Tumor-parenchyma interface and long-term oncologic outcomes after robotic tumor enucleation for sporadic renal cell carcinoma

Robotic-assisted enucleation for renal masses: A comparison of on-clamp and off-clamp approach

INTRODUCTION

In surgically excising renal masses, studies have demonstrated that tumor enucleation is an effective option. However, there is limited literature comparing off-clamp to on-clamp tumor enucleation.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 189 patients who underwent robotic-assisted laparoscopic partial nephrectomy via tumor enucleation by a single surgeon from March 2012 and April 2022. Patients were stratified based on use of renal hilar clamping intraoperatively. Surgical, oncologic, and renal functional outcomes were captured. Variables were analyzed and compared between the two groups using Student's T-tests and Chi-square tests.

RESULTS

Of 189 procedures analyzed, 124 were performed on-clamp and 65 were performed off-clamp. There were no differences in patient demographics or average length of follow-up. There were no differences in estimated blood loss, complications, or hospital length of stay. Recurrence rates were similar for the two groups. The absolute difference in estimated glomerular filtration rate change between the two groups at time of first follow-up was not significant (p = 0.25).

CONCLUSIONS

There is no significant difference in perioperative outcomes such as surgical time, blood loss, or complications between the two groups. Furthermore, there was no significant difference in postoperative kidney function between the two techniques.

Does tumor rupture during robot-assisted partial nephrectomy have an impact on mid-term tumor recurrences?

BACKGROUND

Intraoperative kidney tumor rupture (TR) can occur during robot-assisted partial nephrectomy (RAPN) in daily clinical practice, but there are no solid guidelines on the management and implications of it. The purpose of the study was to investigate the impact of TR on tumor recurrences, what a surgeon should do if this adverse event occurs, and how to avoid it.

PATIENTS AND METHODS

We retrospectively analyzed the first 100 patients who underwent RAPN at University Medical Centre Ljubljana, between 2018 and 2021. Patients were stratified into 2 groups (TR and no-TR) and were compared according to patient, tumor, pathologic, perioperative and postoperative characteristics and tumor recurrences, using the Mann-Whitney U test and chi-squared test.

RESULTS

Of the 100 patients, 14 had TR (14%); this occurred in tumors with higher RENAL nephrometry scores (P = 0.028) and mostly with papillary renal cell carcinomas (P = 0.043). Median warm ischemia time was longer for the TR group (22 vs. 15 min, P = 0.026). In terms of studied outcomes, there were no cases of local or distant recurrence after a median observation time of 39 months (interquartile range, 31-47 months) in both groups. We observed positive surgical margins on the final oncologic report in one case in the no-TR group.

CONCLUSIONS

Tumor rupture during RAPN seems to be of no mid-term oncologic importance. According to presented results, we would recommend surgeons to proceed with tumor resection if this event occurs and abstain from conversion to radical nephrectomy or open partial nephrectomy. However, more similar cases should be studied to make more solid conclusions.

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.

Robotic Partial Nephrectomy for Bilateral Renal Masses

PURPOSE OF REVIEW

There are very few data on patients undergoing robot-assisted partial nephrectomy (RAPN) for bilateral renal masses. The aim of this review is to update the literature and discuss the controversial points on this topic.

RECENT FINDINGS

Nine papers have been published regarding RAPN for bilateral renal masses. In particular, five papers were case reports while the remaining four reported patient series. Concerning the outcomes, all these papers highlighted the safety, feasibility, and efficacy of bilateral RAPN for bilateral renal masses. The literature confirmed RAPN as an optimal procedure for the treatment of bilateral renal masses. However, these outcomes mainly derived from selected group of patients who underwent complex surgical procedures by expert robotic surgeons at high volume centers and cannot be generalizable to all categories of patients or centers. The simultaneous bilateral approach resulted feasible showing some advantages and without higher complications than a staged procedure in particular when clampless or selective clamping techniques were performed.

Mapping single-cell transcriptomes in the intra-tumoral and associated territories of kidney cancer

Tumor behavior is intricately dependent on the oncogenic properties of cancer cells and their multi-cellular interactions. To understand these dependencies within the wider microenvironment, we studied over 270,000 single-cell transcriptomes and 100 microdissected whole exomes from 12 patients with kidney tumors, prior to validation using spatial transcriptomics. Tissues were sampled from multiple regions of the tumor core, the tumor-normal interface, normal surrounding tissues, and peripheral blood. We find that the tissue-type location of CD8+ T cell clonotypes largely defines their exhaustion state with intra-tumoral spatial heterogeneity that is not well explained by somatic heterogeneity. De novo mutation calling from single-cell RNA-sequencing data allows us to broadly infer the clonality of stromal cells and lineage-trace myeloid cell development. We report six conserved meta-programs that distinguish tumor cell function, and find an epithelial-mesenchymal transition meta-program highly enriched at the tumor-normal interface that co-localizes with IL1B-expressing macrophages, offering a potential therapeutic target.

Imaging Features of Renal Masses to Select Optimal Candidates for Tumor Enucleation Partial Nephrectomy

PURPOSE OF REVIEW

The goal of this paper was to critically evaluate preoperative findings that optimally select candidates for renal tumor enucleation partial nephrectomy.

RECENT FINDINGS

Tumor enucleation has been widely accepted as a management option for patients with chronic kidney disease, hereditary renal cell carcinoma, or multifocal disease. Recent evidence suggests safety and efficacy in the management of routine small renal masses. With recent advances in imaging, the literature for ruling out aggressive renal cell carcinoma and selection for tumor enucleation is robust. As the incidence of renal cell carcinoma rises, partial nephrectomy continues to be the mainstay of treatment for localized renal cell carcinoma. Tumor enucleation maximizes preservation of renal parenchyma without hindering oncologic outcomes. It is important to recognize key tumor radiologic findings which urologists may use to optimize patient selection for tumor enucleation.

Surgical margins after partial nephrectomy as prognostic factor for the risk of local recurrence in pT1 RCC: a systematic review and narrative synthesis

Purpose

To systematically review the published literature on surgical margins as a risk factor for local recurrence (LR) in patients undergoing partial nephrectomy (PN) for pT1 renal cell carcinomas (RCC).

Evidence acquisition

A systematic literature search of relevant databases (MEDLINE, Embase and the Cochrane Library) was performed according to the PRISMA criteria up to February 2022. The hypothesis was developed using the PPO method (Patients = patients with pT1 RCC undergoing PN, Prognostic factor = positive surgical margins (PSM) detected on final pathology versus negative surgical margins (NSM) and Outcome = LR diagnosed on follow-up imaging). The primary outcome was the rate of PSM and LR. The risk of bias was assessed by the QUIPS tool.

Evidence synthesis

After assessing 1525 abstracts and 409 full-text articles, eight studies met the inclusion criteria. The percentage of PSM ranged between 0 and 34.3%. In these patients with PSM, LR varied between 0 and 9.1%, whereas only 0–1.5% of LR were found in the NSM-group. The calculated odds ratio (95% confident intervals) varied between 0.04 [0.00–0.79] and 0.27 [0.01–4.76] and was statistically significant in two studies (0.14 [0.02–0.80] and 0.04 [0.00–0.79]). The quality analysis of the included studies resulted in an overall intermediate to high risk of bias and the level of evidence was overall very low. A meta-analysis was considered unsuitable due to the high heterogeneity between the included studies.

Conclusion

PSM after PN in patients with pT1 RCC is associated with a higher risk of LR. However, the evidence has significant limitations and caution should be taken with the interpretation of this data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04016-0.

Predictors of Positive Surgical Margins after Robot-Assisted Partial Nephrectomy for Localized Renal Tumors: Insights from a Large Multicenter International Prospective Observational Project (The Surface-Intermediate-Base Margin Score Consortium)

Background: To explore predictors of positive surgical margins (PSM) after robotic partial nephrectomy (PN) in a large multicenter international observational project, harnessing the Surface-Intermediate-Base (SIB) margin score to report the resection technique after PN in a standardized way. Methods: Data from consecutive patients with cT1-2N0M0 renal masses treated with PN from September 2014 to March 2015 at 16 tertiary referral centers and included in the SIB margin score International Consortium were prospectively collected. For the present study, only patients treated with robotic PN were included. Uni- and multivariable analysis were fitted to explore clinical and surgical predictors of PSMs after PN. Results: Overall, 289 patients were enrolled. Median (IQR) preoperative tumor size was 3.0 (2.3−4.2) cm and median (IQR) PADUA score was 8 (7−9). SIB scores of 0−2 (enucleation), 3−4 (enucleoresection) and 5 (resection) were reported in 53.3%, 27.3% and 19.4% of cases, respectively. A PSM was recorded in 18 (6.2%) patients. PSM rate was 4.5%, 11.4% and 3.6% in case of enucleation, enucleoresection and resection, respectively. Patients with PSMs had tumors with a higher rate of contact with the urinary collecting system (55.6% vs. 27.3%; p < 0.001) and a longer median warm ischemia time (22 vs. 16 min; p = 0.02) compared with patients with negative surgical margins, while no differences emerged between the two groups in terms of other tumor features (i.e., pathological diameter, PADUA score). In multivariable analysis, only enucleoresection (SIB score 3−4) versus enucleation (SIB score 0−2) was found to be an independent predictor of PSM at final pathology (HR: 2.68; 95% CI: 1.25−7.63; p = 0.04), while resection (SIB score 5) was not. Conclusions: In our experience, enucleoresection led to a higher risk of PSMs as compared to enucleation. Further studies are needed to assess the differential impacts of resection technique and surgeon’s experience on margin status after robotic PN.

Simultaneous robotic partial nephrectomy for bilateral renal masses

PURPOSE

There is currently no consensus regarding the optimal treatment strategy for patients presenting with synchronous bilateral renal masses. The decision to perform bilateral procedures on the same intervention or in staged procedures is debated. The aim of this manuscript is to analyse the outcomes of simultaneous robot-assisted partial nephrectomy (RAPN) in a series of patients with bilateral renal masses treated at five Italian robotic institutions.

METHODS

Data from a prospectively maintained multi-institutional database on patients subjected to simultaneous RAPN between November 2011 and July 2019 were reviewed. RAPNs were performed with da Vinci Si or Xi surgical system by expert robotic surgeons. Baseline demographics and clinical features, peri- and post-operative data were collected.

RESULTS

Overall, 27 patients underwent simultaneous bilateral RAPN, and 54 RAPNs were performed without need of conversion; median operative time was 250 minutes, median estimated blood loss was 200 mL. Renal artery clamping was needed for 27 (50%) RAPNs with a median warm ischemia time of 15 minutes and no case of acute kidney injury. Complications were reported in 7 (25.9%) patients, mainly represented by Clavien 2 events (6 blood transfusions). Positive surgical margins were assessed in 2 (3.7%) of the renal cell carcinoma. At the median follow-up of 30 months, recurrence-free survival was 100%.

CONCLUSION

Our data showed that, in selected patients and expert hands, simultaneous bilateral RAPNs could be a safe and feasible procedure with promising results for the treatment of bilateral synchronous renal masses.

Is Preoperative Magnetic Resonance Imaging in a Daily Clinical Setting Useful to Evaluate Tumor Invasion Beyond the Pseudocapsule in Renal Cell Carcinoma?

Background

We wanted to clarify whether preoperative magnetic resonance imaging (MRI) in the clinical setting can evaluate the pathologic pseudocapsule (PC) morphology with high accuracy in renal cell carcinoma (RCC).

Methods

We retrospectively analyzed 34 consecutive patients who underwent MRI (1.5 or 3.0T, 5 mm slices) prior to partial nephrectomy (PN) for RCC at our institution between January 2010 and December 2019. First, the correlation between PC morphology (complete or incomplete) and tumor infiltration to the renal parenchyma was examined as pathologic validation. Second, the concordance rate of PC morphology between pathologic tissue and preoperative MRI was evaluated as radiologic validation. Third, risk factor for renal parenchymal invasion in RCC was analyzed.

Results

In the pathologic validation, parenchymal invasion rates were 11% and 28% in the "complete PC" and "incomplete PC" groups, respectively. In the radiologic validation, pathological PC morphology could be diagnosed on preoperative MRI in 17 patients (50.0%). "None PC" on MRI had the lowest positive predictive value (PPV) (0%), "partial PC" on MRI had a good PPV (76.5%), "complete PC" on MRI had a relatively low PPV (33.3%). Unfortunately, these data were insufficient for diagnostic accuracy. As risk factor for renal parenchymal invasion in RCC, only pathologic subtype (non-clear cell) was found to have significant differences in the multivariate analysis.

Conclusion

The results of this study suggest that renal tumors with pathologically incomplete PC have a high possibility of renal parenchymal invasion. However, it is currently difficult to accurately evaluate pathologic PC morphology by preoperative MRI in the clinical setting.

Impact of surgical approach and resection technique on the risk of Trifecta Failure after partial nephrectomy for highly complex renal masses

INTRODUCTION

We aimed to compare the outcomes of open vs robotic partial nephrectomy (PN), focusing on predictors of Trifecta failure in patients with highly complex renal masses.

PATIENTS AND METHODS

We queried the prospectively collected database from the SIB International Consortium, including 507 consecutive patients with cT1-2N0M0 renal masses treated at 16 high-volume referral centres, to select those with highly complex (PADUA score ≥10) tumors undergoing PN. RT was classified as enucleation, enucleoresection or resection according to the SIB score. Trifecta was defined as achievement of negative surgical margins, no acute kidney injury and no Clavien-Dindo grade ≥2 postoperative surgical complications. Multivariable logistic regression analysis was used to assess independent predictors of Trifecta failure.

RESULTS

113 patients were included. Patients undergoing open PN (n = 47, 41.6%) and robotic PN (n = 66, 58.4%) were comparable in baseline characteristics. RT was classified as enucleation, enucleoresection and resection in 46.9%, 34.0% and 19.1% of open PN, and in 50.0%, 40.9% and 9.1% of robotic PN (p = 0.28). Trifecta was achieved in significantly more patients after robotic PN (69.7% vs. 42.6%, p = 0.004). On multivariable analysis, surgical approach (open vs robotic, OR: 2.62; 95%CI: 1.11-6.15, p = 0.027) and tumor complexity (OR for each additional unit of the PADUA score: 2.27; 95%CI: 1.27-4.06, p = 0.006) were significant predictors of Trifecta failure, while RT was not. The study is limited by lack of randomization; as such, selection bias and confounding cannot be entirely ruled out.

CONCLUSIONS

Tumor complexity and surgical approach were independent predictors of Trifecta failure after PN for highly complex renal masses.

Surgical Insights for the Management of Variant Histology in Renal Cell Carcinoma

PURPOSE

To review the current literature regarding variant (non-clear) histology of renal cell carcinoma (RCC) and the clinical management of these renal tumors.

MATERIAL AND METHODS

A PubMed database search was performed in May 2020 focusing on variant RCC, its diagnosis and associated syndromes, tumor characteristics, and options for management.

RESULTS

A broad range of pathological, clinical and diagnostic characteristics amongst non-ccRCC variants were found to have an impact on the overall management of these tumors. The imaging modalities, frequency of surveillance, and timing for intervention were found to be dependent on the type of genetic alterations, type of histology, and tumor growth rates. The timing and type of surgery as well as the systemic therapy are tailored to the specific tumor type and patient.

CONCLUSION

The findings of this review suggest that clinical management should be considered and adjusted for patients with non-ccRCC histological variants based on tumor subtype and genetic alterations.

Urology Residents Simulation Training Improves Clinical Outcomes in Laparoscopic Partial Nephrectomy

BACKGROUND

Partial nephrectomy (PN) is the preferred modality of treatment for small renal masses. Laparoscopic partial nephrectomy (LPN) has been adopted worldwide and a fundamental role is played by surgical skills. The need for skill instruction outside the operating room is well recognized in the modern models of surgery residency training. We aim to investigate the impact of residents' laparoscopic surgical skills training on the successful implementation of LPN in a reference public teaching hospital in southern Brazil.

METHODS

We accessed all patients undergoing LPN by senior's urology residents at Hospital de Clínicas de Porto Alegre. Patients were stratified in 2 periods of time named 'LPN eras' 1 and 2, to report the training impact on the outcome. LPN era 1 was from October 2012 to February 2017 and LPN era 2 from March 2017 to June 2019. All the senior residents of LPN era 2 followed a simulation training divided into 4 years with a total training time of 244 hours before performing the LPN. Residents from LPN era 1 did not have simulation training.

RESULTS

124 patients underwent LPN during the study period, 53 (42.7%) of those were performed in LPN era 1 and 71 (57.3%) in LPN era 2. Baseline characteristics of the patients in the two groups were similar. The training performed by LPN era 2 residents was able to significantly reduce estimated blood loss, ischemia time and LOS with p value respectively 0.007, 0.001 and 0.001. LPN era 2 group also reached Trifecta in 77.5% of patients, being significantly more than in the LPN era 1 (p = 0.007).

CONCLUSIONS

Simulation in residents surgical training was able to improve clinical outcomes in LPN. These data reinforce the fundamental importance of adequate residents training before performing surgery on a patient.

Case Report: Optimizing Pre- and Intraoperative Planning With Hyperaccuracy Three-Dimensional Virtual Models for a Challenging Case of Robotic Partial Nephrectomy for Two Complex Renal Masses in a Horseshoe Kidney

Objective: To report a case of robot-assisted partial nephrectomy (RAPN) for two highly complex renal tumors in a patient with a Horseshoe kidney (HSK), focusing on the utility of hyperaccuracy three-dimensional (HA3D) virtual models for accurate preoperative and intraoperative planning of the procedure.

Methods: A 74-year-old Caucasian male patient was referred to our Unit for incidental detection of two complex renal masses in the left portion of a HSK. The 50 × 55 mm, larger, predominantly exophytic renal mass was located at the middle-lower pole of the left-sided kidney (PADUA score 9). The 16 × 17 mm, smaller, hilar renal mass was located at the middle-higher pole of the left-sided kidney (PADUA score 9). Contrast-enhanced CT scan images in DICOM format were processed using a dedicated software to achieve a HA3D virtual reconstructions. RAPN was performed by a highly experienced surgeon using the da Vinci Si robotic platform with a three-arm configuration. A selective delayed clamping strategy was adopted for resection of the larger renal mass while a clampless strategy was adopted for the smaller renal mass. An enucleative resection strategy was pursued for both tumors.

Results: The overall operative time was 150 min, with a warm ischemia time of 21 min. No intraoperative or postoperative complications were recorded. Final resection technique according to the SIB score was pure enucleation for both masses. At histopathological analysis, both renal masses were clear cell renal cell carcinoma (ccRCC) (stage pT1bNxMx and pT3aNxMx for the larger and smaller mass, respectively). At a follow-up of 7 months, there was no evidence of local or systemic recurrence.

Conclusions: Surgical management of complex renal masses in patients with HSKs is challenging and decision-making is highly nuanced. To optimize postoperative outcomes, proper surgical experience and careful preoperative planning are key. In this regard, 3D models can play a crucial role to refine patient counseling, surgical decision-making, and pre- and intraoperative planning during RAPN, tailoring surgical strategies and techniques according to the single patient's anatomy.

Robotic-assisted laparoscopic tumor enucleation is a feasible technique for renal hilar tumors: A retrospective study

BACKGROUND AND OBJECTIVE: This study aimed to evaluate the safety and efficacy of robot-assisted laparoscopic tumor enucleation (RAE) for the treatment of renal hilar tumors and to describe our experience with renorrhaphy-related surgical techniques.

METHODS

Retrospective data were collected from 173 consecutive patients who underwent RAE for localized renal tumors (cT1-cT2N0M0) at our hospital between September 2014 and November 2019.

RESULTS

Seventy-five patients had renal hilar tumors and 98 patients had nonhilar tumors. There were no statistical differences between the hilar and nonhilar groups in operation time (190 [115-390] vs. 190 [110-390] min, p = 0.889), warm ischemia time (26 [12-60] vs. 27 [17-41] min, p = 0.257), hospital stay duration (8 [3-16] vs. 7.5 [4-18] days, p = 0.386), renal function (estimated glomerular filtration rate, 102.5 [29.4-144] vs. 101.3 [64.2-134.7] ml/min/1.73 m² , p = 0.631); creatinine level, (76 [43-169] vs. 78.5 [50-281.3] µmol/L, p = 0.673), perioperative complications rate, or surgical margin status. However, patients with hilar tumors lost significantly more blood than did those with nonhilar tumors (250 [50-1500] vs. 200 [20-1200] ml, p = 0.007). During the follow-up period (median, 30 months), three patients in each group experienced recurrence. The 5-year recurrence-free rates were 93.0% and 95.4% in the hilar and nonhilar tumor groups, respectively (p = 0.640).

CONCLUSIONS

For experienced robot laparoscopists, RAE is a safe, effective, and feasible procedure for renal hilar tumors, without increased risk of positive surgical margins or worse midterm oncologic outcomes compared with nonhilar tumors.

Detection of a peritumoral pseudocapsule in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy using enhanced MDCT

To investigate the detection of peritumoral pseudocapsule (PC) using multi-detector row computed tomography (MDCT) for tumors resected by robot-assisted laparoscopic partial nephrectomy (RAPN) for T1 renal cell carcinoma (RCC). Study participants included 206 patients with clinical T1 RCC who underwent RAPN between October 2017 and February 2018. Two radiologists who were blinded to the pathological findings evaluated the computed tomography (CT) images. Radiological diagnosis of a PC was defined by a combination of observations, including a low-attenuation rim between the tumor and renal cortex in the cortico-medullary phase and a high-attenuation rim at the edge of the tumor in the nephrogenic or excretory phase. A PC was detected on CT in 156/206 tumors (76%) and identified by pathology in 182/206 (88%) tumors including 153/166 (92%) clear cell RCC, 13/14 (93%) papillary RCC, and 7/16 (44%) chromophobe RCC. In the whole cohort, CT findings showed a sensitivity of 81.3% (148/182), specificity of 66.7% (16/24), and positive predictive value of 94.9% (148/156). When the data were stratified according to pathological subtypes, MDCT was observed to have a sensitivity of 86.9% (133/153) and specificity of 61.5% (8/13) in clear cell RCC, sensitivity of 38.5% (5/13) and specificity of 100% (1/1) in papillary RCC, and sensitivity of 44.4% (4/7) and specificity of 66.7% (6/9) in chromophobe RCC. A low or high-attenuation rim around the tumor in the cortico-medullary or nephrographic-to-excretory phase indicates a PC of RCC, though the accuracy is not satisfactory even with 64- or 320-detector MDCT.

Contrast-enhanced ultrasound (CEUS) imaging for active surveillance of small renal masses

PURPOSE

To assess the safety and efficacy of contrast-enhanced ultrasound (CEUS) imaging for monitoring small (< 4 cm) renal masses (SRM) in patients undergoing active surveillance (AS).

METHODS

We retrospectively selected all consecutive patients with SRMs who underwent AS for at least 6 months at our Institution between January 2014 and December 2018. CEUS imaging was performed by two experienced genitourinary radiologists at established time points. The accuracy of CEUS for monitoring SRM size was compared with that of CT scan. For solid SRMs, four enhancement patterns (EP) were recorded. Radiological progression was defined as SRM growth rate ≥ 5 mm/year.

RESULTS

Overall, 158/1049 (15.1%) patients with SRMs underwent AS. At a median follow-up of 25 months (IQR 13-39), no patient died due to renal cell carcinoma (RCC). No patients experienced CEUS-related adverse events. There was a large variability in the pattern of growth of SRMs (overall median growth rate: 0.40 mm/year), with 9.5% of SRMs showing radiological progression. The median SRM size was comparable between CEUS and CT scan examinations at all time points. The vast majority (92.7%) of SRMs did not show a change in their EP over time; and there was no association between the SRM's EP and radiological progression or SRM size. Overall, 43 (27.2%) patients underwent delayed intervention (DI); median SRM size, and median growth rate were significantly higher in these patients as compared to those continuing AS.

CONCLUSION

In experienced hands, CEUS is a safe and effective strategy for active monitoring of SRMs in well-selected patients undergoing AS.

Long-Term Oncologic Outcomes After Laparoscopic and Robotic Tumor Enucleation for Renal Cell Carcinoma

OBJECTIVES

Tumor enucleation (TE) optimizes parenchymal preservation with promising short-term oncologic outcomes compared with standard partial nephrectomy (SPN). However, researches/literatures about long-term oncologic outcomes for TE after minimally invasive surgery are scarce. We aim to analyze long-term oncologic outcomes after laparoscopic and robotic tumor enucleation for renal cell carcinoma (RCC).

PATIENTS AND METHODS

We retrospectively analyzed 146 patients who underwent TE with either laparoscopic or robotic approach for localized RCC in our center. Local recurrence, cancer specific survival (CSS), recurrence free survival (RFS), and overall survival (OS) were the main outcomes. Survival curves were generated using a Kaplan-Meier method. Perioperative outcomes and pathological outcomes were also analyzed.

RESULTS

Overall, 98 male and 48 female patients were eligible for the study. The median tumor size was 3.4 cm with a median R.E.N.A.L. score of seven. Warm ischemia was used in 143 patients with a median ischemia time of 20 min and three patients had zero ischemia. Five patients (3.4%) had major complications (> Clavien IIIa) and only two were related to urinary system. The median global glomerular filtration rate (GFR) preserved after surgery was 93%. Pseudocapsule invasion was reported in 50 tumors (34%) and positive surgical margins were found in 3/146 (2.1%) tumors. At a median follow-up of 66 months, local recurrence happened in two patients (1.4%), and systemic recurrence happened in six patients (4.2%). The 5-year CSS, RFS, OS were 95.7, 89.6, and 91.9%, and the 10-year CSS, RFS, OS were 93.8, 89.6, and 90.0%, respectively.

CONCLUSION

This study indicates that tumor enucleation with laparoscopic or robotic approach in experienced hands for the treatment of RCC appears oncologically safe with a median follow-up of more than 5 years. Prospective studies with more patients and longer follow-up will be required to further evaluate oncologic safety after TE.

A preoperative nomogram predicting the pseudocapsule status in localized renal cell carcinoma

Background

Tumor enucleation (TE) surgery for localized renal cell carcinoma (RCC) relies on a complete peritumoral pseudocapsule (PC). Study objective was to develop a preoperative model to predict PC status.

Methods

The prediction model was developed in a cohort that consisted of 170 patients with localized RCC, and data was gathered from 2010 to 2015. Multivariable logistic regression analysis and R were used to generate this prediction model. The statistical performance was assessed with respect to the calibration, discrimination, and clinical usefulness.

Results

The prediction model incorporated the systemic inflammatory markers [neutrophil-lymphocyte ratio (NLR); albumin-globulin ratio (AGR)], CT imaging features (tumor size and necrosis), and clinical risk factors (BMI). The model showed good discrimination, with a C-index of 0.85 (0.78–0.91), and good calibration (P=0.60). The sensitivity and specificity were 62% and 94% respectively. Decision curves and clinical impact curve demonstrated that the current model was clinically useful.

Conclusions

We constructed a model that incorporated both the systematic inflammatory markers and clinical risk factors. It can be conveniently used to preoperatively predict the individualized risk of PC invasion and identify the best candidates to receive TE surgery.

Clinical predictors and significance of adherent perinephric fat assessed with Mayo Adhesive Probability (MAP) score and perinephric fat surface density (PnFSD) at the time of partial nephrectomy for localized renal mass. A single high-volume referral center experience

BACKGROUND

Adherent perinephric fat (APF) could negatively influence surgical outcomes of partial nephrectomy (PN). Novel radiological scores have been introduced to preoperatively detect APF, i.e. Mayo Adhesive Probability (MAP) score and perinephric fat surface density (PnFSD). We aimed to evaluate clinical predictors of APF and the association of MAP and PnFSD with perioperative outcomes after PN.

METHODS

Clinical and radiological data of patients undergoing open or robotic PN were prospectively gathered. Perinephric fat was retrospectively measured by a single expert uro-radiologist. Patients were divided into MAP 0-3 vs. MAP 4-5 and high vs. low PnFSD. Multivariable analysis was performed to seek for clinical predictors of APF.

RESULTS

Overall, 175 patients were entered. Patients with vs. without APF were significantly different regarding age, gender, ASA score, Charlson Comorbidity Index, Body Mass Index, waist circumference, HDL status and metabolic syndrome. Conversely, tumor-related characteristics were not significantly different between the groups. At multivariable analysis, metabolic syndrome was confirmed as the only independent predictor of APF (OR: 24.9; P<0.001). Notably, APF assessed by MAP score or PnFSD was not associated with perioperative outcomes after PN.

CONCLUSIONS

In experienced hands, APF did not impact on intra- or perioperative outcomes after PN. Metabolic syndrome was the only significant predictor of APF in our series.

Predicting positive surgical margins in partial nephrectomy: A prospective multicentre observational study (the RECORd 2 project)

PURPOSE

to evaluate clinical predictors of positive surgical margins (PSMs) in a large multicenter prospective observational study and to develop a clinic nomogram to predict the likelihood of PSMs after partial nephrectomy (PN).

MATERIALS AND METHODS

We prospectively evaluated 4308 patients who had surgical treatment for renal tumors between January 2013 and December 2016 at 26 urological Italian Centers (RECORd 2 project). Two multivariable logistic models were evaluated to predict the likelihood of PSMs. Center caseload was dichotomized using a visual assessment adjusted for several predictors of PSMs. A nomogram predicting PSMs was developed.

RESULTS

Overall, 2076 patients treated with PN were evaluated. pT1a, pT1b, pT2 and pT3a were recorded in 68.7%, 22.6%, 2.1% and 6.6% of the patients, respectively. PSMs were recorded in 342 (16.5%) patients. From a null multivariable model against number of PN/year, 60 PN/year were identified as the best cut-off to define a high-volume centre. At multivariable analysis, clinical stage (cT1a vs. cT2 [OR 1.94]; p = 0.03), volume centre (≤60 PN/year) (OR 2.22; p < 0.0001), imperative vs elective indication (OR 2.10; p = 0.04), surgical technique (laparoscopic vs. open [OR 1.62; p = 0.002), lymphovascular invasion (OR 2.27; p = 0.01) and upstaging to pT3a (OR 2.81; p < 0.0001) were independent predictors of PSMs. The final nomogram included age, ASA score, Charlson score, clinical tumor stage, surgical indication, surgical approach, surgical technique, PADUA score, clamp procedure and volume centre.

CONCLUSIONS

PSMs after PN were significantly more likely in patients with lower clinical stage, higher PADUA score, in individuals referred to laparoscopic PN and in those treated at lower volume centers. We used these data to develop a nomogram to predict such risk.

Management of small renal masses: An interventional radiologist's perspective

Renal cell carcinoma is relatively common malignancy. Its imaging features are often non-specific and can present a diagnostic dilemma for clinicians. Historically, all patients with a renal mass underwent radical nephrectomy. Advances in technology have allowed for an increase in partial nephrectomies and percutaneous ablations. This essay briefly describes some of the imaging findings of renal cell carcinoma and several of its mimics followed by an in-depth review of procedural management with a particular focus on recent advancements.

Accuracy of magnetic resonance imaging to identify pseudocapsule invasion in renal tumors

PURPOSE

To evaluate accuracy of MRI in detecting renal tumor pseudocapsule (PC) invasion and to propose a classification based on imaging of PC status in patients with renal cell carcinoma.

METHODS

From January 2017 to June 2018, 58 consecutive patients with localized renal cell carcinoma were prospectively enrolled. MRI was performed preoperatively and PC was classified, according to its features, as follows: MRI-Cap 0 (absence of PC), MRI-Cap 1 (presence of a clearly identifiable PC), MRI-Cap 2 (focally interrupted PC), and MRI-Cap 3 (clearly interrupted and infiltrated PC). A 3D image reconstruction showing MRI-Cap score was provided to both surgeon and pathologist to obtain complete preoperative evaluation and to compare imaging and pathology reports. All patients underwent laparoscopic partial nephrectomy. In surgical specimens, PC was classified according to the renal tumor capsule invasion scoring system (i-Cap).

RESULTS

A concordance between MRI-Cap and i-Cap was found in 50/58 (86%) cases. ρ coefficient for each MRI-cap and iCap categories was: MRI-Cap 0: 0.89 (p < 0.0001), MRI-Cap1: 0.75 (p < 0.0001), MRI-Cap 2: 0.76 (p < 0.0001), and MRI-Cap3: 0.87 (p < 0.0001). Sensitivity, specificity, positive predictive value, negative predictive value, and AUC were: MRI-Cap 0: Se 97.87% Spec 83.3%, PPV 95.8%, NPV 90.9%, and AUC 90.9; MRI-Cap 1: Se 77% Spec 95.5%, PPV 83.3%, NPV 93.5%, and AUC 0.86; MRI-Cap 2- iCap 2: Se 88% Spec 90%, PPV 79%, NPV 95%, and AUC 0.89; MRI-Cap 3: Se 94% Spec 95%, PPV 88%, NPV 97%, and AUC 0.94.

CONCLUSIONS

MRI-Cap classification is accurate in evaluating renal tumor PC features. PC features can provide an imaging-guided landmark to figure out where a minimal margin could be preferable during nephron-sparing surgery.