Limited Warm Ischemia Research Articles

Functional Recovery From Extended Warm Ischemia Associated With Partial Nephrectomy

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. 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. 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). 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.

Analysis of Atrophy After Clamped Partial Nephrectomy and Potential Impact of Ischemia

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. 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. 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). 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.

V9-08 ROBOTIC-ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY AND IPSILATERAL PYELOLITHOTOMY IN INTRARENAL PELVIS

main renal artery was clamped with an early unclamping (unclamping after one or two running suture in the tumor bed but before parenchymal repair). In the second case, a 4 cm totally endophytic tumor of the left kidney arised in a 66 year-old male. RENAL NEPHROMETRY score was 9-h. An off-clamp technique was chosen. RESULTS: In the first case, warm ischemia time was 24 minutes and estimated blood loss was 500 mL. There were no transfusions or postoperative complications. The patient was discharged on postoperative day 5. Surgical margins were negative. At 1 month postoperatively, 88% of renal function was preserved. In the second case, an important bleeding occurred during tumorectomy. First, the surgeon switched to a selective arterial clamping. The bleeding continued and the surgeon had to clamp the main renal artery. Warm ischemia time was 8 minutes and estimated blood loss was 1200 mL. There were no transfusions or postoperative complications. The patient was discharged on postoperative day 4. Surgical margins were negative. At 1 mont postoperatively, 86% of renal function was preserved. CONCLUSIONS: Hilar tumors are good candidates for the “zero ischemia” techniques during robotic partial nephrectomy. However, they could lead to important bleeding that could increase the surgical morbidity and the risk of positive margins. As recent data suggest that a limited warm ischemia time (< 30 minutes) could have no impact on renal function, the early unclamping technique, which appear safer, could be the preferred option in these patients.

V9-06 ROBOTIC PARTIAL NEPHRECTOMY FOR HILAR TUMORS: ZERO ISCHEMIA OR EARLY UNCLAMPING?

You have accessJournal of UrologyRobotics – Renal1 Apr 2015V9-06 ROBOTIC PARTIAL NEPHRECTOMY FOR HILAR TUMORS: ZERO ISCHEMIA OR EARLY UNCLAMPING? Benoit Peyronnet, Quentin Alimi, Tarek Fardoun, Romain Mathieu, Gregory Verhoest, and Karim Bensalah Benoit PeyronnetBenoit Peyronnet More articles by this author , Quentin AlimiQuentin Alimi More articles by this author , Tarek FardounTarek Fardoun More articles by this author , Romain MathieuRomain Mathieu More articles by this author , Gregory VerhoestGregory Verhoest More articles by this author , and Karim BensalahKarim Bensalah More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.2281AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES An arterial clamping is usually performed during partial nephrectomy in order to decrease blood loss and improve vision during tumorectomy. However, it causes warm ischemia which is potentially harmful for the kidney. The concept of “zero ischemia” robotic partially nephrectomy appeared in the early 2010's. Its aim is to avoid warm ischemia time by omitting to clamp the main renal artery. The aim of this video was to compare two managements of the renal pedicle during robotic partial nephrectomy for hilar tumors: early unclamping vs. zero ischemia. METHODS We present 2 cases of robotic partial nephrectomy for complex (RENAL NEPHROMETRY score ≥ 7) and hilar tumors. In the first case, a 6 cm tumor of the left kidney has been diagnosed in a 57 year-old male. RENAL NEPHROMETRY score was 10-ph. The main renal artery was clamped with an early unclamping (unclamping after one or two running suture in the tumor bed but before parenchymal repair). In the second case, a 4 cm totally endophytic tumor of the left kidney arised in a 66 year-old male. RENAL NEPHROMETRY score was 9-h. An off-clamp technique was chosen. RESULTS In the first case, warm ischemia time was 24 minutes and estimated blood loss was 500 mL. There were no transfusions or postoperative complications. The patient was discharged on postoperative day 5. Surgical margins were negative. At 1 month postoperatively, 88% of renal function was preserved. In the second case, an important bleeding occurred during tumorectomy. First, the surgeon switched to a selective arterial clamping. The bleeding continued and the surgeon had to clamp the main renal artery. Warm ischemia time was 8 minutes and estimated blood loss was 1200 mL. There were no transfusions or postoperative complications. The patient was discharged on postoperative day 4. Surgical margins were negative. At 1 mont postoperatively, 86% of renal function was preserved. CONCLUSIONS Hilar tumors are good candidates for the “zero ischemia” techniques during robotic partial nephrectomy. However, they could lead to important bleeding that could increase the surgical morbidity and the risk of positive margins. As recent data suggest that a limited warm ischemia time (< 30 minutes) could have no impact on renal function, the early unclamping technique, which appear safer, could be the preferred option in these patients. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e776-e777 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Benoit Peyronnet More articles by this author Quentin Alimi More articles by this author Tarek Fardoun More articles by this author Romain Mathieu More articles by this author Gregory Verhoest More articles by this author Karim Bensalah More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

V9-07 FAST BUT NOT FURIOUS - IMPROVE YOUR SURGICAL SKILLS FOR THE RACE AGAINST TIME DURING ROBOTIC-ASSISTED PARTIAL NEPHRECTOMY USING A VALIDATED PERFUSED TRAINING MODEL

main renal artery was clamped with an early unclamping (unclamping after one or two running suture in the tumor bed but before parenchymal repair). In the second case, a 4 cm totally endophytic tumor of the left kidney arised in a 66 year-old male. RENAL NEPHROMETRY score was 9-h. An off-clamp technique was chosen. RESULTS: In the first case, warm ischemia time was 24 minutes and estimated blood loss was 500 mL. There were no transfusions or postoperative complications. The patient was discharged on postoperative day 5. Surgical margins were negative. At 1 month postoperatively, 88% of renal function was preserved. In the second case, an important bleeding occurred during tumorectomy. First, the surgeon switched to a selective arterial clamping. The bleeding continued and the surgeon had to clamp the main renal artery. Warm ischemia time was 8 minutes and estimated blood loss was 1200 mL. There were no transfusions or postoperative complications. The patient was discharged on postoperative day 4. Surgical margins were negative. At 1 mont postoperatively, 86% of renal function was preserved. CONCLUSIONS: Hilar tumors are good candidates for the “zero ischemia” techniques during robotic partial nephrectomy. However, they could lead to important bleeding that could increase the surgical morbidity and the risk of positive margins. As recent data suggest that a limited warm ischemia time (< 30 minutes) could have no impact on renal function, the early unclamping technique, which appear safer, could be the preferred option in these patients.

Warm vs. cold perfusion techniques to rescue rodent liver grafts

A variety of liver perfusion techniques have been proposed to protect liver grafts prior to implantation. We compared hypothermic and normothermic oxygenated perfusion techniques in a rat liver transplant model, using higher risk grafts obtained after cardiac arrest (DCD). Rat livers were subjected to 30 or 60 min in situ warm ischemia, without application of heparin. Livers were excised and stored for 4 h at 4°C, mimicking DCD organ procurement, followed by conventional organ transport. In experimental groups, DCD liver grafts received a 4 h normothermic oxygenated perfusion through the portal vein and the hepatic artery instead of cold storage. The perfusate consisted of either full blood or leukocyte-depleted blood (normothermic groups). Other livers underwent hypothermic oxygenated perfusion (HOPE) for 1 h after warm ischemia and 4 h cold storage (HOPE group). Liver injury was assessed during machine perfusion and after isolated liver reperfusion, and by orthotopic liver transplantation (OLT). DCD livers, subjected to normothermic perfusion, disclosed reduced injury and improved survival compared to cold storage after limited warm ischemia of 30 min (70%; 7/10), but failed to protect from lethal injury in grafts exposed to 60 min warm ischemia (0%; 0/10). This finding was consistent with Kupffer and endothelial cell activation in cold stored and normothermic perfused livers. In contrast, HOPE protected from hepatocyte and non-parenchymal cell injury and led to 90% (9/10) and 63% (5/8) animal survival after 30 and 60 min of donor warm ischemia, respectively. This is the first evidence that HOPE is superior to normothermic oxygenated perfusion in a clinically relevant model through modulation of the innate immunity and endothelial cell activation.

PD17-03 POORLY FUNCTIONING KIDNEYS RECOVER FROM ISCHEMIA DURING PARTIAL NEPHRECTOMY AS WELL AS STRONGLY FUNCTIONING KIDNEYS

You have accessJournal of UrologyKidney Cancer: Localized II1 Apr 2014PD17-03 POORLY FUNCTIONING KIDNEYS RECOVER FROM ISCHEMIA DURING PARTIAL NEPHRECTOMY AS WELL AS STRONGLY FUNCTIONING KIDNEYS Maria Carmen Mir, Toshio Takagi, Rebecca Campbell, Nidhi Sharma, Erick Remer, Jianbo Li, Sevag Demirjian, Jihad Kaouk, and Steve C. Campbell Maria Carmen MirMaria Carmen Mir More articles by this author , Toshio TakagiToshio Takagi More articles by this author , Rebecca CampbellRebecca Campbell More articles by this author , Nidhi SharmaNidhi Sharma More articles by this author , Erick RemerErick Remer More articles by this author , Jianbo LiJianbo Li More articles by this author , Sevag DemirjianSevag Demirjian More articles by this author , Jihad KaoukJihad Kaouk More articles by this author , and Steve C. CampbellSteve C. Campbell More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1510AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives Some authors have proposed that poorly functioning kidneys may not recover from ischemia as well as strongly functioning kidneys, which would have impact on the surgical approaches to partial nephrectomy (PN). Methods A total of 122 consecutive patients undergoing PN at our institution with appropriate studies to facilitate analysis of function and parenchymal mass volume in the operated kidney (CT and SCr within 2 months prior and 4-12 months postoperative) were analyzed. Patients with a contralateral kidney also required renal scans in the same time frame to provide split renal function. Volumetric CT was utilized to measure the volume of functional parenchyma pre and post PN in the operated kidney and the contralateral kidney. GFR was determined by the MDRD2 equation. Recovery of nephron function (GP/VS = % GFR preserved/% volume saved) would be 100% if all nephrons recovered from the ischemic insult. Results Median age was 61 years with approximately 50% of patients having open procedures. Median RENAL score was 7. Cold ischemia was used in 50 patients (median 26 min), while 72 had limited warm ischemia (median 20 min). Median %GFR preserved in the operated kidney was 79.5%. Median parenchymal volume saved was 84%. Function in the contralateral kidney remained stable without significant increase. Overall recovery of nephron function (GP/VS) was 95.5%, and was 100.7% for the cold ischemia subgroup and 93% in the limited warm ischemia subgroup. Recovery of nephron function (GP/VS) was similar for all strata of preoperative eGFR in the operated kidney (<30, 21-45, 46-60, and > 60) as detailed in the table (p > 0.18 for all comparisons), even in the limited warm ischemia subgroup Conclusions Preoperative GFR at PN does not correlate with how well the kidney will recover from the ischemia insult. Our results suggest that the amount vascularized parenchyma preserved by the PN is the main determinant of the postoperative GFR. Even poorly functioning kidneys recover well from the ischemic insult as long as limited warm ischemia or hypothermia are utilized. Preop eGFR Overall Cold Ischemia (n=50) Warm Ischemia (n=72) <30 (20) 101.0 (90-116) 109.0 (105-117) 96.2 (80-113) 31-45 (39) 93.2 (83-109) 97.0 (88-105) 90.6 (77-109) 46-60 (43) 95.5 (87-101) 100.6 (94-107) 92.2 (86-99) >60 (20) 98.7 (91-102) 100.5 (94-104) 96.6 (91-98) p=0.206 p=0.181 p=0.679 © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e540-e541 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Maria Carmen Mir More articles by this author Toshio Takagi More articles by this author Rebecca Campbell More articles by this author Nidhi Sharma More articles by this author Erick Remer More articles by this author Jianbo Li More articles by this author Sevag Demirjian More articles by this author Jihad Kaouk More articles by this author Steve C. Campbell More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

PD17-05 TUMOR ANATOMIC COMPLEXITY PREDICTS GROWTH KINETICS OF RENAL MASSES UNDER ACTIVE SURVEILLANCE

determined by the MDRD2 equation. Recovery of nephron function (GP/VS 1⁄4 % GFR preserved/% volume saved) would be 100% if all nephrons recovered from the ischemic insult. RESULTS: Median age was 61 years with approximately 50% of patients having open procedures. Median RENAL score was 7. Cold ischemia was used in 50 patients (median 26 min), while 72 had limited warm ischemia (median 20 min). Median %GFR preserved in the operated kidney was 79.5%. Median parenchymal volume saved was 84%. Function in the contralateral kidney remained stable without significant increase. Overall recovery of nephron function (GP/VS) was 95.5%, and was 100.7% for the cold ischemia subgroup and 93% in the limited warm ischemia subgroup. Recovery of nephron function (GP/VS) was similar for all strata of preoperative eGFR in the operated kidney ( 60) as detailed in the table (p > 0.18 for all comparisons), even in the limited warm ischemia subgroup CONCLUSIONS: Preoperative GFR at PN does not correlate with how well the kidney will recover from the ischemia insult. Our results suggest that the amount vascularized parenchyma preserved by the PN is the main determinant of the postoperative GFR. Even poorly functioning kidneys recover well from the ischemic insult as long as limited warm ischemia or hypothermia are utilized.

Poorly Functioning Kidneys Recover from Ischemia after Partial Nephrectomy as Well as Strongly Functioning Kidneys

Poorly functioning kidneys may not recover from ischemia as well as strongly functioning kidneys. This could impact surgical approaches to partial nephrectomy. 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. 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 20minutes, 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 ofpreoperative estimated glomerular filtration rates in the operated kidney (p=0.24), even in the warm ischemia subgroup. 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 tothe amount of parenchyma preserved.

Predictors of Precision of Excision and Reconstruction in Partial Nephrectomy

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. 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. 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. 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.

Parenchymal Volume Preservation and Ischemia During Partial Nephrectomy: Functional and Volumetric Analysis

To determine the relative effect of type and duration of ischemia and parenchymal volume preservation on renal function after partial nephrectomy (PN). 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. 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). 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.

1460 FUNCTION PRESERVED IN THE OPERATED KIDNEY AFTER CONVENTIONAL PARTIAL NEPHRECTOMY IS DIRECTLY RELATED TO PARENCHYMAL VOLUME PRESERVATION

INTRODUCTION AND OBJECTIVES: Ultimate decline in GFR after partial nephrectomy (PN) is influenced primarily by type and duration of ischemia and parenchymal volume preserved. The role of ischemia relative to volume preservation has been controversial. OBJECTIVES: To directly evaluate the function specifically in the operated kidney pre and post conventional PN and to assess relationships with type and duration of ischemia and percent parenchymal volume preserved. METHODS: 55 patients with localized renal tumors (2007-11) had necessary studies for analysis; there were no exclusions. This comprised 24 solitary kidneys and 31 bilateral kidneys with pre and post-operative RFS, and the analysis was exclusively focused on the operated kidney. 33 (60%) cases were open and the remainder were MIS. 24 cases (44%) utilized hypothermia and 31 were performed using limited warm ischemia. Volumetric CT scans were utilized to directly measure the volume of functional parenchyma pre (subtracting out the tumor) and post PN in the operated kidney. eGFR in the operated was determined by the MDRD2 equation, along with RFS data for patients with bilateral kidneys. Regression analysis was used to assess the relationships between ultimate GFR preserved in the operated kidney and potential predictive factors. All postoperative analyses were performed between 6-12 months. RESULTS: Median age was 61 years, median tumor size was 3.5 cm, and median RENAL score was 8. Median cold ischemia time (CIT) was 29 min (IQR 23-33) and median warm ischemia time (WIT) was 21 min (IQR 14.25-27.75). Pathology results showed pT1a in 33 (61.1%) and clear cell carcinoma in 41 (74.5%). Median preop GFR in the operated kidney was 47.2 (33.85-56) compared with 36.1 (25.0547.85) postoperatively. Median percent GFR preserved in the operated kidney was 88 (79-95.1). Median percent volume preserved was 83% (75.3-90.5). On regression analysis, percent GFR saved associated most strongly with percent parenchymal preservation (p 0.0001), but also with lower RENAL score (p 0.0174), and marginally with cold ischemia (p 0.0608). In contrast, length of ischemia did not correlate with percent GFR preserved (p 0.2487). Interestingly, function in the contralateral kidney did not change substantially ( 5% in all cases). CONCLUSIONS: Ultimate function after PN primarily correlated with parenchymal volume preservation, while ischemia played a secondary role. Thus, maximal parenchymal preservation with a precise PN should be a priority during conventional PN.

Biomarkers assessing warm ischemic injury using an isolated porcine kidney hemoreperfusion model

Prolonged warm ischemia (WI) occurring in marginal kidney donors together with reperfusion injury determines allograft survival, in which apoptosis and inflammation play crucial roles. There is no single valid biomarker, so far, to assess the degree of kidney donor injury. To define new biomarkers for detecting initial donor ischemic injury, caspase-3, caspase-7, apoptosis, inflammation, HSP70 and renal histological changes were examined in porcine kidneys subjected to 7- 15- 25- or 40-min WI, two-hour cold storage and six-hour hemoreperfusion. Caspase-3 activity was gradually increased by prolonged reperfusion, with a decrease trend against WI time. This result was verified by raised 17 kDa active caspase-3 in postreperfusion kidneys, with elevated 12 kDa active caspase-3 and lowered precursor at seven-minute WI. Active caspase-7 was also doubled by reperfusion with decreased precursor at seven-minute WI, but declined against prolonged WI. Apoptotic cells in tubular and interstitial areas were greatly increased by reperfusion at seven-minute WI, but decreased against prolonged WI. In addition, myeloperoxidase (MPO)+ cells were dramatically increased by reperfusion and presented as a bell-shape against WI time, while HSP70 was significantly increased at 7-min WI, but decreased at 40-min WI after reperfusion. In postreperfusion kidneys, tubular dilation and cell shedding were observed at 7- and 15-min WI, while tubular vacuolation and cell debris were found in tubular lumens at longer WI times. At 40-min WI, early nuclear pyknosis, tubular epithelia detachment and peri-tubular capillary dilation were detected. Furthermore, caspase-3, caspase-7, apoptosis, but not MPO+ cells or HSP70, were correlated with renal function. In conclusion, caspase-3, caspase-7 and apoptosis appear to be better biomarkers than MPO+ cells or HSP70 for assessing warm ischemic injury in donor kidneys. Hemoreperfusion activates caspase-3 and caspase-7, promotes apoptosis of damaged cells in kidneys only with limited WI, which might be beneficial to renal structural re-modeling and functional recovery.

限局性腎腫瘍に対するdaVinci&lt;sup&gt;TM&lt;/sup&gt; Sシステムを用いたロボット支援腹腔鏡下腎部分切除術（RALPN）～初期5症例の治療成績の検討～

For the management of patients with small renal tumor, laparoscopic partial nephrectomy (LPN) provides similar oncological control as radical nephrectomy (RN) and is superior to RN with respect to preserving renal function and preventing chronic kidney disease (CKD). The challenge of LPN is to resect a tumor in a bloodless field within a limited warm ischemia time (WIT) , followed by hemostatic renorrhaphy under restricted movement of laparoscopic forceps. Therefore, LPN still remains challenging to even experienced laparoscopic surgeon. DaVinci device improved the movability of forceps in LPN and provided three-dimensional visualization. We evaluated outcome and safety of our first series of robot-assisted laparoscopic partial nephrectomy (RALPN) for localized kidney tumor. There was no previous report of RALPN undertaken in our country. Since August 2010, our team carried out RALPN for a total of five cases of renal tumor. There were four males and one female with an age range of 41 to 65 years-old. Size of tumor ranged from 15 to 28 mm, located in exophytic region, and four cases in right side and one in left. RALPN was undertaken by single surgeon through transperitoneal approach in two cases and retroperitoneal in tree. RALPN was completed in all patients without conversion to open or hand-assisted surgery. The median operative time and the estimated blood loss were 189 minutes, ranged from 150 to 264, and 29 ml, from 10 to 50, respectively. The median volume of removed tumor and the length of WIT were 7 g, ranged from 4 to 13 g, and 18 minutes, from 13 to 26 minutes, respectively. No complications or reoperations were associated during or post our RALPN cases. Pathological examination of removed tumor showed renal cell carcinoma with negative surgical margin in all cases. Introduction of daVinci device to LPN made this procedure, RALPN, a secured and promising one, which leading to shorten the WIT and to achieve satisfied renorrhaphy. Even for the complex and technically challenging renal tumors, robotic assistance is expected to provide patients the benefit of minimally invasive surgery with safety and satisfactory renal function.

995 THE USE OF WARM ISCHEMIA DURING PARTIAL NEPHRECTOMY IN A PATIENT WITH TWO FUNCTIONING KIDNEYS HAS LITTLE IMPACT ON RENAL FUNCTIONAL OUTCOMES

You have accessJournal of UrologyKidney Cancer: Localized II1 Apr 2010995 THE USE OF WARM ISCHEMIA DURING PARTIAL NEPHRECTOMY IN A PATIENT WITH TWO FUNCTIONING KIDNEYS HAS LITTLE IMPACT ON RENAL FUNCTIONAL OUTCOMES Brian Lane, Inderbir Gill, Ben Larson, and Steven Campbell Brian LaneBrian Lane Grand Rapids, MI More articles by this author , Inderbir GillInderbir Gill Los Angeles, CA More articles by this author , Ben LarsonBen Larson Cleveland, OH More articles by this author , and Steven CampbellSteven Campbell Cleveland, OH More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1964AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Partial nephrectomy (PN) has been demonstrated to provide superior renal functional outcomes when compared to radical nephrectomy for patients with renal cancers. The greatest modifiable risk factor during PN is the duration of regional ischemia, so some have suggested that PN without ischemia be performed whenever feasible. We herein compare outcomes in patients with two functioning kidneys that have undergone PN under limited warm ischemia or no ischemia. METHODS All patients undergoing PN for renal mass in two functioning kidneys were evaluated, and patients undergoing PN with cold ischemia or >20 minutes of warm ischemia were excluded. The subset examined includes 573 patients that underwent PN with <20 minutes of warm ischemia (n=503; PN<20) or no ischemia (n=70; PN0). RESULTS Patients in the PN<20 and PN0 subgroups had similar baseline GFR (median 61 vs 62 mL/min/1.73m2, p<0.001) and postoperative GFR. Among patients with baseline GFR >60, only 7 of 393 PN<20 (1.8%) and 0 of 61 PN0 (0%) had a postoperative GFR < 45 and no patient had GFR <15. At last follow-up, 11.6% of PN<20 and 16% of PN0 patients had GFR<45 (p=0.8) and no patient had GFR <15. Median estimated blood loss was 322 vs. 421 ml (p=0.2). CONCLUSIONS Although warm ischemia during PN increases the risk for chronic kidney disease in patients with a solitary kidney or preoperative renal dysfunction, limited warm ischemia in patients with two functioning kidneys appears safe. The avoidance of ischemia is far more relevant in these other settings and appears unnecessary during “elective” PN. © 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e387 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Brian Lane Grand Rapids, MI More articles by this author Inderbir Gill Los Angeles, CA More articles by this author Ben Larson Cleveland, OH More articles by this author Steven Campbell Cleveland, OH More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Biobanking of Human Pancreas Cancer Tissue: Impact of Ex-Vivo Procurement Times on RNA Quality

Tissue banking has become a major initiative at many oncology centers. The influence of warm ex-vivo ischemia times, storage times, and biobanking protocols on RNA integrity and subsequent microarray data is not well documented. A prospective institutional review board-approved protocol for the banking of abdominal neoplasms was initiated at Memorial Sloan-Kettering Cancer Center in 2001. Sixty-four representative pancreas cancer specimens snap-frozen at various ex-vivo procurement times (< or =10 min, 11-30 min, 31-60 min, >1 h) and banked during three time periods (2001-2004, 2004-2006, 2006-2008) were processed. RNA integrity was determined by microcapillary electrophoresis using the RNA integrity number (RIN) algorithm and by results of laser-capture microdissection (LCM). Overall, 42% of human pancreas cancer specimens banked under a dedicated protocol yielded RNA with a RIN of > or =7. Limited warm ex-vivo ischemia times did not negatively impact RNA quality (percentage of tissue with total RNA with RIN of > or =7 for < or =10 min, 42%; 11-30 min, 58%; 31-60 min, 33%; >60 min, 42%), and long-term storage of banked pancreas cancer biospecimens did not negatively influence RNA quality (total RNA with RIN of > or =7 banked 2001-2004, 44%; 2004-2006, 38%; 2006-2008, 50%). RNA retrieved from pancreatic cancer samples with RIN of > or =7 subject to LCM yielded RNA suitable for further downstream applications. Fresh-frozen pancreas tissue banked within a standardized research protocol yields high-quality RNA in approximately 50% of specimens and can be used for enrichment by LCM. Quality of tissues of the biobank were not adversely impacted by limited variations of warm ischemia times or different storage periods. This study shows the challenges and investments required to initiate and maintain high-quality tissue repositories.

Functional and Oncological Outcomes of Partial Nephrectomy of Solitary Kidneys

We examined outcomes after partial nephrectomy in patients with tumors in a solitary kidney to determine the extent to which patient, surgery and tumor specific variables influenced the glomerular filtration rate and local recurrence postoperatively. Demographics, renal function, comorbidities, renal cell carcinoma history, and operative and pathological data were recorded. The effect on changes in early and late postoperative glomerular filtration rate and local recurrence were analyzed. In 84 patients undergoing a total of 89 partial nephrectomies the mean immediate postoperative decrease in the glomerular filtration rate in those with no ischemia, warm ischemia (mean 12 minutes) and cold ischemia (mean 33 minutes) was 29%, 37% and 45%, respectively (p <0.01). Late glomerular filtration rate decreases were 12%, 6% and 16%, respectively (p = 0.17). Cold ischemia and multiple vascular risk factors were associated with immediate glomerular filtration rate decreases (p = 0.008 and 0.04, respectively). Local recurrence, which developed in 13 patients (18%), was associated with positive margins and T stage (p = 0.01 and 0.02, respectively). End stage renal disease developed in 3 patients (4%) and an additional 5 (6%) required nephrectomy for local recurrence. Partial nephrectomy generally results in a small decrease in the glomerular filtration rate, and limited warm and cold ischemia does not appear to adversely affect long-term renal function. Positive margins and T stage greater than 2 are the most important predictors of local recurrence in a solitary kidney. They pose a significant risk to end stage renal disease-free survival due to the need for completion nephrectomy in many of these patients. Partial nephrectomy should be considered the standard of care in all patients with tumor in the solitary kidney.

Laparoscopic partial nephrectomy: Is it advantageous and safe to clamp the renal artery?

Objectives To compare the outcomes of laparoscopic partial nephrectomy (LPN) performed with and without vascular clamping and to evaluate the impact of clamping on postoperative renal function. Methods A total of 45 patients underwent LPN, 29 with and 16 without vascular occlusion. The two groups were compared regarding complication rates, blood loss, conversion rates, operative time, mean tumor size, and incidence of positive margins. Renal function was evaluated by postoperative dimethyl mercaptosuccinic acid scans. Results The mean blood loss was lower when vascular clamping was applied (320 versus 510 mL, P <0.05) than when it was not. The conversion rates were similar (10.3% versus 12.5%), and the mean operative time was shorter in the nonclamped group (115 versus 126 minutes). Urinary leakage occurred in 2 patients, 1 from each group. The mean tumor diameter was 3.2 cm in the clamped and 1.9 cm in the nonclamped group ( P <0.05). In 2 patients (12.5%) in the nonclamped and 1 patient (3.4%) in the clamped group, the surgical margins were focally positive for tumor. The mean warm ischemia time was 28 minutes, and dimercaptosuccinic acid scans performed in 18 patients showed normal ipsilateral renal function (mean relative function 48%). Conclusions LPN without vascular clamping is feasible in selected cases. However, clamping of the artery seems to be associated with reduced blood loss and a lower incidence of positive margins. Moreover, according to the postoperative dimercaptosuccinic acid scan findings, limited warm ischemia does not seem to result in permanent renal damage. We suggest that clamping of the renal artery should be considered during LPN, even for very small, superficial tumors.

Advances in laparoscopic partial nephrectomy.

The advantages of the laparoscopic approach in the management of kidney tumors are unequivocal and the role of laparoscopy in nephron-sparing surgery is evolving. In a selected group of patients with small exophytic renal tumors laparoscopic partial nephrectomy became an alternative to open partial nephrectomy. However, the application of laparoscopic partial nephrectomy to larger, centrally located tumors or tumors in unfavorable sites is limited by the difficulty of achieving adequate, prompt collecting system closure and hemostasis with a limited warm ischemia time. The most recent developments in laparoscopic partial nephrectomy are the subject of this review. A number of sealant products have been used as an adjunct or principal hemostatic agent in the animal model. Their application in the clinical setting remains limited to small parenchymal bleeding; larger vessels and pelvicaliceal openings are better managed by vascular clamping and intracorporeal suturing. Vascular clamping confers warm ischemia, and attempts at renal hypothermia included cold kidney irrigation through either a ureteral stent or a renal artery cannulation, and the application of ice slush for parenchymal surface cooling. Laparoscopic partial nephrectomy is technically demanding; efforts directed towards facilitating hemostasis, improving renal cooling or shortening the warm ischemia time will expand its indications further.