ischaemia 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 m 2 , 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 Rec ischaemia 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 Rec ischaemia can also contribute. Tumour-related factors strongly influence the PPVP, while surgical efforts can improve the PPVP as observed for patients with solitary kidneys., (© 2024 BJU International.)

Group 3 innate lymphoid cells (ILC3s) regulate inflammation and tissue repair at mucosal sites, but whether these functions pertain to other tissues-like the kidneys-remains unclear. Here, we observed that renal fibrosis in humans was associated with increased ILC3s in the kidneys and blood. In mice, we showed that CXCR6 + ILC3s rapidly migrated from the intestinal mucosa and accumulated in the kidney via CXCL16 released from the injured tubules. Within the fibrotic kidney, ILC3s increased the expression of programmed cell death-1 (PD-1) and subsequent IL-17A production to directly activate myofibroblasts and fibrotic niche formation. ILC3 expression of PD-1 inhibited IL-23R endocytosis and consequently amplified the JAK2/STAT3/RORγt/IL-17A pathway that was essential for the pro-fibrogenic effect of ILC3s. Thus, we reveal a hitherto unrecognized migration pathway of ILC3s from the intestine to the kidney and the PD-1-dependent function of ILC3s in promoting renal fibrosis., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: 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., Materials and Methods: 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., Results: 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/cm 3 of parenchyma was 0.236 postoperatively vs 0.208 preoperatively, p=0.004). Age (-0.85, p <0.01), global preoperative estimated glomerular filtration rate (-0.28, p <0.01) and split renal function of the removed kidney (0.61, p <0.01) were independent predictors of renal functional compensation., Conclusions: Percent renal functional compensation after radical nephrectomy is greater in younger patients, when preoperative estimated glomerular filtration rate is lower and when the removed kidney has more robust function. Increases in measurable parenchymal mass and functional efficiency contribute substantially to renal functional compensation.

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 cm 3 and 36.9 mL/min/1.73 m 2 , respectively. Parenchymal volumes estimated by free-hand scripting vs software analyses correlated strongly (r = 0.98, P < 0.001). Preoperative ipsilateral eGFR based on SRF from PVA vs NRS also correlated strongly (r = 0.94, P < 0.001). Ipsilateral eGFR saved after PN correlated strongly with parenchymal volume preserved (all r >0.60); however, the correlation was much stronger when ipsilateral eGFRs were based on SRF from PVA rather than NRS (z-statistic = 3.15, P = 0.002). For RN patients, preoperative eGFR in the contralateral kidney based on SRF from PVA vs NRS also correlated strongly (r = 0.87, P < 0.001)., Conclusion: PVA has utility for estimation of SRF in patients with renal masses, even though this population is older and more comorbid than renal donors and the tumour can complicate the analysis. PVA can be obtained by software analysis from preoperative cross-sectional imaging and thus readily incorporated into routine clinical practice., (© 2020 The Authors BJU International © 2020 BJU International Published by John Wiley & Sons Ltd.)

Loss of renal function can be a clinically impactful event after partial nephrectomy (PN). We aimed to create a model to predict loss of renal function in patients undergoing PN. Data for 1897 consecutive patients who underwent PN with warm ischemia between 2008 and 2017 were extracted from our institutional database. Loss of renal function was defined as upstaging of chronic kidney disease in terms of the estimated glomerular filtration rate (eGFR) at 3 mo after PN. A nomogram was built based on a multivariable model comprising age, sex, body mass index, baseline eGFR, RENAL score, and ischemia time. Interval validation and calibration were performed using data from 676 patients for whom complete data were available. Receiver operator characteristic (ROC) curves with 1000 bootstrap replications were plotted, as well as the observed incidence versus the nomogram-predicted probability. We also applied the extreme training versus test procedure known as leave-one-out cross-validation. After internal validation, the area under the ROC curve was 76%. The model demonstrated excellent calibration. At an upstaging cutoff of 27% probability, upstaging was predicted with a positive predictive value of 86%. PATIENT SUMMARY: In this report, we created a model to predict postoperative loss of renal function after partial nephrectomy for renal tumors. Inputting baseline characteristics and ischemia time into our model allows early identification of patients at higher risk of renal function decline after partial nephrectomy with good predictive power., (Copyright © 2018. Published by Elsevier B.V.)

Background: Percentage parenchymal mass preserved (PPMP) is a key determinant of functional outcomes after partial nephrectomy (PN); however, predictors of PPMP have not been defined., Objective: To provide a comprehensive analysis of the functional impact of and potential predictive factors for PPMP., Design, Setting, and Participants: We analyzed data for 464 patients managed with PN at our center with necessary studies to determine vascularized parenchymal mass and function preserved within the operated kidney. PPMP was measured from computed tomography scans <2 mo before and 3-12 mo after PN., Intervention: PN., Outcome Measurements/statistical Analysis: Recovery from ischemia was defined as percentage ipsilateral glomerular filtration rate (GFR) preserved normalized by PPMP. We used Pearson correlation to evaluate the relationships between GFR preserved and PPMP. Multivariable logistic regression was used to assess predictors of PPMP., Result and Limitations: Ninety-six patients (21%) had a solitary kidney. The median tumor size and RENAL score were 3.5cm and 8, respectively. Cold/warm ischemia were utilized in 183/281 patients for which the median ischemia time were 28/20min. The median preoperative and postoperative vascularized parenchymal mass in the operated kidney were 194 and 157cm 3 , respectively, resulting in median PPMP of 84%. GFR preservation correlated strongly with PPMP (r=0.64; p<0.001). Recovery from ischemia was suboptimal (<80%) in 71 patients (15%), while suboptimal PPMP (<80%) was a more common adverse event, occurring in 160 patients (34%; p<0.001). Multivariable analysis demonstrated that greater tumor size and complexity were associated with lower PPMP (p≤0.04), while solitary kidney and hypothermia were associated with higher PPMP (p<0.001). Longer ischemia time was also associated with lower PPMP (p=0.003), probably reflecting the complexity of the surgery. Limitations include the retrospective design., Conclusion: PPMP correlates strongly with functional outcomes after PN, and lower PPMP is the most common and important source of functional decline after PN. Larger tumors, greater tumor complexity, and prolonged ischemia time were associated with lower PPMP, while PPMP tended to be greater for solitary kidneys, confirming that PPMP is a modifiable factor., Patient Summary: Kidney function after partial nephrectomy primarily depends on the amount of vascularized kidney preserved by the procedure. Lower recovery of function is seen when operating on larger tumors in unfavorable locations, but preservation of the parenchymal mass can be improved when truly necessary, such as when operating on a tumor in a solitary kidney., (Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Background: The role of renal sympathetic nerve (RSN) in hypertension should be better understood. We aimed to three-dimensionally reconstruct the renal nerves, and explore its anatomical and histochemical characteristics in hypertensive canine model and patients., Methods: Renal arteries with surrounding tissue were collected from canines and cadavers with or without hypertension. Serial renal artery hematoxylin-eosin sections were used for three-dimensional reconstruction, and morphological parameters were collected and analyzed., Results: In hypertensive canines, the mean renal nerve number was 26.71 ± 5.68 versus 19.84 ± 5.68 in controls (P = 0.02), and the middle renal nerve volume was 5.31 ± 2.13 versus 2.60 ± 1.00 μl in controls (P = 0.01). Renal tissue norepinephrine concentrations, tyrosine hydroxylase and substance P immunoreactivity in RSN, and growth-associated protein 43 immunoreactivity in renal ganglion were significantly increased in hypertensive canines. In humans, the renal nerve was evenly distributed along the renal artery in a network pattern. The renal ganglion volume was 72.75 ± 33.43 in hypertensive patients versus 37.04 ± 23.95 μl in controls (P = 0.029) and the mean neuronal size in renal ganglion was 1187.3 ± 219.9 μm in patients versus 714.8 ± 142.7 μm in controls (P = 0.002). Tyrosine hydroxylase immunoreactivity in the RSN was 0.153 ± 0.014 in patients versus 0.104 ± 0.019 in controls (P = 0.013). Growth-associated protein 43 immunoreactivity in the renal ganglion was 86 612.8 ± 14 642.0 in patients versus 33 469.8 ± 15 666.8 μm/mm in controls (P < 0.001)., Conclusion: Our study suggests that RSN and renal ganglion histological remodeling occurs in individuals with hypertension and the distal segment or branches of renal artery might be a promising therapeutic target for RSN modulation therapy.

Background: Nephron mass preservation is a key determinant of functional outcomes after partial nephrectomy (PN), while ischemia plays a secondary role. Analyses focused specifically on recovery of the operated kidney appear to be most informative, yet have only included limited numbers of patients., Objective: To evaluate the relative impact of parenchymal preservation and ischemia on functional recovery after PN using a more robust cohort allowing for more refined perspectives about ischemia., Design, Setting, and Participants: A total of 401 patients managed with PN with necessary studies were analyzed for function and nephron mass preserved specifically within the kidney exposed to ischemia., Intervention: PN., Outcome Measurements and Statistical Analysis: The nephron mass preserved was measured from computed tomography scans <2 mo before and 3-12 mo after PN. Patients with two kidneys were required to have nuclear renal scans within the same timeframes. Recovery from ischemia was defined as the percent function preserved normalized by the percent nephron mass preserved. Pearson correlation was used to evaluate relationships between functional recovery and nephron mass preservation or ischemia time. Multivariable linear regression assessed predictors for recovery from ischemia., Results and Limitations: The median tumor size was 3.5cm and the median RENAL score was 8. Cold and warm ischemia were utilized in 151 and 250 patients, and the median ischemia time was 27 and 21min, respectively. The function preserved was strongly correlated with nephron mass preserved(r=0.63; p<0.001). Median recovery from ischemia was significantly higher for hypothermia (99% vs 92%; p<0.001) and remained consistently strong even with longer duration. Multivariable analysis demonstrated that recovery from ischemia, which normalizes for nephron mass preservation, was significantly associated with ischemia type and duration (both p<0.05). However, each additional 10min of warm ischemia was associated with only a 2.5% decline in recovery from ischemia. Limitations include the retrospective design., Conclusions: Our data suggest that functional recovery from clamped PN is most reliable with hypothermia. Longer intervals of warm ischemia are associates with reduced recovery; however, incremental changes are modest and may not be clinically significant in patients with a normal contralateral kidney., Patient Summary: Functional recovery after clamped partial nephrectomy is primarily dependent on preservation of nephron mass. Recovery is most reliable when hypothermia is applied. Longer intervals of warm ischemia are associated with reduced recovery; however, the incremental changes are modest., (Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Objective: To evaluate contact surface area (CSA) between the tumor and parenchyma as a predictor of ipsilateral parenchyma and function preserved after partial nephrectomy (PN). Previous studies suggested that CSA is a strong predictor of functional outcomes but the limitations of CSA have not been adequately explored., Patients and Methods: Four hundred nineteen patients managed with standard PN for solitary tumor with necessary studies to evaluate and analyze ipsilateral preoperative or postoperative parenchymal mass and function. Parenchymal mass and CSA were measured using contrast-enhanced computed tomography <2 months prior and 3-12months after PN. CSA was calculated: 2πrd, where r = radius and d = intraparenchymal depth. Pearson-correlation evaluated relationships between CSA and ipsilateral parenchymal mass or function preserved. Multivariable regression assessed predictors of function preserved. Conceptually, the CSA paradigm should function better for exophytic tumors than endophytic ones., Results: Median tumor size was 3.5 cm and R.E.N.A.L. was 8. Median global and ipsilateral glomerular filtration rate preserved were 89% and 79%, respectively. Median ipsilateral parenchymal mass preserved was 85% and significantly higher for exophytic masses (P = .001). Median CSA was 22.8 cm 2 and significantly less for exophytic masses (P = .02). CSA associated with both ipsilateral function and mass preserved (both P < .05), but the correlations were only modest (r = 0.25 and 0.36, respectively). On multivariable analysis, CSA associated with function preserved for exophytic masses (P = .01), but not for endophytic ones (P = .27)., Conclusion: CSA associates with functional outcomes after standard PN, although the strength of the correlations was modest, unlike previous studies, and CSA was not an independent predictor for endophytic tumors. Further study will be required to evaluate the utility of CSA in various clinical settings., (Copyright © 2018 Elsevier Inc. All rights reserved.)

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 <2 mo before and 3-12 mo after surgery. Patients with a solitary kidney or multifocal tumors were excluded., 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<0.001) with new-baseline global GFR. Limitations include the retrospective design and the lack of resection outcome data., 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., (Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Purpose: Parenchymal mass loss is the predominant factor associated with functional outcomes after partial nephrectomy. It is primarily due to excised and/or devascularized parenchymal mass. We evaluated the importance of excised and devascularized parenchymal mass relative to functional recovery after partial nephrectomy., Materials and Methods: In 168 patients who underwent partial nephrectomy the necessary studies were done to determine excised and devascularized parenchymal mass, and evaluate parenchymal mass changes and functional loss of the operated kidney. Parenchymal mass loss in the ipsilateral kidney was measured on contrast enhanced computerized tomography less than 2 months before and 3 to 12 months after partial nephrectomy. Excised parenchymal mass was estimated by subtracting tumor volume from specimen volume. Devascularized parenchymal mass was defined as total parenchymal mass loss minus excised parenchymal mass. We used the Pearson correlation to evaluate relationships between glomerular filtration rate preservation and parenchymal mass loss. Multivariable analysis was done to assess factors associated with devascularized parenchymal mass., Results: Median tumor size was 3.4 cm and median R.E.N.A.L. (radius, exophytic/endophytic tumor properties, nearness of tumor to collecting system or sinus, anterior/posterior and location relative to polar lines) score was 7. Warm and cold ischemia was used in 100 and 68 patients, respectively. Median excised parenchymal and devascularized parenchymal mass was 9 and 16 cm 3 , respectively (p <0.001). Total parenchymal mass loss and devascularized parenchymal mass were associated strongly with glomerular filtration rate preservation in the operated kidney (each r ≥0.55, p <0.001). However, excised parenchymal mass was only weakly associated with functional outcomes (r = 0.23). The preoperative glomerular filtration rate and endophytic status were associated with devascularized parenchymal mass on multivariable analysis., Conclusions: To our knowledge we report the first study to specifically evaluate the relative contributions of devascularized and excised parenchymal mass to functional recovery after partial nephrectomy. Our study suggests that devascularized parenchymal mass has more impact, which may have implications regarding surgical technique. Prospective study is required to further evaluate the relative contributions of excised and devascularized parenchymal mass in various settings., (Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate whether excised parenchymal mass (EPM) during partial nephrectomy (PN) correlates with functional decline and can serve as a surrogate for functional outcomes., Materials and Methods: 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 obtained <2 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., Results: 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 cm 3 . Whereas percent parenchymal mass preserved correlated strongly with global and ipsilateral GFR preserved (both P < .001), EPM failed to correlate with functional outcomes on both univariable and multivariable analyses., Conclusion: Our 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., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To evaluate whether surgeons can predict the percent parenchymal mass that will be preserved by partial nephrectomy (PN) based on preoperative imaging, which could have potential utility for preoperative surgical planning and patient counseling. The proportion of preserved viable parenchyma following PN is the primary determinant of functional recovery. However, direct measurement of parenchymal volume preservation (VP) can be complex and time consuming., Materials and Methods: For patients managed with PN at our institution (2007-2014), we randomly selected 45 with a third in each of low, intermediate, or high R.E.N.A.L. complexity groups. All patients had recorded postoperative surgeon assessment of volume preservation (SAVP) and measured VP based on preoperative or postoperative computed tomography. Nine clinical providers predicted VP based solely on review of preoperative imaging while blinded to SAVP and measured VP. Clinical experience of the providers ranged from medical students to experienced urologic surgeons., Results: Median age was 66 years, median tumor size was 4.0 cm, and median R.E.N.A.L. was 8. Median measured VP was 81% (interquartile range of 74-89%). Preoperative prediction of VP correlated poorly with measured VP among the different surgeons (mean correlation coefficient, R = 0.34, range = 0.24-0.40). Surgeon experience provided minimal incremental improvement. Correlation between R.E.N.A.L. and measured VP was also marginal (R = 0.43). In contrast, correlation between postoperative SAVP and measured VP was much more robust (R = 0.75, P <.001)., Conclusion: Preoperative prediction of VP and R.E.N.A.L. score correlated poorly with measured VP for patients managed with PN. In contrast, postoperative SAVP provided a relatively reliable estimate of VP, and should be considered an acceptable substitute in most clinical circumstances., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Acute increase of serum creatinine (SCr) after partial nephrectomy (PN) is primarily due to parenchymal mass reduction or ischemia; however, only ischemia can impact subsequent functional recovery., Objective: We evaluate etiologies of acute kidney injury (AKI) after PN and their prognostic significance., Design, Setting, and Participants: From 2007-2014, 83 solitary kidneys managed with PN had necessary studies for detailed analysis of function and parenchymal mass before/after surgery. AKI was classified by Risk/Injury/Failure/Loss/Endstage classification and defined by either standard criteria (comparison to preoperative SCr) or proposed criteria (comparison to projected postoperative SCr based on parenchymal mass reduction). Subsequent recovery was defined as percent function preserved/percent mass saved., Intervention: PN., Outcome Measurements and Statistical Analysis: Predictive factors for AKI were evaluated by logistic regression. Relationship between AKI grade and subsequent functional recovery was assessed by linear regression., Results and Limitations: Median duration warm ischemia (n=39) was 20 min and hypothermia (n=44) was 29 min. Median parenchymal mass reduction was 11%. AKI occurred in 45 patients based on standard criteria and 38 based on proposed criteria, and reflected injury/failure (grade = 2/3) in 23 and 16 patients, respectively. On multivariable analysis, only ischemia time associated with AKI occurrence (p=0.016). Based on the proposed criteria, median recovery from ischemia was 99% in patients without AKI and 95%/90%/88% for patients with grades 1/2/3 AKI, respectively. The coefficient for association between AKI grade based on proposed criteria and subsequent functional recovery was -4.168 (p=0.018). Main limitation is limited patient cohort., Conclusions: Parenchymal mass reduction and ischemia both contribute to acute changes in SCr after PN. Classification of AKI by proposed criteria significantly associates with subsequent functional recovery. However, more robust numbers will be needed to further assess the merits of the proposed criteria. While AKI is associated with suboptimal recovery, even patients with grade 2/3 AKI reached 88-90% of recovery expected., Patient Summary: Acute decline in function after partial nephrectomy associates with more prolonged ischemia time, and appears to impact subsequent functional recovery. However, most kidneys eventually recover strongly, even if their function is sluggish in the first few days after surgery., (Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Objective: To evaluate the impact of extended warm ischemia on incidence of acute kidney injury (AKI) and ultimate functional recovery after partial nephrectomy (PN), incorporating rigorous control for loss of parenchymal mass, and embedded within comparison to cohorts of patients managed with hypothermia or limited warm ischemia., Materials and Methods: From 2007 to 2014, 277 patients managed with PN had appropriate studies to evaluate changes in function/mass specifically within the operated kidney. Recovery from ischemia was defined as %function saved/%parenchymal mass saved. AKI was based on global renal function and defined as a ≥1.5-fold increase in serum creatinine above the preoperative level., Results: Hypothermia was utilized in 112 patients (median = 27 minutes) and warm ischemia in 165 (median = 21 minutes). AKI strongly correlated with solitary kidney (P < .001) and duration (P < .001) but not type (P = .49) of ischemia. Median recovery from ischemia in the operated kidney was 100% (interquartile range [IQR] = 88%-109%) for cold ischemia, with 6 (5%) noted to have <80% recovery from ischemia. For the warm ischemia group, median recovery from ischemia was 91% (IQR = 82%-101%, P < .001 compared with hypothermia), and 34 (21%) had recovery from ischemia <80% (P < .001). For warm ischemia subgrouped by duration <25 minutes (n = 114), 25-35 minutes (n = 35), and >35 minutes (n = 16), median recovery from ischemia was 92% (IQR = 86%-100%), 90% (IQR = 78%-104%), and 91% (IQR = 80%-96%), respectively (P = .77)., Conclusion: Our results suggest that AKI after PN correlates with duration but not with type of ischemia. However, subsequent recovery, which ultimately defines the new baseline glomerular filtration rate, is most reliable with hypothermia. However, most patients undergoing PN with warm ischemia still recover relatively strongly from ischemia, even if extended to 35-45 minutes., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: Ischemia is a potential contributor to decline of function after partial nephrectomy (PN), although loss of parenchymal mass related to excision and reconstruction appears to be a more significant factor. However, loss of parenchymal mass could also be due to global effects of ischemia leading to parenchymal atrophy. In this study, we evaluated parenchymal volumes in regions away from the operated site to assess for atrophy., Materials and Methods: A total of 164 patients undergoing PN for whom detailed analysis of function and parenchymal mass within the operated kidney could be performed were assessed for opposite pole volume (OPV) before and 4-12 months after surgery. Tumor location was required to be ≥2 cm away from the opposite polar line to exclude local effects related to excision or reconstruction. OPV was estimated by software analysis, and the ratio of the estimates (OPV ratio = postoperative OPV to preoperative OPV) was used to assess for atrophy., Results: Patient demographics and tumor characteristics were representative of conventional PN populations, and warm ischemia (n = 101; median, 21 minutes) and cold ischemia (n = 63; median, 26 minutes) were applied by surgeon discretion. OPVs before and after PN were 63.2 and 62.5 cm(3), respectively (P = .76). The median OPV ratio was 0.99 suggesting that significant atrophy did not occur. OPV ratio was 0.99 for warm ischemia cases and 0.99 for cold ischemia cases (P = .95)., Conclusion: Limited warm ischemia or hypothermia was not associated with significant parenchymal atrophy after PN, which suggests that parenchymal volume loss in this setting is primarily due to excision or reconstruction., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: We assessed compensatory hypertrophy in the contralateral kidney after partial and radical nephrectomy in adults. We also examined predictive factors to facilitate more accurate estimation of global renal function after surgery., Materials and Methods: We analyzed the records of 172 patients who underwent partial or radical nephrectomy with appropriate studies to determine function and parenchymal mass specifically in the operated and contralateral kidneys. All patients required renal scans to provide split renal function preoperatively and postoperatively. Parenchymal volume was measured by computerized tomography. All studies were done less than 2 months preoperatively and 4 to 12 months postoperatively., Results: A total of 113 and 59 patients underwent partial and radical nephrectomy, and median tumor size was 3.5 and 7.0 cm, respectively (p <0.0001). Of patients treated with partial nephrectomy 19% had high complexity tumor compared to 80% of those treated with radical nephrectomy (p <0.0001). Median ipsilateral parenchymal volume was reduced 18% after partial nephrectomy and the median glomerular filtration rate in this kidney decreased 24.4%. The median contralateral kidney function increase after partial nephrectomy was 2.3% vs 21.1% after radical nephrectomy (p <0.0001). Median global function decreased 9.6% after partial nephrectomy vs 32.2% after radical nephrectomy (p <0.0001). A larger percent parenchymal volume loss (p = 0.0001) and fewer comorbidities (p = 0.0072) significantly correlated with greater compensatory hypertrophy in the contralateral kidney on multivariable analysis., Conclusions: Compensatory hypertrophy in adults was limited after partial nephrectomy and it correlated significantly with the amount of parenchymal volume excised. Healthier patients also appeared to respond better. These results may allow for more accurate estimation of global renal function after partial and radical nephrectomy., (Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Poorly functioning kidneys may not recover from ischemia as well as strongly functioning kidneys. This could impact surgical approaches to partial nephrectomy., Materials and Methods: We analyzed the records of 155 consecutive patients treated with partial nephrectomy who underwent appropriate studies to facilitate analysis of function and parenchymal mass in the operated kidney, including computerized tomography and glomerular filtration rate measurement within 2 months preoperatively and 4 to 12 months postoperatively. Patients with a contralateral kidney also underwent renal scan in the same time frame to provide split renal function. Computerized tomography was done to measure functional parenchymal volume before and after partial nephrectomy. Recovery from ischemia, defined as percent glomerular filtration rate saved/percent volume saved, was considered 100% if all nephrons recovered from the ischemic insult., Results: The median R.E.N.A.L. nephrotomy score was 8. Cold ischemia was used in 64 patients and limited warm ischemia was used in 91 (median 27 and 20 minutes, respectively). The median percent glomerular filtration rate saved in the operated kidney was 80% and the median parenchymal volume saved was 83%. The overall median rate of recovery from ischemia was 95%, including 100% for cold ischemia and 92% for limited warm ischemia. Recovery from ischemia was approximately 100% and was similar for all strata of preoperative estimated glomerular filtration rates in the operated kidney (p = 0.24), even in the warm ischemia subgroup., Conclusions: Our results suggest that the quantity of parenchyma preserved is the main determinant of the postoperative glomerular filtration rate after partial nephrectomy as long as limited warm ischemia or hypothermia is used. Even poorly functioning kidneys recover well from the ischemic insult proportionate to the amount of parenchyma preserved., (Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Followup is limited in patients with a solitary kidney who undergo partial nephrectomy. We evaluated overall, cancer specific and recurrence-free survival, and renal function in patients 5 years or greater after open partial nephrectomy., Materials and Methods: We retrospectively reviewed the Cleveland Clinic kidney cancer database, including only patients with a solitary kidney treated with open partial nephrectomy 5 or more years ago (from 1980 to June 2006) who had 6 months or more of followup. Survival and recurrence analyses were calculated using a Cox proportional hazards model. Results are shown as Kaplan-Meier survival curves. Linear regression analysis was done to assess postoperative renal function., Results: A total of 282 patients fit our study inclusion criteria (mean followup 175 months), of whom 233 underwent open partial nephrectomy 10 or more years ago. Actual overall survival was 78.5% and 59.5% at 5 and 10 years, respectively. The average estimated glomerular filtration rate at 5 years or greater and 10 years or greater since open partial nephrectomy was 35.1 and 34.5 ml/minute/1.73 m(2) in 89.7% and 89.6%, respectively, of patients with stage 3 or greater chronic kidney disease. Eight survivors were on intermittent hemodialysis 5 years or more postoperatively, including 5 at 10 years or more. There were 76 recurrences for a calculated 5 and 10-year recurrence-free survival rate of 72% (95% CI 66-879) and 63% (95% CI 57-71), respectively., Conclusions: Open partial nephrectomy in the solitary kidney provides reliable long-term oncological control at 5 and 10 years. Predicted and actual outcomes correspond well. Although most patients have chronic kidney disease postoperatively, it appears stable with minimal progression to dialysis., (Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: To determine the relative effect of type and duration of ischemia and parenchymal volume preservation on renal function after partial nephrectomy (PN)., Materials and Methods: Ninety-two patients with localized renal tumors (2007-2012) managed with PN at our center with necessary studies for analysis were included. This comprised 37 patients with a solitary kidney and 55 with a contralateral kidney. Thirty-five patients were managed with hypothermia and 57 with limited warm ischemia. Volumetric computed tomography was used to measure the volume of functional parenchyma before and after PN in the operated and contralateral kidneys. Glomerular filtration rate (GFR) was determined by the modification of diet in renal disease 2 equation, along with renal scan data for patients with a contralateral kidney. Regression analysis assessed the relationships between %GFR preserved in the operated kidney and potential predictive factors. All postoperative analyses were performed 4-12 months after surgery., Results: Median age was 61 years, median tumor size 3.5 cm, and median RENAL nephrometry score 8. Median cold ischemia time was 28 minutes and median warm ischemia time 21 minutes. Median %GFR preserved in the operated kidney was 79%. Median %parenchymal volume saved was 83%. Function in the contralateral kidney only increased marginally (median increase 6%). On regression analysis, %GFR preserved associated most strongly with %parenchymal volume saved (P <.0001), but also with lower RENAL scores (P = .0457) and the use of hypothermia (P = .0209). In contrast, ischemia time did not correlate with %GFR preserved (P = .5051)., Conclusion: Ultimate function after PN primarily correlated with parenchymal volume preservation, whereas ischemia played a secondary role. Thus, maximal parenchymal preservation with a precise PN should be a priority during PN., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: The precision of excision and reconstruction to optimize vascularized parenchymal preservation is a major determinant of renal function after partial nephrectomy. We assessed partial nephrectomy surgical precision using volumetric computerized tomography and analyzed predictive factors. Materials and Methods: We analyzed the records of 122 patients treated with partial nephrectomy in whom detailed analysis of the precision of excision and reconstruction specific to the operated kidney could be performed. We used volumetric computerized tomography to measure functional parenchymal volume before and after partial nephrectomy in the operated kidney. The glomerular filtration rate in the operated kidney was determined by the MDRD2 (Modification of Diet in Renal Disease 2) equation along with renal scan in patients with a contralateral kidney. Surgical precision was defined as actual postoperative parenchymal volume/predicted postoperative parenchymal volume, presuming loss of a 5 mm rim of normal parenchyma related to excision and reconstruction. Results: Median patient age was 61 years and 64 patients (52%) underwent an open procedure. Cold ischemia was used in 50 patients (median 26 minutes) and limited warm ischemia (median 20 minutes) was used in 72. The R.E.N.A.L. (radius, exophytic/endophytic, nearness of tumor to collecting system or sinus, anterior/posterior and location relative to polar line) nephrometry score indicated low, intermediate and high complexity in 43 (35%), 55 (45%) and 24 patients (20%), respectively. A total of 45 patients (37%) with a solitary kidney were included in analysis. The median precision of excision and reconstruction was 93%. The median preserved glomerular filtration rate was 80% in the operated kidney. A solitary kidney was the only significant predictor of excision and reconstruction precision on univariable and multivariable analysis. Conclusions: A solitary kidney significantly impacted partial nephrectomy surgical precision. This was likely related to the recognized need to preserve as much renal parenchyma as possible to optimize renal function in the absence of a contralateral kidney. [Copyright &y& Elsevier]

Purpose: Gene expression profiling has been shown to provide prognostic information on patients with solitary sporadic renal cell carcinoma. To our knowledge there is no reliable way to differentiate synchronous renal metastasis from bilateral primary tumors in patients with bilateral renal cell carcinoma. We present data using a custom kidney cancer cDNA array that can predict the outcome in patients with unilateral and bilateral renal cell carcinoma. Materials and Methods: Fresh frozen tissue from 38 clear cell renal cell carcinomas was analyzed using a cancer cDNA array containing 3,966 genes relevant to cancer or kidney development. Median followup was 5.3 years. Cancer recurred in 12 patients (43%) and 11 (39%) had died by the last followup. Results: Using a training data set of 8 tumors a 44 gene expression profile distinguishing aggressive and indolent clear cell renal cell carcinoma was identified. Of 29 single clear cell renal cell carcinomas 16 and 13 were predicted to be indolent and aggressive, respectively, by the gene expression profile. Recurrence-free survival at 5 years was 68% and 42% in these 2 groups, respectively (p = 0.032). Clear cell renal cell carcinoma classified as indolent or aggressive according to SSIGN (stage, size, grade and necrosis) score showed a 5-year recurrence-free survival rate of 78% and 42%, respectively (p = 0.021). On Cox proportional hazards analysis the gene expression profile was not an independent predictor of recurrence-free survival after accounting for SSIGN score. Gene expression profile classification correlated with cancer specific survival at 5 years in 4 of 4 patients with metachronous clear cell renal cell carcinoma but in only 2 of 4 with bilateral synchronous clear cell renal cell carcinoma. Conclusions: Gene expression profiling using a kidney cancer relevant cDNA array can differentiate between aggressive and indolent clear cell renal cell carcinomas. Gene expression profile results may be most useful for unilateral clear cell renal cell carcinoma when results are discordant with predictions of tumor behavior based on standard clinicopathological features. In addition, gene expression profiling can provide prognostic information that may help characterize tumors of unknown clinical stage, such as bilateral metachronous clear cell renal cell carcinoma. [Copyright &y& Elsevier]