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

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.

Impact of renal sinus protrusions on achieving trifecta in robot-assisted partial nephrectomy

Objective

The objective of this work is to assess the relationship between the morphological characteristics of a central tumour and the perioperative outcomes of robot-assisted partial nephrectomy (RAPN).

Subjects and Methods

We retrospectively analysed the data from 186 patients with central tumours involving the renal sinus, who underwent RAPN in a single-centre study between February 2015 and June 2022. All cases were assigned a RENAL nephrometry score based on preoperative images. The shape of the protruding portion of the tumour was classified into four types: 'flat', 'spherical', 'single-hump', and 'complex-hump', and was independently assessed by two readers. The trifecta is defined as the warm ischemia time within 25 min, negative surgical margins, and no major postoperative complications. Univariate and multivariate analyses were performed to identify the factors associated with the failing trifecta.

Results

Trifecta was achieved in 113 cases (60.8%), and the achievement rate in flat, spherical, single-hump, and complex-hump types was 83.3%, 74.5%, 64.3%, and 21.3%, respectively. Prolonged warm ischemia time was the primary cause of the failure to achieve the trifecta. The rate of positive surgical margins and upstage to pathological T3a was greater for complex humps while the rate of major complications and postoperative GFR preservation did not differ between shapes. On multivariate analysis for failing trifecta achievement, the complex-hump protrusion was found to be an independent positive predictor (odds ratio: 15.8; p < 0.001), whereas the height and width of protrusion were not significantly related.

Conclusions

The degree of difficulty varied among central tumours, and it was not possible to precisely measure it with existing scoring systems. Complex-hump protrusions strongly correlate with failure to achieve the trifecta. Preoperative assessment of the morphology of protrusion is useful for predicting outcomes.

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.

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.

Are nephrometry scores accurate for the prediction of outcomes in patients with renal angiomyolipoma treated with robot-assisted partial nephrectomy? A multi-institutional analysis

BACKGROUND

Prediction of complications and surgical outcomes is of outmost importance even in patients with benign renal masses. The aim of our study is to test the PADUA, SPARE and R.E.N.A.L. scores to predict nephron sparing surgery (NSS) outcomes in patients presenting with renal angiomyolipoma (RAML).

METHODS

We retrospectively analyzed the clinical and pathological data of 93 patients with AML treated with robot-assisted partial nephrectomy (RAPN) at three tertiary care referral centers. Renal masses were classified according to the PADUA, SPARE and R.E.N.A.L. nephrometry scores. Surgical success was defined according to the novel Trifecta Score. Logistic regression models (LRM) were fitted to predict the achievement of novel Trifecta and the risk of high-grade Clavien-Dindo (CD) complication. The receiver operating characteristics (ROC) curve analysis was used to estimate the accuracy of LRMs.

RESULTS

Of 93 patients, 66 (69.9%) were females; median tumor size was 42 (36-48) mm. Novel Trifecta was achieved in 79 patients (84.9%) and postoperative complications classified as CD>2 occurred in 7 (7.5%) patients. At univariate and multivariate LRMs all three nephrometry scores were significantly associated with novel Trifecta achievement. Similar findings were observed for the prediction of CD>2 complications. The AUCs to predict optimal surgical outcomes and CD>2 complications were 0.791 and 0.912 for PADUA, 0.767 and 0.836 for SPARE and 0.756 and 0.842 for RENAL Score, respectively.

CONCLUSIONS

RAPN appears to be a feasible and safe surgical technique for the treatment of RAML. PADUA, SPARE and RENAL scores can be safely adopted to predict surgical outcomes, with the first one showing a higher accuracy.

New imaging modalities to consider for men with prostate cancer on active surveillance

PURPOSE

To discuss the potential utility of newer imaging modalities including micro-ultrasound and PSMA-PET for the detection of clinically significant prostate cancer, technologies that may gain roles as adjuncts to multiparametric magnetic resonance imaging (mpMRI) in the active surveillance (AS) setting.

METHODS

Narrative review of two new imaging modalities used for primary prostate cancer through April 2021. A targeted search was performed to identify current relevant literature on the role of new imaging modalities for primary prostate cancer using search terms "micro-ultrasound," "molecular imaging," "prostate cancer," "active surveillance," "multiparametric MRI," "PI-RADS," "PRI-MUS," and "detection rate." In addition, references of included articles were screened for further relevant publications.

RESULTS

Micro-ultrasound (micro-US) and prostate-specific membrane antigen-positron emission tomography (PSMA-PET) are increasing in their use and applicability to prostate cancer imaging. Micro-US is used for cancer detection and may identify higher grade cancers more accurately than conventional ultrasound, despite technical hurdles in its initial launch. PSMA-PET is highly sensitive and specific for high-grade and metastatic prostate cancer, though costly and not easily available. Though data are sparse, it may have an emerging role in cancer diagnosis in select localized cases, and in some men considering (or currently on) AS who have indications of more aggressive disease.

CONCLUSION

There are very limited data on micro-US and PSMA-PET in AS patients. However, given the ability of these modalities to identify high-grade cancer, their judicious use in AS patients may be of utility in the future.

New longitudinal component of the RENAL nephrometry score for predicting the operative complexity in transperitoneal robot-assisted partial nephrectomy

BACKGROUND

In transperitoneal robot-assisted partial nephrectomy (RAPN), an L score of 3 points according to RENAL nephrometry scoring system does not necessarily denote operative complexity. This study aimed to assess the efficacy of the newly defined longitudinal component to analyze the operative complexity of RAPN Methods: We retrospectively analyzed transperitoneal RAPNs performed by a single experienced surgeon for renal tumors between 2017 and 2020. L component was defined as L'1 for medially located tumors, L'2 for >50% below the polar line, and L'3 for >50% above the polar line. Multivariate regression analysis was performed to test associations between prolonged console time and preoperative factors. The perioperative outcomes were compared among the three cohorts of L' components using propensity score matching: L'1 vs. L'3 and L'1 vs. L'2.

RESULTS

A total of 220 cases (L'1: 107, L'2, 65, L'3: 48) were analyzed. The median console time was prolonged (>130 min) in 55 patients (median 108, interquartile range: 90-130 min). Longitudinal location (L'3 odds ratio: 2.93, P = 0.01; L'2 odds ratio: 2.32, P = 0.04), high Mayo adhesive probability score (P = 0.001), multiple renal arteries (P = 0.03), and large size (P = 0.04) were significantly associated with prolonged console time. After matching, 26 cases of L'1 and L'3 and 43 cases of L'1 and L'2 were selected. Console time (132 vs. 108 min, P = 0.017) and warm ischemia time (17 vs. 22 min, P = 0.03) were significantly longer in L'3 than in L'1. The difference in console time between L'1 and L'2 was not statistically significant (100 vs. 111 min, P = 0.08) Conclusion: In the new longitudinal assessment, upper location predicted prolonged console time compared to a medial or lower location. The L' component may help preoperatively assess operative complexity.

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.