Robot-assisted partial nephrectomy in cystic tumours: analysis of the Vattikuti Global Quality Initiative in Robotic Urologic Surgery (GQI-RUS) database

Surgical Outcomes of Hugo™ RAS Robot-Assisted Partial Nephrectomy for Cystic Renal Masses: Technique and Initial Experience

Background: The Hugo™ Robot-Assisted Surgery (RAS) system is a new cutting-edge robotic platform designed for clinical applications. Nevertheless, its application for cystic renal tumors has not yet been thoroughly investigated. In this context, we present an initial series of Robot-Assisted Partial Nephrectomy (RAPN) procedures carried out using the Hugo™ RAS system for cystic renal masses. Methods: Between October 2022 and January 2024, twenty-seven RAPN procedures for renal tumors were performed at Fondazione Policlinico Universitario Campus Bio-Medico. Our prospective board-approved dataset was queried for "cystic features" (n = 12). Perioperative data were collected. The eGFR was calculated according to the CKD-EPI formula. Post-operative complications were reported according to the Clavien-Dindo classification. Computed tomography (CT) scans for follow-up were performed according to the EAU guidelines. Trifecta was defined as the coexistence of negative surgical margin status, no Clavien-Dindo grade ≥ 3 complications, and eGFR decline ≤ 30%. Results: All the patients successfully underwent RAPN without the need for conversion or additional port placement. The median docking and console time were 5.5 (IQR, 4-6) and 79.5 min (IQR, 58-91 min), respectively. No intraoperative complications occurred, as well as clashes between instruments or with the bedside assistant. Two minor postoperative complications were recorded (Clavien-Dindo II). At discharge, serum creatinine and eGFR were comparable to preoperative values. Only one patient (8.4%) displayed positive surgical margins. The rate of trifecta achievement was 91.7%. Conclusions: RAPN for cystic renal masses using the novel Hugo™ RAS system can be safely and effectively performed. This robotic system provided satisfactory peri-operative outcomes, preserving renal function and displaying low postoperative complications and a high trifecta rate achievement.

Long-Term Oncologic Outcomes of Off-Clamp Robotic Partial Nephrectomy for Cystic Renal Tumors: A Propensity Score Matched-Pair Comparison of Cystic versus Pure Clear Cell Carcinoma

Few data are available on survival outcomes of partial nephrectomy performed for cystic renal tumors. We present the first long-term oncological outcomes of cystic (cystRCC) versus pure clear cell renal cell carcinoma (ccRCC) in a propensity score-matched (PSM) analysis. Our "renal cancer" prospectively maintained database was queried for "cystRCC" or "ccRCC" and "off-clamp robotic partial nephrectomy" (off-C RPN). The two groups were compared for age, gender, tumor size, pT stage, and Fuhrman grade. A 1:3 PSM analysis was applied to reduce covariate imbalance to <10% and two homogeneous populations were generated. Student t- and Chi-square tests were used for continuous and categorical variables, respectively. Ten-year oncological outcomes were compared between the two cohorts using log-rank test. Univariable Cox regression analysis was used to identify predictors of disease progression after RPN. Out of 859 off-C RPNs included, 85 cases were cystRCC and 774 were ccRCC at histologic evaluation. After applying the PSM analysis, two cohorts were selected, including 64 cystRCC and 170 ccRCC. Comparable 10-year cancer-specific survival probability (95.3% versus 100%, p = 0.146) was found between the two cohorts. Conversely, 10-year disease-free survival probability (DFS) was less favorable for pure ccRCC than cystRCC (66.69% versus 90.1%, p = 0.035). At univariable regression analysis, ccRCC histology was the only independent predictor of DFS probability (HR 2.96 95% CI 1.03-8.47, p = 0.044). At the 10-year evaluation, cystRCC showed favorable oncological outcomes after off-C RPN. Pure clear cell variant histology displayed a higher rate of disease recurrence than cystic lesions.

Perioperative and oncological outcomes of robot-assisted laparoscopic partial nephrectomy for cystic and solid renal masses: Evidence from controlled trials

To evaluate the outcomes of robot-assisted partial nephrectomy (RAPN) for solid and cystic renal tumors. We systematically searched the Cochrane Library, PubMed, EMBASE, and Scopus databases up to March 2023. Review Manager 5.4 performed a pooled analysis of the data for random effects. Besides, sensitivity and subgroup analyses to explore heterogeneity, Newcastle-Ottawa scale, and GRADE to evaluate study quality and level of evidence. Five observational studies comprising 1353 patients (Cystic tumor: 183; Solid tumor: 1083) were included in this study. Compared to solid masses, cystic masses were associated with fewer major complications (odds ratio [OR] = 2.2; 95% confidence intervals [CI] = 1.17 to 4.13; p = 0.01). Additionally, no significant differences were observed between the two groups in terms of operative time, warm ischemia time, blood loss, hospital stay, intraoperative complications, postoperative complications, transfusion rate, postoperative estimated glomerular filtration rate (eGFR), eGFR preservation, positive surgical margin (PSM), recurrence, overall survival (OS), cancer-specific survival (CSS), recurrence-free survival (RFS) and trifecta achievement. RAPN can be performed in cystic renal tumors with perioperative, functional, and oncologic outcomes like those achievable in solid tumors. However, our findings need further validation in a large-sample prospective randomized study.

Perioperative, oncologic, and functional outcomes of robot-assisted partial nephrectomy for special types of renal tumors (hilar, endophytic, or cystic): an evidence-based analysis of comparative outcomes

Purpose

This study aims to perform a pooled analysis to compare the outcomes of robot-assisted partial nephrectomy (RAPN) between complex tumors (hilar, endophytic, or cystic) and non-complex tumors (nonhilar, exophytic, or solid) and evaluate the effects of renal tumor complexity on outcomes in patients undergoing RAPN.

Methods

Four databases were systematically searched, including Science, PubMed, Web of Science, and Cochrane Library, to identify relevant studies published in English up to December 2022. Review Manager 5.4 was used for statistical analyses and calculations. The study was registered with PROSPERO (Registration number: CRD42023394792).

Results

In total, 14 comparative trials, including 3758 patients were enrolled. Compared to non-complex tumors, complex tumors were associated with a significantly longer warm ischemia time (WMD 3.67 min, 95% CI 1.78, 5.57; p = 0.0001), more blood loss (WMD 22.84 mL, 95% CI 2.31, 43.37; p = 0.03), and a higher rate of major complications (OR 2.35, 95% CI 1.50, 3.67; p = 0.0002). However, no statistically significant differences were found between the two groups in operative time, length of stay, transfusion rates, conversion to open nephrectomy and radical nephrectomy rates, estimated glomerular filtration rate (eGFR) decline, intraoperative complication, overall complication, positive surgical margins (PSM), local recurrence, and trifecta achievement.

Conclusions

RAPN can be a safe and effective procedure for complex tumors (hilar, endophytic, or cystic) and provides comparable functional and oncologic outcomes to non-complex tumors.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=394792, identifier CRD42023394792.

Implication of cystic fluid cytology of renal cell carcinoma on surgical practice

OBJECTIVES

To evaluate the incidence of positive cystic fluid cytology and its risk factors in cystic renal cell carcinoma (RCC) addressing its implication on the current surgical practice.

METHODS

All clinically diagnosed Bosniak III, IV cystic renal masses from March 2019 to August 2022 were studied prospectively. Database of patients' demographics and cystic tumor characteristics were recorded. Partial or radical nephrectomies were performed by either laparoscopic or robotic approach. Cystic fluid was collected right after specimen retrieval in the surgical field and examined by pathologist. Cytology results were compared to the demographic, perioperative variables using univariate and multivariate analysis.

RESULTS

A total of 70 patients of histologically confirmed cystic RCC were included. Sixty seven patients underwent radical nephrectomy with laparoscopic or robotic approaches, while 3 patients underwent radical nephrectomy. There was no intraoperative cystic rupture or fluid spillage. Positive cystic fluid cytology findings were identified in 34 (48.6%) patients, while negative cystic fluid cytology were identified in 36 (51.4%) cases. Definite malignant cells were observed in 28 patients while the other six patients showed highly suspicious atypical cells. Histologically, 24 (70.8%) patients were proven clear cell RCC and 25 (73%) showed Fuhrman grade 1 or 2 in final histologic review in positive group. Univariate and multivariate regression analysis between positive and negative cytology groups showed that the presence of the malignant cells in cystic fluid was significantly associated with patients' age (> 55 years) and Bosniak grade of cystic tumor (p < 0.05).

CONCLUSIONS

Definite malignant cells in cystic fluid cytology were observed through our study. Additionally, patients' age (> 55 years) and Bosniak grade were the significant risk factors of positive cytology in cystic RCC. Therefore, necessity of meticulous manipulation of cystic renal tumors, despite their clinical features, should not be underemphasized to avoid the least possible tumor cell seeding in case of cystic rupture when operating such high risk of positive cytology.

Surgical outcomes of robot-assisted laparoscopic partial nephrectomy for cystic renal cell carcinoma

To compare the surgical outcomes of robot-assisted partial nephrectomy (RAPN) between patients with cystic renal cell carcinoma (cRCC) and those with solid RCC (sRCC). We retrospectively analyzed 1065 patients who underwent RAPN between 2013 and 2020 for a pathological diagnosis of RCC. Patients were divided into two groups: cRCC and sRCC. cRCC was diagnosed according to the Bosniak classification system. To minimize selection bias between the two groups, patient variables (patient characteristics) and tumor factors (such as size and complexity) were adjusted using 1:1 propensity score matching. Of the 1065 patients, 94 (9%) were diagnosed with cRCC. Bosniak categories of IIF, III, and IV were noted in 4 (4.2%), 31 (33%), and 59 (63%) patients, respectively. After matching, 83 patients each were assigned to the cRCC and sRCC groups. The operation time in cRCC tended to be longer than in sRCC but not significantly different (164 vs. 150 min, P = 0.0767). Other surgical outcomes, such as change in estimated glomerular filtration rate ( - 5.2 vs.  - 7.2%, P = 0.1577), perioperative complications (14.5 vs. 15.7%, P = 0.9225), estimated blood loss (62 vs. 58 mL, P = 0.5613), or negative surgical margin status (100 vs 99%, P = 0.236), were not significantly different between the two groups. During the follow-up period of about 2 years, one and two patients showed recurrence in the cRCC and sRCC groups, respectively. The surgical outcomes of RAPN were similar between cRCC and sRCC, demonstrating the feasibility of RAPN for cRCC.

Long-Term Functional and Oncologic Outcomes of Robot-Assisted Partial Nephrectomy for Cystic Renal Tumors: A Single-Center Retrospective Study

Objectives: To evaluate the outcomes of robot-assisted partial nephrectomy (RAPN) in cystic renal tumors. Materials and Methods: We retrospectively analyzed patients who underwent RAPN for either cystic (n = 46) or solid (n = 271) renal tumors at Fujita Health University between 2010 and 2019. Cystic renal tumors were diagnosed using cross-sectional imaging. Perioperative, oncologic, and functional outcomes were assessed. Results: The median follow-up periods were 38, 41, and 37 months in the total, cystic, and solid groups, respectively. Most patient characteristics were similar among both groups, while the median age of the cystic group was significantly lower than that of the solid group (p = 0.02). Most perioperative variables and complications were comparable between the two groups. There was no significant difference between the groups in perioperative renal function. The estimated glomerular filtration rate preservation rates were 93.1% and 89.2% in the cystic and solid groups, respectively (p = 0.17). The cystic group showed a higher benign histology rate (19.6% vs 7%) and lower Fuhrman grade than the solid group (24.3% vs 15.1% in grade 1, and 73% vs 81.3% in grade 2), although there was no statistically significant difference between the two groups. In the solid group, 10 patients (3.7%) experienced recurrence, and 2 patients (0.7%) died of renal-cell carcinoma, while none of the patients with cystic tumors experienced recurrence. There was no statistically significant difference between the cystic and solid tumors with respect to 5-year recurrence-free survival (p = 0.18), cancer-specific survival (p = 0.55), and overall survival (p = 0.35). Conclusions: RAPN for cystic renal tumors appears to be safe and feasible with perioperative, long-term functional and oncologic outcomes comparable with those in solid tumors. RAPN can be a safe and effective surgical option for cystic renal tumors.

Partial nephrectomy for a Bosniak IV cystic renal mass mimicking a simple renal cyst adjacent to a solid renal tumor

INTRODUCTION

Renal tumors are often associated with renal cysts. Meanwhile, in some cases there are challenging issues of how to diagnose renal cystic tumors and to decide surgical procedures.

CASE PRESENTATION

A 75-year-old man was referred to our department for a 21-mm tumor by his left kidney. Contrast-enhanced computed tomography showed an intense contrast uptake the tumor, which was adjacent to a 64-mm unilocular renal cyst with no contrasting effects. It was clinically diagnosed as renal cell carcinoma, stage T1aN0M0, and treated with robot-assisted partial nephrectomy, for both the solid tumor and the adjacent cyst. Pathological findings revealed a tumor cell clump within the cyst wall, concurrent with the renal cell carcinoma. The patient has remained free of disease at 1 year after surgery.

CONCLUSION

A partial nephrectomy that includes the entire cyst wall should be considered for renal tumor associated with unilocular renal cyst.

Computed tomography features predicting aggressiveness of malignant parenchymal renal tumors suitable for partial nephrectomy

The aim of this study was to identify and standardize computed tomography (CT) features having a potential role in predicting aggressiveness of malignant parenchymal renal tumors suitable for partial nephrectomy (PN). We performed a non-systematic review of the recent literature to evaluate the potential impact of CT variables proposed by the Society of Abdominal Radiology Disease-Focused Panel on Renal Cell Carcinoma in predicting aggressiveness of newly diagnosed malignant parenchymal renal tumors. The analyzed variables were clinical tumor size, tumor growth rate, enhancement characteristics, amount of cystic component, polar and capsular location, tumor margins and distance between tumor and renal sinus. Unfavorable behavior was defined as: 1) renal cell carcinoma (RCC) with stage ≥pT3; 2) nuclear grade 3 or 4; 3) presence of sarcomatoid de-differentiation; or 4) non-clear cell subtypes with unfavorable prognosis (type 2 papillary RCC, collecting duct or renal medullary carcinoma, unclassified RCC). Beyond clinical tumor size, tumor growth rate, enhancement characteristics, amount of cystic component, tumor margins and distance between tumor and renal sinus are highly relevant features predicting an unfavorable behavior. Moreover, several studies supported the role of necrosis as preoperative predictor of tumor aggressiveness. Peritumoral and intratumoral vasculature as well as capsule status are emerging variables that need to be further evaluated. Tumor size, enhancement characteristics, tumor margins and distance to the renal sinus are highly relevant CT features predicting biological aggressiveness of malignant parenchymal renal tumors. Combination of these parameters might be useful to generate tools to predict the unfavorable behavior of renal tumors suitable for PN.

Risk factors for intraoperative cyst rupture in partial nephrectomy for cystic renal masses

PURPOSE

To determine the risk factors of intraoperative cyst rupture in partial nephrectomy (PN) for a cystic renal mass (CRM) and their effect on the prognosis of patients.

MATERIALS AND METHODS

Patients who underwent partial nephrectomy for CRMs from January 2009 to January 2015 were included. Uni/multivariate Logistic/Cox analysis and Kaplan-Meier analysis were performed.

RESULTS

A total of 174 patients were included in this study. There were 27 (15.5%) intraoperative cyst ruptures. The median follow-up time was 60 months. Multivariate logistic analysis showed that the E component (P = 0.018) and N component (P = 0.022) of the R.E.N.A.L. nephrometry score, Bosniak category III (P = 0.044), and surgeon's experience (P = 0.030) were risk factors associated with intraoperative cyst rupture in PN for CRMs. The 5-year recurrence-free survival (RFS), cancer-free survival (CFS) and overall survival (OS) were 92.7%, 90.32% and 94.4%, respectively, in 124 cases of malignant CRM. Kaplan-Meier analysis demonstrated that 5-year RFS and 5-year CFS in patients with cyst rupture was worse than those without cyst rupture (P = 0.006 and 0.003, respectively). Multivariate Cox analysis revealed that intraoperative cyst rupture was independent risk factor for 5-year RFS and 5-year CFS (P = 0.039 and 0.013, respectively). However, there was no significant difference in OS between the two groups (P = 0.275).

CONCLUSIONS

The prevalence of intraoperative cyst rupture is relatively high. Higher E and N scores, Bosniak category III, and lacking surgical experience (<20 cases) increase the risk of occurrence of intraoperative cyst rupture.

Intraoperative Cyst Rupture during Partial Nephrectomy for Cystic Renal Masses-Does it Increase the Risk of Recurrence?

PURPOSE

Our objective was to assess the prevalence of intraoperative cyst rupture and its impact on oncologic outcomes.

MATERIALS AND METHODS

All patients who underwent partial nephrectomy for a cystic renal mass via an open or robot-assisted approach at a total of 8 academic institutions were included in this retrospective study. All operative reports were carefully reviewed and any description of cyst rupture, cyst effraction or local spillage intraoperatively was recorded as cyst rupture. Multivariate logistic regression analysis was done to assess the variables associated with cyst rupture. Recurrence-free, cancer specific and overall survival was estimated by the Kaplan-Meier method and compared with the log rank test.

RESULTS

Overall 268 patients were included in study. There were 50 intraoperative cyst ruptures (18.7%) in the whole cohort. No preoperative parameter was significantly associated with a risk of intraoperative cyst rupture on univariate or multivariate analysis. Of the cystic renal masses 75% were malignant on the final pathology report. At a median followup of 32 months 5 patients (2.5%) had local recurrence while progression to metastasis was observed in 2%. There were no peritoneal carcinomatosis nor port site metastasis. There was also no local or metastatic recurrence in the subgroup with intraoperative cyst rupture. Estimated recurrence-free survival did not differ significantly between patients with vs without intraoperative cyst rupture at 100% vs 92.7% at 5 years (p = 0.20).

CONCLUSIONS

Intraoperative cyst rupture during partial nephrectomy is a relatively common occurrence but with few oncologic implications.

Outcome Measures Used to Report Kidney Function in Studies Investigating Surgical Management of Kidney Tumours: A Systematic Review

CONTEXT

Most practice decisions relevant to preserving kidney function in patients managed surgically for kidney tumours are driven by observational studies. A wide range of outcome measures are used in these studies, which reduces comparability and increases the risk of reporting bias.

OBJECTIVE

To comprehensively and succinctly describe the outcomes used to evaluate kidney function in studies evaluating surgical management of kidney tumours.

EVIDENCE ACQUISITION

Electronic search of the PubMed database was conducted to identify studies with at least one measure of kidney function in patients managed surgically for kidney tumours, published between January 2000 and September 2017. Abstracts were initially screened for eligibility. Full texts of articles were then evaluated in more detail for inclusion. A narrative synthesis of the evidence was conducted.

EVIDENCE SYNTHESIS

A total of 312 studies, involving 127905 participants, were included in this review. Most were retrospective (n=274) studies and conducted in a single centre (n=264). Overall, 78 unique outcome measures were identified, which were grouped into six outcome categories. Absolute postoperative kidney function (n=187), relative kidney function (n=181), and postoperative chronic kidney disease (n=131) were most frequently reported. Kidney function was predominantly quantified using estimated glomerular filtration rate or creatinine clearance (n=255), most using the modification of diet in renal disease equation (n=182). Only 70 studies provided rationale for specific outcome measures used.

CONCLUSIONS

There is significant variability in the reporting and quantification of kidney function in studies evaluating patients managed surgically for kidney tumours. A standardised approach to measuring and reporting kidney function will increase the effectiveness of outcomes reported and improve relevance of research findings within a clinical context.

PATIENT SUMMARY

Although we know that the removal of a kidney can reduce kidney function, clinical significance of various approaches is a matter of debate. This article demonstrates significant variability in the way kidney function was reported across all studies of patients with kidney cancer undergoing surgery, indicating a need for standardisation.

Robot-assisted partial nephrectomy: systematic review of functional results

PURPOSE OF REVIEW

Various ischemia type during partial nephrectomy for renal cell cancer (RCC) resulted in different postoperative functional outcomes. Our objective was to systematically review the contemporary literature on robot-assisted partial nephrectomy (RPN) and investigate the association of ischemia type and tumor complexity with postoperative functional outcomes of the operated kidney and overall.

RECENT FINDINGS

Forty-five of the 99 reports identified were selected for qualitative analysis. All included studies were observational and nonrandomized. Overall, we found that patients undergoing RPN with zero ischemia and selective artery clamping had a lower decrease in glomerular filtration rates of the operated kidney in comparison to both warm and cold ischemia. This association seems also to play a role in patients with bilateral kidneys harboring complex tumors.

SUMMARY

Zero ischemia and selective artery clamping provide the best functional outcomes following robotic partial nephrectomy. This seems to be of particular relevance in patients with single kidney or tumors of high complexity. Whether these changes are statistically or clinically significant cannot be determined within this systematic review.

Robot-assisted partial nephrectomy confers excellent long-term outcomes for the treatment of complex cystic renal tumors: Median follow up of 58 months

OBJECTIVES

To analyze long-term outcomes of robot-assisted partial nephrectomy for treatment of complex cystic renal tumors.

METHODS

We retrospectively analyzed the data of patients who underwent robot-assisted partial nephrectomy for cystic (n = 32) and solid (n = 263) renal masses at Severance Hospital, Seoul, Korea. The primary outcome was assessment of perioperative safety for cystic tumor. Secondary outcomes were evaluation of long-term oncological and functional results.

RESULTS

Patients' clinical and demographic characteristics were similar among both groups. The median follow up of cystic and solid masses were 58 and 46 months, respectively. Cystic masses were more likely to have low Fuhrman grade 1 and 2 (P = 0.03), and shorter operative time (P = 0.04) compared with solid masses. There was no statistically significant difference regarding warm ischemia time, estimated blood loss, trifecta achievement, length of hospital stay, complication rates and renal function preservation (P > 0.05) between groups. In the solid group, 12 patients (4.1%) recurred, and six patients (2%) died from metastatic renal cell carcinoma, whereas the patients in the cystic group did not have any local or distance recurrence, and the survival rates were 100%. The 5-year cancer-free survival (P = 0.77), cancer-specific survival (P = 0.65) and overall survival (P = 0.83) rates were similar between the groups.

CONCLUSION

Robot-assisted partial nephrectomy appears to be safe and feasible treatment for complex cystic renal masses. It confers excellent long-term oncological outcomes. Robot-assisted partial nephrectomy should be the treatment of choice for complex cysts whenever feasible.