Predicting Strict Trifecta Outcomes after Robot-Assisted Partial Nephrectomy: Comparison of RENAL, PADUA, and C-Index Scores

Nephrometry scores are designed to characterize tumors and stratify the surgical complexity. It remains unclear as to which nephrometry score can accurately predict the surgical outcomes. We aimed to assess the utility of radius, exophytic/endophytic, nearness, anterior/posterior, location (RENAL), preoperative aspects and dimensions used for anatomic classifications (PADUA), and centrality index (C-index) nephrometry scores for predicting the strict Trifecta achievement from a single institution series robotic-assisted partial nephrectomy (RAPN). We retrospectively identified the prospectively maintained robotic surgery database records of 91 patients who underwent RAPN between June 2015 and September 2020 in Antalya Training and Research Hospital. The main outcome of the study was the achievement of strict Trifecta (negative surgical margin, no major urologic complications, warm ischemia time ≤25 min, and ≥85% preservation of estimated glomerular filtration rate). A multivariable analysis was performed to identify the factors of strict Trifecta success. The mean patient age was 55.82 ± 13.37 years with a median clinical tumor size of 3.5 cm (IQR 2.5–4.9). The median RENAL, PADUA, and C-index score were 7(IQR 6–8), 8(IQR 7–10), and 2.01(IQR 1.64–2.72), respectively. A strict Trifecta could be achieved in 54 patients (59.3%). Clinical tumor size (P = 0.011), RENAL risk groups (low:reference; intermediate; P = 0.040; high; P = 0.009), PADUA risk groups (low:reference; intermediate; P = 0.044; high; P = 0.001) and C-index risk groups (low:reference; high; P = 0.015) were the independent predictors of strict Trifecta attainment in the multivariate analysis. None of the nephrometry scores were a superior predictor compared to other nephrometry scores in comparative analysis. RENAL, PADUA, and C-index scores were all independent predictors of a strict Trifecta achievement. Our comprehensive comparison of the three scores identified that none of the nephrometry scores proved to be inferior to others nephrometry scores.

Parallel comparison of R.E.N.A.L., PADUA, and C-index scoring systems in predicting outcomes after partial nephrectomy: A systematic review and meta-analysis

Objective

To parallelly compare the applicability of the radius, exophytic/endophytic, nearness, anterior/posterior, location nephrometry score (R.E.N.A.L.), the Preoperative Aspects and Dimensions Used for an Anatomical (PADUA), and the centrality index (C‐index) scoring systems in predicting clinical outcomes after partial nephrectomy (PN).

Methods

We searched EMBASE, PubMed, Ovid, and Web of Science to perform a meta‐analysis examining the correlation coefficients between three nephrometry scores (NSs) and warm ischemia time (WIT), estimated blood loss (EBL), operation time (OT), length of stay (LOS), and absolute change in eGFR (ACE) up to 25 January 2021.

Results

In total, 13 studies including 1496 patients met the criteria for further analysis. Overall, all scoring systems had statistically significant correlations with the WIT, EBL, OT, ACE and LOS and ACE, except for the correlation between PADUA and LOS (r = 0.16 [−0.00, 0.31], p > 0.05). The C‐index had the strongest correlation with WIT (r = −0.35 [−0.43, −0.26], p < 0.05) and ACE (r = −0.29 [−0.48, −0.10], p < 0.05). Weak correlations were observed between OT as well as EBL and each scoring system. Publication bias was observed in PADUA score predicting ACE (p = 0.04) and high heterogeneity was found in some of our results.

Conclusion

Until now, this is the first meta‐analysis that parallelly compares these three scoring systems in predicting outcomes after PN. We found that all NSs showed a statistically significant correlation with WIT, EBL, OT, and ACE. Moreover, the C‐index scoring system is the best predictor of WIT and ACE. Due to the existence of publication bias and high heterogeneity, more well‐designed and large‐scale studies are warranted for validation.

To our knowledge, this is the first meta‐analysis that parallelly compares these three scoring systems in predicting outcomes after PN. Overall, three scoring systems were significantly correlated with WIT, EBL, OT and ACE. Moreover, the C‐index scoring system outperformed R.E.N.A.L. and PADUA scoring systems in WIT and ACE.

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.

Simplified PADUA Renal (SPARE) Nephrometry Scoring System: External Validation, Interobserver Variability, and Comparison with RENAL and PADUA in a Single-center Robotic Partial Nephrectomy Series

BACKGROUND

The RENAL (radius [R], exophytic/endophytic [E], nearness to collecting system/sinus [N], anterior/posterior [A], and location relative to polar lines [L]) and the PADUA (preoperative aspects and dimensions used for an anatomical classification) scores help in quantifying tumor complexity. However, nephrometry scoring systems have low interobserver variability. To simplify and improve score reproducibility, a new Simplified PADUA Renal (SPARE) scoring system was introduced.

OBJECTIVE

To externally validate the SPARE nephrometry scoring system and to determine its interobserver variability.

DESIGN, SETTING, AND PARTICIPANTS

A total of 202 patients were included in the analysis. We performed a retrospective analysis of robot-assisted partial nephrectomy (RAPN) cases for a single renal mass performed at a single academic institution during the period 2008-2018. For each renal mass, PADUA, RENAL, and SPARE nephrometry scores were calculated.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Three urology residents (URs), two urology attendings (UAs), two radiology residents (RRs), and one radiology attending (RA) retrospectively reviewed computed tomography scans blinded to clinical outcomes. The accuracy of the SPARE nephrometry score in the prediction of any complication (Clavien grade ≥1) was compared with other scoring systems in a univariable and a multivariate fashion. The area under the curve (AUC) and kappa statistics were used to assess interobserver variability of the SPARE score.

RESULTS AND LIMITATIONS

The SPARE score was not inferior to the PADUA and RENAL scores (AUC 0.61, 0.59, and 0.57, respectively, p = 0.43). Patients with intermediate to high SPARE scores had longer operative time (158 vs 135 min, p = 0.10) and a higher rate of complications (28% vs 14%, p = 0.012). Univariable analysis predicting overall complications showed that RRs performed slightly better than URs and UAs using the SPARE score. Interobserver agreement was 84% between an RA and an RR (kappa 0.42), 85% between an RA and a UA (kappa 0.39), and 85% between an RA and a UR (kappa 0.45).

CONCLUSIONS

These findings confirm that the SPARE nephrometry scoring system is a reproducible and easy tool offering overall fair interobserver agreement regardless of years of training or type of practice, while maintaining the predictive capabilities of more established nephrometry scores.

PATIENT SUMMARY

In this study, a novel and simple classification system was assessed using a sample of cases from our institution to define surgical complexity renal masses detected on radiological imaging. Our findings suggest that this tool can be useful in clinical practice to facilitate the characterization of renal masses and predict the complications of surgical treatment.

The superiority of contact surface area as a predictor of renal cortical volume change after partial nephrectomy compared to RENAL, PADUA and C-index: an approach using computed tomography-based renal volumetry

Objective: To evaluate the renal cortical volume (RCV) change after nephron sparing surgery and the predictive value of the nephrometry score in RCV preservation after partial nephrectomy. Materials and methods: Overall, 162 patients with renal tumors that were treated with open partial nephrectomy were retrospectively analyzed. The contact surface area (CSA), RENAL, PADUA and C-index scores were obtained from a preoperative CT scan. The RCV of the tumor-bearing kidney was measured preoperatively and postoperatively using dedicated software. The correlation between the four nephrometry scores and perioperative parameters were evaluated and the scores were compared in terms of their ability to predict a reduction in the RCV. Results: All scores showed a significant association with reduction in RCV (all p < 0.001), percent reduction in RCV (all p < 0.001) and estimated blood loss (all p < 0.05). Only the CSA and PADUA scores showed a significant association with percent reduction in eGFR (p = 0.038 and p = 0.026, respectively). On multivariate analysis, the CSA, PADUA and C-index scores independently affected the percent reduction in RCV (p = 0.003, p = 0.025 and p = 0.013, respectively). On ROC curve analysis, CSA was a better independent predictor of a greater than 10% and 20% reduction in the RCV (AUC 0.87 and 0.72, respectively). Conclusion: CT-based RCV measurement successfully differentiated the RCV change after partial nephrectomy. Compared to the other three nephrometry scores, CSA was a superior predictor of RCV change in the operated kidney.

The role of RENAL, PADUA and C-index scoring systems in predicting the results of partial nephrectomy without ischemia

OBJECTIVE

To evaluate the feasibility and renoprotective effect of off-clamp partial nephrectomy (PN) by renal scoring systems.

METHODS

After approval of the local ethics committee, the radiological and clinical data of patients with renal masses who underwent PN between January 2012 and January 2017 were evaluated in two university hospitals. Total 132 patients who underwent open surgery and off-clamp technique were included. All patients underwent contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) preoperatively. Preoperative demographic data, estimated glomerular filtration rate (e-GFR) and hematocrit changes, operation time, tumor volume and hospitalization time from patients were evaluated separately and statistically for each of the three scoring systems.

RESULTS

Our study consisted of 132 patients with a mean age of 53.9 ± 13.9 with 69 male and 63 female. Statistically significant difference between the risk groups in RENAL and PADUA scoring were found according to tumor T stage and tumor volüme (p <0.005). Statistically significant difference was only found between risk groups of RENAL scoring system in e-GFR reduction (p<0.05). There was no statistically significant difference between the groups in the complications of all three classification systems (p > 0.005).

CONCLUSIONS

In our study, all three scoring sytem successfully predicted the surgical complexity ve surgical outcomes and our results indicate that off-clamp PN has similar success and complications rates when compared to the literature. The off-clamp PN must be kept in mind to maintain postoperative renal functions eligible patients.

Are there limits of robotic partial nephrectomy? TRIFECTA outcomes of open and robotic partial nephrectomy for completely endophytic renal tumors

BACKGROUND

To compare the outcomes of robot-assisted (RAPN) and open partial nephrectomy (OPN) for completely endophytic renal tumors.

METHODS

Consecutive patients undergoing OPN or RAPN for entirely endophytic tumors in four high-volume centers between 2008 and 2016 were identified. Endophytic masses were identified based on sectional imaging. Patient characteristics and surgical outcome were compared using Mann-Whitney-U-test and chi-squared-tests. Uni- and multivariate analyses were performed to identify predictors of TRIFECTA achievement and excisional volume loss.

RESULTS

Out of 1128 patients, 10.9% (64) of RAPN and 13.9% (76) of OPN underwent surgery for entirely endophytic tumors. Operative time was longer for RAPN (169 vs 140 min, P = 0.03) while ischemia time was shorter (13 vs 18 min, P = 0.001). Complication rates were comparable (21% OPN vs 22% RAPN, P = 0.91) and TRIFECTA achievement was not different between the groups (68% OPN vs 75% RAPN, P = 0.39). In multivariate analyses type of surgery was not associated with TRIFECTA achievement or excisional volume loss. Here, only tumor complexity (OR 0.48, P = 0.001) and size (OR 1.01, P = 0.002) were independent predictors.

CONCLUSION

For entirely endophytic tumors, both RAPN and OPN offer good TRIFECTA achievement. This encourages the use of NSS even for these highly complex tumors using the surgeon's preferred approach.

Nephrometry Scores: The Effect of Imaging on Routine Read-out and Prediction of Outcome of Nephron-sparing Surgery

BACKGROUND/AIM

This study investigated the impact of available preoperative imaging on the reliability and predictive accuracy of RENAL and PADUA nephrometry-scoring systems for renal tumors.

PATIENTS AND METHODS

Five urologists determined RENAL and PADUA scores using preoperative imaging data (computed tomography and magnetic resonance imaging) of 100 patients admitted for partial nephrectomy with the following combinations: T0: transverse planes without excretory phase (EP), TC0: transverse and coronal planes without EP, TC1: transverse and coronal planes with EP. Reference standard was obtained by a uro-radiologist. Ischemia time was used as surrogate for surgical complexity.

RESULTS

Assignment of EP significantly reduced interobserver-variability among urologists (p<0.0001). Predictive accuracy for surgical complexity or correct assignment to nephrometry risk groups did not depend on image planes or EP.

CONCLUSION

Interobserver variability, but not predictive accuracy of nephrometric systems, is affected by additional usage of EP.

External validation of four nephrometry scores for trans-peritoneal robotic partial nephrectomy

Introduction

External validation of four nephrometry scores (NS): Centrality index (C-index), arterial based complexity (ABC), preoperative aspects and dimensions used for an anatomical (PADUA) and radius expohytic/endophytic nearness anterior/posterior location (RENAL) scoring systems in patients who have undergone trans-peritoneal robotic assisted partial nephrectomy (RAPN).

Material and methods

A prospective database for RAPN has been maintained. Individual NSs were performed on 3-dimensional reconstructions of MDCT/MRI studies retrospectively by a board certified uroradiologist. Univariate Cox Proportional-Hazard Regression Analysis was performed for each NSs to valuate its predictability for the following parameters: Warm Ischemia Time (WIT), Estimated Blood Loss (EBL), Operative Time (OT), Complication Rates and Positive Margin Rates.

Results

78 RAPNs were performed for suspected renal malignancies. The mean OT, EBL and WIT time was 186.5 minutes (SD - 33.8), 125.5 mls (SD - 188.91) and 16.7 minutes (SD - 5.6) respectively. The overall complication rate was 20.5% (16/78) of which only 2.6% (2/78) were Clavien Grade 3 or higher complications. The mean change in creatinine change at Day - 1 was 12.54 μmol/L (SD - 18.05). On the Cox regression analysis only the Centrality index predicted prolonged WIT with statistical significance: C-Index (0.02), ABC (0.2), PADUA (0.2), RENAL (0.9). ABC predicted operative time with statistical significance: C-index (0.45), ABC (0.0004), PADUA (0.25), RENAL (0.3). None of the NSs could predict overall complication: C-index (0.5), ABC (0.2), PADUA (0.13), RENAL (0.5). None of the NSs predicted EBL: C-index (0.3)0, ABC (0.8), PADUA (0.2), RENAL (0.7). None of the NSs predicted Positive Margin Rates: C-index (0.4), ABC (0.4), PADUA (0.9), RENAL (0.8).

Conclusions

C-index was able to predict prolonged WIT. ABC was a strong predictor of OT. PADUA and RENAL were poor predictors for all measured parameters.

Identifying molecular genetic features and oncogenic pathways of clear cell renal cell carcinoma through the anatomical (PADUA) scoring system

Although the preoperative aspects and dimensions used for the PADUA scoring system were successfully applied in macroscopic clinical practice for renal tumor, the relevant molecular genetic basis remained unclear. To uncover meaningful correlations between the genetic aberrations and radiological features, we enrolled 112 patients with clear cell renal cell carcinoma (ccRCC) whose clinicopathological data, genomics data and CT data were obtained from The Cancer Genome Atlas (TCGA) and The Cancer Imaging Archive (TCIA). Overall PADUA score and several radiological features included in the PADUA system were assigned for each ccRCC. Despite having observed no significant association between the gene mutation frequency and the overall PADUA score, correlations between gene mutations and a few radiological features (tumor rim location and tumor size) were identified. A significant association between rim location and miRNA molecular subtypes was also observed. Survival analysis revealed that tumor size > 7 cm was significantly associated with poor survival. In addition, Gene Set Enrichment Analysis (GSEA) on mRNA expression revealed that the high PADUA score was related to numerous cancer-related networks, especially epithelial to mesenchymal transition (EMT) related pathways. This preliminary analysis of ccRCC revealed meaningful correlations between PADUA anatomical features and molecular basis including genomic aberrations and molecular subtypes.