Renal Pelvic Anatomy Is Associated with Incidence, Grade, and Need for Intervention for Urine Leak Following Partial Nephrectomy

Associations between R.E.N.A.L. nephrometry score and survival outcomes in renal tumours

OBJECTIVE

The radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score could be used to predict surgical outcomes and renal tumour aggressiveness. We aimed to analyse its associations with survival outcomes.

METHODS

We included 1368 patients with sporadic, unilateral and non-metastatic renal tumours who received curative nephrectomy in Zhongshan Hospital from January 2009 to September 2019. Radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores were assigned by three urologists based on preoperative CT/MRI scans. Correlations between parameters or sum of radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores, overall survival and recurrence-free survival were analysed by Kaplan-Meier analyses and the multivariate Cox regression model. We further compared survival outcomes between patients who received partial nephrectomy and patients who received radical nephrectomy.

RESULTS

We observed statistically significant associations between all components of radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores and oncologic outcomes, including R (radius) (overall survival, P < 0.001; recurrence-free survival , P < 0.001), E (exophytic/endophytic) (overall survival, P = 0.003; recurrence-free survival, P < 0.001), N (nearness) (overall survival, P = 0.063; recurrence-free survival, P < 0.001), A (anterior/posterior) (overall survival, P < 0.001; recurrence-free survival, P = 0.005), L (location) (overall survival, P = 0.008; recurrence-free survival, P < 0.001) and suffix 'h' (overall survival, P = 0.237; recurrence-free survival, P = 0.034). Kaplan-Meier curves of overall survival and recurrence-free survival rates were significantly different when stratified by radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score complexity group (overall survival, P < 0.001; recurrence-free survival, P < 0.001). After adjusting for tumour stage and grade, radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score as continuous variables was an adverse independent risk factor for survival outcomes [P = 0.027, hazard ratio (95% confidence interval) = 1.151 (1.016-1.303)] and recurrence-free survival [P < 0.001, hazard ratio (95% confidence interval) = 1.299 (1.125-1.501)]. For tumours with radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores of 4 and 5, partial nephrectomy showed a survival benefit than radical nephrectomy.

CONCLUSION

Both components and complexity groups of the radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score are associated with survival outcomes in renal tumour patients.

Systematic review on active treatment for urinary fistula after partial nephrectomy

INTRODUCTION

Urinary fistula is expected to become more frequent in urological practice as a result of expanding indication of partial nephrectomy given it's oncological results equivalent to those of radical nephrectomy but at a lower risk of progression to chronic kidney disease, lower cardiovascular morbidity, and overall mortality.

OBJECTIVES

Review and compare different techniques of contemporary active management for urinary fistula after partial nephrectomy.

METHODS

A systematic literature search on the MEDLINE database was conducted in March 2020, combining the terms: "urine leak", "urine leakage", "urinary leak" and "urinary fistula", with: "partial nephrectomy", "nephron sparing surgery" and "renal sparing surgery". This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Only articles related to active treatment were eligible. Abstracts in English and Spanish from the last two decades were screened. No restriction based on study design nor the length of follow-up.

PRIMARY OUTCOMES

1) Leak resolution rate 2) Time course of leak resolution and 3) Number of interventions needed for resolution.

RESULTS

Multiple studies were found. There were no randomized controlled trials. Urinary fistula can be solved in many ways with active treatment, with a high success rate (97.5%), an average of 1.4 intervention-per-patients and a mean time for leak resolution of 11 days (median of 3 days).

CONCLUSION

There is a high risk of bias due to the study's methodology. There is a broad range of effective alternatives and various approaches to solve urinary fistula in an appropriate timing.

Nephrometry scoring systems: their importance for the planning of nephron-sparing surgery and the relationships among them

In recent years, the development of new imaging techniques and scoring systems have improved the diagnosis and management of small renal masses. Imaging-based nephrometry scoring systems play an interesting role in the planning of nephron-sparing surgery, providing surgeons with the information necessary to determine the complexity of the renal mass, to deliver the appropriate postoperative care, and to predict adverse outcomes. The aim of this study was to review nephrometry scoring systems, evaluating their characteristics and the relationships among them. The urology and radiology communities should decide which nephrometry scoring system will prevail and be used in daily practice.

A low RENAL Nephrometry Score can avoid the need for the intraoperative insertion of a ureteral catheter in robot-assisted partial nephrectomy

Background

Intraoperative urinary collecting system entry (CSE) in robot-assisted partial nephrectomy (RAPN) may cause postoperative urinary leakage and extend the hospitalization. Therefore, identifying and firmly closing the entry sites are important for preventing postoperative urine leakage. In RAPN cases expected to require CSE, we insert a ureteral catheter and inject dye into the renal pelvis to identify the entry sites. We retrospectively analyzed the factors associated with intraoperative CSE in RAPN and explored the indications of intraoperative ureteral catheter indwelling in RAPN.

Methods

Of 104 Japanese patients who underwent RAPN at our institution from August 2016 to March 2020, 101 were analyzed. The patients were classified into CSE and non-CSE groups. The patients’ background characteristics, RENAL Nephrometry Score (RNS), and surgical outcomes were analyzed.

Results

Intraoperative CSE was observed in 41 patients (41%). The CSE group had a significantly longer operative time, console time, ischemic time, and hospital stay than the non-CSE group. In a multivariable analysis, the N-score (odds ratio [OR] = 3.9, P < 0.05) and RNS total score excluding the L-score (OR = 3.1, P < 0.05) were associated with CSE. In a logistic regression analysis, CSE showed a moderate correlation with the RNS total score excluding the L-score (AUC 0.848, cut-off 5, sensitivity 0.83, specificity 0.73).

Conclusion

A ureteral catheter should not be placed in patients with an RNS total score (excluding the L-score) of ≤ 4.

Modified R.E.N.A.L nephrometry score for predicting the outcome following partial nephrectomy

Background

It was difficult to compare the outcome of partial nephrectomy among different studies due to the absence of standardized description of different renal masses. This problem led to the development of nephrometry scoring systems. R.E.N.A.L. is among the commonest nephrometry scoring systems; however, some studies failed to find any relation between R.E.N.A.L. with perioperative outcome. We evaluated our designed newly modified nephrometry score in prediction of outcome following partial nephrectomy and compared its predictability versus original R.E.N.A.L.

Methods

Fifty-one patients with cT1-2N0M0 renal masses amenable for partial nephrectomy were included prospectively. Different perioperative outcome variables were compared according to complexity level in R.E.N.A.L. and the newly modified nephrometry score.

Results

Clinical staging was T1a (21.6%), T1b (49%), T2a (25.5%), T2b (3.9%). Median R.E.N.A.L. was 9 (4–12). Hilar position and intrarenal pelvis were detected in 19.6% and 68.6%. Low, moderate and high complexity masses were found in 21.6%, 39.2% and 39.2%. Complications and rate of conversion to radical nephrectomy were 17 (33.3%) and 4 (7.8%). The only significantly affected variable (p = 0.039) by R.E.N.A.L. was rate of secondary intervention, but it was higher in low than in high complexity level. In the newly modified nephrometry score, complications (p = 0.037) and rate of positive surgical margin (p = 0.049) were significantly higher with increased complexity level. Although other variables (pelvi-calyceal system entry, operative time, blood loss, hemoglobin loss, blood transfusion and conversion to radical nephrectomy) did not show statistically significant difference according to both scores, they were better associated with the complexity level in the newly modified nephrometry score with their remarkable increase in the high when compared to the low complexity level.

Conclusions

The newly modified nephrometry score was associated with better prediction of outcome of partial nephrectomy when compared to R.E.N.A.L.

The value of renal score in both determining surgical strategies and predicting complications for renal cell carcinoma: A systematic review and meta-analysis

Objectives

Radical nephrectomy (RN) was the standard treatment for renal cell carcinoma (RCC). However, recent studies have found that partial nephrectomy (PN) could achieve similar effects as radical nephrectomy, and has the advantages of less bleeding and shorter hospital stay. The choice of surgical strategies has become a concern of clinicians, which could be guided by renal score introduced by Kutikov et al Therefore, we conducted this meta‐analysis to clarify the value of renal score of determining surgical strategies and predicting complications.

Methods

The keywords “RENAL score,” “renal nephrometry score,” or “nephrometry score” were used to retrieve electronic databases for relevant literature up to Feb 2020, including PubMed, Web of Science, and the Cochrane library. Surgical strategies and complications are outcome measures. Risk ratio (RR) with 95% confidence intervals (CI) is applied to assess the effect size.

Results

A total of 20 studies met the selection criteria for meta‐analysis. There was significant difference in RN operation rate for each subgroup (low‐moderate: RR = 3.50, 95% Cl = 2.60‐4.71, P < .001; low‐high: RR = 6.29, 95% Cl = 4.40‐9.00, P < .001; moderate‐high: RR = 1.80, 95% Cl = 1.39‐2.32, P < .001).The overall incidence of complications from high renal score group was significantly higher than that in low renal score group (low‐moderate: RR = 1.32, 95% Cl = 1.03‐1.69, P = .026; low‐high: RR = 2.45, 95% Cl = 1.48‐4.07, P = .001; moderate‐high: RR = 1.75, 95% Cl = 1.17‐2.61, P = .007).

Conclusions

This meta‐analysis indicated that renal score is an efficient tool for determining surgical strategies and predicting complications in PN. More prospective research is essential to verify the predictive value of renal score.

Predictive Value of Nephrometry Scores in Nephron-sparing Surgery: A Systematic Review and Meta-analysis

CONTEXT

Over the last decade, several nephrometry scores (NSs) have been introduced with the aim of facilitating preoperative decision making, planning, and counseling in the field of nephron-sparing surgery. However, their predictive role remains controversial.

OBJECTIVE

To describe currently available nephrometry scores and to determine their predictive role for different outcomes by performing a systematic review and meta-analysis of the literature.

EVIDENCE ACQUISITION

PubMed, Embase®, and Web of Science were screened to identify eligible studies. Identification and selection of the reports were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). A pooled analysis of NS predictive role of intraoperative, postoperative, oncological, and functional outcomes was performed. Odds ratio was considered the effect size. All the analyses were performed using Stata 15.0, and statistical significance was set at p≤ 0.05.

EVIDENCE SYNTHESIS

Overall, 51 studies meeting our inclusion criteria were identified and considered for the analysis. Except for one prospective randomized trial, all the studies were retrospective. All the studies were found to be of intermediate quality, except for one of high quality. Most studies assessed the predictive role of the Radius-Exophytic/Endophytic-Nearness-Anterior/Posterior-Location (RENAL) and Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) scores, mostly regarding complications after nephron-sparing surgery. RENAL was an independent predictor of an on-clamp procedure (p< 0.001). Mayo Adhesive Probability score was related to adhesive perinephric fat (p= 0.005). Continuous and high-complexity RENAL scores were predictors of warm ischemia time (WIT; p= 0.006 and p< 0.001, respectively). Continuous (p< 0.001) and high-complexity (p< 0.001) PADUA scores were related to WIT. Continuous and high-complexity RENAL scores were predictors of overall complications (p= 0.002 and p< 0.001, respectively). PADUA score was related to complications both as continuous (p< 0.001) and as a categorical value (p< 0.002). The RENAL scores R=3 (p= 0.008), E=2 (p= 0.039), and hilar location (p= 0.006) were predictors of histological malignancy. Continuous and categorical RENAL scores were independent predictors of an estimated glomerular filtration rate (eGFR) increase (p= 0.006 and p< 0.001, respectively). The Diameter-Axial-Polar score (p= 0.018) and Peritumoral Artery Scoring System (PASS; p= 0.02) were also independent predictors.

CONCLUSIONS

The literature regarding nephrometry scoring systems is sparse, and mostly focused on RENAL and PADUA, which are easy to calculate and have a good correlation with most outcomes. Renal Pelvic Score is the best predictor of pelvicalyceal entry/repair and urine leak, whereas Surgical Approach Renal Ranking and PASS strongly predict surgical approach and renal function variation, respectively. Other nephrometry scores based on mathematical models are limited by their complexity, and they lack evidence supporting their predictive value.

PATIENT SUMMARY

We reviewed the medical literature regarding the use and value of so-called "nephrometry scores," which are scoring systems based on radiological imaging and made to grade the complexity of a renal tumor. We analyzed whether these scoring systems can predict some of the outcomes of patients undergoing surgical removal of renal tumors.

Preliminary Kidney Parenchymal Ligation Using Endoloop Ligatures-A Simple Method to Achieve a Trifecta in Laparoscopic Partial Nephrectomy Without Hilar Clamping for Polar Complex Tumors

OBJECTIVE

To describe a novel and simple technique of preliminary kidney parenchymal ligation using Endoloop ligatures during laparoscopic partial nephrectomy (PN) without hilar clamping for polar complex tumor cases.

METHODS

The subjects were 17 patients who had a renal mass with a R.E.N.A.L. nephrometry score ≥7 (7/8/9/10 in 3/6/6/2 patients, respectively) located in the pole of the kidney. Patient-specific 3D reconstructed kidney images were created for preoperative planning in all cases. The renal hilar vessels were meticulously dissected and definitive tumor feeders were sacrificed when the branches directly perfused the peri-tumor area. Following the vascular microdissection, a circumferential cortex-depth incision on the kidney was made all around the tumor. Consequently, several Endoloop ligatures were placed in the incised tumor base to ligate the parenchyma preliminarily. Step-by-step Endoloop tightening facilitated effective parenchymal dissection without the urinary tract. After confirming that the tumor base parenchyma was ligated sufficiently, tumor resection was completed. Neither inner- nor outer-layer renorrhaphy sutures were placed.

RESULTS

Perioperative outcomes were satisfactory and all patients had negative surgical margins with no damage in the tumor capsule. Urological complications and renal function lower than predicted at 3 months after surgery involved 1 and 3 cases, respectively. The rate of PN trifecta achievement was 82% (14/17) despite the complexity of the 17 tumors.

CONCLUSION

The current technique helped surgeons achieve the trifecta in patients with polar complex masses treated with laparoscopic PN. Use of this technique can provide surgeons with a bloodless operative field even during PN without hilar clamping.

Prediction of Intraoperative Urinary Collecting System Entry in Patients with Peripheral Renal Tumors Undergoing Partial Nephrectomy: Usefulness of Tumor-Centered Multiplanar Reconstruction

OBJECTIVE

To assess the usefulness of tumor-centered multiplanar reconstruction (TC-MPR) for predicting intraoperative urinary collecting system (UCS) entry in patients with peripheral renal tumors undergoing partial nephrectomy (PN).

METHODS

Dynamic computed tomography images of 50 peripheral cT1 renal tumors treated with laparoendoscopic PN were analyzed. TC-MPR generated a digital cross-sectional image showing the tumor center and the closest calyx on a same plane. Patients and tumor characteristics including the distance from the tumor margin to the closest calyx (MPR-distance), and the angle formed by 2 tangent lines from the closest calyx to the tumor (MPR-angle) were assessed.

RESULTS

Intraoperative UCS entry was observed in 15 patients (30%). The patients who experienced intraoperative UCS entry had a higher RENAL score, wider MPR-angle, and shorter MPR-distance than those who did not (p = 0.04, p = 0.001, p < 0.001, respectively). Multivariate analysis identified MPR-angle as an independent factor for intraoperative UCS entry (p < 0.001).

CONCLUSIONS

The spatial information assessed using TC-MPR serves as a predictive factor for intraoperative UCS entry during PN.

Comparative Effectiveness of Surgical Treatments for Small Renal Masses

In the management of small renal masses (SRMs), treatment options include partial nephrectomy (PN), radical nephrectomy (RN), ablation, renal biopsy, and active surveillance. Large series retrospective and meta-analyses demonstrate PN may confer greater preservation of renal function, overall survival, and equivalent cancer control when compared with RN. As newer therapies emerge, we should critically evaluate the risks and benefits associated with the surgical management of SRMs among patients with competing comorbidities, complex tumors, and high-risk disease. Among younger patients with SRMs amenable to resection, optimization of postoperative patient health should be prioritized.

Complications of Renal Surgery

The incidence of the small renal mass continues to increase owing to the aging population and the ubiquity imaging. Most of these tumors are stage I tumors. Management strategies include surveillance, ablation, and extirpation. There is a wide body of literature favoring nephron-sparing approaches. Although nephron-sparing surgery may yield decreased long-term morbidity, it is not without its drawbacks, including a higher rate of complications. Urologists must be attuned to the complications of surgery and develop strategies to minimize risk. This article reviews expected complications of surgery on renal masses and risk stratification schema.

Active Surveillance for Small Renal Masses: When Less is More

CONTEXT

A marked increase in incidentally detected small renal masses (SRMs) has occurred over the past decade. Active surveillance (AS) has emerged as an initial management option for these patients.

OBJECTIVE

(1) To determine selection criteria, assess appropriate imaging modalities and surveillance frequencies, and define triggers for delayed intervention (DI) for patients on AS. (2) To describe oncologic outcomes for patients on AS protocols.

EVIDENCE ACQUISITION

The PubMed database was queried for English language articles using the keywords "surveillance" and "renal mass" or "renal cell carcinoma" or "kidney cancer." The level of evidence, sample size, study design, and relevance to the review were considered as inclusion criteria.

EVIDENCE SYNTHESIS

A total of 69 manuscripts were included in the review. Selection criteria at initial evaluation for patients interested in AS include patient-related factors (eg, age, baseline renal function, other comorbidities), tumor-related factors (size, complexity, history of growth, possible renal mass biopsy), and patient preferences (illness uncertainty, quality of life). Cross-sectional imaging is the preferred initial imaging modality. Surveillance imaging should be performed at frequent intervals (3-4 mo) up front; intervals can be reduced over time if favorable growth kinetics are demonstrated. Delayed intervention (DI) should be considered for rapid tumor growth (eg,>0.5cm/yr), an increase in maximum tumor diameter >3-4cm, malignant renal mass biopsy results, development of symptoms, or patient preferences. Oncologic outcomes in well-controlled studies demonstrate a metastatic rate of 1-2%. Most patients who undergo DI remain eligible for nephron-sparing approaches; oncologic outcomes are not compromised by DI strategies.

CONCLUSIONS

A period of initial AS is safe for most patients with SRMs. Management decisions should focus on a thorough assessment of risk-benefit trade-offs, judiciously integrating patient-related factors, tumor-related factors, and patient preferences.

PATIENT SUMMARY

A period of initial active surveillance for kidney masses of ≤4cm in diameter is safe in most patients. Frequent imaging and follow-up are necessary to determine if the tumor grows. If delayed intervention becomes necessary, cancer outcomes are not compromised by the initial choice of active surveillance when patients adhere to close follow-up regimens.

Renal Tumor Anatomic Complexity: Clinical Implications for Urologists

Anatomic tumor complexity can be objectively measured and reported using nephrometry. Various scoring systems have been developed in an attempt to correlate tumor complexity with intraoperative and postoperative outcomes. Nephrometry may also predict tumor biology in a noninvasive, reproducible manner. Other scoring systems can help predict surgical complexity and the likelihood of complications, independent of tumor characteristics. The accumulated data in this new field provide provocative evidence that objectifying anatomic complexity can consolidate reporting mechanisms and improve metrics of comparisons. Further prospective validation is needed to understand the full descriptive and predictive ability of the various nephrometry scores.

Study of predictive factors affecting the prolonged urinary leakage after percutaneous nephrolithotomy

Objective:

To evaluate the factors that may influence the prolonged urinary leakage following percutaneous nephrolithotomy (PCNL).

Materials and Methods:

A total of 936 consecutive patients underwent PCNL during the study period from April 2013 to December 2014 at our center, and data were recorded prospectively. Patients who required stage PCNL, chronic renal failure and diabetic patients, concurrent ureteric stone and patients in whom double-J stent was placed because of ureteropelvic injury, or pelvicalyceal extravasation were excluded from the study. After exclusion, 576 patients were included in the study. The predictive factors that may lead to prolonged urinary leakage after PCNL were broadly categorized into patient-related factors and procedure-related factors. Patients were divided into two groups: Group 1 (n = 32) – Required double-J stent placement due to prolonged urinary leakage (>48 h) after removal of the nephrostomy tube. Group 2 (n = 544) – Did not require double-J stent placement.

Results:

Patient-related factors such as stone complexity, grade of hydronephrosis, renal parenchymal thickness in access line, and intra-parenchymal renal pelvis were most important factors for prolonged urinary leakage (P < 0.05, P < 0.05, P < 0.05, and P < 0.05, respectively), while procedure-related factors such as multiple punctures, surgeon's experience, and residual stones were most important factors for prolonged urinary leakage (P < 0.05, P < 0.05, and P < 0.05, respectively).

Conclusion:

In the present study, several factors appear to affect post-PCNL prolonged urinary leakage. We suggest that patients who are at increased risk of prolonged urinary leakage double-J stent should be placed at the end of PCNL procedure.

Variability of inter-observer agreement on feasibility of partial nephrectomy before and after neoadjuvant axitinib for locally advanced renal cell carcinoma (RCC): independent analysis from a phase II trial

OBJECTIVE

To evaluate how many patients could have undergone partial nephrectomy (PN) rather than radical nephrectomy (RN) before and after neoadjuvant axitinib therapy, as assessed by five independent urological oncologists, and to study the variability of inter-observer agreement.

PATIENTS AND METHODS

Pre- and post-systemic treatment computed tomography scans from 22 patients with clear cell renal cell carcinoma in a phase II neoadjuvant axitinib trial were reviewed by five independent urological oncologists. R.E.N.A.L. nephrometry score and κ statistics were calculated.

RESULTS

The median R.E.N.A.L. nephrometry score changed from 11 before treatment to 10 after treatment (P = 0.002). Five tumours with moderate complexity before axitinib treatment remained moderate complexity after treatment. Of 17 tumours with high complexity before axitinib treatment, three became moderate complexity after treatment. The overall κ statistic was 0.611. Moderate-complexity κ was 0.611 vs a high-complexity κ of 0.428. Before axitinib treatment the κ was 0.550 vs 0.609 after treatment. After treatment with axitinib, all five reviewers agreed that only five patients required RN (instead of eight before treatment) and that 10 patients could now undergo PN (instead of three before treatment). The odds of PN feasibility were 22.8-times higher after treatment with axitinib.

CONCLUSIONS

There is considerable variability in inter-observer agreement on the feasibility of PN in patients treated with neoadjuvant targeted therapy. Although more patients were candidates for PN after neoadjuvant axitinib therapy, it remains difficult to identify these patients a priori.

A Literature Review of Renal Surgical Anatomy and Surgical Strategies for Partial Nephrectomy

CONTEXT

A detailed understanding of renal surgical anatomy is necessary to optimize preoperative planning and operative technique and provide a basis for improved outcomes.

OBJECTIVE

To evaluate the literature regarding pertinent surgical anatomy of the kidney and related structures, nephrometry scoring systems, and current surgical strategies for partial nephrectomy (PN).

EVIDENCE ACQUISITION

A literature review was conducted.

EVIDENCE SYNTHESIS

Surgical renal anatomy fundamentally impacts PN surgery. The renal artery divides into anterior and posterior divisions, from which approximately five segmental terminal arteries originate. The renal veins are not terminal. Variations in the vascular and lymphatic channels are common; thus, concurrent lymphadenectomy is not routinely indicated during PN for cT1 renal masses in the setting of clinically negative lymph nodes. Renal-protocol contrast-enhanced computed tomography or magnetic resonance imaging is used for standard imaging. Anatomy-based nephrometry scoring systems allow standardized academic reporting of tumor characteristics and predict PN outcomes (complications, remnant function, possibly histology). Anatomy-based novel surgical approaches may reduce ischemic time during PN; these include early unclamping, segmental clamping, tumor-specific clamping (zero ischemia), and unclamped PN. Cancer cure after PN relies on complete resection, which can be achieved by thin margins. Post-PN renal function is impacted by kidney quality, remnant quantity, and ischemia type and duration.

CONCLUSIONS

Surgical renal anatomy underpins imaging, nephrometry scoring systems, and vascular control techniques that reduce global renal ischemia and may impact post-PN function. A contemporary ideal PN excises the tumor with a thin negative margin, delicately secures the tumor bed to maximize vascularized remnant parenchyma, and minimizes global ischemia to the renal remnant with minimal complications.

PATIENT SUMMARY

In this report we review renal surgical anatomy. Renal mass imaging allows detailed delineation of the anatomy and vasculature and permits nephrometry scoring, and thus precise, patient-specific surgical planning. Novel off-clamp techniques have been developed that may lead to improved outcomes.

Feasibility and accuracy of computational robot-assisted partial nephrectomy planning by virtual partial nephrectomy analysis

OBJECTIVES

To evaluate the feasibility and accuracy of virtual partial nephrectomy analysis, including a color-coded three-dimensional virtual surgical planning and a quantitative functional analysis, in predicting the surgical outcomes of robot-assisted partial nephrectomy.

METHODS

Between 2012 and 2014, 20 patients underwent virtual partial nephrectomy analysis before undergoing robot-assisted partial nephrectomy. Virtual partial nephrectomy analysis was carried out with the following steps: (i) evaluation of the arterial branch for selective clamping by showing the vascular-supplied area; (ii) simulation of the optimal surgical margin in precise segmented three-dimensional model for prediction of collecting system opening; and (iii) detailed volumetric analyses and estimates of postoperative renal function based on volumetric change. At operation, the surgeon identified the targeted artery and determined the surgical margin according to the virtual partial nephrectomy analysis. The surgical outcomes between the virtual partial nephrectomy analysis and the actual robot-assisted partial nephrectomy were compared.

RESULTS

All 20 patients had negative cancer surgical margins and no urological complications. The tumor-specific renal arterial supply areas were shown in color-coded three-dimensional model visualization in all cases. The prediction value of collecting system opening was 85.7% for sensitivity and 100% for specificity. The predicted renal resection volume was significantly correlated with actual resected specimen volume (r(2) = 0.745, P < 0.001). The predicted estimated glomerular filtration rate was significantly correlated with actual postoperative estimated glomerular filtration rate (r(2) = 0.736, P < 0.001).

CONCLUSIONS

Virtual partial nephrectomy analysis is able to provide the identification of tumor-specific renal arterial supply, prediction of collecting system opening and prediction of postoperative renal function. This technique might allow urologists to compare various arterial clamping methods and resection margins with surgical outcomes in a non-invasive manner.

Is radical nephrectomy a legitimate therapeutic option in patients with renal masses amenable to nephron-sparing surgery?

The decision to perform a radical nephrectomy (RN) or a partial nephrectomy (PN), not unlike most decisions in clinical practice, ultimately hinges on the balance of risk. Do the higher risks of a more complex surgery (PN) justify the theoretical benefits of kidney tissue preservation? Data suggest that for patients with an anatomically complex renal mass and a normal contralateral kidney, for whom additional surgical intensity may be risky, such as the elderly and comorbid, RN presents a robust treatment option. Nevertheless, PN, especially for small and anatomically simple renal masses in young patients without comorbidities should remain the surgical reference standard, as preservation of renal tissue can serve as an 'insurance policy' not only against future renal functional decline, but also against the possibility of tumour development in the contralateral kidney. In the present review, we outline the ongoing debate between the role of RN and PN in treatment of the enhancing renal mass.

Internal validation of the renal pelvic score: a novel marker of renal pelvic anatomy that predicts urine leak after partial nephrectomy

OBJECTIVE

To internally validate the renal pelvic score (RPS) in an expanded cohort of patients undergoing partial nephrectomy (PN).

MATERIALS AND METHODS

Our prospective institutional renal cell carcinoma database was used to identify all patients undergoing PN for localized renal cell carcinoma from 2007 to 2013. Patients were classified by RPS as having an intraparenchymal or extraparenchymal renal pelvis. Multivariate logistic regression models were used to examine the relationship between RPS and urine leak.

RESULTS

Eight hundred thirty-one patients (median age, 60 ± 11.6 years; 65.1% male) undergoing PN (57.3% robotic) for low (28.9%), intermediate (56.5%), and high complexity (14.5%) localized renal tumors (median size, 3.0 ± 2.3 cm; median nephrometry score, 7.0 ± 2.6) were included. Fifty-four patients (6.5%) developed a clinically significant or radiographically identified urine leak. Seventy-two of 831 renal pelvises (8.7%) were classified as intraparenchymal. Intrarenal pelvic anatomy was associated with a markedly increased risk of urine leak (43.1% vs 3.0%; P <.001), major urine leak requiring intervention (23.6% vs 1.7%; P <.001), and minor urine leak (19.4% vs 1.2%; P <.001) compared with that in patients with an extrarenal pelvis. After multivariate adjustment, RPS (intraparenchymal renal pelvis; odds ratio [OR], 24.8; confidence interval [CI], 11.5-53.4; P <.001) was the most predictive of urine leak as was tumor endophyticity ("E" score of 3 [OR, 4.5; CI, 1.3-15.5; P = .018]), and intraoperative collecting system entry (OR, 6.1; CI, 2.5-14.9; P <.001).

CONCLUSION

Renal pelvic anatomy as measured by the RPS best predicts urine leak after open and robotic partial nephrectomy. Although external validation of the RPS is required, preoperative identification of patients at increased risk for urine leak should be considered in perioperative management and counseling algorithms.

Anatomic complexity quantitated by nephrometry score is associated with prolonged warm ischemia time during robotic partial nephrectomy

OBJECTIVE

To assess the association between nephrometry score (NS) and prolonged warm ischemia time (WIT) in patients undergoing robotic partial nephrectomy (RPN) for clinically localized renal masses.

METHODS

We queried our prospectively maintained kidney cancer database to identify all patients undergoing RPN for localized tumors from 2007-2012. Patient and tumor characteristics were compared between complexity groups using analysis of variance and chi square tests. Multivariate logistic regression models were used to examine the relationship between NS complexity and warm ischemia >30 minutes.

RESULTS

Three hundred seventy-five patients (mean age, 59 ± 11 years; mean Charlson comorbidity index, 1.0 ± 1.3) undergoing RPN under warm ischemia for clinically localized renal tumors (mean tumor size, 3.1 ± 1.5 cm; mean NS, 6.8 ± 1.8) met inclusion criteria and had NS available. Stratified by complexity, groups differed with respect to age at surgery, tumor size, proximity to the hilum, collecting system entry, estimated blood loss, and operative time (all P values ≤.05). Significant differences in mean WIT were observed when comparing low (19.4 ± 12.1 minutes), intermediate (28.6 ± 12.8 minutes), and high (36.1 ± 13.7 minutes) NS complexity groups (P <.0001). Adjusting for confounders, patients with intermediate (odds ratio, 2.1; confidence interval, 1.2-3.9) and high (odds ratio, 3.7; confidence interval, 1.1-11.8) NS complexity were more likely to require prolonged WIT when compared with patients with low complexity tumors.

CONCLUSION

In our large institutional cohort, quantification of anatomic complexity using the NS is associated with WIT >30 minutes in patients undergoing RPN for localized renal tumors. This provides further evidence that standardized reporting of tumor anatomic complexity affords meaningful outcome comparisons.

Morphometric scores for renal tumors: what does the radiologist need to know?

Numerous therapeutic options are possible in the treatment of renal carcinomas including radical nephrectomy, partial nephrectomy, cryoablation, radiofrequency, active follow-up and among surgical treatments, different approaches may be used such as laparotomy, laparoscopy, robotic-assisted intervention. The choice between these different procedures is partially based on the anatomic conditions of the tumors. Different anatomic scores determined from cross-sectional imaging have been built to predict the complexity of the surgical procedure. The goals of this article are to review the relevant morphologic pattern for management of patients with renal tumors, to know how to calculate these different scores and to understand the clinical applications of these scores.