Renal Artery Clamping Research Articles

Oat1/3 restoration protects against renal damage after ischemic AKI.

Expression of proximal tubular organic anion transporters Oat1 and Oat3 is reduced by PGE2 after renal ischemia and reperfusion (I/R) injury. We hypothesized that impaired expression of Oat1/3 is decisively involved in the deterioration of renal function after I/R injury. Therefore, we administered probenecid, which blocks proximal tubular indomethacin uptake, to abolish the indomethacin-mediated restoration of Oat1/3 regulation and its effect on renal functional and morphological outcome. Ischemic acute kidney injury (iAKI) was induced in rats by bilateral clamping of renal arteries for 45 min with 24-h follow-up. Low-dose indomethacin (1 mg/kg) was given intraperitoneally (ip) at the end of ischemia. Probenecid (50 mg/kg) was administered ip 20 min later. Indomethacin restored the expression of Oat1/3, PAH net secretion, and PGE2 clearance. Additionally, indomethacin improved kidney function as measured by glomerular filtration rate (GFR), renal perfusion as determined by corrected PAH clearance, and morphology, whereas it reduced renal cortical apoptosis and nitric oxide production. Notably, indomethacin did not affect inflammation parameters in the kidneys (e.g., monocyte chemoattractant protein-1, ED1+ cells). On the other hand, probenecid blocked the indomethacin-induced restoration of Oat1/3 and moreover abrogated all beneficial effects. Our study indicates that the beneficial effect of low-dose indomethacin in iAKI is not due to its anti-inflammatory potency, but in contrast to its restoration of Oat1/3 expression and/or general renal function. Inhibition of proximal tubular indomethacin uptake abrogates the beneficial effect of indomethacin by resetting the PGE2-mediated Oat1/3 impairment, thus reestablishing renal damage. This provides evidence for a mechanistic effect of Oat1/3 in a new model of the induction of renal damage after iAKI.

Evaluation of functional outcomes after laparoscopic partial nephrectomy using renal scintigraphy: clamped vs clampless technique.

To examine differences in postoperative renal functional outcomes when comparing clampless with conventional laparoscopic partial nephrectomy (LPN) by using renal scintigraphy, and to identify the predictors of poorer postoperative renal functional outcomes after clampless LPN. Between September 2010 and September 2012, 87 patients with renal masses suitable for LPN were prospectively enrolled in the study. From September 2010 to September 2011, LPN with renal artery clamping was performed and from September 2011 to September 2012 clampless LPN (no clamping of renal artery) was performed. Patients who underwent clampless LPN were unselected and consecutive, and the procedure was performed at the end of surgeon's learning curve. Patients were divided into two groups according to warm ischaemia time (WIT): group A, conventional LPN and group B, clampless-LPN (WIT = 0 min). Demographic and peri-operative data were collected and analysed and functional outcomes were evaluated using biochemical markers and renal scintigraphy at baseline and at 3 months after surgery. The percentage loss of renal function, evaluated according to renal scintigraphy, was calculated. Chi-squared and Student's t-tests were carried out and regression analysis was performed. Group A was found to be similar to group B in all variables measured except for WIT and blood loss (P < 0.001). The percentage reduction in renal scintigraphy values was not significantly different between the groups (reductions of 5% in group A and 6% in group B for split renal function [SRF] and 12% in group A and 17% in group B for estimated renal plasmatic flow [ERPF]; P = 0.587 and P = 0.083, respectively). Multivariate analysis in group B showed that the lower the baseline values of SRF and ERPF, the poorer the postoperative functional outcome of the treated kidney. In our experience, even clampless LPN was not found to be functionally harmless. The patients who benefitted most from a clampless approach were those with the poorest baseline renal function.

Experience of laparoscopic partial nephrectomy using a kidney grasper in selective cases.

To evaluate the feasibility of regional cramp in laparoscopic partial nephrectomy, we performed partial nephrectomy using a kidney grasper that enabled the application of ischemia to a limited region of the kidney. The subjects were 5 renal cell carcinoma patients. The mean tumor diameter was 15 mm. There were 2 male and 3 female patients. A transperitoneal approach was used in all cases. Following the standard procedure of laparoscopic partial resection, the hilum of the kidney was confirmed and treated to prepare for rapidly applying clamping with forceps. Tumor resection and suture were then performed under partial warm ischemia using a kidney grasper. Surgery could be completed in 4 patients using this method. In the remaining patient, control of bleeding was considered difficult during tumor resection after applying partial ischemia, and so the procedure was switched to renal artery clamping using bulldog forceps. In the 4 patients in whom a kidney grasper was used, the mean partial warm ischemia time was 23.6 minutes (range, 23-25 minutes), and the mean blood loss was 110 mL (range, 20-260 mL). This procedure may be a useful option in ischemia for partial nephrectomy.

Current evidence on lasers in laparoscopy: partial nephrectomy.

Laser-assisted partial nephrectomy (PN) can benefit from the excellent coagulative properties of lasers to provide a bloodless tumor excision without the necessity for renal artery clamping. In this review, we aim to determine the current clinical implementation of laser assistance during laparoscopic nephron-sparing surgery. An extensive literature evaluation on laser-assisted PN was performed. Experimental work on animals and review articles were excluded. Current literature regarding laser-assisted PN is scarce. Available data consist mostly of small cohorts providing low level of evidence. Even though initial studies with currently available laser modalities demonstrated promising results, several drawbacks in each technique need to be addressed before being widely accepted as a standard care. Experience with laser-assisted laparoscopic PN is steadily increasing and uniformly documenting favorable results. As urologist became more familiar with laser technology by its implementation in other clinical entities and with the increasing interest in nephron-sparing management of renal tumors, the use of laser assistance during PN should be expected to play a major role in future.

The Effect of Ischemic Preconditioning in the Experimental Model of Renal Ischemia Reperfusion Injury Using Single Nephrectomized Porcine.

Purpose: We evaluate organ protective function of remote ischemic preconditioning (IPC) in renal ischemia reperfusion injury using a single-kidney porcine model. Methods: A total of 15 Yorkshire pigs, weighting 35-38kg and 20 week-old, were used. One week (as an adaption period) later from left nephrectomy, we performed IPC and right renal artery clamping (warm ischemia). We divided the animals into 3 experimental groups of 5 animals each; control group: 90 min warm ischemia without IPC, group 1: 2 cycles of 10 min IPC followed by 90 min warm ischemia, group 2: 2 cycles of 10 min IPC, and 24 hours as a window period followed by 90 min warm ischemia. Urinary NGAL, KIM-1, IL-18, cystatin C and microalbumin were measured as renal injury makers before renal ischemia at POD 1 and 3. Also gene microarray was investigated using kidney tissue after euthanasia. Results: There were no differences in serum creatinine changes between groups (figure 1). However, Group 3 showed lower level of KIM-1 and NGAL than control and group 1 at 72 hours. Microalbumin also showed a tendency of lower level in group 2. In the microarray, group 1 had 198 gene expression differences compared to the control group (figure 2). However group 2 had 1027 gene expression differences. Ischemic precondition groups (group 1 & 2) had 179 altered gene expressions in common that are mostly related with apoptosis, inflammation, and oxidation. When we compare group 1 and 2, group 2 had more increases in inflammation regulatory gene expressions (C3, C1QA, and SAA2).Figure: No Caption available.Table: No Caption available.Conclusion: Remote IPC can mitigate renal damage from ischemia reperfusion injury. Late window IPC is especially more efficient than early window.

Differential Effect of COX1 and COX2 Inhibitors on Renal Outcomes following Ischemic Acute Kidney Injury

Background/Aims: We have previously shown that 1 mg/kg indomethacin improves expression and functionality of renal organic anion transporters Oat1 and Oat3 after renal ischemia and furthermore improves renal outcome after ischemia. As we detected differential effects of COX1 or COX2 inhibitors on organic anion transport after ischemia and reperfusion in culture, we investigated the effect of the SC560 (COX1 inhibitor) and SC58125 (COX2 inhibitor) on expression of Oat1/3 and renal outcome after ischemic acute kidney injury (iAKI). Methods: iAKI was induced in rats by bilateral clamping of renal arteries for 45 min. SC560 or SC58125 (1 mg/kg each) were given intraperitoneally as soon as reperfusion started. Sham-treated animals served as controls. Oat1/3 were determined by qPCR and Western blot. Glomerular filtration rate (GFR), p-aminohippurate (PAH) clearance and PAH extraction ratio was determined. All parameters were detected 24 h after ischemia. Renal plasma flow was calculated. Results: In clamped animals SC560 (COX1 inhibitor) restored expression of Oat1/3, as well as renal perfusion. Additionally, SC560 substantially improved kidney function as measured by GFR. Application of the COX2 inhibitor SC58125 did not exert these beneficial effects. Conclusion: Our study indicates that COX1 inhibitor SC560 applied after ischemia prevents ischemia-induced downregulation of Oat1/3 during reperfusion and has a substantial protective effect on kidney function. Whether and to what particular extent this apparent improvement of function is mechanistically due to beneficial effects on tubular function, renal perfusion or glomerular filtration will be the scope of future studies.

‘Scarless' Laparoscopic Urologic Surgery by the Combination of Mini-Laparoscopic and Laparoendoscopic Single-Site Surgery Equipment

Objective: We evaluated reconstructive and oncological laparoendoscopic single-site surgery (LESS) combined with mini-laparoscopic instruments as standard equipment. Patients and Methods: 30 patients underwent reconstructive and oncological LESS: mini-laparoscopic-assisted LESS pyeloplasty (LESS-P, n = 18), mini-laparoscopic-assisted LESS partial nephrectomy (LESS-PN, n = 7) or mini-laparoscopic-assisted LESS radical prostatectomy (LESS-RP, n = 5). Perioperative data were prospectively collected. Results: The 18 LESS-P cases had operative times ranging between 120 and 180 min (average 147.9 min). Estimated blood loss ranged between 100 and 300 ml (average 202.1 ml). Two patients required additional management for failed reconstruction. LESS-PN was performed in 7 patients with tumor size ranging between 2.5 and 3.8 cm (average 2.7 cm). Average operative time and blood loss were 155 (140-180) min and 321.4 (250-550) ml, respectively. Renal artery clamping took place in 1 case. LESS-RP was performed in 5 patients; average operative time was 156 (140-180) min and average blood loss 196 (100-400) ml. Functional and oncological outcome was directly comparable to laparoscopic radical prostatectomy. Conclusion: The combination of LESS and mini-laparoscopic instrumentation as routine equipment of reconstructive LESS reveals a different perspective for ‘scarless' urologic surgery.

V9-06 ROBOTIC-ASSISTED MANAGEMENT OF SYMPTOMATIC INTRAPARENCHYMAL CALYCEAL DIVERTICULA

You have accessJournal of UrologyTransplantation/Urolithiasis1 Apr 2014V9-06 ROBOTIC-ASSISTED MANAGEMENT OF SYMPTOMATIC INTRAPARENCHYMAL CALYCEAL DIVERTICULA Justin Gyorfi and Jay Raman Justin GyorfiJustin Gyorfi More articles by this author and Jay RamanJay Raman More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.2313AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Calyceal diverticula are uncommon urine-containing cavities within the renal parenchyma that communicate with the collecting system through a narrow channel. Although usually small and asymptomatic, large calyceal diverticula can lead to urine stasis, pain, infection, and stone formation. Management for symptomatic calyceal diverticula can be accomplished via percutaneous, open, or minimally invasive approaches. Diverticula that are located deep within renal parenchyma can be difficult to manage due to challenges in identifying the lesion at time of surgery, inability to locate the patent communication from the collecting system, or significant hemorrhage from surrounding parenchyma. METHODS This video demonstrates a robot-assist laparoscopic calyceal diverticulectomy in a 17 year old male who presented with intractable right flank pain and nausea with vomiting and was subsequently found on CT urography to have an intraparenchymal calyceal diverticulum. Prior to flank positioning, a ureteral catheter was placed cystoscopically to allow irrigation-based localization of the diverticular communication to the renal collecting system. During the procedure, intraoperative renal ultrasonography was employed to identify the margins of dissection and a laparoscopic bulldog clamp was placed on the renal artery just prior to dissection to help minimize blood loss and maintain good operative visibility. RESULTS The diverticulum was identified by renal ultrasonography, dissected and the small communicating channel to the renal collecting system was oversewn. Blood loss was 50cc and renal artery clamp time was 24 minutes. Operative time was 202 minutes. There were no intraoperative or post-operative complications. The patient was discharged on post-operative day 1. Post-operatively, the patient's presenting symptoms of flank pain and nausea with vomiting resolved. Follow-up imaging noted complete resolution. CONCLUSIONS In this video, we demonstrate a safe and reproducible way of managing a symptomatic intraparenchymal calyceal diverticulum. Essential technical components during this robotic-assisted approach include placement of a ureteral catheter prior to dissection, use of intraoperative renal ultrasonography, and temporary clamping of the renal artery. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e848 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Justin Gyorfi More articles by this author Jay Raman More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Hydro-Jet-assisted laparoscopic partial nephrectomy with no renal arterial clamping: a preliminary study in a single center

To describe our experience with Hydro-Jet-assisted laparoscopic partial nephrectomy (LPN) with no renal arterial clamping in 35 patients with renal cell carcinoma. Hydro-Jet technique was used to incise the renal parenchyma, dissect the intrarenal vessels and collecting system during the LPN procedure in 35 patients with renal cell carcinoma. Patient demographics, tumor characteristics, perioperative data and renal function parameters were collected prospectively. All procedures were performed by a single surgeon. All LPN procedures were completed without conversion to open surgery or nephrectomy. The mean operation duration was 113.6 min (range 72-202). The mean blood loss was 149.4 ml (range 30-530). No Clavien ≥3 complication was observed in any patient. There was no significant difference between the preoperative GFR of the affected kidney and GFR at 3 months postoperation (54.9 vs. 54.2 ml/min, p = 0.063). Clear cell carcinoma was confirmed histopathologically in 30 patients (85.7%), papillary renal cell carcinoma in four patients (11.4%) and chromophobe renal cell carcinoma in one patient (2.9%), all with negative surgical margins. No tumor recrudescence was observed during the mean follow-up period of 6.32 months (range 3-9 months). The Hydro-Jet-assisted no-clamping LPN technique is safe, feasible and effective in selected cases. It could avoid intraoperative ischemia-reperfusion injury to the kidney. The learning curve should be further discussed, and its feasibility with larger and more complex endophytic tumors should be further explored in future controlled clinical trials with larger samples and long-term follow-up periods.

The Impact of Stem Cells on Electron Fluxes, Proton Translocation, and ATP Synthesis in Kidney Mitochondria after Ischemia/Reperfusion

Tissue damage by ischemia/reperfusion (I/R) results from a temporary cessation of blood flow followed by the restoration of circulation. The injury depresses mitochondrial respiration, increases the production of reactive oxygen species (ROS), decreases the mitochondrial transmembrane potential, and stimulates invasion by inflammatory cells. The primary objective of this work was to address the potential use of bone marrow stem cells (BMSCs) to preserve and restore mitochondrial function in the kidney after I/R. Mitochondria from renal proximal tubule cells were isolated by differential centrifugation from rat kidneys subjected to I/R (clamping of renal arteries followed by release of circulation after 30 min), without or with subcapsular administration of BMSCs. Respiration starting from mitochondrial complex II was strongly affected following I/R. However, when BMSCs were injected before ischemia or together with reperfusion, normal electron fluxes, electrochemical gradient for protons, and ATP synthesis were almost completely preserved, and mitochondrial ROS formation occurred at a low rate. In homogenates from cultured renal cells transiently treated with antimycin A, the coculture with BMSCs induced a remarkable increase in protein S-nitrosylation that was similar to that found in mitochondria isolated from I/R rats, evidence that BMSCs protected against both superoxide anion and peroxynitrite. Labeled BMSCs migrated to damaged tubules, suggesting that the injury functions as a signal to attract and host the injected BMSCs. Structural correlates of BMSC injection in kidney tissue included stimulus of tubule cell proliferation, inhibition of apoptosis, and decreased inflammatory response. Histopathological analysis demonstrated a score of complete preservation of tubular structures by BMSCs, associated with normal plasma creatinine and urinary osmolality. These key findings shed light on the mechanisms that explain, at the mitochondrial level, how stem cells prevent damage by I/R. The action of BMSCs on mitochondrial functions raises the possibility that autologous BMSCs may help prevent I/R injuries associated with transplantation and acute renal diseases.

Renal Cell Carcinoma Detected by Preoperative Kidney Transplant Donor Examination: A Case Report

A 37-year-old man undertook preoperative examination for donor nephrectomy for living kidney transplantation. Computerized tomography revealed a small renal mass (1.9 cm in diameter) with contrast enhancement on his left kidney. We couldn't exclude malignant potential for the small mass. Laparoscopic left partial nephrectomy without renal artery clamp was successfully carried out to obtain pathologic diagnosis while preserving his renal function and priority as a donor. He was judged to be an inappropriate donor candidate owing to the histopathologic report suggesting clear cell carcinoma. The patient has been followed for 27 months without any evidence of recurrence.

Bis maltolato oxovanadium (BMOV) and ischemia/reperfusion-induced acute kidney injury in rats

BackgroundThe aim of the present study was to test the potential protective effects of the organic vanadium salt bis (maltolato) oxovanadium (BMOV; 15 mg/kg) in the context of renal ischemia/reperfusion (30 min of ischemia) and its effects on renal oxygenation and renal function in the acute phase of reperfusion (up to 90 min post-ischemia).MethodsIschemia was established in anesthetized and mechanically ventilated male Wistar rats by renal artery clamping. Renal microvascular and venous oxygenation were measured using phosphorimetry. Creatinine clearance rate, sodium reabsorption, and renal oxygen handling efficiency were considered markers for renal function.ResultsThe main findings were that BMOV did not affect the systemic and renal hemodynamic and oxygenation variables and partially protected renal sodium reabsorption.ConclusionsPretreatment with the organic vanadium compound BMOV did not protect the kidney from I/R injury.

Mini-Flank Supra-12th Rib Incision for Open Partial Nephrectomy Compared with Laparoscopic Partial Nephrectomy and Traditional Open Partial Nephrectomy

PurposeThe purpose of this study was to report our approach of partial nephrectomy (PN) using a supra-12th rib mini-flank incision. We compared mini-incision open partial nephrectomy (MI-OPN) with open partial nephrectomy (OPN) and laparoscopic partial nephrectomy (LPN) to verify whether MI-OPN can be an alternative to OPN and LPN.MethodsThis was a retrospective single-center study including 194 patients who underwent partial nephrectomy (PN) between February 2005 and December 2010. Demographic, perioperative, and complication data were compared among the MI-OPN group, OPN group and LPN group.ResultsNo statistical differences were reported in either group for age, sex, BMI, tumour side (right or left kidney), RENAL nephrometry scores, PADUA score and preoperative eGFR. The operative time was longer in LPN group when compared with MI-OPN and OPN group (all P<0.001). The warm ischemia time of LPN group was longer than MI-OPN group (P = 0.032) and OPN group (P = 0.005). The length of stay of LPN group was shorter than OPN group (P = 0.018), but was similar to MI-OPN group (P = 0.094). The incidence of renal artery clamping was lower in OPN group when compared with MI-OPN and LPN group (all P<0.001). More estimated blood loss was found in OPN group when compared with MI-OPN group (p = 0.003) and LPN group (P = 0.014). The overall incidence of postoperative complications was similar.ConclusionsThe approach of MI-OPN can couple the benefits of both minimally invasive and open partial nephrectomy techniques with less estimated blood loss, shorter operative time, shorter length of stay, less postoperative complications, and a smaller incision. MI-OPN may be an effective alternative to laparoscopic or traditional open approaches, which maybe more suitable for the tumors with high RENAL nephrometry score or PADUA score.

Robotic Partial Nephrectomy with Superselective Versus Main Artery Clamping: A Retrospective Comparison

BackgroundConcerns have been raised regarding partial nephrectomy (PN) techniques that do not occlude the main renal artery. ObjectiveCompare the perioperative outcomes of superselective versus main renal artery control during robotic PN. Design, setting, and participantsA retrospective analysis of 121 consecutive patients undergoing robotic PN using superselective control (group 1, n=58) or main artery clamping (group 2, n=63). InterventionGroup 1 underwent tumor-specific devascularization, maintaining ongoing arterial perfusion to the renal remnant at all times. Group 2 underwent main renal artery clamping, creating global renal ischemia. Outcome measurements and statistical analysisPerioperative and functional data were evaluated. The Pearson chi-square or Fisher exact and Wilcoxon rank sum tests were used. Results and limitationsAll robotic procedures were successful, all surgical margins were negative, and no kidneys were lost. Compared with group 2 tumors, group 1 tumors were larger (3.4 vs 2.6cm, p=0.004), more commonly hilar (24% vs 6%, p=0.009), and more complex (PADUA 10 vs 8, p=0.009). Group 1 patients had longer median operative time (p<0.001) and transfusion rates (24% vs 6%, p<0.01) but similar estimated blood loss (200 vs 150ml), perioperative complications (15% vs 13%), and hospital stay. Group 1 patients had less decrease in estimated glomerular filtration rate at discharge (0% vs 11%, p=0.01) and at last follow-up (11% vs 17%, p=0.03). On computed tomography volumetrics, group 1 patients trended toward greater parenchymal preservation (95% vs 90%, p=0.07) despite larger tumor size and volume (19 vs 8ml, p=0.002). Main limitations are the retrospective study design, small cohort, and short follow-up. ConclusionsRobotic PN with superselective vascular control enables tumor excision without any global renal ischemia. Blood loss, complications, and positive margin rates were low and similar to main artery clamping. In this initial developmental phase, limitations included more perioperative transfusions and longer operative time. The advantage of superselective clamping for better renal function preservation requires validation by prospective randomized studies. Patient summaryPreserving global blood flow to the kidney during robotic partial nephrectomy (PN) does not lead to a higher complication rate and may lead to better postoperative renal function compared with clamped PN techniques.

Effect of Methanol Extract from Cassia mimosoides var. nomame on Ischemia/Reperfusion-induced Renal Injury in Rats

Objectives : The purpose of this study was to determine whether the methanol extract of Cassia mimosoides var. nomame Makino, a naturally growing plant in Korea, could prevent the renal-ischemia/reperfusion injury in a rat model or not. Methods : The radical scavenging activities of the extracts, and ascorbic acid as a positive control, were measured in vitro. At one hour after an intraperitoneal injection of the extract (400 mg/kg), renal ischemia/reperfusion injury was generated by 40 min clamping of the left renal artery in rats. After renal ischemia/reperfusion and 24 hr restoration of blood circulation, the serum creatinine concentration was measured. And the extent of epithelial cell injury and apoptosis was assessed by various staining technologies. The Bax/Bcl-2 ratio and activated caspase-3 were assessed by immunohistochemistry. Results : The extract showed a slightly lower level of radical scavenging activity than that of ascorbic acid. Compared to those of the vehicle-treated group, the extract-treated group displayed a significantly smaller tubular epithelial cell injury of 54% reduction in the outer medulla region and a lower serum creatinine concentration of 50% reduction. It seems that the reduction in cellular injury is due to the attenuation of the Bax/Bcl-2 ratio, and the inhibition of caspase-3 activation by the extract of Cassia mimosoides. Conclusions : Cassia mimosoides var. nomame Makino could be a good candidate for a prophylactic agent against the ischemia/reperfusion/induced kidney injury.

Effect of a Novel Nuclear Factor-κB Activation Inhibitor on Renal Ischemia-Reperfusion Injury

In kidney transplantation, the relationship between prolonged warm or cold ischemic storage of kidneys and a higher incidence of delayed graft function is previously known, and delayed graft function has been known to aggravate poor long-term graft survival. We investigated the effect of a novel nuclear factor-κB activation inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on renal ischemia-reperfusion (I/R) injury. DHMEQ was administered to Lewis rats once just before renal artery clamping (DHMEQ pretreatment group), and the effect on I/R injury was investigated. In the DHMEQ pretreatment group, the 24-hr urine volume on days 1 to 3 after I/R was significantly larger, and the protein concentration of the urine on days 2 to 7 was significantly smaller than in the untreated group. The serum creatinine level was significantly improved, and significantly lower levels of the inflammatory cells and inflammatory cytokines were present in the kidneys on day 1. The relative ratio of nuclear to cytoplasmic nuclear factor-κB and oxidative stress of kidney tissue on day 1 were significantly decreased. Treatment with DHMEQ before renal artery clamping may therefore be useful for renal I/R injury and application to renal transplantation is expected.

Explicit role of peroxisome proliferator–activated receptor gamma in gallic acid–mediated protection against ischemia-reperfusion–induced acute kidney injury in rats

BackgroundGallic acid is a polyphenolic compound and is reported to be renoprotective because of its antioxidant activity in various preclinical studies. Gallic acid has been reported to activate peroxisome proliferator–activated receptor gamma (PPAR-γ) in vitro. However, the relevance of the interplay between gallic acid and PPAR-γ in various pathologic conditions is yet to be established in vivo. The present study investigated the protective role of gallic acid against ischemia-reperfusion–induced acute kidney injury (AKI) and the possible involvement of PPAR-γ in gallic acid–mediated renoprotection. Materials and methodsThe AKI was induced in rats through bilateral clamping of renal arteries for 40 min followed by reperfusion for 24 h. The AKI was assessed by the quantification of creatinine clearance, blood urea nitrogen, uric acid, potassium level, fractional excretion of sodium, and urinary microproteins. The oxidative stress in renal tissues was quantified in terms of myeloperoxidase activity, thiobarbituric acid reactive substances, superoxide anion generation, and reduced glutathione level. The histopathologic changes in renal tissues were assessed by hemotoxylin and eosin staining. The rats were administered gallic acid (50, 100, and 200 mg/kg) orally for 7 d before subjecting them to AKI. ResultsThe renal ischemia–reperfusion induced significant changes in plasma, urinary, and tissue parameters. The administration of gallic acid at three dose levels offered a significant protection against renal ischemia-reperfusion–induced AKI. The prior treatment with PPAR-γ antagonist, bisphenol A diglycidyl ether, significantly abolished the renoprotective effect of gallic acid that confirms the involvement of PPAR-γ in gallic acid–mediated renoprotection. ConclusionsIt is concluded that the activation of PPAR-γ significantly contributes toward gallic acid–mediated protection against ischemia-reperfusion–induced AKI.

Surgeon Assessment of Renal Preservation with Partial Nephrectomy Provides Information Comparable to Measurement of Volume Preservation with 3-Dimensional Image Analysis

The strongest predictors of renal function after partial nephrectomy are the preoperative glomerular filtration rate and the amount of preserved parenchyma. Measuring volume preservation by 3-dimensional imaging is accurate but time-consuming. Percent functional volume preservation was designed to replace surgeon assessment of volume preservation with a less labor intensive, objective assessment. We compared volume preservation with 3-dimensional imaging, percent functional volume preservation and surgeon assessment of volume preservation as predictors of renal function after partial nephrectomy. We calculated volume preservation with 3-dimensional imaging, percent functional volume preservation and surgeon assessment of volume preservation in 41 patients with preoperative and postoperative cross-sectional imaging available. Surgeon assessment was validated internally in another 75 patients. Short-term and long-term renal function was assessed with univariate and multivariate linear regression models. Median parenchymal preservation was 85% (range 37% to 105%) by 3-dimensional imaging, 91% (range 51% to 114%) by percent functional preservation and 88% (range 45% to 99%) by surgeon assessment. Each method strongly correlated with nadir glomerular filtration rate (r(2) = 0.75, 0.65 and 0.78) and latest glomerular filtration rate (r(2) = 0.65, 0.66 and 0.67, respectively, each p <0.0001). Univariate analysis revealed that age, preoperative glomerular filtration rate, renal nephrometry score and each assessment were significant predictors of renal function (p <0.05). On multivariate analysis parenchymal preservation was the strongest predictor (p <0.0001). Models using volume preservation with 3-dimensional imaging, percent functional volume preservation and surgeon assessment of volume preservation were statistically similar in the ability to predict the nadir and latest glomerular filtration rates. In an additional validation cohort surgeon assessment remained strongly correlated with nadir glomerular filtration rate (r(2) = 0.74) and latest glomerular filtration rate (r(2) = 0.73, each p <0.0001). Surgeon assessment of volume preservation provides a reliable estimate of renal functional preservation with characteristics comparable to those of more time intensive alternatives. We propose that surgeon assessment of volume preservation should be routinely reported to facilitate analysis of partial nephrectomy outcomes.

Effect of novel vitamin D receptor activator paricalcitol on renal ischaemia/reperfusion injury in rats

Despite the developments in modern medicine, acute renal injury is still a challenging and common health problem. It is well known that ischaemia and reperfusion takes place in pathological mechanisms. Efforts to clarify the pathophysiology and interventions to improve outcomes are essential. Our study aimed to investigate whether the prophylactic use of paricalcitol is beneficial in renal ischaemia/reperfusion (I/R) injury. Twenty-four Wistar albino rats were assigned randomly to four groups. Right nephrectomies were performed at the time of renal arterial clamping. Sham surgery was performed on the rats in group 1. For the rats in group 2, the left renal artery was clamped for 45 minutes. The rats in group 3 received paricalcitol for seven days (0.2μg/kg/day); following this, a right nephrectomy and left renal arterial clamping were not performed. The rats in group 4 received paricalcitol for seven days (0.2μg/kg/day); following this, a right nephrectomy and left renal arterial clamping for 45 minutes were performed. Tissue thiobarbituric acid reactive substances (TBARS), superoxide dismutase, sulfhydryl groups as well as nitric oxide metabolites, serum urea and creatinine levels were measured for all four groups. In group 4, there were some improvements in terms of TBARS, nitrite, nitrate, superoxide dismutase and creatinine levels. In the histopathological evaluation, paricalcitol therapy improved tubular necrosis and medullar congestion but there was no significant difference in terms of tubular cell swelling, cellular vacuolisation or general damage. Immunohistopathological examination revealed lower scores for vascular endothelial growth factor in the group 4 rats than in group 2. Paricalcitol therapy improved renal I/R injury in terms of serum and histopathological parameters. These potential beneficial effects need to be further investigated.

Comparison of the Transperitoneal and Retroperitoneal Approach in Robot-Assisted Partial Nephrectomy in an Initial Case Series in Japan

To compare the results from the transperitoneal and retroperitoneal approaches in our initial case series of robot-assisted partial nephrectomy (RAPN) in terms of surgical time, renal artery clamping time, postoperative renal function, adverse events, and surgical margin status. The initial 26 consecutive RAPNs performed for solid renal tumors in our hospital were categorized by the approach used, transperitoneal or retroperitoneal, and compared for body mass index, tumor size, R.E.N.A.L. nephrometry score, PADUA score, tumor location, surgical time, renal artery clamping time, renal function change after surgery, operative blood loss, surgical margin status, and adverse events (AEs). The median tumor size was 25 mm (range 15-50). A transperitoneal approach was used in 16 patients and a retroperitoneal approach was used in 10 patients. There was no significant difference in renal tumor and patient characteristics between the two groups except tumor location (anterior tumor was significantly more in the transperitoneal approach and posterior tumor was significantly more in retroperitoneal approach (P=0.0144 and P=0.0100, respectively)). Operative time (239 ± 63.0 minutes in the transperitoneal group vs. 193 ± 40.6 minutes in the retroperitoneal group), warm ischemic time (24.3 ± 9.07 minutes in the transperitoneal group vs. 24.7 ± 8.35 minutes in the retroperitoneal group) and AEs (1/16 in the transperitoneal group vs. 1/10 in the retroperitoneal group; both cases were Clavien-Dindo grade I) did not show any significant difference between the two approaches (P=0.0792, 0.5485, and 0.7270, respectively). The retroperitoneal approach in RAPN appears to be a safe and technically feasible minimally invasive option for nephron-sparing surgery, based on our initial case series, and showed equivalent outcomes to those of the transperitoneal approach even though it was an initial robotic renal surgery series. Future studies, including a larger number of cases, are planned to draw more definitive conclusions.