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Purpose: We sought to determine the predictors of short-term and long-term renal function impairment after partial nephrectomy., Materials and Methods: Clinical data on 769 consecutive patients who underwent partial nephrectomy were prospectively recorded at a total of 19 urological Italian centers from 2009 to 2012 in the RECORd 1 (Italian Registry of Conservative Renal Surgery) Project. We extracted clinical data on 708 of these patients who were alive, free of recurrent disease and with a minimum 2-year functional followup., Results: Of the patients 47.3% underwent open, 36.6% underwent laparoscopic and 16.1% underwent robot-assisted partial nephrectomy. The median baseline estimated glomerular filtration rate was 84.5 ml/minute/1.73 m 2 (IQR 69.9-99.1). Immediate (day 3 postoperatively), early (month 1) and late (month 24) renal function impairment greater than 25% from baseline was identified in 25.3%, 21.6% and 14.8% of cases, respectively. Female gender and the baseline estimated glomerular filtration rate were independent predictors of immediate, early and late renal function impairment. Age at diagnosis was an independent predictor of immediate and late impairment. Uncontrolled diabetes was an independent predictor of late impairment only. Open and laparoscopic approaches, and pedicle clamping were independent predictors of immediate and early renal function impairment. Overall 58 of 529 patients (11%) experienced postoperative cardiovascular events. Body mass index and late renal function impairment were independent predictors of those events., Conclusions: Surgically modifiable factors were significantly associated with worse immediate and early functional outcomes after partial nephrectomy while clinically unmodifiable factors affected renal function during the entire followup. Late renal function impairment is an independent predictor of postoperative cardiovascular events., (Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: We determined the effects of warm ischemia time on the recovery of renal function after partial nephrectomy under pneumoperitoneum., Materials and Methods: In this prospective study 37 consecutive patients who underwent laparoscopic partial nephrectomy or robot-assisted partial nephrectomy between June 2008 and May 2009 to remove a single cT1 renal tumor were evaluated using (99m)Tc-diethylenetriamine pentaacetic acid renal scintigraphy preoperatively, and at 3 and 12 months postoperatively., Results: The most significant reduction in the glomerular filtration rate of the affected kidney at 3 and 12 months after surgery (p = 0.018, p = 0.036, respectively) was seen for a warm ischemia time cutoff of 28 minutes. The glomerular filtration rate of the affected kidney was consistently and significantly reduced at 3 and 12 months postoperatively (-22.4% to -30.6%, p <0.001) in patients with a warm ischemia time greater than 28 minutes. In contrast, no significant glomerular filtration rate change was seen in patients with a warm ischemia time of 28 minutes or less. In terms of the contributional change of the affected kidney to total renal function, there is a trend toward a recovery after an initial decrease in both groups with a warm ischemia time greater than 28 minutes vs 28 minutes or less. On multivariate analysis warm ischemia time was a strong independent predictor of glomerular filtration rate reduction even 12 months after surgery (β = -1.3; 95% CI -1.8, -0.7; p <0.001)., Conclusions: If the warm ischemia time is greater than 28 minutes during laparoscopic partial nephrectomy or robot-assisted partial nephrectomy, the functional damage to the affected kidney progresses even up to 1 year after surgery., (Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Ischemic damage during partial nephrectomy increases with each minute of warm ischemia, leading some groups to advocate hypothermia in all cases or partial nephrectomy without vascular occlusion as a primary technique. The renal functional implications of these approaches have not been well studied in patients who undergo elective partial nephrectomy., Materials and Methods: We evaluated early and late renal functional outcomes in 1,132 patients with 2 functioning kidneys and normal preoperative serum creatinine who underwent partial nephrectomy without regional ischemia (58), with less than 30-minute warm ischemia (809) or with cold ischemia (265)., Results: The preoperative, postoperative and latest glomerular filtration rates were not significantly different in the 3 groups. At latest followup the relative decrease in renal function was less in cases without regional ischemia than in those with less than 30-minute warm ischemia and those with cold ischemia (0.5% vs 13% and 11%, respectively, p <0.001). In part this reflected selection bias since tumor size and the amount of parenchyma removed were lowest in that group (p <0.001). On multivariate analysis the percent of parenchyma preserved and the baseline glomerular filtration rate were strongly associated with the postoperative and latest glomerular filtration rates (p <0.001) but the partial nephrectomy approach was not (p >0.05). Adverse short or long-term renal functional outcomes were marginally increased in patients with 20 to 30-minute warm ischemia. However, such events were uncommon and renal failure developed in only 4 of 1,132 patients (less than 0.4%)., Conclusions: During elective partial nephrectomy a warm ischemia time of less than 20 minutes is not associated with clinically relevant functional loss compared to that of alternative techniques. However, longer warm ischemia time may correlate with ischemic injury and should be avoided., (Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Factors that determine renal function after partial nephrectomy are not well-defined, including the impact of cold vs warm ischemia, and the relative importance of modifiable and nonmodifiable factors. We studied these determinants in a large cohort of patients with a solitary functioning kidney undergoing partial nephrectomy., Materials and Methods: From 1980 to 2009, 660 partial nephrectomies were performed at 4 centers for tumor in a solitary functioning kidney under cold (300) or warm (360) ischemia. Data were collected in institutional review board approved registries and followup averaged 4.5 years. Preoperative and postoperative glomerular filtration rates were estimated via the Chronic Kidney Disease-Epidemiology Study equation., Results: At 3 months after partial nephrectomy median glomerular filtration rate decreased by equivalent amounts with cold or warm ischemia (21% vs 22%, respectively, p = 0.7), although median cold ischemic times were much longer (45 vs 22 minutes respectively, p <0.001). On multivariable analyses increasing age, larger tumor size, lower preoperative glomerular filtration rate and longer ischemia time were associated with decreased postoperative glomerular filtration rate (p <0.05). When percentage of parenchyma spared was incorporated into the analysis, this factor and preoperative glomerular filtration rate proved to be the primary determinants of ultimate renal function, and duration of ischemia lost statistical significance., Conclusions: This nonrandomized, comparative study suggests that within the relatively strict parameters of conventional practice, ie predominantly short ischemic intervals and liberal use of hypothermia, ischemia time was not an independent predictor of ultimate renal function after partial nephrectomy. Long-term renal function after partial nephrectomy is determined primarily by the quantity and quality of renal parenchyma preserved, although type and duration of ischemia remain the most important modifiable factors, and warrant further study., (Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: The kidney is often exposed to warm ischemia during laparoscopic partial nephrectomy. Warm ischemia time is associated with acute and possible long-term renal damage, particularly beyond a 30-minute threshold. We evaluated patient and tumor characteristics that might predict prolonged warm ischemia time., Materials and Methods: A prospective institutional database was searched for patients who underwent laparoscopic partial nephrectomy with renal vessel clamping. Warm ischemia time was treated as a continuous and a categorical (more or less than 30 minutes) variable. The association between warm ischemia time, and preoperative and surgical parameters was evaluated using linear and logistic regression analysis. The latter analysis was used to develop and internally validate a preoperative nomogram to predict warm ischemia time longer than 30 minutes., Results: On multivariate linear regression analysis tumor size (coefficient 1.6, 95% CI 0.7-2.6, p = 0.001), body mass index (coefficient 0.3, 95% CI 0.1-0.5, p = 0.005) and central tumor location (coefficient 3.7, 95% CI 0.5-7, p = 0.02) were independent predictors of longer warm ischemia time. Patients with 2 or more of certain risk factors, including body mass index greater than 30 kg/m(2), tumor greater than 4 cm and a centrally located tumor, were 5 times more likely to have warm ischemia time greater than 30 minutes than patients without the risk factors (p = 0.002). A nomogram incorporating predictors of longer warm ischemia time showed 75.4% accuracy., Conclusions: Greater tumor size, central tumor location and higher body mass index are associated with longer warm ischemia time. By incorporating these 3 risk factors into a nomogram prolonged warm ischemia time (greater than 30 minutes) can be accurately predicted preoperatively.

Purpose: We determined the maximal renal tolerance of warm ischemia using renal cortical interstitial metabolic changes to identify a potential real-time marker of irreparable renal function., Materials and Methods: Using a single kidney model 3 groups of 5 pigs each underwent 120, 150 and 180 minutes of warm ischemia, respectively. Microdialysis samples were collected before, during and after ischemia. Renal function assessments consisting of serum creatinine and GFR measurements were performed before ischemia and on post-ischemia days 1, 5, 9, 14 and 28. Kidneys exposed and not exposed to ischemia were collected for histological study., Results: Interstitial glucose and pyruvate concentrations decreased, while lactate concentrations increased to stable levels during ischemia. Glutamate spiked at 30 minutes of ischemia and subsequently tapered, while glycerol increased throughout warm ischemia time. At post-ischemia day 28 renal function returned to pre-ischemia baseline levels in the group with 120 minutes of ischemia but did not recover to baseline in the 150 and 180-minute ischemic groups. Functional data correlated with histological findings. The 120-minute maximal renal tolerance of warm ischemia correlated with a mean +/- SD glycerol concentration of 167 +/- 24 micromol/l., Conclusions: Interstitial glycerol is a real-time, renal unit specific, minimally invasive marker of renal function deterioration. Exposure of porcine kidneys to ischemic insults resulting in renal cortical interstitial glycerol concentrations higher than 167 micromol/l is associated with irreparable functional damage in this model.

Purpose: Partial nephrectomy is being increasingly performed to treat renal cell carcinoma. Because warm ischemia is induced during many open and laparoscopic partial nephrectomy surgeries, its impact on postoperative kidney function has received renewed attention. We assessed the current state of knowledge pertaining to warm ischemic kidney injury and renal functional outcomes., Materials and Methods: A review of the literature from 1947 to 2007 pertaining to warm ischemic kidney injury was performed. Data from relevant animal and clinical studies were assessed and compared., Results: Animal studies have described the relationship between the duration of warm ischemia and the magnitude of subsequent renal dysfunction. However, direct translation of these data to clinical practice is limited by significant anatomical and physiological differences among species. Current clinical data support a safe warm ischemia time limit of 30 minutes in patients with normal preoperative kidney function. To date no scientifically rigorous clinical study has established a warm ischemia dose-response curve. Additionally, no algorithm exists to predict the risk of acute kidney injury and chronic kidney disease in patients undergoing transient warm ischemia., Conclusions: Clinical use of glomerular filtration rate measurement, kidney injury biomarkers and the application of glomerular filtration rate based renal functional diagnostic criteria may allow improved diagnosis, management and reporting of renal functional outcomes. Prospective, controlled clinical studies are much needed to accurately characterize the relationship between warm ischemia and renal dysfunction.