Comparison of surgical outcomes between enucleation and standard resection in robot-assisted partial nephrectomy for completely endophytic renal tumors through a 1:1 propensity score-matched analysis

Perioperative and Mid-Term Oncological and Functional Outcomes After Partial Nephrectomy for Entirely Endophytic Renal Tumors: A Prospective Multicenter Observational Study (The RECORD2 Project)

BACKGROUND AND OBJECTIVES

Totally endophytic renal tumors are a unique subset that pose significant technical challenges during partial nephrectomy (PN). The aim of this study was to evaluate the perioperative, oncologic, and functional outcomes of PN in this particular setting.

MATERIALS AND METHODS

We retrospectively evaluated 4151 patients who had surgical treatment for renal tumors between January 2013 and December 2016 at 26 urological Italian Centers (RECORD 2 project). Only patients treated with PN for entirely endophytic renal tumor were considered for final analyses.

RESULTS

A total of 211 patients were included, with a median PADUA score of 10 (IQR 9-11). Open, laparoscopic, and robotic approaches were used in 94 (44.5%), 52 (24.6%), and 65 (30.8%) cases, respectively. While surgical approach did not impact complication rates, robotic PN had significantly lower median blood loss (100 vs. 185 vs. 175 cc, p = 0.04) and shorter operative time (126 vs. 140 vs. 160 min, p = 0.01) compared to open and laparoscopic PN. At a median follow-up of 36.3 months (IQR 21.9-49.2), recurrence-free survival was 93.8%. Median %eGFR drop at 24 months was 12.1 (IQR 5.1-21.9), with significant eGFR loss (≥25%) in 36 (17.1%) patients. The robotic approach was associated with a lower %eGFR drop at 1-month and 1-year evaluations, but the benefit diminished at 24 months. Multivariate analysis showed age and open surgery as independent predictors of renal function loss at 1 month and Trifecta failure.

CONCLUSIONS

The conservative management of entirely endophytic renal tumors is associated with favorable functional and oncologic outcomes. Whenever technically feasible, conservative surgery should be prioritized to optimize early renal function recovery.

Does the transfer of knowledge from the pioneer generation to the second-generation speed-up the learning curve of robot-assisted partial nephrectomies? TRANSFER trial (UroCCR n°83)

Objectives

The objective is to compare the learning curves between two pioneer and three second-generation surgeons for RAPN in terms of WIT, CD and positive surgical margins.

Materials and methods

The charts of consecutive RAPNs of three centres were reviewed from the UroCCR prospective database. The experience was assessed by a regression model for each group. There was a univariate analysis on three consecutive sequences of 15 procedures. The learning speed for WIT was explored graphically by polynomial regression after cubic splines. Finally, CUSUM charts were obtained.

Results

There were 1203 RAPN in the pioneer group and 119 performed by second-generation surgeons. There was a significant difference in the distribution of tumour size (p < 0.001) and the RENAL score (p < 0.001). The operative time was longer in the first group (p > 0.001). Independent factors for a higher WIT were the second group (p < 0.001), higher experience (p < 0.001) the collinearity between the group and experience (p < 0.001), the RENAL score (p < 0.001) and blood loss (p < 0.001). Adjusted Loess regressions showed a plateau of WIT at 400 procedures for the pioneers and a significant decrease at 20 procedures for the second generation. CUSUM chart analysis showed a 'staircase' pattern of the learning process, with three major steps at 150, 200 and 300 procedures. The major limitation is the difference in sample size between the two arms.

Conclusions

Learning curve patterns would reflect a transfer of knowledge to the second-generation, as opposed to the establishment of standards by the pioneers.

Quantifying preserved renal volume and function in patients undergoing standard partial nephrectomy vs. tumor enucleation for localized renal tumors

INTRODUCTION

Renal parenchymal volume loss from standard partial nephrectomy (SPN) is a significant prognosticator for postoperative renal function. Tumor enucleation (TE) minimizes parenchymal loss compared to SPN. Little is known regarding discrete changes in renal function associated with volume loss. We sought to quantify the differences between SPN and TE in preserving parenchymal volume and estimated glomerular filtration rate (eGFR).

METHODS

We identified 420 patients who underwent robotic partial nephrectomy (SPN or TE) at our tertiary care center from 2009 to 2022. Parenchymal volumes were calculated using TeraRecon 3D reconstruction software from axial imaging performed preoperatively and within 6 months postoperatively. Renal volume preserved and renal function were evaluated with multivariable linear and logistic regression models.

RESULTS

At 1 year, eGFR was 7% lower in patients undergoing SPN compared to TE (P < 0.01). Across both SPN and TE, only volume of preserved parenchyma was predictive of eGFR and chronic kidney disease (CKD) progression (both P < 0.01). TE preserved more healthy parenchymal volume compared to SPN (median percentage 97.6% vs 89.2%; P < 0.001). Each 1% of volumetric loss corresponded to a 0.35% decrease in eGFR at 1 year postoperatively (P < 0.01).

CONCLUSIONS

Volume of preserved renal parenchyma was the strongest factor associated with preserved eGFR and reduced odds of CKD progression. TE preserved more parenchyma than SPN, which translated to higher eGFR preservation at 1 year postoperatively.

Impact of tumor dissecting technique on trifecta achievement in patients requiring extended warm ischemia during robot-assisted partial nephrectomy

PURPOSE

To clarify specific factors associated with surgical outcomes in robot-assisted partial nephrectomy (RAPN) that require extended warm ischemia time (WIT), which may have a negative impact, but cannot always be avoided.

METHODS

We included 1,182 patients who had RAPN performed between January 2016 and December 2022 from a prospectively generated multi-institutional RAPN database, divided into normal WIT (nWIT) (≤ 20 min; 843 patients) and extended WIT (eWIT) (> 20 min; 339 patients) groups. Primary outcome measures were WIT and the Surface-Intermediate-Base (SIB) margin score, which contribute to postoperative trifecta achievement. Results were compared between the two groups using logistic regression.

RESULTS

Patients in the eWIT group had larger tumors, higher RENAL nephrometry scores, and lower SIB scores than those of the nWIT group. The trifecta achievement rate was significantly different between the two groups (nWIT: 70.1 vs. 49.0%, p < 0.001). In the nWIT group, WIT (coefficient: -0.105 [standard error 0.020], p < 0.001) and SIB score (coefficient: -0.107 [0.053], p = 0.045) were significant predictors of trifecta achievement. In the eWIT group, the SIB score (coefficient - 0.216 [0.082], p = 0.008) was significantly associated with trifecta attainment, whereas WIT only showed a trend toward significance. Limitations included a lack of long-term survival, renal function, and chronic complications data.

CONCLUSIONS

For patients with eWIT during RAPN, the tumor dissection technique may be more important than WIT in predicting postoperative outcomes. Further prospective studies are required to confirm our results.

Comparison of surgical outcomes of robot-assisted laparoscopic partial nephrectomy performed by a single experienced surgeon according to two reconstruction methods, including single-layer and double-layer renorrhaphy

This study aimed to assess the surgical outcomes of single-layer versus double-layer renorrhaphy in robot-assisted laparoscopic partial nephrectomy (RAPN) performed by an experienced surgeon.We enrolled 655 patients who underwent RAPN between January 2019 and June 2023. After excluding those with multiple tumors or incomplete medical records, 554 patients were included in the final analysis. We compared surgical outcomes between single-layer renorrhaphy (outer cortical closure) and double-layer renorrhaphy (inner layer suture and outer cortical closure), adjusting for preoperative factors such as sex, age, body mass index, American Society of Anesthesiologists score, preoperative estimated glomerular filtration rate (eGFR), preoperative complications (diabetes or hypertension), surgical approach (transperitoneal or retroperitoneal), tumor size, and tumor complexity, using propensity score matching. Of the 554 patients analyzed, 59 were classified into the single-layer group and 495 into the double-layer group. Before matching, the double-layer group had more complex and larger tumors. After matching, 58 patients were included in each group. The single-layer group showed significantly shorter operative times (91 min vs. 100 min, p = 0.0361), lower estimated blood loss (EBL) (7.9 ml vs. 27 ml, p = 0.021), and better preservation of eGFR (- 1.2% vs. - 5.1%, p = 0.0313). Other outcomes, such as perioperative complications and postoperative hospital stay, were not significantly different between the groups. Single-layer renorrhaphy demonstrated better surgical outcomes, including shorter operative time, lower EBL, and better preservation of kidney function, compared to double-layer renorrhaphy. These findings suggest that single-layer reconstruction may optimize RAPN outcomes in selected patients.

A systematic review of robot-assisted partial nephrectomy outcomes for advanced indications: Large tumors (cT2-T3), solitary kidney, completely endophytic, hilar, recurrent, and multiple renal tumors

Objective

Robot-assisted partial nephrectomy (RAPN) has become widely used for treatment of renal cell carcinoma and it is expanding in the field of complex renal masses. The aim of this systematic review was to analyze outcomes of RAPN for completely endophytic renal masses, large tumors (cT2-T3), renal cell carcinoma in solitary kidney, recurrent tumors, completely endophytic and hilar masses, and simultaneous and multiple tumors.

Methods

A comprehensive search in the PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases was performed in December 2022 for English language papers. The primary endpoint was to evaluate the role of RAPN in the setting of each category of complex renal masses considered. The secondary endpoint was to evaluate the surgical and functional outcomes.

Results

After screening 1250 records, 43 full-text manuscripts were selected, comprising over 8500 patients. Twelve and thirteen studies reported data for endophytic and hilar renal masses, respectively. Five and three studies reported outcomes for cT2-T3 and solitary kidney patients, respectively. Four studies focused on redo-RAPN for recurrent tumors. Two studies investigated simultaneous bilateral renal masses and five reports focused on multiple tumor excision in ipsilateral kidney.

Conclusion

Over the past decade, evidence supporting the use of RAPN for the most challenging nephron-sparing surgery indications has continuously grown. Although limitations remain including study design and lack of detailed long-term functional and oncological outcomes, the adoption of RAPN for the included advanced indications is associated with favorable surgical outcomes with good preservation of renal function without compromising the oncological result. Certainly, a higher likelihood of complication might be expected when facing extremely challenging cases. However, none of these indications should be considered per se an exclusion criterion for performing RAPN. Ultimately, a risk-adapted approach should be employed.

Surgical Management of Localized Disease and Small Renal Masses

The incidence of renal cancer has increased over the past several decades, but mortality has declined. This is thought to be related in part to earlier detection of renal masses which portend excellent 5-year survival rates. Management of small renal masses and localized disease include both nonsurgical and surgical options. The choice of intervention is ultimately based on comprehensive evaluation and shared decision-making. This article provides a comprehensive review of the current surgical management options for localized renal cancer.

Resection Techniques During Robotic Partial Nephrectomy: A Systematic Review

Context

The resection technique used to excise tumor during robotic partial nephrectomy (RPN) is of paramount importance in achieving optimal clinical outcomes.

Objective

To provide an overview of the different resection techniques used during RPN, and a pooled analysis of comparative studies.

Evidence acquisition

The systematic review was conducted according to established principles (PROSPERO: CRD42022371640) on November 7, 2022. A population (P: adult patients undergoing RPN), intervention (I: enucleation), comparator (C: enucleoresection or wedge resection), outcome (O: outcome measurements of interest), and study design (S) framework was prespecified to assess study eligibility. Studies reporting a detailed description of resection techniques and/or evaluating the impact of resection technique on outcomes of surgery were included.

Evidence synthesis

Resection techniques used during RPN can be broadly classified as resection (non-anatomic) or enucleation (anatomic). A standardized definition for these is lacking. Out of 20 studies retrieved, nine compared "standard" resection versus enucleation. A pooled analysis did not reveal significant differences in terms of operative time, ischemia time, blood loss, transfusions, or positive margins. Significant differences favoring enucleation were found for clamping management (odds ratio [OR] for renal artery clamping 3.51, 95% confidence interval [CI] 1.13-10.88; p = 0.03), overall complications (OR for occurrence 0.55, 95% CI 0.34-0.87; p = 0.01) major complications (OR for occurrence 0.39, 95% CI 0.19-0.79; p = 0.009), length of stay (weighted mean difference [WMD] -0.72 d, 95% CI -0.99 to -0.45; p < 0.001), and decrease in estimated glomerular filtration rate (WMD -2.64 ml/min, 95% CI -5.15 to -0.12; p = 0.04).

Conclusions

There is heterogeneity in the reporting of resection techniques used during RPN. The urological community must improve the quality of reporting and research produced accordingly. Positive margins are not specifically related to the resection technique. Focusing on studies comparing standard resection versus enucleation, advantages with tumor enucleation in terms of avoidance of artery clamping, overall/major complications, length of stay, and renal function were found. These data should be considered when planning the RPN resection strategy.

Patient summary

We reviewed studies on robotic surgery for partial kidney removal using different techniques to cut away the kidney tumor. We found that a technique called "enucleation" was associated with similar cancer control outcomes in comparison to the standard technique and had fewer complications, better kidney function after surgery, and a shorter hospital stay.

Positive surgical margin's impact on short-term oncological prognosis after robot-assisted partial nephrectomy (MARGINS study: UroCCR no 96)

The oncological impact of positive surgical margins (PSM) after robot-assisted partial nephrectomy (RAPN) is still under debate. We compared PSM and Negative Surgical Margins (NSM) in terms of recurrence-free survival (RFS), metastasis-free survival (MFS) and overall survival (OS) after RAPN, and we identified predictive factors of PSM. Multi-institutional study using the UroCCR database, which prospectively included 2166 RAPN between April 2010 and February 2021 (CNIL DR 2013-206; NCT03293563). Two groups were retrospectively compared: PSM versus NSM. Prognostic factors were assessed using Kaplan-Meyer curves with log-Rank test, cox hazard proportional risk model and logistic regression after univariate comparison. 136 patients had PSM (6.3%) and 2030 (93.7%) had NSM. During a median follow-up of 19 (9-36) months after RAPN, 160 (7.4%) recurrences were reported. Kaplan-Meier curves and analysis suggested that RFS, MFS and OS were not affected by a PSM (p = 0.68; 0.71; 0.88, respectively). In multivariate analysis predictors of PSM were a lower RENAL score (p = 0.001), longer warm ischemia time (WIT) (p = 0.003) and Chromophobe Renal Cell Carcinoma (chrRCC) (p = 0.043). This study found no impact of PSM on RFS, MFS or OS, and predictors of PSM were the RENAL score, WIT and chrRCC.

Partial Nephrectomy Versus Radical Nephrectomy for Endophytic Renal Tumors: Comparison of Operative, Functional, and Oncological Outcomes by Propensity Score Matching Analysis

Purpose

The study aimed to compare operative, functional, and oncological outcomes between partial nephrectomy (PN) and radical nephrectomy (RN) for entophytic renal tumors (ERTs) by propensity score matching (PSM) analysis.

Methods

A total of 228 patients with ERTs who underwent PN or RN between August 2014 and December 2021 were assessed. A PSM in a 1:1 ratio was conducted to balance the differences between groups. Perioperative characteristics, renal functional, and oncological outcomes were compared between groups. Univariate and multivariate logistic and Cox proportional hazard regression analyses were used to determine the predictors of functional and survival outcomes.

Results

After PSM, 136 cases were matched to the PN group (n = 68) and the RN group (n = 68). Patients who underwent RN had shorter OT, less EBL, and lower high-grade complications (all p <0.05) relative to those who underwent PN. However, better perseveration of renal function was observed in the PN group, which was reflected in 48-h postoperative AKI (44.1% vs. 70.6%, p = 0.002), 1-year postoperative 90% eGFR preservation (45.6% vs. 22.1%, p = 0.004), and new-onset CKD Stage ≥III at last follow-up (2.9% vs. 29.4%, p <0.001). RN was the independent factor of short-term (OR, 2.812; 95% CI, 1.369–5.778; p = 0.005) and long-term renal function decline (OR, 10.242; 95% CI, 2.175–48.240; p = 0.003). Furthermore, PN resulted in a better OS and similar PFS and CSS as compared to RN (p = 0.042, 0.15, and 0.21, respectively). RN (OR, 7.361; 95% CI, 1.143–47.423; p = 0.036) and pT3 stage (OR, 4.241; 95% CI, 1.079–16.664; p = 0.039) were independent predictors of overall mortality.

Conclusion

Among patients with ERTs, although the PN group showed a higher incidence of high-grade complications than RN, when technically feasible and with experienced surgeons, PN is recommended for better preservation of renal function, longer OS, and similar oncological outcomes.

Robotic-assisted tumor enucleation versus standard margin partial nephrectomy: Perioperative, renal functional, and oncologic outcomes for low and intermediate complexity renal masses

PURPOSE

Standard margin partial nephrectomy (SPN) with sharp incision across normal renal parenchyma carries perioperative morbidity and renal functional implications. Tumor enucleation (TE) is an alternative approach using a natural plane of dissection around the tumor pseudocapsule to maximize parenchymal preservation. We compared perioperative, functional, and oncologic outcomes for robotic-assisted TE to SPN.

MATERIALS AND METHODS

Patients ≥18 years of age undergoing robotic-assisted TE or SPN were included (2008-2020). Baseline demographics and tumor characteristics were compared. Perioperative, renal functional, and oncologic outcomes were assessed for comparative effectiveness.

RESULTS

A total of 467 patients were included with 176 (37.7%) TE and 291 (62.3%) SPN. Baseline characteristics and final histology were comparable; 18% of patients had baseline stage 3 chronic kidney disease. TE had lower median blood loss, operative time, length of stay, and fewer complications compared to SPN. Positive margin rates were higher for TE vs. SPN (8.5% vs. 3.4%, P = 0.04) with similar recurrence rates (2.3% vs. 3.4%, P = 0.48) and no difference in cancer-specific or overall survival with median 4.0 years follow-up. Baseline estimated glomerular filtration rate was comparable (76.1 vs. 78.2, P = 0.63) while renal function in the first year was better preserved with TE (74.6 vs. 68.1, P < 0.001) showing an 8-point estimated glomerular filtration rate (P = 0.001) advantage after adjustment. The rate of stage ≥3 chronic kidney disease by 12 months was lower for TE compared to SPN (21.5% vs. 34.1%, P = 0.006).

CONCLUSIONS

TE is an alternative approach to SPN associated with favorable perioperative and renal functional outcomes. While positive margin rates are higher, longer-term recurrence rates are no different suggesting pseudocapsule disruption during TE has limited impact on oncologic outcomes.

Tumor enucleation for the treatment of T1 renal tumors: A systematic review and meta-analysis

Purpose

To evaluate the clinical efficacy and safety of tumor enucleation (TE) compared with partial nephrectomy (PN) for T1 renal cell carcinoma.

Materials and Methods

According to protocol, we searched multiple data sources for published and unpublished randomized controlled trials and nonrandomized studies (NRSs) in any language. We performed systematic review and meta-analysis according to the Cochrane Handbook for Systematic Reviews of Interventions and rated the certainty of the evidence (CoE) using the GRADE framework.

Results

We are uncertain about the effects of TE on perioperative (mean difference [MD] 3.38, 95% CI 1.52 to 5.23; I²=68%; 4 NRSs; 942 participants; very low CoE) and long-term (MD 2.31, 95% CI -1.40 to 6.01; I²=57%; 4 NRSs; 542 participants; very low CoE) residual renal function. TE may result in little to no difference in short-term residual renal function (MD 1.04, 95% CI 0.25 to 1.83; I²=0%; 2 NRSs; 256 participants; low CoE). We are uncertain about the effects of TE on cancer-specific mortality (risk ratio [RR] 0.90, 95% CI: 0.11 to 7.28; I²=0%; 2 NRSs; 551 participants; very low CoE) and major adverse events (RR 0.48, 95% CI: 0.30 to 0.79; I²=0%; 10 NRS; 2,360 participants; very low CoE).

Conclusions

While TE appears to have similar effects on short term postoperative residual renal function, there were uncertainties on mortality and major adverse events. However, we need rigorous RCTs to elucidate the effects of TE as the evidence stems mostly from NRSs.