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

Can Simplified PADUA Renal (SPARE) Nephrometry scoring system help predict renal function outcomes after robot-assisted partial nephrectomy? (UroCCR study 93)

BACKGROUND

The SPARE Nephrometry Score (NS) is described as easier to implement than the RENAL and PADUA NSs, currently more widely used. Our objective was to compare the accuracy of SPARE NS in predicting renal function outcomes following RAPN.

METHODS

A multicentric retrospective study was conducted using French kidney cancer network (UroCCR, NCT03293563) database. All patients included had RAPN for cT1 renal tumors between May 2010 and March 2021. SPARE was compared to RENAL, PADUA and Tumor Size to predict postoperative acute kidney injury (AKI), chronic kidney disease (CKD) upstaging, de novo CKD at 3-6 months follow-up and Trifecta failure. The ability of the different NSs and tumor size to predict renal function outcomes was evaluated using uni- and multivariate logistic regression models.

RESULTS

According to our study criteria, 1171 patients were included. Mean preoperative tumor size and estimated glomerular filtration rate (eGFR) were 3.4±1.4 cm and 85.8 mL/min/1.73 m2. In total, 266 (22.7%), 87 (7.4%), 94 (8%), and 624 (53.3%) patients had AKI, de novo CKD, CKD upstaging, and Trifecta failure, respectively. In multivariate analysis, all three NSs and tumor size were independent predictors of AKI, CKD de novo, CKD upgrade and Trifecta failure. There was no significant difference between all three NS and tumor sizes in predicting renal function outcomes.

CONCLUSIONS

SPARE Score seems to be a valid alternative to predict renal function outcomes after RAPN. Nevertheless, in our study, tumor size was as accurate as NSs in predicting postoperative outcomes and, therefore, seems to be the logical choice for surgical decisions.

Nephrometric scoring system: Recent advances and outlooks

A nephrometry scoring system is a key standard to evaluate the feasibility of partial nephrectomy (PN). Whether based on two-dimensional or three-dimensional images, simplicity, effectiveness, and practicality are the keys to the nephrometric scoring system. Since the emergence of RENAL score in 2009, numerous scoring systems based on different anatomical parameters are established to seek accurately and few parameters to assess the risk of PN and complications. This study aimed to achieve a three-game winning streak in PN more easily and efficiently (negative resection margin, maximum preservation of normal nephron function, and avoiding short-term and long-term complications). Using PubMed, we counted 28 kinds of nephrometric scoring systems. We considered only English literatures published and excluded editorials, commentaries, and meeting abstracts. To the best of our knowledge, this is to date and most comprehensive summary as well as an outlook of the nephrometric scoring system.

Combination of holographic imaging with robotic partial nephrectomy for renal hilar tumor treatment

OBJECTIVES

To evaluate the clinical value of the holographic imaging technology in combination with robotic-assisted partial nephrectomy (RAPN) for renal hilar tumor treatment.

PATIENTS AND METHODS

From Dec. 2018 to Dec. 2021, patients diagnosed with renal hilar tumor were included in this retrospective study. Before the surgery, the engineers established the holographic image models based on the enhanced CT data. The models were used in patient consultation, pre-surgery planning and surgery simulation. During the RAPN, the navigation was achieved by real-time overlapping of the holographic images on the robotic surgery endoscopic views. The navigation technique helped the surgeon to identify the important anatomic structures such as tumor, renal vein, renal artery, and pelvis.

RESULTS

There were total of eight patients with renal hilar tumor who underwent RAPN combined with holographic imaging technique. The mean age was 57.3 years, the median ASA score was 2. The mean tumor size was 42.4 mm and the median RENAL Nephrometry score was 9.5. The clinical stages were cT1a (37.5%) and cT1b (62.5%). All the procedures were performed uneventfully by one surgeon. The mean operative time was 144.3 min, and the mean warm ischemia time was 27.9 min. The mean estimated blood loss was 86.3 ml. There was no conversion to open surgery or radical nephrectomy. There were no Clavien-Dindo ≥ 3 perioperative complications.

CONCLUSIONS

Using the holographic imaging technique, the pre-surgery planning, simulation of renal arterial clamp and excision of the tumor, and intraoperative navigation were feasible and helpful in facilitating RAPN.

Predicting Complications After Robotic Partial Nephrectomy: Back to Simplicity

BACKGROUND

Robotic partial nephrectomy (RPN) has a significant morbidity. Nephrometry scores have been described to predict the occurrence of complications. Their usefulness is debated.

OBJECTIVE

To evaluate the clinical utility of three nephrometry scores (radius, exophytic/endophytic, nearness, anterior/posterior, location [RENAL], preoperative aspects and dimensions used for an anatomical [PADUA], and simplified PADUA Renal [SPARE]) to predict perioperative outcomes and compare their performance to the simple measurement of tumor size in a large cohort of patients who underwent RPN.

DESIGN, SETTING, AND PARTICIPANTS

We analyzed 1581 consecutive patients who underwent RPN for small renal masses.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Tumor size, RENAL, PADUA, and SPARE scores were calculated based on preoperative imaging. Correlation between scores, estimated blood loss (EBL), operative time (OT), and warm ischemia time (WIT) were calculated. Logistic regression analyses were performed to identify predictors of overall and major complications. The area under the curve was used to identify models with the highest discrimination. Decision curve analyses determined the net benefit associated with their use.

RESULTS AND LIMITATIONS

The median age was 62 yr (interquartile range [IQR]: 52-70) and the median tumor size was 35 mm (IQR: 25-47). Postoperative complications were observed in 346 patients (21.9%), including 5.6% of major complications. All scores were significantly correlated with EBL, OT, and WIT. However, correlation coefficients were all <0.3, suggesting a weak association. Nephrometry scores and tumor size were significant predictors of overall complications in univariate and adjusted multivariable logistic regression model analysis. However, decision curve analysis demonstrated net benefit of tumor size comparable with all nephrometry scores. Finally, neither nephrometry scores nor tumor size was found to be associated with the risk of major complications.

CONCLUSIONS

Tumor size has the same ability as nephrometry scores to predict perioperative outcomes of RPN.

PATIENT SUMMARY

We evaluated the association between tumor size, nephrometry scores, and perioperative outcomes of robotic partial nephrectomy (RPN). We found that tumor size could predict perioperative outcomes of RPN as well as nephrometry scores.

External validation of SPARE nephrometery score in predicting overall complications, trifecta and pentafecta outcomes following robot-assisted partial nephrectomy

BACKGROUND

There is an ongoing need and search for a simple yet accurate nephrometry scoring system for predicting the postoperative outcomes after partial nephrectomy (PN). Simplified PADUA Renal (SPARE) Nephrometry Scoring System, a simplified version of Preoperative Aspects and Dimensions Used for an Anatomical Classification (PADUA) has been proposed as a predictor of postoperative complications following PN recently. However, this score has never been externally validated and assessed as a predictor of trifecta and pentafecta outcomes of PN. In the current study, we applied the SPARE scoring system to our robot-assisted PN cohort (RAPN).

METHODS

Prospectively maintained data of patients, who underwent RAPN from November 2014 to December 2018, was abstracted. Imaging was analyzed to calculate SPARE and RENAL nephrometry scores (RNS) by two urologists, independently. SPARE was compared with complications, trifecta outcomes, pentafecta outcomes, and RENAL nephrometry scoring (RNS).

RESULTS

Data of 201 RAPN patients were analyzed. The mean SPARE score was 3 (range 0-11). One hundred thirteen patients were classified as low risk, 64 as intermediate risk, and 24 as high risks. On multivariate analysis SPARE score alone predicted complications (OR=1.37, P=0.014) and trifecta outcomes (OR=0.75, P=0.000) while age (OR=0.96, P=0.042), preoperative eGFR (OR=0.97, P=0.001) and SPARE scores (OR=0.81, P=0.016) were predictors for pentafecta outcomes. Receiver operated curve (ROC) analysis between SPARE and RNS in predicting the complications; trifecta and pentafecta outcomes had a comparable area under the curve.

CONCLUSIONS

Our study validates the SPARE nephrometry scoring system in predicting postoperative complications, trifecta, and pentafecta outcomes in a RAPN cohort. The predictive accuracy of SPARE is similar to RNS.

Multi-institutional Retrospective Validation and Comparison of the Simplified PADUA REnal Nephrometry System for the Prediction of Surgical Success of Robot-assisted Partial Nephrectomy

BACKGROUND

The use of a nephron-sparing surgery for the treatment of localized renal masses is being pushed to more challenging cases. However, this procedure is not devoid of risks, and the Radius, Exophytic/Endophytic, Nearness, Anterior/Posterior, Location (RENAL) and Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) classifications are commonly employed in the prediction of complications. Recently, the Simplified PADUA REnal (SPARE) scoring system has been proposed with the aim to provide a more simple system, to improve its reproducibility to predict postoperative risks.

OBJECTIVE

We aim to retrospectively validate and compare the proposed new SPARE system in a multi-institutional population.

DESIGN, SETTING, AND PARTICIPANTS

The Transatlantic Robotic Nephron-sparing Surgery (TRoNeS) study group collected data from 737 patients subjected to robot-assisted partial nephrectomy (RAPN) between 2010 and 2016 at three tertiary care referral centers. Of these patients, 536 presented complete demographic and clinical data.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Renal masses were classified according to the SPARE, RENAL, and PADUA nephrometry scores, and surgical success was defined according to the margin, ischemia, and complication scores.

RESULTS AND LIMITATIONS

Of 536 patients, 340 were male; the median age was 61 (53-69) yr and preoperative tumor size was 30 (22-43) mm. The margin, ischemia, and complication score was achieved in 399 of cases (74.4%). All three nephrometry scores were significant predictors of surgical outcomes both in univariate and in adjusted multivariate logistic regression model analysis. In accuracy analysis, the area under the curve (AUC) of the SPARE scoring system (0.73) was significantly higher than those of the PADUA (0.65) and RENAL (0.68) nephrometry scores in predicting surgical success.

CONCLUSIONS

The SPARE score appears to be a promising and reliable score for the prediction of surgical outcomes of RAPN, showing a higher accuracy relative to the traditional PADUA and RENAL nephrometry scores. Further, prospective studies are warranted before its introduction in clinical practice.

PATIENT SUMMARY

The Simplified PADUA REnal (SPARE) score is a reproducible and simple nephrometry score, offering better predictive capabilities of surgical success and complications.