Postoperative eGFR Research Articles

Novel Hat–Spherical partial nephrectomy for localized kidney cancer treatment

Objective To present a novel Model for partial nephrectomy and evaluate its oncological, functional outcomes and complication risks in the application for localized kidney cancer treatment. Methods Two hundred and ten patients with localized kidney cancer underwent open or laparoscopic Hat–Spherical partial nephrectomy from Mar. 2011 to Dec. 2013, and were included for this retrospective analysis. Of the 210 patients, 145 were males and 65 were females. The age ranged from 25 to 78 (56±12) years. The tumor greatest dimension was ≤4.0 cm in 143 cases (68.1%), 4.1–7.0 cm in 49 cases (23.3%) and >7.0 cm in 18 patients (8.6%). According to PADUA (Preoperative Aspects and Dimensions Used for an Anatomical) classification, 90, 86 and 34 patients were respectively stratified as low– (42.9%), intermediate– (40.9%) and high–risk (16.1%) groups. In contrast to traditional technique, the key points of Hat–Spherical partial nephrectomy were as follows: after clamping, the renal capsule was incised sharply 3–5 mm away from the tumor edge, and the incision plane was wedge–shaped and towards the tumor pseudocapsule. The transition between pseudocapsule and normal renal parenchyma was the ideal surgical plane. When reached, the tumor was bluntly separated from the surrounding parenchyma following the natural plane. When close the bottom or approaching the renal sinus, the tumor was enucleated along the pseudocapsule. The positive surgical margin rate, warm ischemic time, complication rate and the postoperative eGFR decline were evaluated. The criteria, in which the 3 key outcomes of negative cancer margin, minimal renal functional decrease and no urological complications, were applied to evaluate the Hat–Spherical partial nephrectomy technique. Results Ninety–two patients underwent open Hat–Spherical partial nephrectomy. The mean operation time was 120±45 min, the mean warm ischemic time was 15±5 min. The estimated blood loss was 246±188 ml. Twenty–two patients (23.9%) needed renal calyceal repairing. One hundred and eighteen patients underwent laparoscopic Hat–Spherical partial nephrectomy. The mean operation time and warm ischemic time were 145±50 min and 23±7 min, respectively. The mean estimated blood loss was 185±120 ml and 30 patients (25.4%) needed renal calyceal repairing. The rate of positive surgical margin was 0.95% (2/210). A total of 42 patients (20.0%) experienced complications during 30 days postoperatively, including 36 ClavienⅠ–Ⅱ minor complications and 6 cases of Clavien Ⅲ–Ⅳ major complications. There were 6 postoperative bleeding events (2.9%) and 4 urine leakages (1.9%). There was no perioperative death. The median (range) follow–up was 18 (10–38) mon. The mean decrease in postoperative eGFR was 9.8±20.4 ml/(min· 1.73 m2), and 62 patients had a greater than 10% reduction in the actual vs volume predicted postoperative eGFR. Until the last follow–up, there was no local recurrence and distant metastasis. Trifecta outcome was achieved in 85 patients (40.5%). Conclusions The Hat–Spherical partial nephrectomy has three main technical advantages, including safely keeping negative surgical margin, maximal preservation of renal parenchyma and reducing the risk of vessel and renal calyceal injury. The superiority of Hat–Spherical technique over traditional partial nephrectomy needs further validation by prospective comparative clinical trials. Key words: Kidney cancer; Hat–Spherical partial nephrectomy; Transition zone

Novel prediction model of renal function after nephrectomy from automated renal volumetry with preoperative multidetector computed tomography (MDCT).

The predictive model of postoperative renal function may impact on planning nephrectomy. To develop the novel predictive model using combination of clinical indices with computer volumetry to measure the preserved renal cortex volume (RCV) using multidetector computed tomography (MDCT), and to prospectively validate performance of the model. Total 60 patients undergoing radical nephrectomy from 2011 to 2013 participated, including a development cohort of 39 patients and an external validation cohort of 21 patients. RCV was calculated by voxel count using software (Vincent, FUJIFILM). Renal function before and after radical nephrectomy was assessed via the estimated glomerular filtration rate (eGFR). Factors affecting postoperative eGFR were examined by regression analysis to develop the novel model for predicting postoperative eGFR with a backward elimination method. The predictive model was externally validated and the performance of the model was compared with that of the previously reported models. The postoperative eGFR value was associated with age, preoperative eGFR, preserved renal parenchymal volume (RPV), preserved RCV, % of RPV alteration, and % of RCV alteration (p < 0.01). The significant correlated variables for %eGFR alteration were %RCV preservation (r = 0.58, p < 0.01) and %RPV preservation (r = 0.54, p < 0.01). We developed our regression model as follows: postoperative eGFR = 57.87 - 0.55(age) - 15.01(body surface area) + 0.30(preoperative eGFR) + 52.92(%RCV preservation). Strong correlation was seen between postoperative eGFR and the calculated estimation model (r = 0.83; p < 0.001). The external validation cohort (n = 21) showed our model outperformed previously reported models. Combining MDCT renal volumetry and clinical indices might yield an important tool for predicting postoperative renal function.

Ipsilateral renal function preservation after robot-assisted partial nephrectomy (RAPN): an objective analysis using mercapto-acetyltriglycine (MAG3) renal scan data and volumetric assessment.

To objectively assess ipsilateral renal function (IRF) preservation and factors influencing it after robot-assisted partial nephrectomy (RAPN). Our database was queried to identify patients who had undergone RAPN from 2007 to 2013 and had complete pre- and postoperative mercapto-acetyltriglycine (MAG3) renal scan assessment. The estimated glomerular filtration rate (eGFR) for the operated kidney was calculated by multiplying the percentage of contribution from the renal scan by the total eGFR. IRF preservation was defined as a ratio of the postoperative eGFR for the operated kidney to the preoperative eGFR for the operated kidney. The percentage of total eGFR preservation was calculated in the same manner (postoperative eGFR/preoperative eGFR × 100). The amount of healthy rim of renal parenchyma removed was assessed by deducting the volume of tumour from the volume of the PN specimen assessed on pathology. Multivariable linear regression was used for analysis. In all, 99 patients were included in the analysis. The overall median (interquartile range) total eGFR preservation and IRF preservation for the operated kidney was 83.83 (75.2-94.1)% and 72 (60.3-81)%, respectively (P < 0.01). On multivariable analysis, volume of healthy rim of renal parenchyma removed, warm ischaemia time (WIT) > 30 min, body mass index (BMI) and operated kidney preoperative eGFR were predictive of IRF preservation. Using total eGFR tends to overestimate the degree of renal function preservation after RAPN. This is particularly relevant when studying factors affecting functional outcomes after nephron-sparing surgery. IRF may be a more precise assessment method in this setting. Operated kidney baseline renal function, BMI, WIT >30 min, and amount of resected healthy renal parenchyma represent the factors with a significant impact on the IRF preservation. RAPN provides significant preservation of renal function as shown by objective assessment criteria.

Impact of partial nephrectomy on kidney function in patients with renal cell carcinoma.

BackgroundThis study aimed to compare the changes in kidney function and the association of tumor size and renal outcomes between patients with renal cell carcinoma (RCC) who underwent radical nephrectomy (RN) and those who underwent partial nephrectomy (PN).MethodsA retrospective cohort study was conducted for 557 patients with an RCC of ≤7 cm in diameter and normal contralateral kidney function who underwent PN or RN. PN was performed for 218 (39%) patients. Renal outcomes included the incidence of acute kidney injury (AKI), new-onset chronic kidney disease (CKD), and a ≥25% decline in eGFR 1 year after surgery.ResultsSerial changes in eGFR were compared during the 3 years of follow-up. Postoperative eGFR was significantly lower in patients undergoing RN than in those undergoing PN. The incidence of AKI and new-onset CKD was significantly higher in patients after RN (70.1% vs. 24.3%, respectively; P <0.001) than after PN (55.7% vs. 6.2%, respectively; P <0.001). According to the multivariable logistic regression analysis, RN was an independent risk factor for a ≥25% decline in kidney function after 1 year regardless of the tumor size, even after adjusting for various covariates.ConclusionsCompared to PN, RN for even a moderate sized RCC leads to an increased incidence of AKI and new-onset CKD, and is a significant risk factor for kidney function decline. Therefore, PN should be considered as the choice of surgical treatment for RCCs that are ≤7 cm in diameter in order to preserve renal function postoperatively.

Comparison of Shockwave Lithotripsy and Flexible Ureteroscopy for the Treatment of Kidney Stones in Patients with a Solitary Kidney

To compare the outcomes of these minimally invasive procedures in this patient population. The database of our institution has been retrospectively reviewed, and medical records of urolithiasis patients with a solitary kidney who underwent flexible ureteroscopy (F-URS) or extracorporeal shock wave lithotripsy (SWL) between January 2009 and December 2012 were examined. Retreatment rates, complications, changes in estimated glomerular filtration rates (eGFRs), chronic kidney disease (CKD) stages, and stone-free rates were compared between the two groups. Stones of 48 patients (mean age: 48.8±15.4, range: 14-76) with solitary kidneys were treated with SWL (n=30, 62.5%) or F-URS (n=18, 37.5%). Patient demographics and stone related parameters were similar. The most common stone location was the pelvis in the SWL group (36.6%), whereas it was the pelvis and a calix in the F-URS group (38.8%). Complications and success rates were similar in both groups, however, patients in the SWL group needed more sessions to achieve stone clearance (2.2±0.89 vs 1.06±0.24, p=0.0001). Preoperative and postoperative eGFR and CKD stage changes were also similar. Both SWL and F-URS are effective and safe techniques, which can be used for the treatment of stones in patients with solitary kidneys. However, patients treated with SWL need more sessions to achieve stone clearance.

Impact of warm ischemia time on the change of split renal function after minimally invasive partial nephrectomy in Taiwanese patients

BackgroundNephron-sparing surgery has become the standard treatment for T1 renal tumors. However, relevant data on the Taiwanese population are lacking, and most of the current literature uses global instead of split renal function (SRF) for postoperative renal function follow-up. We evaluated the postoperative renal function after minimally invasive partial nephrectomy in Taiwanese patients. MethodsWe retrospectively reviewed our database from April 2004 to July 2012 and enrolled patients who received laparoscopic partial nephrectomy (LPN) or robot-assisted partial nephrectomy (RPN). The estimated glomerular filtration rate (eGFR) and SRF were calculated as representatives of renal function. The preoperative and 6- and 12-month postoperative renal functions were assessed. Freidman test was used to evaluate pre- and postoperative renal function changes; Wilcoxon test was used for comparing the renal function of each period. ResultsThe 6- and 12-month postoperative SRF values were decreased compared with the preoperative values. Multivariate analysis revealed that older age was related to a lower postoperative eGFR, and a longer warm ischemia time was related to a decreased postoperative SRF. Patients with a warm ischemia time of >30 minutes were correlated with a larger mean tumor size, higher “preoperative aspects and dimensions used for an anatomical” score, greater amount of blood loss during the operation, longer postoperative hospital stay, and lower postoperative SRF compared with patients with a warm ischemia time of <30 minutes. Patients in the RPN group had shorter warm ischemia time and higher 6-month postoperative SRF compared with patients in the LPN group. ConclusionSRF is more sensitive for postoperative follow-up than eGFR. Longer warm ischemia time is associated with poorer postoperative renal function. RPN is a safe and feasible alternative to LPN.

Effect of Treatment Modality on Post-Operative Renal Function in Patients with Upper Tract Urothelial Cancer

Background: While endoscopic management (EM) and distal ureterectomy (DU) provide renal-sparing alternatives to radical nephroureterectomy (NU), the effects on renal function have never directly been compared. Objectives: While NU is the gold standard for treating upper tract urothelial carcinoma (UTUC), EM and DU have become popular for certain lesions. However, the true effect of these procedures on renal function has been under-studied. We analyzed the impact of EM, DU, and NU on post-operative renal function in both the short- and long-term intervals. Methods: Patients undergoing EM, DU, or NU for UTUC were included. Clinicopathologic information was collected. eGFR values were calculated via MDRD formula. Absolute change in eGFR was compared amongst groups. Linear mixed model regression analysis was used to determine the impact of procedure type on post-operative eGFR. Results: 273 patients underwent 325 procedures from 1991 to 2012. In both short- and long-term intervals, post-operative eGFR was significantly worse following NU compared to EM. For the long-term interval, this difference remained while controlling for age, race, gender, pathologic stage, pre-operative hydronephrosis, and having a solitary kidney (all p<0.05). Post-operative eGFR change was not significantly impacted by DU compared to EM. Conclusion: EM is superior to NU and equivalent to DU in preserving post-operative eGFR for UTUC patients. The non-inferiority of DU in this outcome validates its use as a kidney-sparing alternative alongside EM. The effects of these treatment modalities on renal function should be considered with oncologic outcomes when deciding management for these patients.

Preoperative predictors of renal function decline after radical nephroureterectomy for upper tract urothelial carcinoma

To model renal function after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). To identify predictors of renal function decline after surgery, thereby allowing the identification of patients likely to be ineligible for cisplatin-based chemotherapy in the adjuvant setting. We retrospectively identified 374 patients treated with RNU for UTUC at three centres between 1995 and 2010. Estimated glomerular filtration rate (eGFR) was calculated using Chronic Kidney Disease Epidemiology Collaboration equation before RNU and at early (1-5 months after RNU) and late (>5 months) time points after RNU. Only patients deemed eligible for cisplatin-based chemotherapy before RNU (preoperative glomerular filtration rate [GFR] ≥60 mL/min/1.73 m(2) ) were included. Multivariable analysis identified the preoperative predictors of eGFR after RNU at early postoperative and late postoperative time points. A total of 163 patients had an eligible early post-RNU eGFR measurement and 172 had an eligible late eGFR measurement. The median eGFR declined by 32% and did not show a significant trend toward recovery over time (P = 0.4). On multivariable analysis preoperative eGFR and patient age were significantly associated with early and late postoperative eGFR, while Charlson comorbidity index score was significantly associated with late postoperative eGFR alone. In patients with normal preoperative eGFR (≥60 mL/min/1.73 m(2) ), renal function decreases by one-third after RNU and does not show evidence of recovery over time. Elderly patients and those with pre-RNU eGFR closer to 60 mL/min/1.73 m(2) (lower eGFR in the present cohort) are more likely to be ineligible for adjuvant cisplatin-based chemotherapy regimens because of renal function loss after RNU.

Abstract 114: The prediction of postoperative renal function from renal cortex volumetry with preoperative multidetector computed tomography

Abstract INTRODUCTION: To predict the postoperative total renal function after renal surgery, we measured preserved renal cortex volume and examined the estimation of postoperative eGFR of from preoperative multidetector CT. MATERIALS AND METHODS: From 2011 to 2013, 39 patients with preoperative contrast enhanced multi detector CT were underwent renal removal surgery at Teikyo University Hospital. Preoperative and postoperative renal function were assessed by estimating glomerular filtration rate (eGFR). The renal cortex volume (RCV) was calculated automatically by imaging volumetry computer software. Addition of normal side RCV and disease side RCV that was subtracted by tumor region determined as total RCV. The postoperative RCV was defined as preserved renal cortex volume (RCV preservation), which is normal side RCV. The factors that affected the postoperative renal function were examined by univariate and multivariate analysis. For developing the models to estimate postoperative eGFR, we used stepwise (backward elimination) method for identifying the predictors. To assess of the relative quality of these statistical models, both Akaike information criterion (AIC) and Root mean square error of the cross validation (RMSE CV) were calculated. Then tour model was examined as the external validation with 10 patients in Jyuntendo University Hospital. RESULTS: The postoperative eGFR value was associated with age (P &amp;lt;0.01), preserved Renal Parenchymal Volume, and preserved Renal Cortex Volume (P &amp;lt;0.01, P =0.03, respectively). With univariate analysis, %GFR alternation significant correlated with % RCV preservation (r = 0.58, p &amp;lt;0.01) and with % RPV preservation (r = 0.54, p &amp;lt;0.01). Age and preoperative eGFR show poor statistically significant correlations. The alteration of renal cortex volume is the strongest predictor for the postoperative eGFR alteration rate.From the results, we identified the independent predictors of eGFR. AIC and RMSE CV values were 198.7 and 60.4 respectively. Our developed regression model as follows: postoperative eGFR=57.87 -0.55(Age)-15.01(BSA)+0.30(preoperative eGFR)+52.92(% RCV preservation). A strong correlation was seen between postoperative eGFR and estimation model (R=0.805, p &amp;lt;0.001 and RMSE value was 7.16). The results of external validation cohort, residual sum of squares of our equation was calculated as 647.77, which show better predictive value than the previous reported estimation models. CONCLUSIONS: Preoperative MDCT based RCV measurements are associated with postoperative renal function in patients undergoing renal surgery. Computer aided image analysis system makes this procedure simple and reproducible method. Combining CT renal volumetry and patient data might be the important prediction tool for postoperative renal function and risk assessment tool for the CKD after renal surgery. Citation Format: Shuji Isotani, Hiroshi Shimoyama, Yasuhiro Noma, Keisuke Saito, Satoru Muto, Hisamitsu Ide, Raizo Yamaguchi, Shigeo Horie. The prediction of postoperative renal function from renal cortex volumetry with preoperative multidetector computed tomography. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 114. doi:10.1158/1538-7445.AM2014-114

Interobserver variability of R.E.N.A.L., PADUA, and centrality index nephrometry score systems.

To assess interobserver variability of R.E.N.A.L., preoperative aspects and dimensions used for an anatomical classification system (PADUA), and centrality index (C-Index) systems among observers with varying degrees of clinical experience and each system's subscale correlation with surgical outcome metrics. Computed tomography images of 90 patients who underwent open, laparoscopic, or robot-assisted laparoscopic partial nephrectomy were scored by one radiology fellow, two urology fellows, one radiology resident, and one secondary school student. Agreement among readers was determined calculating intraclass correlation coefficients. Associations between radiology fellow scores (reference standard as reader with greatest clinical experience), ischemia time, and percent change in postoperative estimated glomerular filtration rate (eGFR) were evaluated using Spearman's correlation. Agreement using C-Index method (ICC=0.773) was higher than with PADUA (ICC=0.677) or R.E.N.A.L (ICC=0.660). Agreement between reference and secondary school student was lower than with other physicians, although the differences were not statistically significant. The reference's scores were significantly (p<0.05) associated with ischemia time on all three scoring systems and with percent change in eGFR at 6weeks using C-Index (p=0.016). Tumor size, nearness to sinus, and location relative to polar lines (R.E.N.A.L.) and tumor size, renal sinus involvement, and collecting system involvement (PADUA) correlated with ischemia time (all p≤0.001). No R.E.N.A.L. or PADUA subscales significantly correlated with percent change in postoperative eGFR. Clinical experience reduces interobserver variability of existing nephrometry systems though not significantly and less so when using directly measureable anatomic variables. Consistently, only measures of tumor size and distance to intrarenal structures were useful in predicting clinically relevant outcomes.

Impact of renal surgery for cortical neoplasms on lipid metabolism

To examine the incidence of and risk factors for development of hyperlipidaemia in patients undergoing radical nephrectomy (RN) or partial nephrectomy (PN) for renal cortical neoplasms, as hyperlipidaemia is a major source of morbidity in chronic kidney disease (CKD). We conducted a two-centre retrospective analysis of 905 patients (mean age 57.5 years, mean follow-up 78 months), who underwent RN (n = 610) or PN (n = 295) between July 1987 and June 2007. Demographics, preoperative and postoperative hyperlipidaemia were recorded. De novo hyperlipidaemia was defined as that ocurring ≥6 months after surgery in cases where laboratory values met National Cholesterol Education Program Adult Treatment Panel III definitions. The Kaplan-Meier method was used to assess freedom from de novo hyperlipidaemia. Multivariable analysis was conducted to determine the risk factors for de novo hyperlipidaemia. There were no significant differences with respect to demographics, preoperative glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) (P = 0.123) and hyperlipidaemia (P = 0.144). Tumour size (cm) was significantly larger in the RN group vs the PN group (7.0 vs 3.7; P < 0.001). Significantly greater postoperative GFR <60 mL/min/1.73 m(2) was noted in the RN group (45.7 vs 18%, P < 0.001). Significantly, more de novo hyperlipidaemia developed in the RN group than in the PN group (23 vs 6.4%; P < 0.001). The mean time to development of hyperlipidaemia was longer for PN than for RN (54 vs 44 months; P = 0.03). Five-year freedom from de novo hyperlipidaemia probability was 76% for RN vs 96% for PN (P < 0.001). Multivariable analysis showed that RN (odds ratio [OR] 2.93; P = 0.0107), preoperative GFR <60 mL/min/1.73 m(2) (OR 1.98; P = 0.037) and postoperative GFR <60 mL/min/1.73 m(2) (OR 7.89; P < 0.001) were factors associated with hyperlipidaemia development. Patients who underwent RN had a significantly higher incidence of and shorter time to development of de novo hyperlipidaemia. RN and pre- and postoperative eGFR <60 mL/min/1.73 m(2) were associated with development of hyperlipidaemia. Further follow-up and prospective investigation are necessary to confirm these findings.

Can Selective Arterial Clamping With Fluorescence Imaging Preserve Kidney Function During Robotic Partial Nephrectomy?

To compare renal functional outcomes in robotic partial nephrectomy (RPN) with selective arterial clamping guided by near-infrared fluorescence (NIRF) imaging to a matched cohort of patients who underwent RPN without selective arterial clamping and NIRF imaging. From April 2011 to December 2012, NIRF imaging-enhanced RPN with selective clamping was used in 42 cases. Functional outcomes of successful cases were compared with a cohort of patients, matched by tumor size, preoperative estimated glomerular filtration rate (eGFR), functional kidney status, age, sex, body mass index, and American Society of Anesthesiologists score, who underwent RPN without selective clamping and NIRF imaging. In matched-pair analysis, selective clamping with NIRF was associated with superior kidney function at discharge, as demonstrated by postoperative eGFR (78.2 vs 68.5mL/min/1.73m(2); P=.04), absolute reduction of eGFR (-2.5 vs-14.0mL/min/1.73m(2); P<.01), and percent change in eGFR (-1.9% vs-16.8%; P<.01). Similar trends were noted at 3month follow-up, but these differences became nonsignificant (P[eGFR]= .07; P[absolute reduction of eGFR]= .10; andP[percent change in eGFR]= .07). In the selective clamping group, a total of 4 perioperative complications occurred in 3 patients, all of which were Clavien grade I-III. Use of NIRF imaging was associated with improved short-term renal functional outcomes whencompared with RPN without selective arterial clamping and NIRF imaging. With this effect attenuated at later follow-up, randomized prospective studies and long-term assessment ofkidney-specific functional outcomes are needed to further assess the benefits of this technology.

Reply

We appreciate this thoughtful commentary and agree that estimated glomerular filtration rate (eGFR) does not represent a perfect metric to evaluate any clinical benefits attributable to integration of fluorescence-enhanced selective clamping into robotic partial nephrectomy. However, certain points should be considered before using this as a basis to conclude that the results presented here are without meaning. First, although our patient population does indeed display a wide range of postoperative eGFR and includes some with paradoxical eGFR increases (in both control and selective clamp cohorts), such a distribution is consistent with literature values from a number of prior large and multi-institutional studies. 1 Scoll B.J. Uzzo R.G. Chen D.Y. et al. Robot-assisted partial nephrectomy: a large single-institutional experience. Urology. 2010; 75: 1328-1334 Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar , 2 Patel M.N. Krane L.S. Bhandari A. et al. Robotic partial nephrectomy for renal tumors larger than 4 cm. Eur Urol. 2010; 57: 310-316 Abstract Full Text Full Text PDF PubMed Scopus (126) Google Scholar , 3 Kumar R.K. Sammon J.D. Kaczmarek B.F. et al. Robot-assisted partial nephrectomy in patients with baseline chronic kidney disease: a multi-institutional propensity score-matched analysis. Eur Urol. 2014; 65: 1205-1210 Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar Second, although eGFR is certainly sensitive to the multitude of factors identified by the commentators, these would need to have preferentially affected eGFR in 1 of the 2 groups for a detection bias to be introduced. In the absence of any such evidence, one would assume that eGFR variability affected both the control and selective clamp cohorts in a similar manner. Lastly, we agree that future analyses of this technique in the present and other populations would benefit by integrating degree of parenchyma sparing, as well as additional patient or tumor characteristics, outcome metrics, and longer follow-up. Such work could further delineate the contribution of minimized ischemia vs parenchymal volume sparing in ultimate renal function, while perhaps providing additional guidance on indications for this and other approaches to partial nephrectomy. In the interim, however, we believe that the results presented here serve as promising evidence of successful intraoperative minimization of ischemic kidney injury. Editorial CommentUrologyVol. 84Issue 2PreviewThe authors have published excellent results with the use of near-infrared imaging (NIRF) and selective clamp robotic partial nephrectomy. We use NIRF, as the authors do, to facilitate selective clamping and believe the technology to be highly predictable for renal perfusion. However, one may speculate that there may be an unrecognized error in the quantified renal functional benefits. Full-Text PDF

Predictors of Postoperative Decline in Estimated Glomerular Filtration Rate in Patients Undergoing Robotic Partial Nephrectomy

To identify prognostic indicators of estimated glomerular filtration rate (eGFR) following robotic partial nephrectomy (RPN). In a retrospective study of RPN patients, we examined data describing age, gender, eGFR, body mass index (BMI), tumor size (TS), length of stay, and estimated blood loss (EBL). Changes in eGFR (i.e., renal function trajectory [RFT]) and chronic kidney disease (CKD) stage shift were analyzed with mixed model linear and logistic regression analyses, Chi-squared, and t-tests. Changes in eGFR (RFT) were determined in 122 patients at baseline and at 6- and 12-month follow-up visits. Mean age, TS, and Charlson comorbidity index (CCI) were 62±11 years, 3±1.2 cm, and 4.8±1.8, respectively. The pre- and postoperative eGFR was lower in patients >60 years. Preoperative eGFR was unrelated to gender, BMI>30 kg/m(2), histopathology, nuclear grade, and TS. Univariate analyses determined that age, BMI>30, EBL>200 mL, CCI>5, and TS were associated with greater declines in eGFR. Reduced eGFR was also associated with warm ischemia time ≥22 minutes, while age was associated with a ≥1 worsening of British CKD classification. Using multivariate analysis, only age was significantly associated with a decline in eGFR, which was greater in patients with a normal preoperative eGFR. Patient age, BMI>30, EBL>200 mL, CCI>5, and TS were predictors of greater postoperative declines in eGFR. Although a decline in eGFR was proportionally greater in low stage CKD, postoperative changes are associated with advancing age.

MP64-14 “TRIFECTA” AFTER PARTIAL NEPHRECTOMY IN SOLITARY KIDNEY.

MP64-14 “TRIFECTA” AFTER PARTIAL NEPHRECTOMY IN SOLITARY KIDNEY.

MP30-03 THE EFFICACY OF ROBOTIC PARTIAL NEPHRECTOMY IN T1B TUMORS: COMPARATIVE ANALYSIS.

INTRODUCTION AND OBJECTIVES: We evaluated the perioperative and postoperative outcomes between T1a and T1b patients with Renal Cell Carcinoma who underwent robotic partial nephrectomy. METHODS: 86 patients with clinically T1a renal tumor and 39 patients with clinically T1b RCC underwent a warm ischemia robotic partial nephrectomy, from 2008 to 2012. Patients who underwent off clamp robotic partial nephrectomy were excluded from the study. Operative and warm ischemia time, serum creatinine, estimated Glomerular Filtration Rate (eGFR), blood loss, days of drain preservation and hospitalization, surgical complications and positive margins were estimated in both cohorts and analyzed with SPSS v 18. RESULTS: Baseline characteristics were similar in both cohorts. Significant differences existed between the two cohorts with regard to operative time (p1⁄40.03), warm ischemia time (p1⁄40.01) and estimated blood loss (p1⁄40.001). In T1b cohort there was a trend towards increased surgical complications grade III according to modified Clavien-Diado classification system (p1⁄40.053). Postoperative serum Creatinine and eGFR, days of drain preservation and hospitalization, and positive surgical margins were not significant different between the two cohorts. Patients with 4-5cm. tumors had also longer operating time (p1⁄40.009), longer warm ischemia time (p1⁄40.01) and higher blood loss (p1⁄40.001) compared to patients with T1a tumors. These differences did not exist between patients with 4-5cm. and 57cm. RCC Operative time was the only variable which could predict the existence of surgical complications in binary multivariate logistic regression analysis (p1⁄40.019). CONCLUSIONS: Robotic partial nephrectomy is a feasible and safe approach, but differences in operative outcomes exist between T1a and T1b RCC. Operative time, warm ischemia time, blood loss and surgical complications are increased in T1b tumors in contrast with T1a tumors, without affecting the functional and the oncologic outcome. Source of Funding: none

MP30-04 PREOPERATIVE PREDICTION OF HISTOPATHOLOGICAL FINDINGS ON SMALL RENAL MASSES IN PATIENTS WHO UNDERWENT PARTIAL NEPHRECTOMY

INTRODUCTION AND OBJECTIVES: We evaluated the perioperative and postoperative outcomes between T1a and T1b patients with Renal Cell Carcinoma who underwent robotic partial nephrectomy. METHODS: 86 patients with clinically T1a renal tumor and 39 patients with clinically T1b RCC underwent a warm ischemia robotic partial nephrectomy, from 2008 to 2012. Patients who underwent off clamp robotic partial nephrectomy were excluded from the study. Operative and warm ischemia time, serum creatinine, estimated Glomerular Filtration Rate (eGFR), blood loss, days of drain preservation and hospitalization, surgical complications and positive margins were estimated in both cohorts and analyzed with SPSS v 18. RESULTS: Baseline characteristics were similar in both cohorts. Significant differences existed between the two cohorts with regard to operative time (p1⁄40.03), warm ischemia time (p1⁄40.01) and estimated blood loss (p1⁄40.001). In T1b cohort there was a trend towards increased surgical complications grade III according to modified Clavien-Diado classification system (p1⁄40.053). Postoperative serum Creatinine and eGFR, days of drain preservation and hospitalization, and positive surgical margins were not significant different between the two cohorts. Patients with 4-5cm. tumors had also longer operating time (p1⁄40.009), longer warm ischemia time (p1⁄40.01) and higher blood loss (p1⁄40.001) compared to patients with T1a tumors. These differences did not exist between patients with 4-5cm. and 57cm. RCC Operative time was the only variable which could predict the existence of surgical complications in binary multivariate logistic regression analysis (p1⁄40.019). CONCLUSIONS: Robotic partial nephrectomy is a feasible and safe approach, but differences in operative outcomes exist between T1a and T1b RCC. Operative time, warm ischemia time, blood loss and surgical complications are increased in T1b tumors in contrast with T1a tumors, without affecting the functional and the oncologic outcome. Source of Funding: none

PD16-06 PATIENT-BASED 3D PRINTED ORGAN MODEL PROVIDES TANGIBLE SURGICAL NAVIGATION: A NOVEL AID TO CLAMPLESS PARTIAL NEPHRECTOMY

INTRODUCTION AND OBJECTIVES: To incorporate a computer-assisted volumetric assessement of potential spared paranchyma from preoperative CT scans to predict chronic kidney disease (CKD) at 6 months from extirpative renal surgery. METHODS: We performed a retrospecitve analysis of radical (RN) or partial nephrectomy (PN) patients with compatable CT scans from our institution. We used Vitrea v.6.3 computer software program (Vital Images, Minnetonka, MN) to create a 3D volume of the tumor, 1 cm margin, ipsilateral kidney (Figure), and contralateral kidney (cm3). Primary outcome analyzed was development of postoperative CKD (estimated glomerular filtration rate<60 mL/min/ 1.73 m2 by MDRD equation). We performed linear regression using preoperative GFR, total RENAL nephrometry score, and volumes (excluding tumor) to predict 6-month GFR and tested with 5-fold cross validation. The GFR generated by our analysis was compared to postoperative eGFR for prediction of CKD to calculate test characteristics [sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV)] and area under the curve (AUC). RESULTS: We included 130 patients (79 PN/51 RN) from our database from 3/2000 to 2/2013 and a median eGFR follow-up of 6.1 (4.2-36) months. Median age was 58 (IQR: 49-67), 83 (61%) men, and 53 (57%) Caucasian. Median tumor volume was 24.6 (IQR: 7e82) cm3. The most signifant corrlates of post operative renal function were preoperative eGFR (p<0.001), Isipateral volume (p<0.001), and estimated margin volume (p<0.001). RENAL nephromery score (p1⁄40.285) and contralateral renal volume (p1⁄40.418) were non-signficant. In multivariate linear regression, the predicted GFR correlated with postoperative GFR at 6 months (R21⁄40.518, p<0.001). Using the model, prediction of postoperative CKD noted an AUC of 0.752 (95% CI 0.662-0.842; p1⁄4<0.001) with accompanying sensitivity (86.7%), specificity (63.6%), positive predicitve value (76.5%), and negative predictive value (77.8%). CONCLUSIONS: Preoperative GFR and computer assisted predicted renal volume spared are able to predict 6-month postoperative occurance of CKD. While prospective validation is requisite, this technique may provide valuable information regarding risk of postoperative CKD in clincial decision-making regarding partial or radical nephrectomy and post-operative expectations.

MP59-19 ASSESSMENT OF PREDICTORS OF RENAL FUNCTION IMPAIRMENT AFTER ROBOT-ASSISTED PARTIAL NEPHRECTOMY

You have accessJournal of UrologyKidney Cancer: Localized IV1 Apr 2014MP59-19 ASSESSMENT OF PREDICTORS OF RENAL FUNCTION IMPAIRMENT AFTER ROBOT-ASSISTED PARTIAL NEPHRECTOMY Vincenzo Ficarra, Alessandro Volpe, Giacomo Novara, Marta Rossanese, Sam Bhayani, and Alexandre Mottrie Vincenzo FicarraVincenzo Ficarra More articles by this author , Alessandro VolpeAlessandro Volpe More articles by this author , Giacomo NovaraGiacomo Novara More articles by this author , Marta RossaneseMarta Rossanese More articles by this author , Sam BhayaniSam Bhayani More articles by this author , and Alexandre MottrieAlexandre Mottrie More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1815AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives Little information is available on renal functional impairment after robot-assisted partial nephrectomy (RAPN). Aim of the study was to identify the predictors of postoperative decline of renal function in a large series of patients who underwent elective RAPN for localized renal tumors. Methods We retrospectively analyzed data on 196 consecutive patients who underwent RAPN for localized renal masses at two referral centers from Sep 9/2008 to 9/2010. Serum creatinine (sCr) and estimated glomerular filtration rate (eGFR) calculated with the MDRD equation were assessed in all cases preoperatively and 6 mos after surgery. eGFR values ≥60 ml/min/1.73 m2 were considered normal. The independent role of age, gender, baseline eGFR, surgeon experience, warm ischemia time (WIT) and presence of grade 3-4 postoperative complications according to Clavien/Dindo to predict postoperative RFI was assessed using linear regression analysis. WIT was considered as continuous variable and as categorical variable using cut-off values of 20 min and 30 min. Results Mean patient age was 58.7±12.7 yrs. Mean clinical tumor size and PADUA score were 2.8±1.3 cm and 8.3±1.5, respectively. Mean WIT was 18.3±8.1 minutes. Intra or postoperative complications were observed in 25 cases (12.8%). 40 (20.4%) tumours were benign at pathology. Pathological stage was pT1a in 134 (85.9%) cases, pT1b in 19 (12.2%), pT2 in 2 (1.3%) and 1 pT3a (0.6%). Mean sCr increased from 0.96±0.30 to 1±0.47 mg/dl 6 mos after RAPN (p<0.001). Mean eGFR decreased from 82.2±26.5 to 74.38±27 ml/min/1.73 m2 6 mos after RAPN (p<0.001). In the 168 cases with normal baseline renal function (85.7%), eGFR decreased below 60 ml/min/1.73 m2 in 32 cases (19%). At multivariable analysis only WIT as continuous variable (p=0.03) and baseline eGFR values (p<0.001) turned out to be independent predictors of postoperative eGFR values. The same predictive model was tested using WIT as categorical variable with cut-offs at 20 min and 30 min. In the first model only preoperative eGFR remained statistically significant (p<0.001). In the second model, WIT > 30 min (p=0.03) and baseline eGFR (p<0.001) turned out to be independent predictors of postoperative eGFR. Conclusions A statistically significant decrease of sCr and eGFR occurs 6 months after RAPN. The renal functional loss does not seem to be clinically significant in the majority of cases, but 20% of patients with normal renal function show a clinically significant decline of eGFR values after surgery. eGFR values 6 months after RAPN are mainly influenced by baseline eGFR values and by a WIT >30 minutes. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e657 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Vincenzo Ficarra More articles by this author Alessandro Volpe More articles by this author Giacomo Novara More articles by this author Marta Rossanese More articles by this author Sam Bhayani More articles by this author Alexandre Mottrie More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

PD16-05 COMPUTER ASSISTED RENAL VOLUMETRIC ASSESSMENT TO PREDICT POSTOPERATIVE RENAL FUNCTION PRIOR TO EXTIRPATIVE RENAL SURGERY

You have accessJournal of UrologyKidney Cancer: Localized I1 Apr 2014PD16-05 COMPUTER ASSISTED RENAL VOLUMETRIC ASSESSMENT TO PREDICT POSTOPERATIVE RENAL FUNCTION PRIOR TO EXTIRPATIVE RENAL SURGERY Michael Liss, Dominique Caovan, Robert Deconde, Michael Gabe, Kerrin Palazzi, Nishant Patel, Ramzi Jabaji, Hak Lee, David Karow, Giovanna Casola, and Ithaar Derweesh Michael LissMichael Liss More articles by this author , Dominique CaovanDominique Caovan More articles by this author , Robert DecondeRobert Deconde More articles by this author , Michael GabeMichael Gabe More articles by this author , Kerrin PalazziKerrin Palazzi More articles by this author , Nishant PatelNishant Patel More articles by this author , Ramzi JabajiRamzi Jabaji More articles by this author , Hak LeeHak Lee More articles by this author , David KarowDavid Karow More articles by this author , Giovanna CasolaGiovanna Casola More articles by this author , and Ithaar DerweeshIthaar Derweesh More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1150AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives To incorporate a computer-assisted volumetric assessement of potential spared paranchyma from preoperative CT scans to predict chronic kidney disease (CKD) at 6 months from extirpative renal surgery. Methods We performed a retrospecitve analysis of radical (RN) or partial nephrectomy (PN) patients with compatable CT scans from our institution. We used Vitrea v.6.3 computer software program (Vital Images, Minnetonka, MN) to create a 3D volume of the tumor, 1 cm margin, ipsilateral kidney (Figure), and contralateral kidney (cm3). Primary outcome analyzed was development of postoperative CKD (estimated glomerular filtration rate<60 mL/min/1.73 m2 by MDRD equation). We performed linear regression using preoperative GFR, total RENAL nephrometry score, and volumes (excluding tumor) to predict 6-month GFR and tested with 5-fold cross validation. The GFR generated by our analysis was compared to postoperative eGFR for prediction of CKD to calculate test characteristics [sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV)] and area under the curve (AUC). Results We included 130 patients (79 PN/51 RN) from our database from 3/2000 to 2/2013 and a median eGFR follow-up of 6.1 (4.2-36) months. Median age was 58 (IQR: 49-67), 83 (61%) men, and 53 (57%) Caucasian. Median tumor volume was 24.6 (IQR: 7–82) cm3. The most signifant corrlates of post operative renal function were preoperative eGFR (p<0.001), Isipateral volume (p<0.001), and estimated margin volume (p<0.001). RENAL nephromery score (p=0.285) and contralateral renal volume (p=0.418) were non-signficant. In multivariate linear regression, the predicted GFR correlated with postoperative GFR at 6 months (R2=0.518, p<0.001). Using the model, prediction of postoperative CKD noted an AUC of 0.752 (95% CI 0.662-0.842; p=<0.001) with accompanying sensitivity (86.7%), specificity (63.6%), positive predicitve value (76.5%), and negative predictive value (77.8%). Conclusions Preoperative GFR and computer assisted predicted renal volume spared are able to predict 6-month postoperative occurance of CKD. While prospective validation is requisite, this technique may provide valuable information regarding risk of postoperative CKD in clincial decision-making regarding partial or radical nephrectomy and post-operative expectations. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e488 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Michael Liss More articles by this author Dominique Caovan More articles by this author Robert Deconde More articles by this author Michael Gabe More articles by this author Kerrin Palazzi More articles by this author Nishant Patel More articles by this author Ramzi Jabaji More articles by this author Hak Lee More articles by this author David Karow More articles by this author Giovanna Casola More articles by this author Ithaar Derweesh More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...