Surgical metastasectomy for metastatic renal cell carcinoma in the era of targeted and immune therapy: a narrative review.

PURPOSE: Metastatic renal cell carcinoma (mRCC) still harbours a big propensity for future metastasis. Combinations of immune and targeted therapies are currently the cornerstone of management with a less clear role for surgical metastasectomy (SM). METHODS: We performed a narrative review of literature searching for the available evidence on the yield of surgical metastasectomy in the era of targeted and immune therapies. The review consisted of a PubMed search of relevant articles using the Mesh terms:" renal cell carcinoma", "surgery¼, «resection", "metastasectomy", "molecular targeted therapies", "immune checkpoint inhibitors" alone or in combination. RESULTS: In this review, we exposed the place of surgical metastasectomy within a multimodal treatment algorithm for mRCC Also, we detailed the patient selection criteria that yielded the best results when SM was performed. Finally, we discussed the feasibility and advantages of SM per organ site. CONCLUSION: Our work was able to show that SM could be proposed as a consolidation treatment to excise residual lesions that were deemed unresectable prior to a combination of systemic therapies. Contrastingly, it can be proposed as an upfront treatment, leaving systemic therapies as an alternative in case of future relapse. However, patient selection regarding their performance status, metastatic sites, number of lesions and tumorous characteristics is of paramount importance.

Open versus robotic partial nephrectomy in obese patients: a multi-institutional propensity score-matched analysis (UroCCR 43-Robese study).

INTRODUCTION: There is limited evidence on the outcomes of robotic partial nephrectomy (RPN) and open partial nephrectomy (OPN) in obese patients (BMI ≥ 30 kg/m2). In this study, we aimed to compare perioperative and oncological outcomes of RPN and OPN. METHODS: We relied on data from patients who underwent PN from 2009 to 2017 at 16 departments of urology participating in the UroCCR network, which were collected prospectively. In an effort to adjust for potential confounders, a propensity-score matching was performed. Perioperative outcomes were compared between OPN and RPN patients. Disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared using the log-rank test. RESULTS: Overall, 1277 obese patients (932 robotic and 345 open were included. After propensity score matching, 166 OPN and 166 RPN individuals were considered for the study purposes; no statistically significant difference among baseline demographic or tumor-specific characteristics was present. A higher overall complication rate and major complications rate were recorded in the OPN group (37 vs. 25%, p = 0.01 and 21 vs. 10%, p = 0.007; respectively). The length of stay was also significantly longer in the OPN group, before and after propensity-score matching (p < 0.001). There were no significant differences in Warm ischemia time (p = 0.66), absolute change in eGFR (p = 0.45) and positive surgical margins (p = 0.12). At a median postoperative follow-up period of 24 (8-40) months, DFS and OS were similar in the two groups (all p > 0.05). CONCLUSIONS: In this study, RPN was associated with better perioperative outcomes (improvement of major complications rate and LOS) than OPN. The oncological outcomes were found to be similar between the two approaches.

Glomerular Filtration Rate Measured Based on Iomeprol Clearance Assessed at CT Urography in Living Kidney Donor Candidates.

Background Estimating glomerular filtration rate (GFR) from serum creatinine can be inaccurate, and current procedures for measuring GFR are time-consuming and cumbersome. Purpose To develop a method for measuring GFR based on iomeprol clearance assessed at CT urography in kidney donor candidates and compare this with iohexol clearance (reference standard for measuring GFR). Materials and Methods This cross-sectional retrospective study included data from kidney donor candidates who underwent both iohexol clearance and CT urography between July 2016 and October 2022. CT-measured GFR was calculated as the iomeprol excretion rate in the urinary system between arterial and excretory phases (Hounsfield units times milliliters per minute) divided by a surrogate for serum iomeprol concentration in the aorta at the midpoint (in Hounsfield units). Performance of CT-measured GFR was assessed with use of mean bias (mean difference between CT-measured GFR and iohexol clearance), precision (the distance between quartile 1 and quartile 3 of the bias [quartile 3 minus quartile 1], with a small value indicating high precision), and accuracy (percentage of CT-measured GFR values falling within 10%, 20%, and 30% of iohexol clearance values). Intraobserver agreement was assessed for 30 randomly selected individuals with the Lin concordance correlation coefficient. Results A total of 75 kidney donor candidates were included (mean age, 51 years ± 13 [SD]; 45 female). The CT-measured GFR was unbiased (1.1 mL/min/1.73 m2 [95% CI: -1.9, 4.1]) and highly precise (16.2 mL/min/1.73 m2 [quartiles 1 to 3, -6.6 to 9.6]). The accuracy of CT-measured GFR within 10%, 20%, and 30% was 61.3% (95% CI: 50.3, 72.4), 88.0% (95% CI: 80.7, 95.4), and 100%, respectively. Concordance between CT-based GFR measurements taken 2 months apart was almost perfect (correlation coefficient, 0.99 [95% CI: 0.98, 0.99]). Conclusion In living kidney donors, GFR measured based on iomeprol clearance assessed at CT urography showed good agreement with GFR measured based on iohexol clearance. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Davenport in this issue.

Machine-learning approach for prediction of pT3a upstaging and outcomes of localized renal cell carcinoma (UroCCR-15).

OBJECTIVES: To assess the impact of pathological upstaging from clinically localized to locally advanced pT3a on survival in patients with renal cell carcinoma (RCC), as well as the oncological safety of various surgical approaches in this setting, and to develop a machine-learning-based, contemporary, clinically relevant model for individual preoperative prediction of pT3a upstaging. MATERIALS AND METHODS: Clinical data from patients treated with either partial nephrectomy (PN) or radical nephrectomy (RN) for cT1/cT2a RCC from 2000 to 2019, included in the French multi-institutional kidney cancer database UroCCR, were retrospectively analysed. Seven machine-learning algorithms were applied to the cohort after a training/testing split to develop a predictive model for upstaging to pT3a. Survival curves for disease-free survival (DFS) and overall survival (OS) rates were compared between PN and RN after G-computation for pT3a tumours. RESULTS: A total of 4395 patients were included, among whom 667 patients (15%, 337 PN and 330 RN) had a pT3a-upstaged RCC. The UroCCR-15 predictive model presented an area under the receiver-operating characteristic curve of 0.77. Survival analysis after adjustment for confounders showed no difference in DFS or OS for PN vs RN in pT3a tumours (DFS: hazard ratio [HR] 1.08, P = 0.7; OS: HR 1.03, P > 0.9). CONCLUSIONS: Our study shows that machine-learning technology can play a useful role in the evaluation and prognosis of upstaged RCC. In the context of incidental upstaging, PN does not compromise oncological outcomes, even for large tumour sizes.

Oncocytoma on renal mass biopsy: is it still the same histology when surgery is performed? Results from UroCCR-104 study.

PURPOSE: To describe clinical features of patients with oncocytoma on renal biopsy (RMB), correlation with final histology on surgically treated patients, and predictive factors of discrepancy between RMB and final histology. METHODS: This was a retrospective study conducted in the framework of the UroCCR project (NCT03293563). All tumors with oncocytoma on RMB were selected and all pathological reports were reviewed. Patients with the RMB simultaneously performed with a focal treatment, synchronous bilateral tumors and ambiguous RMB report were excluded. Discrepancy between RMB and definitive histology was evaluated using a uni- and multivariable logistic regression analyses model. RESULTS: Overall, 119 tumors with oncocytoma on RMB, from 15 centers, were included. Of those, 54 (45.4%) had upfront surgery and 65 (54.6%) had active surveillance (AS). In renal masses with initial active surveillance, with a median follow-up of 28 months, 23 (19.3%) underwent surgery, 4 (3.4%) received focal treatment and 38 (31.9%) remained on AS. On final pathology, only 51 of the 75 surgically treated tumors (68.0%) had oncocytoma, while 24 presented malignant tumors (mainly chromophobe carcinoma (19.2%), and hybrid oncocytic/chromophobe tumor (HOCT) (6.8%)) leading to a discrepancy of 32.0% between RMB and final pathology. The only predictive factor of a discrepancy between RMB and definitive histology was a biopsy done outside of the center (Odds ratio: 3.22 [95%-confidence interval: 1.08-9.61], p = 0.03). CONCLUSION: Despite the increase of RMB in more and more centers, histologic discrepancy between RMB and definitive histology remains significant. This information should be discussed with patients and taken into consideration before treatment decision.

Nephrometry scores to predict oncological outcomes following partial nephrectomy (UroCCR Study 70).

PURPOSE: Partial nephrectomy (PN) for large or complex renal tumors can be difficult and associated with a higher risk of recurrence than radical nephrectomy. We aim to evaluate the clinical useful of nephrometry scores for predicting oncological outcomes in a large cohort of patients who underwent PN for renal cell carcinomas. METHODS: Our analysis included patients who underwent PN for renal cell carcinoma in 21 French academic centers (2010-2020). RENAL, PADUA, and SPARE scores were calculated based on preoperative imaging. Uni- and multivariate cox models were performed to identify predictors of recurrence-free survival and overall survival. The area under the curve (AUC) was used to identify models with the highest discrimination. Decision curve analyses (DCAs) determined the net benefit associated with their use. RESULTS: A total of 1927 patients were analyzed with a median follow-up of 32 months (14-45). RENAL score (p = 0.01), age (p = 0.002), histological type (p = 0.001), high nuclear grade (p = 0.001), necrotic component (p < 0.001), and positive margins (p = 0.005) were significantly related to recurrence in multivariate analyses. The discriminative performance of the 3 radiological scores was modest (65, 63, and 63%, respectively). All 3 scores showed good calibration, which, however, deteriorated with time. Decision curve analysis of the three models for the prediction of overall and recurrence-free survival was similar for all three scores and of limited clinical relevance. CONCLUSION: The association between nephrometry scores and oncological outcomes after NP is very weak. The use of these scores for predicting oncological outcomes in routine practice is therefore of limited clinical value.

Partial nephrectomy in solitary kidneys: comparison between open surgery and robotic-assisted laparoscopy on perioperative and functional outcomes (UroCCR-54 study).

PURPOSE: The management of solitary kidney tumors is a surgical challenge, requiring irreproachable results on both oncological and functional outcomes. The goal of our study was to compare the perioperative results of robotic-assisted partial nephrectomy (RAPN) to open surgery in this indication. METHODS: We led a multicentric study based on the prospectively maintained French national database UroCCR. Patients who underwent partial nephrectomy on a solitary kidney between 1988 and 2020 were included. Clinical and pathological data were retrospectively analyzed. The main outcome of the study was the analysis of the variation of the estimated glomerular filtration rate (eGFR) calculated according to MDRD at 3, 6, 12, and 24 months depending on the chosen surgical approach. The secondary outcomes were the comparison of Trifecta success, perioperative complications, and length of hospital stay. RESULTS: In total, 150 patients were included; 68 (45%) in the RAPN group and 82 (55%) in the open surgery group. The two groups were comparable for all data. The variation of eGFR at 3, 6, 12, or 24 months was comparable without any significant difference between the 2 groups (p = 0.45). Trifecta was achieved in 40% of the patients in the RAPN group and 33% in the open group (p = 0.42). A significant difference was observed for the length of stay, 5 days for the robot group versus 9 days for the open surgery group (p < 0.0001). CONCLUSION: In our study, the surgical approach did not modify functional results and we noted a significant decrease in hospital stay and complications in the RAPN group. RAPN is a safe and efficient method for management of kidney tumors in solitary kidneys.

Minimally invasive nephron-sparing treatments for T1 renal cell cancer in patients over 75 years: a comparison of outcomes after robot-assisted partial nephrectomy and percutaneous ablation.

PURPOSE: To compare the oncological and perioperative outcomes of robot-assisted partial nephrectomy (RPN) and percutaneous thermal ablation (PTA) for treatment of T1 renal cell cancer (RCC) in patients older than 75 years. MATERIALS AND METHODS: Retrospective national multicenter study included all patients older than 75 years treated for a T1 RCC by RPN or PTA between January 2010 and January 2021. Patients' characteristics, tumor data, and perioperative and oncological outcomes were compared. RESULTS: A total of 205 patients for 209 procedures (143 RPN and 66 PTA) were included. In the PTA group, patients were older (80.4 ± 3.7 vs. 79 ± 3.7 years (p = 0.01)); frailer (ASA score (2.43 ± 0.6 vs. 2.17 ± 0.6 (p < 0.01)); and more frequently had a history of kidney surgery (16.7% [11/66] vs. 5.6% [8/143] (p = 0.01)) than in the RPN group. Tumors were larger in the RPN group (2.7 ± 0.7 vs. 3.2 ± 0.9 cm (p < 0.01)). Operation time, length of hospital stay, and increase of creatinine serum level were higher in RPN (respectively 92.1 ± 42.7 vs. 150.7 ± 61.3 min (p < 0.01); 1.7 ± 1.4 vs. 4.2 ± 3.4 days (p < 0.01); 1.9 ± 19.3% vs. 10.1 ± 23.7 (p = 0.03)). Disease-free survival and time to progression were similar (respectively, HR 2.2; 95% CI 0.88-5.5; p = 0.09; HR 2.1; 95% CI 0.86-5.2; p = 0.1). Overall survival was shorter for PTA that disappeared after Cox adjusting model (HR 3.3; 95% CI 0.87-12.72; p = 0.08). CONCLUSION: Similar oncological outcomes are observed after PTA and RPN for T1 RCC in elderly patients. CLINICAL RELEVANCE STATEMENT: Robot-assisted partial nephrectomy and percutaneous thermal ablation have similar oncological outcomes for T1a kidney cancer in patients over 75 years; however, operative time, decrease in renal function, and length of hospital stay were lower with ablation. KEY POINTS: • After adjusting model for age and ASA score, similar oncological outcomes are observed after percutaneous thermal ablation and robot-assisted partial nephrectomy for T1 renal cell cancer in elderly patients. • Operation time, length of hospital stay, and increase of creatinine serum level were higher in the robot-assisted partial nephrectomy group.

Impact of Renal Cell Carcinoma Histological Variants on Recurrence After Partial Nephrectomy: A Multi-Institutional, Prospective Study (UROCCR Study 82).

BACKGROUND: The prognostic impact of renal cell carcinoma (RCC) morphotype remains unclear in patients who undergo partial nephrectomy (PN). Our objective was to determine the risk factors for recurrence after PN, including RCC morphotype. METHODS: Patients with RCC who had undergone PN were extracted from the prospective, national French database, UroCCR. Patients with genetic predisposition, bilateral or multiple tumours, and those who had undergone secondary totalization were excluded. Primary endpoint was 5-year, recurrence-free survival (RFS), and secondary endpoint was overall survival (OS). Risk factors for recurrence were assessed by multivariable Cox regression analysis. RESULTS: Overall, 2,767 patients were included (70% male; median age: 61 years [interquartile range (IQR) 51-69]). Most (71.5%) of the PN procedures were robot-assisted. Overall, 2,573 (93.0%) patients were recurrence free, and 74 died (2.7%). Five-year RFS was 84.9% (IQR 82.4-87.4). A significant difference in RFS was observed between RCC morphotypes (p < 0.001). Surgical margins (hazard ratio [HR] = 2.0 [95% confidence interval (CI): 1.3-3.2], p < 0.01), pT stage >1 (HR = 2.6 [95% CI: 1.8-3.7], p < 0.01]) and Fuhrmann grade >2 (HR = 1.9 [95% CI: 1.4-2.6], p < 0.001) were risk factors for recurrence, whereas chromophobe subtype was a protective factor (HR = 0.08 [95% CI: 0.01-0.6], p = 0.02). Five-year OS was 94.0% [92.4-95.7], and there were no significant differences between RCC subgroups (p = 0.06). The main study limitation was its design (multicentre national database), which may be responsible for declarative bias. CONCLUSIONS: Chromophobe morphotype was significantly associated with better RFS in RCC patients who underwent PN. Conversely, pT stage, Fuhrman group and positive surgical margins were risk factors for recurrence.

Three-Year Outcomes in Kidney Transplant Recipients Switched From Calcineurin Inhibitor-Based Regimens to Belatacept as a Rescue Therapy.

Background: The long-term benefits of conversion from calcineurin inhibitors (CNIs) to belatacept in kidney transplant recipients (KTr) are poorly documented.Methods: A single-center retrospective work to study first-time CNI to belatacept conversion as a rescue therapy [eGFR <30 ml/min/1.73 m2, chronic histological lesions, or CNI-induced thrombotic microangiopathy (TMA)]. Patient and kidney allograft survivals, eGFR, severe adverse events, donor-specific antibodies (DSA), and histological data were recorded over 36 months after conversion. Results: We included N = 115 KTr. The leading cause for switching was chronic histological lesions with non-optimal eGFR (56.5%). Three years after conversion, patient, and death-censored kidney allograft survivals were 88% and 92%, respectively, eGFR increased significantly from 31.5 ± 17.5 to 36.7 ± 15.7 ml/min/1.73 m2 (p < 0.01), the rejection rate was 10.4%, OI incidence was 5.2 (2.9-7.6) per 100 person-years. Older age was associated with death, eGFR was not associated with death nor allograft loss. No patient developed dnDSA at M36 after conversion. CNI-induced TMA disappeared in all cases without eculizumab use. Microvascular inflammation and chronic lesions remained stable. Conclusion: Post-KT conversion from CNIs to belatacept, as rescue therapy, is safe and beneficial irrespective of the switch timing and could represent a good compromise facing organ shortage. Age and eGFR at conversion should be considered in the decision whether to switch.

Comparison of the iliac, vaginal and umbilical graft extraction in robot-assisted laparoscopic living donor nephrectomy.

PURPOSE: To compare different extractions routes for robot-assisted living donor nephrectomy in terms of post-operative pain and renal function recovery. METHODS: Live donor kidney transplantation data from our institution were reviewed from November 2011 to March 2017. Postoperative pain was estimated using cumulative painkillers consumption. Variables were compared between the 3 groups with ANOVA for continuous data, χ2 test for categorial data. A survival analysis with Kaplan-Meier curve assessing time to transplant recipient nadir was performed to compare the renal function recovery. RESULTS: Sixty-three RLDN were performed (23 iliac, 23 vaginal and 17 umbilical extractions). There was no significant difference between the three groups in terms of operative time, blood lost, warm ischemia time, cumulative painkiller consumption and renal function recovery time. Postoperative complications for Umbilical, Vaginal and Iliac were, respectively, of 0, 3 and 1. No major difference was found between the 3 groups beside a slightly longer hospital stay in the iliac group. CONCLUSION: Iliac incision might impact post-operative pain with a moderate but significant longer hospital stay. Vaginal extraction is an option when cosmetic outcomes present a real demand. The three options appeared to be safe and should be discussed with the patient in regard of the surgeon experience.

1,000 Retroperitoneoscopic Procedures of the Upper Urinary Tract: Analysis of Complications.

BACKGROUND AND OBJECTIVE: To evaluate risk factors and complications of retroperitoneoscopic procedures of upper urinary tract and adrenal gland. METHODS: From 1994 to 2016, 1,000 retroperitoneal laparoscopies were performed - 476 nephrectomies, 201 adrenalectomies, 103 partial nephrectomies, 91 pyeloplasties, 70 nephro-ureterectomies, and 59 miscellaneous surgeries (diverticulectomy). Data collection was prospective. We analyzed age, body mass index (BMI), American Society of Anesthesiologists (ASA) score, operative time, blood loss, hospitalization stay and complications. Risks factors were explored with univariate and multivariate analysis. RESULTS: The mean BMI was 25 and median ASA 2. The mean operative time was 136 mn, mean blood loss 149 mL. There were 49 conversions. Of the patients, 41 required re-interventions, predominantly due to urinary fistula or post-operative bleeding. Post-operatively, 145 complications were recorded. In multivariate analysis, partial nephrectomies (OR 2.12, p = 0.031, 95% CI [1.07-4.22]) and pyeloplasties (OR 1.97, p = 0.02, 95% CI [1.11-3.48]) were significantly more at risk of complication than nephrectomies. An ASA score of 3 was also a significant risk factor of complications (OR 2.3, p = 0.014, 95% CI [1.17-4.47]) and an increased BMI carried a higher risk of conversion. There was no significant difference of conversion or complication rates between the first and last 500 patients. CONCLUSIONS: Upper urinary tract and adrenal surgeries can be performed by retroperitoneal laparoscopy. This surgical technic is safe and reproducible. The choice of the technic must be oriented by ASA, BMI and the type of surgery.

Prostate cancer incidence on cystoprostatectomy specimens is directly linked to age: results from a multicentre study.

OBJECTIVE: To assess the incidence and age-related histopathological characteristics of incidentally diagnosed prostate cancer from specimens obtained via radical cystoprostatectomy (RCP) for muscle-invasive bladder cancer. PATIENTS AND METHODS: A retrospective review of the histopathological features of 2424 male patients who underwent a RCP for bladder cancer was done at eight centres between January 1996 and June 2012. No patient had preoperative suspicion of prostate cancer. Statistical analyses were performed in different age-related groups. RESULTS: Overall, prostate cancer was diagnosed in 518 men (21.4%). Incidences varied significantly according to age (5.2% in those aged <50 years to 30.5% in those aged >75 years, P < 0.001). Most of the prostate cancers were considered as 'non-aggressive', that is to say organ-confined (≤pT2) and well-differentiated (Gleason score <7). Tumour-Node-Metastasis (TNM) stage and proportion with a Gleason score of ≥7 were significantly greater in older patients (P < 0.001). Apart from age, there were no preoperative predictive factors for 'non-aggressive' prostate-cancer status. At the end of the follow-up, only nine patients (1.7%) had biochemical recurrence of prostate cancer, and no preoperative predictive factors were identified. CONCLUSION: The rate of incidentally diagnosed prostate cancer from RCP specimens is ≈20%, most of them being organ-confined and well-differentiated. The probability of having a 'non-aggressive' prostate cancer decreases in older men.

Clinicopathological characteristics of incidental prostate cancer discovered from radical cystoprostatectomy specimen: a multicenter French study.

PURPOSE: The present study assessed the incidence and histopathological features of incidentally diagnosed prostate cancer (PCa) in specimens from radical cystoprostatectomy (RCP) for bladder cancer. The patient outcomes also were evaluated. METHODS: We retrospectively reviewed the histopathological features and survival data of 4,299 male patients who underwent a RCP for bladder cancer at 25 French centers between January 1996 and June 2012. No patients had preoperative clinical or biological suspicion of PCa. RESULTS: Among the 4,299 RCP specimens, PCa was diagnosed in 931 patients (21.7%). Most tumors (90.1%) were organ-confined (pT2), whereas 9.9% of them were diagnosed at a locally advanced stage (≥pT3). Gleason score was <6 in 129 cases (13.9%), 6 in 575 cases (61.7%), 7 (3 + 4) in 149 cases (16.0%), 7 (4 + 3) in 38 cases (4.1%), and >7 in 40 cases (4.3%). After a median follow-up of 25.5 months (interquartile range 14.2-47.4), 35.4% of patients had bladder cancer recurrence and 23.8% died of bladder cancer. Only 16 patients (1.9%) experienced PCa biochemical recurrence during follow-up, and no preoperative predictive factor was identified. No patients died from PCa. CONCLUSIONS: The rate of incidentally diagnosed PCa in RCP specimens was 21.7%. The majority of these PCas were organ-confined. PCa recurrence occurred in only 1.9% of cases during follow-up.

SAFE: Multi-institutional study of time to complications after robot-assisted partial nephrectomy, selection of a population eligible for outpatient management (UroCCR 90).

INTRODUCTION: The average hospital length of stay after robotic-assisted partial nephrectomy (RAPN) is 3 days, with a current trend towards outpatient cases, although no population has been identified. The main objective of the study was to analyze the time to onset of post-operative complications, identify risk factors for significant early complications in order to define a population eligible for outpatient case. MATERIAL AND METHOD: The study included 3342 patients with clinically localized renal tumors who underwent RAPN surgery between 2010 and 2021. The primary endpoint was the occurrence of significant complications (SC) (Clavien Dindo>2 (CD)). A CS-free survival analysis was performed. A multivariate logistic regression model was fitted to predict the risk of early significant complications (ESC) after RAPN. RESULTS: The rates of total complications and SC were 14.99% and 3.59% respectively. Median time to SC was significantly longer at 3 days [3.9 - 5.7] versus 2 days [2.4 - 3] for total complications (p=0.012). The majority of complications occurred within the first 72 hours, and the risk factors for early SC (<72h ) (ESC) were clamping time (p= 0.04) and ASA>2 score (p= 0.007). Analysis of survival without ESC showed a significant impact of clamping time (p=0.043) on complication-free survival. CONCLUSION: Using standard preoperative variables, we were able to determine that the only factor influencing the occurrence of postoperative ESC was ASA score >2 and thus define it as a primary eligibility criterion for an indication of outpatient RAPN subject to a clamp time of less than 20 minutes.

Preparing for the Worst: Management and Predictive Factors of Open Conversion During Minimally Invasive Renal Tumor Surgery (UroCCR-135 Study).

Background and objective: Data regarding open conversion (OC) during minimally invasive surgery (MIS) for renal tumors are reported from big databases, without precise description of the reason and management of OC. The objective of this study was to describe the rate, reasons, and perioperative outcomes of OC in a cohort of patients who underwent MIS for renal tumor initially. The secondary objective was to find the factors associated with OC. Methods: Between 2008 and 2022, of the 8566 patients included in the UroCCR project prospective database (NCT03293563), who underwent laparoscopic or robot-assisted minimally invasive partial (MIPN) or radical (MIRN) nephrectomy, 163 experienced OC. Each center was contacted to enlighten the context of OC: "emergency OC" implied an immediate life-threatening situation not reasonably manageable with MIS, otherwise "elective OC". To evaluate the predictive factors of OC, a 2:1 paired cohort on the UroCCR database was used. Key findings and limitations: The incidence rate of OC was 1.9% for all cases of MIS, 2.9% for MIRN, and 1.4% for MIPN. OC procedures were mostly elective (82.2%). The main reason for OC was a failure to progress due to anatomical difficulties (42.9%). Five patients (3.1%) died within 90 d after surgery. Increased body mass index (BMI; odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1.01-1.09, p = 0.009) and cT stage (OR: 2.22, 95% CI: 1.24-4.25, p = 0.008) were independent predictive factors of OC. Conclusions and clinical implications: In MIS for renal tumors, OC was a rare event (1.9%), caused by various situations, leading to impaired perioperative outcomes. Emergency OC occurred once every 300 procedures. Increased BMI and cT stage were independent predictive factors of OC. Patient summary: The incidence rate of open conversion (OC) in minimally invasive surgery for renal tumors is low. Only 20% of OC procedures occur in case of emergency, and others are caused by various situations. Increased body mass index and cT stage were independent predictive factors of OC.