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Small renal mass incidentally diagnosed are common findings nowadays due to the widespread of imaging. Renal mass biopsy is still underutilized by urologists due to its non-diagnostic rates. Confocal microscopy allows for rapid imaging of fresh tissue samples. We report the feasibility of using confocal technology for determining the quality of the renal core at renal mass biopsy on 4 consecutive cases at our institution.

Despite the important relationship between renorrhaphy and functional outcomes of partial nephrectomy, the urological guidelines do not provide recommendations about the optimal renorrhaphy technique. We carried out the first pooled literature analysis of the impact of suture technique on ultimate renal function after partial nephrectomy. Three studies comparing interrupted versus running suture including data on glomerular filtration rate (GFR) were included, for a total of 124 versus 269 patients. No significant differences were found between pre- and postoperative GFR in either patients who received an interrupted suture (weighted mean difference, -4.88ml/min, 95% confidence interval [CI] -11.38; 1.63, p=0.14) or those who received a running suture (-3.42ml/min, 95% CI -9.96; 3.12, p=0.31). Three studies comparing single- versus double-layer renorrhaphy included data on GFR (321 vs 199 patients). A benefit in functional outcomes favored single-layer technique (-3.19ml/min, 95% CI -8.09; 1.70, p=0.2 vs -6.07ml/min, 95% CI -10.75; -1.39, p=0.01). In conclusion, our quantitative synthesis suggests a renal functional benefit of the single-layer closure during partial nephrectomy. PATIENT SUMMARY: The available studies on renal functional data included in the present review suggest that "less is more" for renorrhaphy after partial nephrectomy. The single-layer renorrhaphy technique showed advantages in renal functional outcomes compared with the double-layer technique., (Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Purpose: Partial nephrectomy is the accepted standard of care for treatment of patients with small renal masses. The primary goal while performing partial nephrectomy is cancer control with a secondary important goal of maximizing renal function preservation with minimal perioperative morbidity. Recent studies have highlighted the importance of renal parenchymal quality and quantity postoperatively rather than duration of ischemia in determining long-term renal function. We review the available data regarding perioperative renal function optimization with special interest in ischemia during partial nephrectomy, highlighting the controversies and establishing future lines of investigation., Materials and Methods: We performed a comprehensive literature review for the years 1970 to 2014 via MEDLINE(®), PubMed(®) and the Cochrane Library. Review was consistent with the PRISMA (Preferred Reporting Items for Systemic Reviews and Meta-Analyses) criteria. We used MeSH (Medical Subject Headings) terms for the search including "acute kidney injury/failure," "carcinoma, renal cell/carcinoma of kidney/neoplasm of kidney," "kidney failure, chronic/end-stage kidney disease," "ischemia-reperfusion" and "warm ischemia/cold ischemia." Relevant review articles were included. Abstracts from major urological/surgical conferences were reviewed. All studies included were performed in adults, were written in English and had an abstract available., Results: Our traditional knowledge of renal ischemia is derived from animal studies, ie kidney transplant and retrospective partial nephrectomy series that indicate the risk of renal function impairment for every minute of ischemia. Careful evaluation of historical studies highlights flaws of the use of ischemia duration as a dichotomous marker (25 or 30 minutes) while predicting renal function outcomes. Recent studies have revealed no effect of duration of ischemia on ultimate kidney function in the short or long term. Quality and quantity of parenchyma preserved postoperatively are key predictors of ultimate renal function after partial nephrectomy. Traditionally partial nephrectomy has been performed with hilar occlusion to provide a relatively bloodless surgical field allowing effective oncologic control during tumor excision with secure management of blood vessels, collecting system and renal reconstruction. Selective clamping and nonclamping techniques have been proposed to avoid the perceived harmful effects of ischemia, although they convert a complex surgery into a more challenging procedure, potentially limiting the widespread use of partial nephrectomy for management of renal cancers. Promising urine and blood-based biomarkers (NGAL, KIM-1) in the context of critical care settings and global stress have been observed to predict acute kidney injury. Within the partial nephrectomy environment the usefulness of those markers needs to be further investigated. To date, no study has proved their usefulness in the setting of partial nephrectomy., Conclusions: Based on the available evidence, use of a single cutoff for duration of ischemia time as a dichotomous value for renal function outcomes in the setting of partial nephrectomy is flawed. Renal ischemia is a controversial topic with a shifted paradigm within the last decade. Current evidence has shown that patients with 2 kidneys undergoing nephron sparing surgery can tolerate ischemia times of more than 30 minutes without a clinically significant decline in renal function. Biomarkers predictive of renal tubular injury fail to predict acute kidney injury in the context of partial nephrectomy. Indications for partial nephrectomy could be significantly expanded as the safety of limited renal ischemia is now better understood., (Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: To compare freehand scripting and semiautomated renal parenchymal volume measurements on preoperative or postoperative computed tomography scans and assess relationships between parenchymal volume loss and functional changes within the operated kidney after partial nephrectomy (PN)., Materials and Methods: Fifty patients (16 solitary kidneys, 34 bilateral kidneys) with renal tumors managed by PN with necessary studies for analysis were included. Freehand scripting and semiautomated threshold-based analysis were performed before and 4-12 months after PN to obtain preoperative normal parenchymal volumes, projected residual parenchymal volumes, and actual postoperative volumes. Glomerular filtration rate was determined by the Modification of Diet in Renal Disease 2 equation along with nuclear renal scan to provide split function for patients with 2 kidneys. Limits of agreement and Bland-Altman analyses were performed. The relationship between the amount of vascularized parenchyma preserved and renal function saved was correlated for each measurement method using Pearson correlation., Results: The semiautomated method yielded estimates that were higher than freehand scripting by a mean of 14 cm(3) for estimation of preoperative normal parenchymal volume, 21 cm(3) for projected residual parenchymal volume, and 9 cm(3) for actual postoperative parenchymal volume. For the semiautomated method, correlation between the amount of normal parenchyma preserved and renal function saved was 0.52 (95% confidence interval [CI], 0.28-0.69; P <.001), and for the scripting method, correlation was 0.60 (95% CI, 0.39-0.76; P <.001)., Conclusion: Semiautomated and freehand scripting measurements of parenchymal volumes were relatively consistent before and after PN, although the semiautomated approach tended to yield volumes that were approximately 5%-10% higher on average. Measurement of parenchymal volume changes by both approaches correlated significantly with functional changes after PN., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: Partial nephrectomy is the reference standard for the management of small renal tumors and is commonly used for localized kidney cancer. A primary goal of partial nephrectomy is to preserve as much renal function as possible. New baseline glomerular filtration rate after partial nephrectomy can have prognostic significance with respect to long-term outcomes. Recent studies provide an increased understanding of the factors that determine functional outcomes after partial nephrectomy as well as preventive measures to minimize functional decline. We review these advances, highlight ongoing controversies and stimulate further research., Materials and Methods: A comprehensive literature review consistent with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria was performed from January 2006 to April 2014 using PubMed®, Cochrane and Ovid Medline. Key words included partial nephrectomy, renal function, warm ischemia, hypothermia, nephron mass, parenchymal volume, surgical approaches to partial nephrectomy, preoperative and intraoperative imaging, enucleation, hemostatic agents and energy based resection. Relevant reviews were also examined as well as their cited references. An additional Google Scholar search was conducted to broaden the scope of the review. Only English language articles were included in the analysis. The primary outcomes of interest were the new baseline level of function after early postoperative recovery, percent decline in function, potential etiologies and preventive measures., Results: Decline in function after partial nephrectomy averages approximately 20% in the operated kidney, and can be due to incomplete recovery from the ischemic insult or loss of nephron mass related to parenchymal excision or collateral damage during reconstruction. Compensatory hypertrophy in the contralateral kidney after partial nephrectomy in adults is marginal and decline in global renal function for patients with 2 kidneys averages about 10%, although there is some variance based on tumor size and location. Irreversible ischemic injury can be minimized by pharmacological intervention or surgical approaches such as hypothermia, limited warm ischemia, or zero or segmental ischemia. Excessive loss of nephron mass can be minimized by improved preoperative or intraoperative imaging, use of a bloodless field, enucleation and vascular microdissection. Hemostatic agents or energy based resection that minimizes the need for parenchymal and capsular suturing can also optimize preservation of the vascularized nephron mass., Conclusions: Our understanding of the decline in renal function after partial nephrectomy has advanced considerably, including better appreciation of its magnitude and impact in various settings, possible etiologies and potential preventive measures. Many controversies persist and this remains an important area of investigation., (Copyright © 2015 American Urological Association Education and Research, Inc. Published by 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.)

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.)