|Year : 2020 | Volume
| Issue : 2 | Page : 146-147
Simplified PADUA REnal nephrometry system: A refitted PADUA score
Department of Urology, PGIMER, Chandigarh, India
|Date of Submission||17-Oct-2019|
|Date of Acceptance||20-Dec-2019|
|Date of Web Publication||07-Apr-2020|
Department of Urology, PGIMER, Chandigarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sharma G. Simplified PADUA REnal nephrometry system: A refitted PADUA score. Indian J Urol 2020;36:146-7
| Summary|| |
Simplified PADUA REnal nephrometry system (SPARE) has been recently proposed by Ficarra et al., the same group that proposed the initial preoperative aspects and dimensions used for an anatomical classification (PADUA) system. The study was published in British Journal of Urology International in April 2019. The main aim of this study was to simplify the original PADUA system and to assess whether the addition of another parameter, i.e., tumor contact surface area (CSA), has any effect on the predictive accuracy for complication rates. In this multicentric study, retrospective analysis of data of 531 patients who had undergone partial nephrectomy (PN) was performed. Computed tomography (CT) images of all the patients were evaluated and PADUA score and CSA were calculated. Data for various demographic and perioperative outcomes were retrieved for all the patients. Of these 531 patients, 237 underwent open PN, 152 (28.6%) laparoscopic PN, and 142 robot-assisted PN. Predictive accuracy of each of the variable included in the original PADUA system was again tested on these patients. The study authors excluded polar location from the PADUA system as it did not achieve statistical significance on the analysis, and also, they clubbed renal sinus involvement or collecting system involvement together as they recognized that “patients with only urinary collecting system involvement were similar to cases with any involvement.” They also assessed the feasibility of addition of another variable, i.e., tumor CSA. However, they found that tumor CSA was not predictive of complications in a multivariate analysis; moreover, the addition of CSA to PADUA or SPARE did not result in a significant change in area under curve on receiver operating characteristic (ROC) curve analysis. On ROC curve analysis, there was no significant difference in the predictive accuracy of the two models, i.e., SPARE and PADUA. The study authors also performed regression analysis to identify predictors of change in absolute estimated glomerular filtration rate (eGFR) and found that tumor CSA, but not SPARE, could predict a change in eGFR.
| Comment|| |
Ever since the introduction of RENAL and PADUA scores in 2009, there have been a plethora of other nephrometry scores described to ascertain the complexity of renal masses for PN. Most of these systems are based on tumor-based variables and very few are based on patient-related factors. Despite their limitations, RENAL and PADUA scores have remained popular in the academic centers for evaluating tumor complexity as they are simple, reproducible, and do not require complex imaging protocols. In a bid to simplify the original PADUA scores, the study authors proposed new Simplified PADUA Renal (SPARE) nephrometry score containing four features (rim location, renal sinus involvement, exophytic rate, and maximum tumor size) and omitted urinary calyceal system and polar location from the original system. Although externally validated by multiple studies, PADUA score had the disadvantage of being lengthy and cumbersome. Like the original PADUA score, SPARE has been evaluated only to predict the risk of complications, which also depends on other nontumor-related factors such as surgeon's experience, surgical approach, age, and comorbidities. Providing predictive accuracy of SPARE for perioperative outcomes in terms of trifecta (complications, warm ischemia outcome, and margin) would have been a better approach, which now needs to be explored in future studies. Surgical approach is another important factor to be considered, since RENAL and PADUA scores were postulated in the era when open PN was common. With the expansion of the robotic platform, most of the partial nephrectomies today are being performed using the robotic assistance. Schiavina et al. have reported that PADUA and RENAL scores can predict perioperative outcomes in the patients undergoing robotic PN also. SPARE system has been reported to predict complications for all the three surgical approaches, i.e., open, laparoscopic, and robot. However, its ability to predict trifecta outcomes in different surgical approach, remains to be established. SPARE system has the edge over the other scoring systems as it can be easily determined using axial images of simple contrast-enhanced CT scans and does not require special imaging protocols. However, before advocating wider application of the SPARE system, its external validation with different surgical approaches and trifecta outcomes is required. Another concern with these nephrometry scores is of interobserver variability, which needs to be addressed for SPARE by further studies.
Financial support and sponsorship: Nil.
Conflicts of interest: There are no conflicts of interest.
| References|| |
Ficarra V, Porpiglia F, Crestani A, Minervini A, Antonelli A, Longo N, et al
. The Simplified PADUA REnal (SPARE) nephrometry system: A novel classification of parenchymal renal tumours suitable for partial nephrectomy. BJU Int 2019;124:621-8.
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