External validation of the RENAL nephrometry score in renal tumours treated by 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.

RPN (Radius, Position of tumour, iNvasion of renal sinus) Classification and Nephrometry Scoring System: An Internationally Developed Clinical Classification To Describe the Surgical Difficulty for Renal Masses for Which Robotic Partial Nephrectomy Is Planned

Background

The surgical difficulty of partial nephrectomy (PN) varies depending on the operative approach. Existing nephrometry classifications for assessment of surgical difficulty are not specific to the robotic approach.

Objective

To develop an international robotic-specific classification of renal masses for preoperative assessment of surgical difficulty of robotic PN.

Design setting and participants

The RPN classification (Radius, Position of tumour, iNvasion of renal sinus) considers three parameters: tumour size, tumour position, and invasion of the renal sinus. In an international survey, 45 experienced robotic surgeons independently reviewed de-identified computed tomography images of 144 patients with renal tumours to assess surgical difficulty of robot-assisted PN using a 10-point Likert scale. A separate data set of 248 patients was used for external validation.

Outcome measurements and statistical analysis

Multiple linear regression was conducted and a risk score was developed after rounding the regression coefficients. The RPN classification was correlated with the surgical difficulty score derived from the international survey. External validation was performed using a retrospective cohort of 248 patients. RPN classification was also compared with the RENAL (Radius; Exophytic/endophytic; Nearness; Anterior/posterior; Location), PADUA (Preoperative Aspects and Dimensions Used for Anatomic), and SPARE (Simplified PADUA REnal) scoring systems.

Results and limitation

The median tumour size was 38 mm (interquartile range 27-49). The majority (81%) of renal tumours were peripheral, followed by hilar (12%) and central (7.6%) locations. Noninvasive and semi-invasive tumours accounted for 37% each, and 26% of the tumours were invasive. The mean surgical difficulty score was 5.2 (standard deviation 1.9). Linear regression analysis indicated that the RPN classification correlated very well with the surgical difficulty score (R2 = 0.80). The R2 values for the other scoring systems were: 0.66 for RENAL, 0.75 for PADUA, and 0.70 for SPARE. In an external validation cohort, the performance of all four classification systems in predicting perioperative outcomes was similar, with low R2 values.

Conclusions

The proposed RPN classification is the first nephrometry system to assess the surgical difficulty of renal masses for which robot-assisted PN is planned, and is a useful tool to assist in surgical planning, training and data reporting.

Patient summary

We describe a simple classification system to help urologists in preoperative assessment of the difficulty of robotic surgery for partial kidney removal for kidney tumours.

CT of the urinary tract revisited

Computed tomography (CT) of the abdomen is usually appropriate for the initial imaging of many urinary tract diseases, due to its wide availability, fast scanning and acquisition of thin slices and isotropic data, that allow the creation of multiplanar reformatted and three-dimensional reconstructed images of excellent anatomic details. Non-enhanced CT remains the standard imaging modality for assessing renal colic. The technique allows the detection of nearly all types of urinary calculi and the estimation of stone burden. CT is the primary diagnostic tool for the characterization of an indeterminate renal mass, including both cystic and solid tumors. It is also the modality of choice for staging a primary renal tumor. Urolithiasis and urinary tract malignancies represent the main urogenic causes of hematuria. CT urography (CTU) improves the visualization of both the upper and lower urinary tract and is recommended for the investigation of gross hematuria and microscopic hematuria, in patients with predisposing factors for urologic malignancies. CTU is highly accurate in the detection and staging of upper tract urothelial malignancies. CT represents the most commonly used technique for the detection and staging of bladder carcinoma and the diagnostic efficacy of CT staging improves with more advanced disease. Nevertheless, it has limited accuracy in differentiating non-muscle invasive bladder carcinoma from muscle-invasive bladder carcinoma. In this review, clinical indications and the optimal imaging technique for CT of the urinary tract is reviewed. The CT features of common urologic diseases, including ureterolithiasis, renal tumors and urothelial carcinomas are discussed.

The safety and efficacy of laparoscopic microwave ablation-assisted partial nephrectomy: a new avenue for the treatment of cystic renal tumors

PURPOSE

Clinically, the management of cystic renal masses is tricky. The study aims to evaluate the safety and efficacy of laparoscopic microwave ablation-assisted partial nephrectomy (LMAPN) for cystic renal tumors.

METHODS AND MATERIALS

Between November 2017 and January 2022, LMAPN was performed on 43 patients (29 men and 14 women; age range: 22-80 years; median age 54 years) with Bosniak category III (n = 15) or IV (n = 28) cystic renal tumors (size range: 1.2-5.0 cm; mean size 2.8 cm). The median follow-up period was 26 months (range: 7-56 months). Baseline and perioperative data, pathological features, renal function, postoperative complications and oncologic outcomes were collected and evaluated.

RESULTS

Forty-three cystic renal tumors were successfully managed by LMAPN. The mean operating time was 79 min (range: 40-130 min). The mean time of renal pedicle clamping was 19 min (range: 12-25 min). Mean intraoperative blood loss was 28.4 mL (range: 10-80 mL). The mean postoperative hospitalization duration was 4 days (range: 2-6 days). Negative surgical margins were diagnosed in all cases. During the follow-up, no patient appeared with distant metastasis, wound or peritoneal cavity implantation. No major but minor complications of Clavien-Dindo grade I were encountered after the operation. The 1-, 3- and 4-year overall survival rate was 100%, 96.6% and 88.5%, respectively.

CONCLUSION

This is the first study focusing on LMAPN for cystic renal tumors, demonstrating its favorable feasibility, safety and disease control. Long-term follow-up is necessary to draw conclusions on the preference and advantages of the new therapeutic approach.

Comparison of Differential Functional Outcomes After Partial Nephrectomy Between Moderate and High Complex Renal Tumor Evaluated with Diethylenetriamine Pentaacetic Acid Scan: A Propensity Score Matched Analysis

OBJECTIVE

The aim of this study was to compare functional outcomes after partial nephrectomy (PN) between moderate and high complex renal tumors evaluated with a diethylenetriamine pentaacetic acid (DTPA) scan [moderate vs. high: RENAL nephrometry score (RNS) 7-9 vs. 10-12].

METHODS

From January 2004 to December 2019, 471 patients with an RNS of 7-9 (moderate) and 164 patients with an RNS of 10-12 (high) who underwent PN were analyzed for renal function outcomes. The glomerular filtration rate (GFR) was measured using a DTPA scan and calculated the GFR using the Modification of Diet in Renal Disease (MDRD) formula, respectively. Trifecta/pentafecta outcome, recurrence-free survival, and overall survival were compared after propensity score matched analysis (PSMA).

RESULTS

After PSMA, 156 cases in each group were matched without significant difference in the preoperative factor. At the postoperative first year, there was no significant difference in the trifecta (p = 0.320), MDRD-based (p = 0.729), or DTPA-based pentafecta achievement rate (p = 0.964) between groups. At postoperative 5 years, DTPA-based total GFR (93.6% vs. 93.8%) and the operated kidney GFR preservation rate (89.9% vs. 81.7%) did not differ significantly (p > 0.05). Kaplan-Meier survival analysis showed no significant differences in survival outcomes (p > 0.05). Significant predictors of de novo chronic kidney disease (CKD) stage 3 or higher at the postoperative first year were age [hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.03-1.17, p = 0.005] and preoperative DTPA-based total GFR (HR 0.94, 95% CI 0.91-0.98, p = 0.001).

CONCLUSION

High complex tumors can be treated with PN without significant deterioration in renal function. The postoperative function of the operated kidney was preserved by up to 80% in the long term compared with the preoperative period. However, PN should be selectively performed with caution to avoid the occurrence of postoperative CKD.

The role of RENAL score in predicting complications after robotic partial nephrectomy

BACKGROUND

The aim of this study was to evaluate the association between tumor complexity based on RENAL nephrometry score and complications.

METHODS

We retrospectively identified 2555 patients who underwent RPN for renal cell carcinoma. Major complication was defined as Clavien Grade ≥3. The relationship between baseline demographic, clinical characteristics, perioperative and postoperative outcomes, and tumor complexity were assessed using ^χ2 test of independence, Fisher's Exact Test and Kruskal Wallis Test. An unadjusted and adjusted logistic regression model was used to assess the relationship between major complication and demographic, clinical characteristics, and perioperative outcomes.

RESULTS

There was a significant relationship between tumor complexity and WIT (P<0.001), operative time (P<0.001), estimated blood loss (P<0.001), and major complication (P=0.019). However, there was no relationship with overall complications (P=0.237) and length of stay (LOS) (P=0.085). In the unadjusted model, higher tumor complexity was associated with major complication (P=0.009). Controlling for other variables, there was no significant difference between major complication and tumor complexity (low vs. moderate, P=0.142 and high, P=0.204). LOS (P<0.001) and operative time (P=0.025) remained a significant predictor of major complication in the adjusted model.

CONCLUSIONS

Tumor complexity is not associated with an increase in overall or major complication rate after RPN. Experience in high-volume centers is demonstrating a standardization of low complications rates after RPN independent of tumor complexity.

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.

Nephrometry Scores: Can Preoperative Assessment of Sectional Imaging Really Mirror Intraoperative Renal Tumor Anatomy?

INTRODUCTION

To compare RENAL, preoperative aspects and dimensions used for an anatomical (PADUA) classification, and Mayo Adhesive Probability (MAP) scores with the respective intraoperative findings and surgeon's assessment in predicting surgical outcome of patients undergoing partial nephrectomy.

METHODS

Data of 150 eligible patients treated at the University Medical Center Mannheim between 2016 and 2018 were analyzed. Tumors were radiologically and intraoperatively assessed by PADUA, RENAL, and MAP scores and surgeon's assessment. Correlations and regression models were created to predict ischemia time (IT), major complications, and Trifecta (negative surgical margin, IT < 25 min, and absence of major complications).

RESULTS

There were strong correlations between radiological and intraoperative RENAL (r = 0.68; p < 0.001) and PADUA scores (r = 0.72; p < 0.001). Radiological RENAL, PADUA, and MAP scores and surgeon's assessment were independent predictors of Trifecta (OR = 0.71, p = 0.015; OR = 0.77, p = 0.035; OR = 0.65, p = 0.012; OR = 0.40, p = 0.005, respectively). IT showed significant associations with radiological RENAL, PADUA, and surgeon's assessment (OR = 1.41, p = 0.033; OR = 1.34, p = 0.044; OR = 3.04, p = 0.003, respectively). MAP score proved as only independent predictor of major complications (OR = 2.12, p = 0.002).

CONCLUSION

Radiologically and intraoperatively assessed scores correlated well with each other. Intraoperative nephrometry did not outperform radiological scores in predicting outcome confirming the value of the existing systems. MAP score correlates well with surgeon's assessment of perirenal fat and major complications underlining the importance of perirenal fat characteristics.

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.

Validation of radius exophytic/endophytic nearness anterior/posterior location and preoperative aspects and dimensions used for an anatomical nephrometric scores in patients undergoing partial nephrectomy for renal cancer: A single-center experience and literature review

Introduction:

Nephrometric scores are used to predict perioperative and postoperative complications, with no uniform results in the current literature.

Materials and Methods:

A retrospective study of 141 patients in a single center who underwent open partial nephrectomy between June 2006 and 2016 for T1a and T1b renal tumor was conducted. Univariate and multivariate analyses were used to evaluate the correlations between preoperative aspects and dimensions used for an anatomical (PADUA) and radius exophytic/endophytic nearness anterior/posterior location (RENAL) scores and their components with pre-, peri-, and post-operative parameters. Linear regression (F-tests) and logical regression models were used to test for significance of the association and predictability of outcomes.

Results:

Total RENAL score (P = 0.032), its components R (P = 0.004), E (P = 0.022), L (P = 0.011), and total PADUA score (P = 0.016) were significantly associated with ischemic time. In postoperative complications, the PADUA components: sinus line location (P = 0.008), lateral/medial rim score (P = 0.029), and collecting system score (P = 0.006) showed significance. None of the variables showed correlation with operation time and change in estimated glomerular filtration rate (eGFR). On multivariate analysis, sinus line location and gender (P = 0.012) showed significance in predicting eGFR changes and RENAL score component: A (P = 0.049) was significant in predicting estimated blood loss. Both RENAL and PADUA components were significantly associated with hospital length of stay.

Conclusion:

Both RENAL and PADUA scores showed important correlation in predicting outcomes. We further demonstrated the importance of knowing the individual components of the scores, which can independently give outcome predictions. The scoring systems can still be improved and standardized for broad clinical use with larger cohort and multicenter-based studies.

Renal Tumor Invasion Depth and Diameter are the Two Most Accurate Anatomical Features Regarding the Choice of Radical Versus Partial Nephrectomy

BACKGROUND AND AIMS

To evaluate simple tumor characteristics (renal tumor diameter and parenchymal invasion depth) compared with more complex classifications, that is, Renal Tumor Invasion Index (RTII) and Preoperative Aspects and Dimensions Used for an Anatomical classification, in predicting the type of nephrectomy (radical vs partial) performed.

MATERIAL AND METHODS

A total of 915 patients who had undergone either partial nephrectomy ( n = 388, 42%) or radical nephrectomy ( n = 527, 58%) were identified from the Helsinki University Hospital kidney tumor database between 1 January 2006 and 31 December 2014. Tumor maximum diameter and depth of invasion into the parenchyma were estimated from computed tomography or magnetic resonance imaging images and compared with Preoperative Aspects and Dimensions Used for an Anatomical and Renal Tumor Invasion Index. Logistic regression and receiver operating curves were used to compare the parameters at predicting the type of nephrectomy.

RESULTS AND CONCLUSION

All the anatomical variables of receiver operating curve/area under the curve analyses were significant predictors for the type of nephrectomy. Parenchymal invasion (area under the curve 0.91; 95% confidence interval, 0.89-0.93), RTII (area under the curve 0.91; 95% confidence interval, 0.89-0.93), and diameter (area under the curve 0.91; 95% confidence interval, 0.89-0.93) performed significantly better than Preoperative Aspects and Dimensions Used for an Anatomical classification (area under the curve 0.88; 95% confidence interval, 0.85-0.89). In multivariable analysis, invasion depth was the best predictor of nephrectomy type (percentage correct, 85.6%). Addition of one anatomic parameter into the model of non-anatomical cofactors improved the accuracy of the model significantly, but the addition of more parameters did not. Parenchymal invasion depth and tumor diameter are the most accurate anatomical features for predicting the nephrectomy type. All potential anatomical classification systems should be tested against these two simple characteristics.

Reproducibility and interobserver agreement of the R.E.N.A.L. nephrometry score: focus on imaging features

OBJECTIVE

To investigate the reproducibility and interobserver agreement for R.E.N.A.L. nephrometry scoring system.

MATERIALS AND METHODS

Two independent radiologists retrospectively analyzed 46 consecutive patients with renal masses, between 2008 and 2012, using the R.E.N.A.L. nephrometry score (RENAL-NS), which is based on the evaluation of five anatomical features of the tumor, as evaluated with computed tomography or magnetic resonance imaging: Radius, Exophytic/endophytic properties, Nearness to the collecting system, Anterior or posterior descriptor, and Location relative to the polar line. Tumor complexity was graded as low, intermediate, or high. The interobserver agreement was calculated for the total score and for the score for each parameter. Surgical excision of the tumors was used as the standard of reference.

RESULTS

The interobserver agreement for each of the RENAL-NS parameters, respectively, a hilar location, and the total score was 98%, 80%, 100%, 89%, 85%, 89%, and 93% of patients, corresponding to kappa values of 0.96, 0.65, 1.00, 0.75, 0.72, 0.78, and 0.88, respectively. The Nearness, Radius, and total score showed the best agreement. For the cases that were discordant in terms of the final score, no major implications in surgical planning were observed.

CONCLUSION

The RENAL-NS is a structured, useful system to assess the anatomical features of renal tumors. It is easily applicable and reproducible, even for less experienced radiologists.

Evaluation of the Clinical Use of Robot-Assisted Retroperitoneal Laparoscopy and Preoperative RENAL Scoring for Nephron Sparing Surgery in Renal Tumor Patients

The present study aims to compare the operative outcomes following the use of robot-assisted retroperitoneal partial nephrectomy (RARPN) with radius, exophytic/endophytic, nearness to sinus, anterior/posterior, and location (RENAL) scoring or laparoscopic retroperitoneal partial nephrectomy (LRPN) for the treatment of renal tumors. Eighty-three nephron-sparing surgery (NSS) procedures performed between January 2013 and December 2015 were reviewed. The study set consisted of 26 robot-assisted retroperitoneal laparoscopes, of which 3 were high risk (RENAL score ≥10), 11 were medium risk (RENAL score ≥7 < 9), and 12 were low risk (RENAL score <7) and 57 laparoscopic retroperitoneal partial nephrectomy procedures (7 high, 22 medium, and 28 low risk). All surgeries were successful in the absence of conversion or transfusion. Operative times were 96.0 ± 16.9 and 110.0 ± 19.4 min for RARPN and LRPN, respectively (P < 0.05). Warm ischemia times (WITs) were 17.6 ± 3.1 and 22.8 ± 3.5 min, respectively (P < 0.05). Estimated blood losses (EBLs) were 45 ± 15 and 97 ± 25 mL, respectively (P < 0.05). No statistical significance was found in duration of drainage, intestinal recovery time, hospital stay, serum creatinine, and perioperative complications (P > 0.05). RARPN affords significant advantages in outcomes of WIT, EBL, and recovery time over conventional LRPN owing to an increased accuracy in excision and suturing. Patients bearing high-risk renal tumors (RENAL score ≥10) are suitable candidates for RARPN.

Collaborative Review of Risk Benefit Trade-offs Between Partial and Radical Nephrectomy in the Management of Anatomically Complex Renal Masses

BACKGROUND

While partial nephrectomy (PN) is the recommended treatment for many small renal masses, anatomically complex tumors necessitate a clear understanding of the potential risks and benefits of PN and radical nephrectomy (RN).

OBJECTIVE

To critically review the comparative effectiveness evidence of PN versus RN; to describe key trade-offs involved in this treatment decision; and to highlight gaps in the current literature.

EVIDENCE ACQUISITION

A collaborative critical review of the medical literature was conducted.

EVIDENCE SYNTHESIS

Patients who undergo PN for an anatomically complex or large mass may be exposed to perioperative and potential oncologic risks that could be avoided if RN were performed, while patients who undergo RN may forgo long-term benefits of renal preservation. Decision-making regarding the optimal treatment with PN or RN among patients with anatomically complex or large renal mass is highly nuanced and must balance the risks and benefits of each approach. Currently, high-quality evidence on comparative effectiveness is sparse. Retrospective comparisons are plagued by selection biases, while the one existing prospective randomized trial, albeit imperfect, suggests that nephron-sparing surgery may not benefit all patients.

CONCLUSIONS

For anatomically complex tumors, PN preserves renal parenchyma but may expose patients to higher perioperative risks than RN. The risks and benefits of each surgical approach must be better objectified for identification of patients most suitable for complex PN. A prospective randomized trial is warranted and would help in directing patient counseling.

PATIENT SUMMARY

Treatment decisions for complex renal masses require shared decision-making regarding the risk trade-offs between partial and radical nephrectomy.

Utility of the RENAL index -Radius; Exophytic/endophytic; Nearness to sinus; Anterior/posterior; Location relative to polar lines- in the management of renal masses

CONTEXT

The growing incidence of renal masses and the wide range of available treatments require predictive tools that support the decision making process. The RENAL index -Radius; Exophytic/endophytic; Nearness to sinus; Anterior/posterior; Location relative to polar lines- helps standardise the anatomy of a renal mass by differentiating 3 groups of complexity. Since the introduction of the index, there have been a growing number of studies, some of which have been conflicting, that have evaluated the clinical utility of its implementation.

OBJECTIVE

To analyse the scientific evidence on the relationship between the RENAL index and the main strategies for managing renal masses.

ACQUISITION OF THE EVIDENCE

A search was conducted in the Medline database, which found 576 references on the RENAL index. In keeping with the PRISM Declaration, we selected 100 abstracts and ultimately reviewed 96 articles.

SYNTHESIS OF THE EVIDENCE

The RENAL index has a high degree of interobserver correlation and has been validated as a predictive nomogram of histological results. In active surveillance, the index has been related to the tumour growth rate and probability of nephrectomy. In ablative therapy, the index has been associated with therapeutic efficacy, complications and tumour recurrence. In partial nephrectomy, the index has been related to the rate of complications, conversion to radical surgery, ischaemia time, function preservation and tumour recurrence, a finding also observed in radical nephrectomy.

CONCLUSIONS

The RENAL index is an objective, reproducible and useful system as a predictive tool of highly relevant clinical parameters such as the rate of complications, ischaemia time, renal function and oncological results in the various currently accepted treatments for the management of renal masses.

Prospective assessment and histological analysis of adherent perinephric fat in partial nephrectomies

OBJECTIVES

The complexity of partial nephrectomy (PN) is partly anticipated by morphometric tumor-based scores that do not consider patient-related issues such as adherent perinephric fat (APF). Also, the objective is to prospectively assess the predictive factors of APF during PN, its effect on complications, and to correlate it to the histological reality.

METHODS

A total of 125 consecutive patients undergoing robotic or open PN were prospectively included. The Mayo adhesive probability score (MAP score) was compared to the peroperative presence of APF defined by a score≥2. Adipose tissue was analyzed histologically for fibrosis and inflammatory infiltrate of CD68+macrophages. Univariate and multivariate logistic regression analyses were performed to evaluate predictive factors of APF, and outcomes were compared using chi-square and Kruskal-Wallis tests.

RESULTS

APF was present in 51 patients (40.8%) and associated with slight longer operating time and increased blood loss. Warm ischemia time, margins, transfusion, and the Clavien-Dindo score were not different. In multivariate analysis, only male sex, age, waist circumference, fat density on computed tomography, and MAP score were significant predictors of APF. A radioclinical score was more predictive of APF than MAP score alone. Histologically, there was no macrophage infiltration but larger adipocytes in APF without significant differences in fibrosis.

CONCLUSIONS

APF can be accurately predicted using radioclinical data as the MAP score, combined with sex, age, and waist circumference. APF is associated with increased operative time and blood loss without postoperative complications. Histological analysis finds larger adipocytes in APF without inflammatory infiltrate, and no difference in fibrosis.

Predictive factors for complete renal tumor ablation using RFA

BACKGROUND

Radiofrequency ablation (RFA) can be used to treat renal masses in patients where surgery is preferably avoided. As tumor size and location can affect ablation results, procedural planning needs to identify these factors to limit treatment to a single session and increase ablation success.

PURPOSE

To identify factors that may affect the primary efficacy of complete renal tumor ablation with radiofrequency after a single session.

MATERIAL AND METHODS

Percutaneous RFA (using an impedance based system) was performed using computed tomography (CT) guidance. Fifty-two renal tumors (in 44 patients) were retrospectively studied (median follow-up, 7 months). Data collection included patient demographics, tumor data (modified Renal Nephrometry Score, histopathological diagnosis), RFA treatment data (electrode placement), and follow-up results (tumor relapse). Data were analyzed through generalized estimating equations.

RESULTS

Primary efficacy rate was 83%. Predictors for complete ablation were optimal electrode placement (P = 0.002, OR = 16.67) and increasing distance to the collecting system (P = 0.02, OR = 1.18). Tumor size was not a predictor for complete ablation (median size, 24 mm; P = 0.069, OR = 0.47), but all tumors ≤2 cm were completely ablated. All papillary tumors and oncocytomas were completely ablated in a single session; the most common incompletely ablated tumor type was clear cell carcinoma (6 of 9).

CONCLUSION

Optimal electrode placement and a long distance from the collecting system are associated with an increased primary efficacy of renal tumor RFA. These variables need to be considered to increase primary ablation success. Further studies are needed to evaluate the effect of RFA on histopathologically different renal tumors.

R.E.N.A.L. nephrometry score predicts postoperative recurrence of localized renal cell carcinoma treated by radical nephrectomy

Background

We investigated the association between the R.E.N.A.L. nephrometry score (RNS) and the postoperative recurrence of localized renal cell carcinoma (RCC).

Methods

We retrospectively analyzed a database comprising 91 patients with non-small localized RCC (pT1b–T2b) treated by radical nephrectomy at our hospital from January 2002 to March 2010. RNS was scored based on imaging findings at diagnosis. The Cox proportional hazards model was used to predict recurrence-free survival (RFS) and to calculate hazard ratio (HR).

Results

The median age at operation was 63 years (range, 30–85 years). Postoperative recurrence occurred in 19 patients (21 %). Median RNS sum was 9 (range, 5–11). High RNS sum (10–12) was significantly associated with RFS (P = 0.0012). Multivariate analysis revealed that high RNS sum [HR, 9.05; 95 % confidence interval (CI), 2.11–63.9; P = 0.0019] were significantly associated with RFS. Regarding each component of RNS, only the L component, which referred to tumor location relative to the polar line, was associated with RFS (HR, 15.0; 95 % CI, 2.68–396; P = 0.0006).

Conclusions

RNS was associated with RFS in cases of non-small localized RCC (pT1b–2b), thus supporting its utility as a prognostic factor.

Predicting length of stay after robotic partial nephrectomy

INTRODUCTION

To investigate factors predictive of length of stay (LOS) after robotic partial nephrectomy (RPN) in an effort to identify patients suitable for RPN with overnight stay at outpatient surgical facilities.

MATERIALS AND METHODS

Retrospective chart review of patients who underwent RPN at Memorial Sloan Kettering Cancer Center from January 2007 to July 2012 was conducted. Univariate and multivariate analyses were performed to identify the main predictors of LOS. The discrimination of the multivariate model was measured using the area under the curve (AUC); tenfold cross-validation was performed to correct for over-fit.

RESULTS

One hundred and eighty-six patients were included in the analysis; 84 (45 %) had LOS of ≤1 day (median LOS 2 day; interquartile range 1-2). On univariate analysis, preoperative variables associated with LOS > 1 included larger tumors (P < 0.0001), lower estimated glomerular filtration rate (P = 0.003), older age (P = 0.006), female gender (P = 0.035), and higher comorbidity score (P = 0.015); operative variables associated with LOS > 1 day included greater estimated blood loss (P < 0.0001) and longer operative (P < 0.0001) and ischemia (P < 0.0001) times. The AUC of the preoperative model was 0.61 (95 % CI 0.52-0.69) after tenfold cross-validation.

CONCLUSIONS

LOS after RPN is influenced by age, gender, medical comorbidities, and tumor size. However, when analyzed retrospectively, these factors had limited ability to predict LOS after RPN with sufficient accuracy to develop a prediction tool.

Multidetector CT imaging of complications after laparoscopic nephron-sparing surgery

Purpose

Laparoscopic nephron-sparing surgery (L-NSS) is increasingly performed to treat localised renal lesions. However, the associated morbidity is non-negligible, with a rate of major complications approaching 10 %.

Methods and Results

This paper provides an overview of indications, surgical techniques and results of L-NSS; explains the incidence, risk factors and manifestations of postoperative complications; discusses the preferred multidetector computed tomography (CT) acquisition techniques; illustrates the appearance of normal postoperative images following L-NSS; and reviews, with example images, the most common and unusual iatrogenic complications. These include haematuria, haemorrhage, vascular injuries, infections and urinary leaks. Most emphasis is placed on CT, which provides rapid, reliable triage and follow-up of iatrogenic complications after L-NSS, identifying occurrences that require transarterial embolisation or repeated surgery.

Conclusions

Multidetector CT allows precise assessment of the surgical resection site; detection of pneumoperitoneum and subcutaneous emphysema; quantification of retroperitoneal blood; and identification of active bleeding, pseudoaneurysms, arterio-venous fistulas, abscess collections and extravasated urine.

Teaching Points

• Laparoscopic nephron-sparing surgery (NSS) is increasingly performed to treat renal lesions.

• Radiologists are increasingly requested to investigate suspected post-surgical NSS complications.

• Post-NSS complications include haemorrhage, haematuria, vascular injuries, infections and urinary leaks.

• Multidetector CT allows choice between conservative treatment, transarterial embolisation or surgery.

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.

Analysis of the impact of adherent perirenal fat on peri-operative outcomes of robotic partial nephrectomy

INTRODUCTION

Adherent perirenal fat (APF) can be defined as inflammatory fat sticking to renal parenchyma, whose dissection is difficult and makes it troublesome to expose the tumour. Our objective was to evaluate the impact of APF on the technical difficulty of robot-assisted partial nephrectomy (RPN).

PATIENTS AND METHODS

We analysed data of 202 patients who underwent RPN for a small renal tumour. Patients were divided into two groups according to the presence of APF. Peri-operative data were compared between the two groups. Predictors of APF were evaluated by univariate and multivariate analysis. The validity of the MAP score (radiological scoring system) was also assessed.

RESULTS

APF was observed in 80 patients (39.6 %). Tumour complexity and surgeon's experience were similar between both groups. Operative time was 40 min longer in the APF group (188.5 vs. 147.9 min, p < 0.0001). Blood loss was twice higher, and transfusions were more common in the APF group (694 vs. 330 ml, p < 0.0001 and 19 vs. 5.8 %, p = 0.003, respectively). APF was associated with an increased risk of conversion to open surgery (11.2 vs. 0 %, p = 0.0002) or radical nephrectomy (6.2 vs. 0.8 %, p = 0.03). In multivariate analysis, male gender (OR 13.2, p < 0.0001), obesity (OR 1.2, p = 0.007), hypertension (OR 3.7, p = 0.02), and MAP score (OR 3.3; p < 0.0001) were significant predictors of APF.

CONCLUSION

During RPN, APF is associated with increased bleeding and a higher risk of conversion to open surgery and to radical nephrectomy. Male gender, hypertension, obesity, and MAP score are predictors of APF.

The association between renal tumour scoring system components and complications of partial nephrectomy

INTRODUCTION

We evaluate the associations between 3 renal tumour scoring systems and their components with perioperative complications of partial nephrectomy.

METHODS

A consecutive cohort of partial nephrectomy patients was analyzed. Patient characteristics were abstracted from medical records. PADUA scores (preoperative aspects and dimensions used for anatomic classification), RENAL (radius exophyic/endophytic nearness anterior/posterior location scoring) nephrometry scores, and Centrality index (C-index) were determined from preoperative axial images by 2 independent reviewers. Cases were evaluated for postoperative complications up to 30 days after surgery. Pre-specified complication definitions were used for 33 potential medical and surgical complications. Unadjusted and adjusted associations between overall scores, individual components, and complications were determined using log binomial regression.

RESULTS

In total, 118 patients were included in the study. Of these, 36 (30.5%) surgical complications occurred in 27 (22.9%) patients. Fourteen (11.9%) were Clavien grade ≥3. Overall PADUA score was significantly associated with surgical and overall complications after adjusting for potential confounders. Among all components of the 3 scoring systems, only tumour diameter and exophytic/endophytic nature of the tumour were significantly associated with complications after adjusting for the other components of the respective scoring system (p < 0.05).

CONCLUSIONS

Renal tumour scoring systems may help predict the risk of complications after partial nephrectomy. Further refinement of current systems is required. A first step would be to include only components that are significantly associated with complications.

Prediction of complications after partial nephrectomy by RENAL nephrometry score

INTRODUCTION

Discussing and planning the appropriate management for suspicious renal masses can be challenging. With the development of nephrometry scoring methods, we aimed to evaluate the ability of the RENAL nephrometry score to predict both the incidence of postoperative complications and the change in renal function after a partial nephrectomy.

METHODS

This was a retrospective study including 128 consecutive patients who underwent a partial nephrectomy (open and laparoscopic) for renal lesions in a tertiary UK referral centre. Univariate and multivariate ordinal regression models were used to identify associations between Clavien-Dindo classification and explanatory variables. The Kendall rank correlation coefficient was used to examine an association between RENAL nephrometry score and a drop in estimated glomerular filtration rate (eGFR) following surgery.

RESULTS

An increase in the RENAL nephrometry score of one point resulted in greater odds of being in a higher Clavien-Dindo classification after controlling for RENAL suffix and type of surgical procedure (odds ratio [OR]: 1.29, 95% confidence interval [CI]: 1.04-1.64, p=0.043). Furthermore, a patient with the RENAL suffix 'p' (ie posterior location of tumour) had increased odds of developing more serious complications (OR: 2.60, 95% CI: 1.07-6.30, p=0.042). A correlation was shown between RENAL nephrometry score and postoperative drop in eGFR (Kendall's tau coefficient -0.24, p=0.004).

CONCLUSIONS

To our knowledge, this is the first study that has shown the predictive ability of the RENAL nephrometry scoring system in a UK cohort both in terms of postoperative complications and change in renal function.

Significant impact of R.E.N.A.L. nephrometry score on changes in postoperative renal function early after robot-assisted partial nephrectomy

BACKGROUND

Our objective was to evaluate the significance of the R.E.N.A.L. nephrometry score (RNS)--developed to quantitatively evaluate the complexity of renal tumors in a reproducible manner--in perioperative and renal functional outcomes following robot-assisted partial nephrectomy (RAPN).

METHODS

This study assessed 48 consecutive patients with renal tumors who underwent RAPN. Preoperative RNS for each patient was calculated, and its impact on several parameters associated with perioperative outcomes, including postoperative renal function, was investigated with Spearman's rank correlation test.

RESULTS

Mean RNS in the 48 patients was 6.8; of these 48 patients, 21 (43.7%), 24 (50.0%), and three (6.3%) were classified into low-, moderate-, and high-complexity groups, respectively. The RNS was significantly correlated with resected tumor weight and postoperative changes in estimated glomerular filtration rate (eGFR) at both 1 and 4 weeks--but not age, body mass index (BMI), preoperative eGFR, operative time, warm ischemia time, estimated blood loss, postoperative complications, or eGFR-- after RAPN. No component of the RNS (R: radius; E: exophytic/endophytic properties; N: nearness of tumor to the collecting system or sinus; A: anterior/posterior; L: location relative to polar lines) alone had a significant impact on postoperative changes in eGFR at 1 and 4 weeks, whereas resected tumor weight was significantly associated with the R and E subcategories.

CONCLUSIONS

Measurement of total RNS is useful for predicting renal functional outcomes early after RAPN.

Warm ischemia time and postoperative complications after partial nephrectomy for renal cell carcinoma

OBJECTIVE

To evaluate the correlations between PADUA and RENAL scores, WIT and postoperative complications in a cohort of patients who underwent elective open or minimally invasive nephron sparing surgery for renal cell carcinoma.

MATERIAL AND METHODS

We analyzed 96 consecutive patients who underwent partial nephrectomy for renal cell carcinoma between 2004 and 2013 at our Institution. The Spearman test was used to compare categorical variables. For all statistical analyses, a two-sided P < .05 was considered statistically significant.

RESULTS

The median (IQR) PADUA score was 7 (7-8) and the median (IQR) RENAL score was 7 (6-8). The median (IQR) warm ischemia time was 14 min (8-20). Low grade and high grade postoperative complications were found in 27 (28.1%) and 6 (6.3%) patients, respectively. PADUA risk group categories significantly correlated with WIT > 20 minutes and high grade postoperative complications, respectively (P = .04), regardless of the surgical approach. RENAL risk group categories significantly predicted longer hilar clamping time in our cohort (P = .04), but no statistically significant correlations with high grade postoperative complications were found.

CONCLUSIONS

In our retrospective series nephrometric scores demonstrated to significantly predict longer warm ischemia time and higher postoperative complications, especially in those patients with more challenging and complex renal tumors. Therefore, when planning to perform partial nephrectomy, urologists should widely use these comprehensive tools.

R.E.N.A.L. Nephrometry scoring: how well correlated are urologist, radiologist, and collaborator scores?

PURPOSE

R.E.N.A.L. Nephrometry Score (NS) is an imaging-based (CT/MRI) scoring system commonly used by urologists to standardize the reporting of renal masses by enabling quantification of anatomical characteristics. We sought to examine the inter-rater correlation of NS between urologists, radiologists, and tumor-board collaborators.

METHODS

We identified adult patients undergoing partial or radical nephrectomy over 10 years (n=2450). Patients with autosomal dominant polycystic kidney disease (ADPKD), metastatic disease, masses >10 cm, and studies in which the study urologists or radiologists partook in patient care were excluded. Preoperative imaging was evaluated and patients with multiphasic CT available were included. Scans were provided to the reviewers to evaluate with a R.E.N.A.L. nephrometry questionnaire. Results were analyzed using kappa correlation coefficients.

RESULTS

One hundred twenty patients met inclusion criteria with mean age of 59.5 years. The majority of cases were partial nephrectomies (72%). Eighty-five percent of the tumors were malignant, with 26% having high-grade histology. The mean (standard deviation) overall NS was 6.8 (1.9) with fair correlation among reviewers (κ=0.222). Collaborators had the highest inter-rater correlation, ranging from 0.41 to 0.84 for NS component scores, compared with 0.42-0.85 for radiologists and 0.36-0.86 for urologists. "R" scores were best correlated (κ>0.8). NS correlation ranged between 0.16 and 0.31 for the groups while the NS complexity category correlation ranged between 0.50 and 0.61.

CONCLUSIONS

Despite being naive to NS, inter-radiologist scoring patterns were better correlated than inter-urologist. The urologist and radiologist collaborating in tumor board showed the highest agreement, suggesting that a multidisciplinary approach in the characterization of renal masses may provide benefit to patient management.

Laparoscopic radical and partial nephrectomy: The clinical efficacy and acceptance of the techniques

The laparoscopic approach has been established as the surgical procedure of choice for radical nephrectomy during the recent years. The advantages of the laparoscopic radical nephrectomy in comparison to the open approach are well-documented. The oncological results of the laparoscopic approach are similar to the open procedure while the post-operative morbidity is lower. Laparoscopic partial nephrectomy seems to gain ground to its open counterpart, as the accumulation of experience in the technique grows. In this review, a PubMed search in the latest literature on radical and partial laparoscopic nephrectomy took place and the outcome of the search is presented. Several issues about the surgical techniques and clinical efficacy are discussed. In addition, the preliminary experience in laparoscopic nephrectomy of one of the authoring institutions is also presented.

Factors Influencing the Operative Approach to Renal Tumors: Analyses According to RENAL Nephrometry Scores

Purpose

To evaluate the relationship between RENAL nephrometry score (RNS) and operative approach for renal masses.

Materials and Methods

This study included 206 consecutive patients who underwent renal tumor surgery between January 2008 and October 2012. We divided the patients into four groups by surgical approach: open radical nephrectomy (ORN, 53 patients), laparoscopic radical nephrectomy (LRN, 83 patients), open partial nephrectomy (OPN, 31 patients), and laparoscopic partial nephrectomy (LPN, 39 patients). We retrospectively assessed the RNS for each surgery group and evaluated the relationship between this score and operative approach.

Results

The mean RNSs of the ORN, LRN, OPN, and LPN groups were 9.75, 8.35, 6.72, and 5.76, respectively. When the RNS was analyzed according to nephron-sparing, the mean RNSs of the RN groups (ORN and LRN) and the PN groups (OPN and LPN) were significantly different (8.89 and 6.09, respectively; p<0.001). All the individual components of the RNS were significantly different between RN and PN. In the RN groups, the criteria for open versus laparoscopic surgery were based on tumor size ('R' score=2.43 for open, 1.54 for laparoscopic, p<0.001) and tumor location relative to the polar line ('L' score=2.55 for open, 2.09 for laparoscopic, p=0.006). In the PN groups, the criteria for open or laparoscopic surgery were based only on exophytic/endophytic property ('E' score=1.87 for open, 1.41 for laparoscopic, p=0.046).

Conclusions

The RNS was significantly different in all surgery groups. The decision to take a laparoscopic approach was primarily influenced by the R and L scores for RN and by the E score for PN.

Clinical analysis of the PADUA and the RENAL scoring systems for renal neoplasms: a retrospective study of 245 patients undergoing laparoscopic partial nephrectomy

OBJECTIVE

To investigate the clinical significance of preoperative aspects and dimensions used for anatomic (PADUA) and radius exophytic/endophytic nearness anterior/posterior location (RENAL) scoring systems for renal neoplasms in patients undergoing laparoscopic partial nephrectomy.

METHODS

A retrospective analysis was carried out on clinical data of 245 Chinese patients with renal neoplasms undergoing laparoscopic partial nephrectomy from June 2008 to June 2012. The perioperative complications and variables, as well as PADUA and RENAL score, were compared.

RESULTS

The PADUA and RENAL scoring systems were significantly associated with percent change in estimated glomerular filtration rate (P = 0.032 and P = 0.026 respectively), whereas the RENAL scoring system was also significantly associated with warm ischemia time (P = 0.032). On multivariate analysis, both scores were able to predict percent change in estimated glomerular filtration rate (PADUA, P = 0.011; RENAL, P = 0.028). There were no significant associations between the two scoring systems assessed and the occurrence of complications or tumor stage. The correlation between PADUA classification and RENAL nephrometry score was significant (P < 0.0001). Fleiss' generalized kappa was 0.69-0.89 for the various components of the PADUA score and 0.67-0.89 for the RENAL nephrometry components.

CONCLUSIONS

The PADUA classification and RENAL nephrometry score are comprehensive assessment tools for delineating renal tumor anatomy. The reproducibility of the PADUA and RENAL scores is substantial, but further research is required to evaluate its performance in more accurately predicting operative and patient-related outcomes.