Clamped Partial Nephrectomy Research Articles

Long-term effect of acute ischemic injury on the kidney underwent clamped partial nephrectomy

GFR reaches a new baseline, primarily correlating with nephron-mass preservation, 1-12months after partial nephrectomy (PN). However, does the ipsilateral GFR experience subsequent decline, and does acute ischemic injury has long-term effect on the operated kidney? 319 patients with two kidneys and unilateral clamped PN were analyzed. All had preoperative, new-baseline, and latest follow-up imaging/serum creatinine levels. Annual ipsilateral GFR decline rate (AIGDR) was defined as new-baseline GFR minus latest follow-up GFR normalized by new-baseline GFR, per year. Spectrum score was used to reflect the degree of acute ischemic injury in the operated kidney. 100 subjects searching for health screening served as controls. Predictive factors for AIGDR were assessed. The median AIGDR was 2.25%, significantly higher than controls (0.88%, p= 0.036). With some contralateral hypertrophy, the global annual GFR decline was similar to that of controls (0.81% vs. 0.88%, p= 0.7). Spectrum score correlated significantly with AIGDR (p= 0.037). These results support that acute ischemic injury has long-term effect on the operated kidney.

Every decade counts: a narrative review of functional recovery after partial nephrectomy.

To provide a narrative review of the major advances regarding ischaemia and functional recovery after partial nephrectomy (PN), along with the ongoing controversies. Key articles reflecting major advances regarding ischaemia and functional recovery after PN were identified. Special emphasis was placed on contributions that changed perspectives about surgical management. Priority was also placed on randomized trials of off-clamp vs on-clamp cohorts. A decade ago, 'Every minute counts' was published, showing strong correlations between duration of ischaemia and development of acute kidney injury (AKI) and chronic kidney disease after clamped PN. This reinforced perspectives that ischaemia was the main modifiable factor that could be addressed to improve functional outcomes and helped spur efforts towards reduced or zero ischaemia PN. These approaches were associated with strong functional recovery and some peri-operative risk, although they were generally safe in experienced hands. Further research demonstrated that, when parenchymal volume changes were incorporated into the analyses, ischaemia lost statistical significance, and percent parenchymal volume saved proved to be the main determinant. Cold ischaemia was confirmed to be highly protective, and limited warm ischaemia also proved to be safe. The reconstructive phase of PN, with avoidance of parenchymal devascularization, appears to be most important for functional outcomes. Randomized trials of on-clamp vs off-clamp PN have shown minimal impact of ischaemia on functional recovery. The past decade has witnessed great progress regarding functional recovery after PN, with many lessons learned. However, there are still unanswered questions, including: What is the threshold of warm ischaemia at which irreversible ischaemic injury begins to develop? Are some cohorts at increased risk for AKI or irreversible ischaemic injury? and Which patients should be prioritized for zero-ischaemia PN?

What Happens to the Preserved Renal Parenchyma After Clamped Partial Nephrectomy?

BackgroundMost partial nephrectomies (PNs) are performed with hilar occlusion to reduce blood loss and optimize visualization. However, the histologic status of the preserved renal parenchyma years after PN is unknown. ObjectiveTo compare the histologic chronic kidney disease (CKD) score of renal parenchyma before and years after PN, and to explore factors associated with CKD-score increase and glomerular filtration rate (GFR) decline. Design, setting, and participantsA retrospective review of 147 renal cell carcinoma patients who underwent PN and subsequent radical nephrectomy (RN) due to tumor recurrence was performed in 19 Chinese centers and Cleveland Clinic. Macroscopic normal renal parenchyma was evaluated at least 5 mm away from the tumor in PN specimens and at remote sites in RN specimens. InterventionPN/RN and ischemia. Outcome measurements and statistical analysisHistologic CKD score (0–12) represents a summary of glomerular/tubular/interstitial/vascular status. Predictive factors for a substantial increase of CKD score (≥3) were evaluated by logistic regression. Results and limitationsSixty-five patients with all necessary data were analyzed. The median interval between PN and RN was 2.4 yr. Median durations of warm ischemia (n = 42) and hypothermia (n = 23) were both 23 min. The histologic CKD score was increased after RN in 47 (72%) patients, with 29 (45%) experiencing more substantial increase (≥3). There was no significant difference in the change of CKD score related to the type and duration of ischemia (p = 0.7 and p = 0.4, respectively) or interval from PN to RN (p > 0.9). However, patients with comorbidities of hypertension, diabetes, and/or pre-existing CKD (hypertension [HTN]/diabetes mellitus [DM]/CKD) demonstrated increased rate and extent of CKD-score increase. On univariate analysis, HTN/DM/CKD was the only predictor of a substantial CKD-score increase (odds ratio: 3.53 [1.12–11.1]). Decline of GFR was modest and similar between patients with/without a substantial CKD-score increase. ConclusionsWithin the context of conventional, limited durations of ischemia, histologic deterioration of preserved parenchyma after PN appears to be primarily due to pre-existing medical comorbidities rather than ischemia. A subsequent decline in renal function was mild and independent of histologic changes. Patient summaryAfter clamped PN, the preserved renal parenchyma demonstrated histologic deterioration in many cases, which correlated with the presence of comorbidities such as hypertension, diabetes mellitus, or chronic kidney disease. In contrast, the type and duration of ischemia did not correlate with histologic changes after PN, suggesting that ischemia insult had only limited impact on parenchyma deterioration.

Nephron sparing surgery for renal tumors-comparison of off-clamp partial nephrectomy with hilar clamping.

Background and Objective:Open partial nephrectomy (PN) is still considered gold standard procedure for T1 localized renal tumors. Conventional technique involves clamping of the renal artery with or without vein however, renal ischemia produces a certain level of damage to the kidneys. This study aims to investigate potential effect of off-clamp vs. hilar clamping PN on renal function.Methods:This is a retrospective cohort study of patients who underwent unilateral, open partial nephrectomy for renal tumors b/w January 2009 December 2016 at our institution. A total of 90 partial nephrectomies were performed of which 65 cases were eligible for analysis. Non clamping technique was used in 43 while clamp was applied in 22 patients. Variables studied were patients’ demographics, clinical variables, the laterality, tumors size and location, R.E.N.A.L nephrometry score, blood loss, tumor histology and surgical margins. Patients’ renal function (serum creatinine and eGFR) were determined pre-operatively, at 3 and 12 months follow up. Data was analyzed on SPSS v. 22.Results:Both the groups were comparable with regards to pre-operative renal function. Mean radiological size of tumor was 4.71±1.31 and 3.81±1.0 (0.003) in two groups respectively. Mean R.E.N.A.L nephrometry score was 6.1±1.5 in off-clamp group compared to 7.05 ± 1.7 in clamp group (p=0.04). No statistically significant difference was found in operative duration, blood loss, positive surgical margins and intra/ peri-operative complications. At three months and one year, renal function was better preserved in non-clamp group compared to clamp group (p=0.001 and 0.007 respectively).Conclusion:Off clamp open partial nephrectomy is safe and feasible option leading to less decline in renal function.

Ischemia and Functional Recovery from Partial Nephrectomy: Refined Perspectives

BackgroundNephron mass preservation is a key determinant of functional outcomes after partial nephrectomy (PN), while ischemia plays a secondary role. Analyses focused specifically on recovery of the operated kidney appear to be most informative, yet have only included limited numbers of patients. ObjectiveTo evaluate the relative impact of parenchymal preservation and ischemia on functional recovery after PN using a more robust cohort allowing for more refined perspectives about ischemia. Design, setting, and participantsA total of 401 patients managed with PN with necessary studies were analyzed for function and nephron mass preserved specifically within the kidney exposed to ischemia. InterventionPN. Outcome measurements and statistical analysisThe nephron mass preserved was measured from computed tomography scans <2 mo before and 3–12 mo after PN. Patients with two kidneys were required to have nuclear renal scans within the same timeframes. Recovery from ischemia was defined as the percent function preserved normalized by the percent nephron mass preserved. Pearson correlation was used to evaluate relationships between functional recovery and nephron mass preservation or ischemia time. Multivariable linear regression assessed predictors for recovery from ischemia. Results and limitationsThe median tumor size was 3.5cm and the median RENAL score was 8. Cold and warm ischemia were utilized in 151 and 250 patients, and the median ischemia time was 27 and 21min, respectively. The function preserved was strongly correlated with nephron mass preserved(r=0.63; p<0.001). Median recovery from ischemia was significantly higher for hypothermia (99% vs 92%; p<0.001) and remained consistently strong even with longer duration. Multivariable analysis demonstrated that recovery from ischemia, which normalizes for nephron mass preservation, was significantly associated with ischemia type and duration (both p<0.05). However, each additional 10min of warm ischemia was associated with only a 2.5% decline in recovery from ischemia. Limitations include the retrospective design. ConclusionsOur data suggest that functional recovery from clamped PN is most reliable with hypothermia. Longer intervals of warm ischemia are associates with reduced recovery; however, incremental changes are modest and may not be clinically significant in patients with a normal contralateral kidney. Patient summaryFunctional recovery after clamped partial nephrectomy is primarily dependent on preservation of nephron mass. Recovery is most reliable when hypothermia is applied. Longer intervals of warm ischemia are associated with reduced recovery; however, the incremental changes are modest.

MP59-12 FUNCTIONAL & TRIFECTA OUTCOMES IN SOLITARY KIDNEY: UNCLAMPED VS CLAMPED PARTIAL NEPHRECTOMY

You have accessJournal of UrologyKidney Cancer: Surgical Therapy III1 Apr 2015MP59-12 FUNCTIONAL & TRIFECTA OUTCOMES IN SOLITARY KIDNEY: UNCLAMPED VS CLAMPED PARTIAL NEPHRECTOMY Andre Luis de Castro Abreu, Rocco Papalia, Inderbir Gill, Giuseppe Simone, Mariaconsiglia Ferriero, Riccardo Mastroianni, Kelvin Wong, Raed Azhar, Raj Satkunasivam, Charles Metcalfe, Osamu Ukimura, Monish Aron, Mihir Desai, and Michele Gallucci Andre Luis de Castro AbreuAndre Luis de Castro Abreu More articles by this author , Rocco PapaliaRocco Papalia More articles by this author , Inderbir GillInderbir Gill More articles by this author , Giuseppe SimoneGiuseppe Simone More articles by this author , Mariaconsiglia FerrieroMariaconsiglia Ferriero More articles by this author , Riccardo MastroianniRiccardo Mastroianni More articles by this author , Kelvin WongKelvin Wong More articles by this author , Raed AzharRaed Azhar More articles by this author , Raj SatkunasivamRaj Satkunasivam More articles by this author , Charles MetcalfeCharles Metcalfe More articles by this author , Osamu UkimuraOsamu Ukimura More articles by this author , Monish AronMonish Aron More articles by this author , Mihir DesaiMihir Desai More articles by this author , and Michele GallucciMichele Gallucci More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.2172AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To assess renal functional and trifecta outcomes of clamped versus unclamped minimally invasive partial nephrectomy (PN) in patients with a solitary kidney (SK). METHODS We retrospectively analyzed data of 129 patients undergoing PN in solitary kidney at 2 high-volume referral centers (1999-2014). PN was performed either by clamped technique (CC-PN; global renal ischemia with main artery clamped) or by unclamped technique (UC-PN; no global ischemia with no clamping/tumor-specific clamping only). Trifecta after PN was achieved when estimated glomerular filtration rate (eGFR) decreased < 10% from baseline, cancer margins were negative and there were no urological complications in a given patient. Demographics, perioperative, renal function and Trifecta outcomes were analyzed. Exploratory univariate and multivariable Cox regression were applied for predicting Trifecta after MIS-PN (p<0.05 significant). RESULTS CC-PN and UC-PN were performed in 64 and 65 patients, respectively. Mean tumor size (3.4 vs 3.9 cm, p=0.13) and baseline eGFR (60 vs 57, p = 0.34) were similar between groups. UC-PN cohort was older (62 vs 67 yrs, p = 0.02) with more central tumors (48% vs 77%, p =0.001). Robotic PN was more frequent in the UC-PN (17% vs 69%, p < 0.001). UC-PN patients had shorter mean warm ischemia time (WIT; 24 vs 0 min, p =<0.001) and operative time (4.3 vs 3.7 hrs, p = 0.04). Peri-operative outcomes were similar between CC-PN vs UN-PN groups: mean estimated blood loss (514 vs 285 cc, p =0.40), hospital stay (7.4 vs 4.9 days, p =0.86) and transfusion rate (28% vs 15 %, p =0.09). Overall complications trended to be lower for UN-PN (36% vs 20%, p =0.051), however urological complications were similar (11% vs 8%). RCC histology (78% vs 83%) and negative margins (98% vs 96%) were similar. Mean eGFR decrease was 30% for CC-PN vs 6% for UN-PN (p<0.0001). Similarly, in the UC-PN cohort, more patients maintained pre-operative eGFR (22% vs 64%, p < 0.0001) and fewer patients had new-onset CKD stage 3 (33% vs 6%, p < 0.001). Trifecta outcomes were more common in the UC-PN cohort (20% vs 69%, p < 0.0001). On univariate analysis baseline eGFR, WIT and UN-PN were predictors for achieving Trifecta. On multivariate analysis, UN-PN predicted for Trifecta. Main limitation is retrospective analysis and small number of patients. CONCLUSIONS In the solitary kidney setting, unclamped PN conferred superior functional and Trifecta outcomes compared to clamped PN. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e734 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Andre Luis de Castro Abreu More articles by this author Rocco Papalia More articles by this author Inderbir Gill More articles by this author Giuseppe Simone More articles by this author Mariaconsiglia Ferriero More articles by this author Riccardo Mastroianni More articles by this author Kelvin Wong More articles by this author Raed Azhar More articles by this author Raj Satkunasivam More articles by this author Charles Metcalfe More articles by this author Osamu Ukimura More articles by this author Monish Aron More articles by this author Mihir Desai More articles by this author Michele Gallucci More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Assessment of outcomes in partial nephrectomy incorporating detailed functional analysis.

To assess perioperative morbidity and margins after conventional clamped partial nephrectomy (PN) while also using volumetric analysis to differentiate the contributions of parenchymal volume loss and recovery from ischemia. The study analyzed 163 patients who underwent PN with appropriate studies to allow analysis of function and parenchymal mass specifically in the operated kidney. Recovery from ischemia (glomerular filtration rate saved/volume saved) would be 100% if all nephrons recovered from ischemia. Precision (postoperative parenchymal volume/predicted parenchymal volume, presuming loss of a 5-mm rim of parenchyma related to excision and reconstruction) reflects efforts to optimize the amount of vascularized parenchyma saved with the PN. Trifecta was defined as negative margins, no Clavien grade 3-5 or urologic complications, and both recovery ≥80% and precision ≥80%. An open procedure was performed in 82 patients (50%), and 59 (36%) had a solitary kidney. Warm ischemia was used in 96 patients (59%). The RENAL nephrometry score (radius, exophytic/endophytic properties of the tumor, nearness of tumor deepest portion to the collecting system or sinus, anterior/posterior descriptor, and the location relative to polar lines) was intermediate in 74 (45%) and high complexity in 38 (23%). Median recovery from ischemia was 95% and was ≥80% in 143 patients (88%). Median precision of excision/reconstruction was 93% and was ≥80% in 138 patients (85%). All tumors had negative surgical margins. Perioperative complications occurred in 13 patients (9%). Trifecta was achieved in 113 patients (69%). Multivariable analysis identified solitary kidney as the only significant predictor of trifecta. Given careful patient selection and commensurate surgical expertise, excellent outcomes can be obtained with conventional clamped PN. Analysis of parenchymal volumes is necessary to facilitate comprehensive evaluation of functional outcomes after PN, allowing differentiation of nephron loss vs failure to recover from ischemia.

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

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

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.

Selective clamping under the usage of near-infrared fluorescence imaging with indocyanine green in robot-assisted partial nephrectomy: a single-surgeon matched-pair study

To present a single-surgeon matched-pair analysis to show the feasibility of combining the technique of selective clamping with usage of near-infrared fluorescence imaging in robot-assisted partial nephrectomy and to investigate short-term renal function outcomes. Twenty-two patients underwent selective clamping partial nephrectomy with the application of indocyanine green (ICG). Out of this cohort, a matched-pair analysis for R.E.N.A.L. nephrometry parameter was employed for 15 exactly matching partners. Demographic, surgical, pathological and kidney function data were collected for the initial cohort, and matched-pair comparison was made between the subgroups retrospectively. Robot-assisted partial nephrectomy without clamping of the hilum was possible in 21 patients; in one patient, main artery clamping was necessary due to bleeding. Mean clinical tumor size was 37.7 mm. Mean selective clamping ischemia time was 11.6 min with an estimated blood loss of 347 ml. No intraoperative complications occurred, and postoperative complications (n = 4), including two major urological (urinoma, late-onset acute hemorrhage) complications, were found. There were no side effects of ICG administration. Matched-pair analysis for 15 patients showed similar demographic and surgical data without any significant differences in tumor characteristics. Comparing short-term renal function outcomes, significantly decreased estimated glomerular filtration rate reduction in the selective clamping group with an absolute loss of 5.1 versus 16.1 ml/min in the global ischemia cohort (p = 0.045) could be observed. Robot-assisted partial nephrectomy with selective clamping of the tumor feeding vascular branches is a promising technique for reduced ischemic renal trauma. This may lead to improved kidney function preservation.

Factors Affecting Renal Function After Open Partial Nephrectomy—A Comparison of Clampless and Clamped Warm Ischemic Technique

To analyze factors impacting postoperative renal function after open partial nephrectomy using both the clampless and clamped warm-ischemic technique. We studied a cohort of patients who underwent clamped partial nephrectomy (n = 164) and clampless partial nephrectomy (n = 64) from March 2002 to March 2009 with ≥ 12-months follow-up. Clamped partial nephrectomy used hilar occlusion before resection. Clampless partial nephrectomy used focal radio frequency coagulation to facilitate hemostasis before resection, nonischemic dissection/resection with hydro-dissection, or sharp resection after local compression. Demographics, tumor characteristics/RENAL nephrometry scores, perioperative variables, and complications were compared between the two methods. Multivariable analysis was performed to identify factors predicting de novo estimated glomerular filtration rate <60. Patient characteristics were similar between groups. Mean RENAL score was greater in clamped (6.9) vs clampless (6.4, P = .026); complications (P = .430) and urine leaks (clampless partial nephrectomy 3.1% vs clamped-PN 7.3%, P = .360) were similar. Mean warm ischemia time (min) was 24.5 for clamped partial nephrectomy. De novo estimated glomerular filtration rate <60(%) at last follow up was 13.5 (clamped) vs 3.1 (clampless) (P = .071). Multivariable analysis of the entire cohort revealed increasing body mass index (OR 1.1, P = .042) and RENAL score (OR 1.71, P = .002) as being independently associated with development of postoperative de novo estimated glomerular filtration rate <60. Multivariable analysis of the clamped subgroup demonstrated increasing body mass index (OR 1.12, P = .028), RENAL score (OR 1.56, P = .010), and ischemia time (OR 1.15, P = .042) as independent factors associated with de novo estimated glomerular filtration rate <60. Body mass index and RENAL score were factors predictive of development of de novo estimated glomerular filtration rate <60 after partial nephrectomy, with increasing warm ischemia time also being predictive in clamped partial nephrectomy patients. Further investigation and long-term functional data are requisite.