Preservation Of Renal Parenchyma Research Articles

Justification of the renoprotective action of the mixture of sodium chloride and sodium bicarbonate solutions in phenylhydrazine intoxication

The authors conducted a study on 35 white Wistar outbred rats to investigate the possibility of correcting acute kidney damage induced by the administration of phenylhydrazine at a dose of 100 mg/kg by introducing a mixture of sodium chloride and sodium bicarbonate solutions into the body. The research results identified changes in the kidneys upon phenylhydrazine administration, including the loss of some capillary glomeruli, eosinophilic deposits in Bowman's spaces and tubular lumens, and lymphoid infiltration in the interstitium. Rats receiving a mixture of sodium chloride and sodium bicarbonate solutions in their drinking water showed positive changes in their kidneys: no loss of capillary glomeruli was observed, and eosinophilic deposits were absent in most tubules. Lymphocyte aggregation was only observed around some renal vessels. The authors suggest that the intake of additional sodium and bicarbonate into the body, along with alkalinization of the primary urine, promotes the excretion of hemolysis products caused by phenylhydrazine, which contributes to renoprotection and preservation of renal parenchyma.

Does Utilizing IRIS, a Segmented Three-dimensional Model, Increase Surgical Precision During Robotic Partial Nephrectomy?

Preservation of renal parenchyma is a major goal when performing a partial nephrectomy. IRIS anatomical visualization software generates a segmented 3D model, allowing improved visualization of the tumor and surrounding structures. We hypothesize that using IRIS intraoperatively during partial nephrectomy on complex tumors increases the precision of surgical procedures and therefore may result in more tissue preservation. We identified 74 non-IRIS and 19 IRIS patients who underwent partial nephrectomy, with nephrometry scores of 9, 10, and 11. Propensity scores were used to match 18 pairs of patients on nephrometry score, age, and tumor volume. Pre- and postoperative imaging (MRI/CT) was obtained. Volumes of the preoperative tumor and preoperative whole kidney were obtained to calculate predicted postoperative whole kidney volume and then compared to actual postoperative whole kidney volume. Mean differences between predicted and actual postoperative whole kidney volumes were 19.2 cm3 (SD=20.2) and 32 cm3 (SD=16.1, P = .0074) for IRIS and non-IRIS groups, respectively. The mean improvement in precision for the IRIS procedure was 12.8 cm3 (95% confidence interval, 2.5 to Inf; P = .02). There was no significant change in mean glomerular filtration rate from baseline to 6 months postoperatively between IRIS and non-IRIS groups (-6.39, SD=15.8 vs -9.54, SD=13.3; P = .5). No significant differences in complication rates (0 vs 1, P = .2), worsening glomerular filtration rate staging (5 vs 4, P = 1), and >25% decrease in glomerular filtration rate (3 vs 4, P = 1) were found between IRIS and non-IRIS groups. We demonstrated that using IRIS intraoperatively when performing partial nephrectomy on complex tumors is associated with improved surgical precision.

MP68-15 DOES UTILIZING IRIS, A SEGMENTED THREE-DIMENSIONAL MODEL, PRESERVE RENAL PARENCHYMAL VOLUME DURING ROBOTIC PARTIAL NEPHRECTOMY?

You have accessJournal of UrologyCME1 Apr 2023MP68-15 DOES UTILIZING IRIS, A SEGMENTED THREE-DIMENSIONAL MODEL, PRESERVE RENAL PARENCHYMAL VOLUME DURING ROBOTIC PARTIAL NEPHRECTOMY? Teona Iarajuli, Christina Caviasco, Tanner Corse, Katherine Kim, Jennifer Nguyen, Ruth Sanchez DE LA Rosa, Simon Gelman, Nick Spagnuolo, Hannah Sidoti, Mitchell Miller, and Michael Stifelman Teona IarajuliTeona Iarajuli More articles by this author , Christina CaviascoChristina Caviasco More articles by this author , Tanner CorseTanner Corse More articles by this author , Katherine KimKatherine Kim More articles by this author , Jennifer NguyenJennifer Nguyen More articles by this author , Ruth Sanchez DE LA RosaRuth Sanchez DE LA Rosa More articles by this author , Simon GelmanSimon Gelman More articles by this author , Nick SpagnuoloNick Spagnuolo More articles by this author , Hannah SidotiHannah Sidoti More articles by this author , Mitchell MillerMitchell Miller More articles by this author , and Michael StifelmanMichael Stifelman More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003331.15AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Preservation of renal parenchymal volume is one of the major goals of surgeons performing a partial nephrectomy (PN). IRIS anatomical visualization software generates a segmented 3D model, allowing surgeons to better visualize the tumor, renal vasculature, collecting system, and their relationship. We hypothesize that using a segmental 3D model intra-operatively during PN on complex tumors would improve renal parenchymal volume preservation. METHODS: We identified 74 non-IRIS and 19 IRIS patients who underwent PN from January 1st, 2019 to January 1st, 2022, with nephrometry scores of 9, 10, 11, and had complete pre and postoperative axial imaging. We completed propensity score matching (PSM) based on nephrometry score, age, BMI, and tumor volume and finalized 18 PS matched pairs. Pre and postoperative imaging (MRI or CT) were obtained from patient charts on Fuji PACS and quality screened by our researchers. Volumes of the preoperative renal tumor mass and whole kidney volume were obtained and used to calculate predicted postoperative volume. Measured postoperative renal volumes were compared to the predicted postoperative volumes. Statistical analysis was performed using a paired one-sided t-test. All analyses were performed using R. RESULTS: The mean predicted postoperative kidney volume in the IRIS and non-IRIS groups were 194.1 cm3 (71.5) and 218.9 cm3 (SD=48.9), and postoperative whole kidney volume was 175.0 cm3 (SD=73.5) and 186.9 cm3 (SD=47.2). Mean difference between predicted and actual postoperative whole kidney volume in the IRIS group was statistically smaller, 19.2 cm3 (SD=20.2), than the non-IRIS group, 32 cm3 (SD=16.1, p=0.0074). Percent difference from predicted kidney volume in the IRIS group was 10.9% vs. 17.1% in the non-IRIS group. There was no significant change in mean GFR from baseline to 6-month postoperative period between IRIS and non-IRIS groups (-6.39, SD=15.8 vs. -9.54, SD=13.3; p=0.374). Additionally, no significant difference in complication rates (0 vs. 1, p=0.235), frequency of patients who experienced worsening GFR staging (5 vs 4, p=1.00) and >25% decrease in GFR levels (3 vs. 4, p=1.00) were found between IRIS and non-IRIS groups respectively. CONCLUSIONS: We demonstrated that using a segmental 3D model intra-operatively when performing a partial nephrectomy on complex tumors improves renal parenchymal preservation. The long-term clinical significance of this preservation remains to be determined. Source of Funding: No Funding © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e959 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Teona Iarajuli More articles by this author Christina Caviasco More articles by this author Tanner Corse More articles by this author Katherine Kim More articles by this author Jennifer Nguyen More articles by this author Ruth Sanchez DE LA Rosa More articles by this author Simon Gelman More articles by this author Nick Spagnuolo More articles by this author Hannah Sidoti More articles by this author Mitchell Miller More articles by this author Michael Stifelman More articles by this author Expand All Advertisement PDF downloadLoading ...

EPO synthesis induced by HIF-PHD inhibition is dependent on myofibroblast transdifferentiation and colocalizes with non-injured nephron segments in murine kidney fibrosis.

Erythropoietin (EPO) is regulated by hypoxia-inducible factor (HIF)-2. In the kidney, it is produced by cortico-medullary perivascular interstitial cells, which transdifferentiate into collagen-producing myofibroblasts in response to injury. Inhibitors of prolyl hydroxylase domain (PHD) dioxygenases (HIF-PHIs) activate HIF-2 and stimulate kidney and liver EPO synthesis in patients with anemia of chronic kidney disease (CKD). We examined whether HIF-PHIs can reactivate EPO synthesis in interstitial cells that have undergone myofibroblast transdifferentiation in established kidney fibrosis. We investigated Epo transcription in myofibroblasts andcharacterized the histological distribution of kidney Epo transcripts by RNA in situ hybridization combined with immunofluorescence in mice with adenine nephropathy (AN) treated with HIF-PHI molidustat. Lectin absorption chromatography was used to assess liver-derived EPO. In addition, we examined kidney Epo transcription in Phd2 knockout mice with obstructive nephropathy. In AN, molidustat-induced Epo transcripts were not found in areas of fibrosis and did not colocalize with interstitial cells that expressed α-smooth muscle actin, a marker of myofibroblast transdifferentiation. Epo transcription was associated with megalin-expressing, kidney injury molecule 1-negative nephron segments and contingent on residual renal function. Liver-derived EPO did not contribute to serum EPO in molidustat-treated mice. Epo transcription was not associated with myofibroblasts in Phd2 knockout mice with obstructive nephropathy. Our studies suggest that HIF-PHIs do not reactivate Epo transcription in interstitial myofibroblasts and that their efficacy in inducing kidney EPO in CKD is dependent on the degree of myofibroblast formation, the preservation of renal parenchyma and the level of residual renal function.

Long term renal function following selective angioembolization for iatrogenic vascular lesions after partial nephrectomy: A matched case-control study.

PurposePartial nephrectomy is associated with a 1%–2% risk of renal iatrogenic vascular lesion (IVL) that are commonly treated with selective angioembolization (SAE). The theoretical advantage of SAE is preservation of renal parenchyma by targeting only the bleeding portion of the kidney. Our study aims to assess the long-term effect of SAE on renal function, especially that this intervention requires potentially nephrotoxic contrast load injection.Materials and MethodsA retrospective review of patients undergoing partial nephrectomy between 2002 and 2018 was performed, and patients who developed IVL were identified. A 1:4 matched case-control analysis was performed. Paired t-test and χ2 test were used for continuous and categorical variables, respectively. Multivariable logistic and Cox proportional hazards regression analyses were used to identify risk factors and confounders for SAE and postoperative renal function.ResultsEighteen patients found to have an IVL after partial nephrectomy were matched with 72 control patients. IVL's were more common in patients after minimally invasive partial nephrectomy (89% vs. 70%, p=0.008) and in those with higher RENAL nephrometry scores (8.8±2.0 vs. 6.5±1.8, p<0.001). On multivariable analysis, lower RENAL scores proved to decrease the odds of requiring postoperative SAE. No significant difference in renal function outcomes was seen at 24 months of follow-up after surgery.ConclusionsSAE for the management of IVL following partial nephrectomy is a safe and efficient procedure with no significant impact on short or long-term renal function. Less complex renal tumors with lower RENAL scores are less likely to require postoperative SAE.

Surgical Navigation Improves Renal Parenchyma Volume Preservation in Robot-Assisted Partial Nephrectomy: A Propensity Score Matched Comparative Analysis.

We investigated the relationship between the surgical navigation system and postoperative parenchyma preservation volume, and assessed the feasibility of image guided surgery in robot-assisted partial nephrectomy. We developed surgical navigation with registration between real-time endoscopic images using 3-dimensional virtual reality models for robot-assisted partial nephrectomy. Surgical outcomes of 44 (nonsurgical navigation group) and 102 (surgical navigation group) patients between June 2013 and December 2018 were retrospectively analyzed. To adjust for potential baseline confounders propensity score matching (1:1) was performed. Renal parenchymal preservation rate and extraparenchymal volume with a tumor including functional and oncological outcomes ("trifecta" defined as warm ischemia time of less than 25 minutes, no complications and negative surgical margins; "pentafecta" defined as trifecta plus greater than 90% preservation of estimated glomerular filtration rate at 12 months postoperatively and chronic kidney disease up staging) were evaluated using volumetric analysis and compared. After matching, 42 patients were allocated to each group. No significant differences in baseline characteristics; complications; and intraoperative, trifecta and pentafecta outcomes were observed between the 2 groups. Pathological T stages were significantly different between the groups (T1a/T1b/T2a or more 25/10/7 in the nonsurgical navigation group vs 35/7/0 in the surgical navigation group, p=0.003). Extraparenchymal volumes and parenchyma volume preservation rates were significantly higher in the surgical navigation group (21.4 vs 17.2 ml, p=0.041 and 83.5% vs 90.0%, p=0.042, respectively). Surgical navigation was positively associated with improved parenchyma preservation volume (p=0.003). Surgical navigation preserves renal parenchyma in robot-assisted partial nephrectomy and may contribute to improvement in postoperative renal function.

Outcomes and peri-operative complications of robotic pyelolithotomy.

Standard of care for large or complex renal stones is percutaneous nephrolithotomy. Robotic pyelolithotomy, however, may be a feasible alternative, but limited data exist on its outcomes and complications. Our study objective was to describe the outcomes and peri-operative complications of robotic pyelolithotomy for complex renal calculi. We performed a retrospective analysis of robotic pyelolithotomy at our tertiary academic institution from 2015 to 2018. Demographics, stone clearance rates, complications, estimated blood loss, operative time, and length of stay were reported. 15 patients were included with a median age of 59years (SD 15.3, 27-80) and BMI 25kg/m2 (SD 4.6, 20.9-35.7). Median follow-up was 4months. Median stone size was 3cm (SD 1.2cm, 2-5cm). Concomitant pyeloplasty was performed in 2 patients, complete stone clearance in 11 (73%) cases and 4 out of 5 (80%) with a solitary stone. Median operative time was 191.5min (SD 64.8min, 110-303min), with no open conversion. Median EBL was 70ml (SD 65ml, 20-250ml) and median length of stay was 1day (SD 1day, 1-5days). Median change in creatinine and eGFR were - 0.02mg/dl and + 3ml/min/1.73m2. There were no cases of sepsis or post-operative fever and only one case of transfusion. Robotic pyelolithotomy appears safe and effective. Ultimately, less bleeding, lower septicemia, renal parenchymal preservation, and favorable stone-free rates in a single procedure make this as an attractive option in the management of select patients with large renal stone disease.

Re: How a Donor Nephrectomy Population Can Help Give Perspective to the Effects of Renal Parenchymal Preservation During Partial Nephrectomy

Re: How a Donor Nephrectomy Population Can Help Give Perspective to the Effects of Renal Parenchymal Preservation During Partial Nephrectomy

V09-09 ROBOT-ASSISTED LAPAROSCOPIC PYELOTOMY & ILEAL URETER SUBSTITUTION: VIDEO DEMONSTRATION

You have accessJournal of UrologyPediatric Urology1 Apr 2018V09-09 ROBOT-ASSISTED LAPAROSCOPIC PYELOTOMY & ILEAL URETER SUBSTITUTION: VIDEO DEMONSTRATION Rachel Shannon, BS, Deborah L. Jacobson, MD, Edward M. Gong, MD, and Bruce W. Lindgren, MD Rachel Shannon, BSRachel Shannon, BS More articles by this author , Deborah L. Jacobson, MDDeborah L. Jacobson, MD More articles by this author , Edward M. Gong, MDEdward M. Gong, MD More articles by this author , and Bruce W. Lindgren, MDBruce W. Lindgren, MD More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.2181AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES While robot-assisted laparoscopic (RAL) ileal ureter substitution is a known treatment option for managing recurrent ureteral stricture, video documentation of this procedure is lacking. We aim to visually demonstrate the surgical technique used in an RAL pyelotomy & ileal ureter substitution. METHODS We present an 18 year old female with a history of cystinuria, recurrent urolithiasis, chronic kidney disease (stage 3), solitary functioning kidney, recurrent ureteropelvic junction (UPJ) obstruction, and worsening renal function. She had previously undergone multiple procedures for urolithiasis management, a failed laser endopyelotomy, and a failed RAL pyeloplasty. It was elected to perform RAL pyelotomy with removal of renal calculi and ileal ureter substitution to address stenosis at the UPJ and ureter caliber. RESULTS The patient was placed in a modified supine position and the da Vinci XI robotic surgical system was docked. Ports were placed in the umbilicus, right lower quadrant, epigastric area, and inferior to the umbilical port, left of the midline. The ureter was dissected out and spatulated laterally through the strictured UPJ. A flexible cystoscope was inserted through a robotic port and multiple renal stones were retrieved. A 26cm segment of ileum was harvested, passed through a window in the colonic mesentery, and anastomosed to the renal pelvis. The native ureter was transected and tied off. A stent was placed antegrade and the distal end of the ileal limb was anastomosed to the bladder wall. Total operative time was nearly 12 hours and estimated blood loss was 100mL. The patient was discharged home in stable condition on post-operative day 7. The ureteral stent was removed at 4 weeks. Post-operative cystogram was without evidence of extravasation. Renal ultrasound obtained 10 months post-operatively demonstrated near-complete resolution of the hydronephrosis with renal parenchymal preservation. The patient demonstrated stable renal function 20 months post-operatively. CONCLUSIONS This video demonstrates the surgical technique used in an RAL pyelotomy and ileal ureter substitution in the setting of recurrent UPJ obstruction and chronic nephrolithiasis. The patient continues to report excellent results 20 months post-operatively. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e905 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Rachel Shannon, BS More articles by this author Deborah L. Jacobson, MD More articles by this author Edward M. Gong, MD More articles by this author Bruce W. Lindgren, MD More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

EXTRACORPOREAL RENAL SURGERY (LITERATURE REVIEW)

Currently, along with the development of gravity blood surgery and transplantation, nephron-sparing surgery has become an established surgical treatment, particularly in situations in which preservation of renal parenchyma is critical. Nephron-sparing surgery includes kidney removal, different kinds of ablation, in vivo and ex vivo surgeries on the renal parenchyma and renal vascular peduncle. This review demonstrates historical experience in surgical treatment of unconventional clinical cases in urgent and plan urology, vascular surgery, and oncology, as well as evolution from traditional nephrectomy to extracorporeal renal surgery. The technique of ex vivo renal surgery is described. Our own experience of performing surgeries for non organ retroperitoneal tumors has been also shown.

Simple Enucleation for Renal Tumors: Indications, Techniques, and Results.

Kidney cancer is the 13th most common malignancy worldwide with significant increase in Stage I renal cell cancer (RCC). Surgical excision by nephron sparing surgery (NSS) remains the treatment of choice for small renal masses (SRMs). One of the variants of partial nephrectomy is simple enucleation (SE) or tumor enucleation (TE). The present review comments on the indications and technical aspects of SE as well as its outcomes. SE/TE has shown both perioperative and oncologic satisfactory results, comparable to partial nephrectomy (PN). It is a valid technique for SRMs and achieves maximum renal parenchymal preservation with an insignificant impact on renal function.

Nefropatías vasculares

Maintaining renal function and renal parenchymal preservation depends among other factors on the kidney vasculature, contributing to this objective all the blood vessels from the the main renal artery to the glomerular capillaries. Many diseases with vascular substrate are responsible for the development of renal failure, although the pathogenesis, clinical findings, prognosis and treatment can be very heterogeneous. We will review in this chapter a group of systemic diseases with renal involvement as part of their clinical presentation: nephrosclerosis, ischemic nephropathy, atheroembolic disease and thrombotic microangiopathy.

Editorial Comment

The development of chronic kidney disease is associated with an increased risk of cardiovascular events and all-cause mortality in large population-based studies. 1 Sun M. Trinh Q.D. Bianchi M. et al. A non-cancer-related survival benefit is associated with partial nephrectomy. Eur Urol. 2012; 61: 725-731 Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar , 2 Go A.S. Chertow G.M. Fan D. et al. Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. N Engl J Med. 2004; 351: 1296-1305 Crossref PubMed Scopus (8722) Google Scholar , 3 Levey A.S. Coresh J. Chronic kidney disease. Lancet. 2012; 379: 165-180 Abstract Full Text Full Text PDF PubMed Scopus (1212) Google Scholar Therefore, preservation of renal function remains an important consideration for patients undergoing renal surgery. The determinants of renal function after partial nephrectomy (PN) remain controversial and clinically relevant. 4 Thompson R.H. Lane B.R. Lohse C.M. et al. Renal function after partial nephrectomy: effect of warm ischemia relative to quantity and quality of preserved kidney. Urology. 2012; 79: 356-360 Abstract Full Text Full Text PDF PubMed Scopus (272) Google Scholar The quantity and quality of renal parenchymal preservation and the ischemic interval likely impact functional recovery after PN. 4 Thompson R.H. Lane B.R. Lohse C.M. et al. Renal function after partial nephrectomy: effect of warm ischemia relative to quantity and quality of preserved kidney. Urology. 2012; 79: 356-360 Abstract Full Text Full Text PDF PubMed Scopus (272) Google Scholar , 5 Thompson R.H. Lane B.R. Lohse C.M. et al. Every minute counts when the renal hilum is clamped during partial nephrectomy. Eur Urol. 2010; 58: 340-345 Abstract Full Text Full Text PDF PubMed Scopus (537) Google Scholar Correlations of Tumor Size, RENAL, Centrality Index, Preoperative Aspects and Dimensions Used for Anatomical, and Diameter-axial–polar Scoring With Warm Ischemia Time in a Single Surgeon's Series of Robotic Partial NephrectomyUrologyVol. 83Issue 5PreviewTo evaluate the association of tumor size, renal nephrometry systems (RNSs), including RENAL, centrality index (C-index), preoperative aspects and dimensions used for anatomical, and diameter-axial-polar scoring, and individual categories of these RNSs with warm ischemia time (WIT). Full-Text PDF

The management of bilateral Wilms tumor.

Wilms tumor (WT) is the most common malignant renal tumor in childhood. Approximately 5-7% of WT patients present with bilateral disease, either synchronously or metachronously. Bilateral WT usually occurs in younger children and more often in girls. Management of a child with bilateral WT is very challenging. In contrast to unilateral WT, there has not been uniform agreement about the therapeutic strategy in the management of bilateral WT. As surgery is a critical component in the treatment of WT, the aim is to achieve a high cure rate while maintaining adequate long-term renal function in patients with bilateral WT. In the past, radical surgical procedures which lead to the patients on dialysis have been traditionally recommended in these patients. After several multicentre trials, bilateral biopsies followed by pre-operative chemotherapy and then renal salvage surgery have been recommended. The management of bilateral WT has evolved from primary surgical extirpation to kidney-preserving resection after preoperative chemotherapy. Preoperative chemotherapy often results in significant reduction in tumor size, thereby facilitating subsequent renal salvage. The analysis of children with bilateral WT shows that preservation of renal parenchyma is possible following initial preoperative chemotherapy. Only centers with experience in bilateral WT should treat the cases with bilateral WT to provide optimal treatment.

Reply

The previously mentioned perspective represents a great summary of the status of this field, with quality, quantity, and ischemia time representing the main determinants of ultimate renal function after partial nephrectomy. In reality, we have made a great progress over the past few years. As recently as 2010 there was a near total focus on ischemia, and we now have a much greater appreciation of its relative contributions. We have learned that most preserved nephrons will recover from the ischemic insult, provided that it is maintained within reasonable limits or associated with hypothermia. The commentary also alludes to one of the ongoing controversies that will mandate further investigation, namely whether patients with pre-existing chronic kidney disease are more vulnerable to ischemic injury. Our experience with more than 600 patients with a solitary kidney managed with partial nephrectomy, most of whom have had pre-existing chronic kidney disease, suggests otherwise. However, to our knowledge, a comprehensive analysis of this specific issue has not been reported yet. Editorial CommentUrologyVol. 82Issue 2PreviewThis study evaluates the role of volume preservation and ischemia during open and minimally invasive partial nephrectomy as evaluated by functional (Mag3) and computed tomography volumetric analysis using free-hand scripting. The authors find that the ultimate renal function after partial nephrectomy was primarily driven by parenchymal preservation with ischemia playing a secondary role as long as it was within a limited period. The article elaborates and further supports the concept of renal parenchymal preservation as the primary predictor of unilateral renal function after partial nephrectomy. Full-Text PDF

Editorial Comment

This study evaluates the role of volume preservation and ischemia during open and minimally invasive partial nephrectomy as evaluated by functional (Mag3) and computed tomography volumetric analysis using free-hand scripting. The authors find that the ultimate renal function after partial nephrectomy was primarily driven by parenchymal preservation with ischemia playing a secondary role as long as it was within a limited period. The article elaborates and further supports the concept of renal parenchymal preservation as the primary predictor of unilateral renal function after partial nephrectomy. It certainly adds to our knowledge of the physiology of the remnant kidney, and the authors' use of free-hand scripting introduces a more granular analysis which supports previous studies from this and other groups, using what could be described as possibly less precise measures. Parenchymal Volume Preservation and Ischemia During Partial Nephrectomy: Functional and Volumetric AnalysisUrologyVol. 82Issue 2PreviewTo determine the relative effect of type and duration of ischemia and parenchymal volume preservation on renal function after partial nephrectomy (PN). Full-Text PDF ReplyUrologyVol. 82Issue 2PreviewThe previously mentioned perspective represents a great summary of the status of this field, with quality, quantity, and ischemia time representing the main determinants of ultimate renal function after partial nephrectomy. In reality, we have made a great progress over the past few years. As recently as 2010 there was a near total focus on ischemia, and we now have a much greater appreciation of its relative contributions. We have learned that most preserved nephrons will recover from the ischemic insult, provided that it is maintained within reasonable limits or associated with hypothermia. Full-Text PDF

Virtual Surgical Planning: A Novel Aid to Robot-Assisted Laparoscopic Partial Nephrectomy

Incidental detection of small renal masses has significantly increased over the last two decades with the advent of cross-sectional imaging. The shift in stage has been met with a shift in treatment modality because the preservation of renal parenchyma can prevent adverse outcomes. Robot-assisted laparoscopic partial nephrectomy (RALPN) needs significant surgeon expertise, and preoperative planning is imperative. Between December 2010 and September 2011, virtual surgical planning (VSP) was used in consecutive patients with renal tumors that were suspicious for renal-cell carcinoma who were undergoing RALPN by a single surgeon. Three-dimensional (3D) reconstructions were examined and manipulated preoperatively, and an operative plan formulated. Intraoperative anatomy and preoperative 3D reconstructions were compared in real time. A total of 10 patients underwent RALPN with preoperative VSP. Average patient age at intervention was 54.6 years and average tumor size was 4.3 cm (range 1.7-7.5 cm). Tumor laterality was evenly distributed. Nephrometry score ranged from 5A to 10P, and final tumor pathology results revealed malignancy in 80%. No complications occurred intraoperatively, and an excellent correlation was noted between preoperative 3D reconstruction and intraoperative anatomy. All patients underwent a successful partial nephrectomy with no positive margins on final pathology results. Mean length of surgery was 232.9 minutes (range 156-435 min), and mean estimated blood loss was 370 mL (range 75-1800 mL). Warm ischemia time ranged from 20 to 50 minutes (mean 33.9 min). Data regarding postoperative renal function were available for six patients with an average loss of function of 9.5% (range 2%-17%). The implementation of this novel technology has significantly improved our ability to plan RALPN preoperatively. Tumor depth and complexity of tumor resection are assessed and the appropriate operative intervention and approach planned. Tumor proximity to vascular structures and collecting system were reliably predicted and therefore anticipated. Overall, these advantages created a safer surgical endeavor.

Renal function and oncologic outcomes in nephron sparing surgery for renal masses in solitary kidneys

With low life expectancy rates in hemodialysis patients, the preservation of renal parenchyma must be weighed against the oncological outcomes in considering partial nephrectomy (PN) in solitary kidneys. The main objective of this study was to assess the oncologic and functional outcomes after PN in patients with solitary kidneys. A retrospective analysis of the Columbia University Medical Center Urologic Oncology database found 38 patients who underwent PN in the setting of a solitary kidney from 1988-2008. Chronic kidney disease (CKD) was defined as GFR of <60 cc/min/1.73 m(2). Kaplan-Meier analysis was used to estimate overall survival, cancer-specific survival, and local recurrence-free survival. The study group was followed for a median of 29 months, with a mean age of 63.2 years (range 35-83). Only one patient required postoperative long-term hemodialysis. Two out of 38 patients had a Clavien III postoperative complication. Twenty-one (55.3%) of the patients had preoperative CKD, while 29 (76%) patients had CKD postoperatively. Those who had CKD at the most recent follow-up had significantly larger tumors removed (P < 0.05). Of the 32 patients with renal cell carcinoma (RCC), 6 (18.8%) had a local recurrence at a median 32.6 months. The 5-year overall, disease-specific, and recurrence-free survival rates were 59.6, 77.5, and 45.7%, respectively. PN in the setting of a solitary kidney poses difficult challenges for surgical and clinical management. Nephron sparing surgery for the treatment of RCC is feasible with low surgical complication rates, satisfactory disease-specific survival rates, and acceptable preservation of renal function.

Renal parenchymal preservation after percutaneous renal angioplasty and stenting

The intent of endovascular therapy for symptomatic atherosclerotic renal artery stenosis (ARAS) is to preserve parenchyma and avoid renal-related morbidity. The aim of this study is to examine the impact of renal artery intervention on parenchymal preservation. We performed a retrospective analysis of records from patients who underwent endovascular intervention for ARAS and were followed by duplex ultrasound between 1990 and 2008. Renal volume (in cm(3)) was estimated in all patients as renal length (cm) x renal width (cm) x renal depth (cm) x 0.5. The normal renal volume was calculated as 2 x body weight (kg) in cm(3). Failure of preservation was considered to be a persistent 10% decrease in volume. Clinical benefit defined as freedom from renal-related morbidity (increase in persistent creatinine >20% of baseline, progression to hemodialysis, death from renal-related causes) was calculated. Five hundred ninety-two renal artery interventions were performed. One hundred eighty-six kidneys suffered parenchymal loss (>5%) with an actuarial parenchymal loss rate of 29% +/- 1% at five years respectively. There were no significant differences in age, gender, starting renal volume, or kidney size. However, patients with parenchymal loss had lower eGFR (45 +/- 24 vs 53 +/- 24 mL/min/1.73 m(2); Loss vs noLoss, P = .0002, Mean +/- SD) higher resistive index (0.75 +/- 0.9 vs 0.73 +/- 0.10; P = .0001) and worse nephrosclerosis grade (1.43 +/- 0.55 vs 1.30 +/- 0.49; P = .006) then those not suffering parenchymal loss. Parenchymal loss was associated with significantly worse five-year survival (26% +/- 4% vs 48% +/- 2%; Loss vs noLoss; P < .001) and freedom from renal-related morbidity (70% +/- 5% vs 82% +/- 2%; P < .05) with increased numbers progressing to dialysis (17% vs 7%; P < .006). While parenchymal preservation occurs in most patients, parenchymal loss occurs in 31% of patients and is associated with markers of impaired parenchymal perfusion (resistive index and nephrosclerosis grade) at the time of intervention. Pre-existing renal size or volumes were not predictive of parenchymal loss. Parenchymal loss is associated with a significant decrease in survival and a marked increased renal related morbidity and progression to hemodialysis.

Hypoxic pre-conditioning in a rat renal ischemia model: an evaluation of the use of hydralazine

With the advent of improved diagnostic and imaging techniques, it is now possible to detect renal cancers in their very early stages, when they are still present as small renal masses. In these situations, use of laparoscopic partial nephrectomy (LPN) techniques are indicated and have gained acceptance in major medical institutions worldwide, offering comparable oncological outcomes and improving quality of life in the patient when contrasted with open nephrectomy procedures. However, a complication that may occur during or after this surgery is the possibility of compromising renal function, as a result of extended ischemia times of more than 30 min. We have undertaken a systematic study of the potential of several agents that may enhance renal parenchymal preservation without causing unwanted renal dysfunction as a result of enhanced ischemia times. In this study, we have evaluated the potential of one such agent under study, namely hydralazine, which was shown earlier to enhance hypoxia inducible factor-1α (HIF-1α) levels in experimental animal systems. Our aim was to determine whether enhanced levels of HIF-1α via pre-treatment with hydralazine had a reno-protective effect after ischemic injury. Rats were injected with hydralazine or saline for 5 days prior to right nephrectomy and 40 min of cross-clamping of the left renal pedicle. Ischemic damage was monitored via serum chemistry and renal pathology. In our system, we found that hydralazine pre-treatment, even though it enhanced HIF-1α levels in the kidney, it also increased serum creatinine and worsened the morphological damage to the renal tubules in the ischemic kidney. We conclude that even though this agent was described as a powerful inhibitor of prolyl hydroxylases, enhancing the levels of HIF-1α, it should be approached with caution when it is considered to enhance warm ischemia time and minimize the renal damage subsequent to LPN.