Preoperative aspirin and anticoagulants do not affect partial nephrectomy bleeding

INTRODUCTION

Studies have reached mixed conclusions on the role of antiplatelet and anticoagulant agents on postoperative complications of partial nephrectomies. This study examines whether preoperative anticoagulation use affected the risk of hemorrhagic complications after partial nephrectomy.

MATERIALS AND METHODS

This is a retrospective chart review of all partial nephrectomies performed between 2017 and 2022 at a single institution. For each operation, preoperative data was gathered on whether the patient was on anticoagulation, the type and dose of anticoagulation, and how many days the anticoagulation was held preoperatively. Bivariate analyses for continuous measures were performed using Student's t-tests when there were two comparison groups and ANOVA models when there were more than two comparison groups and Chi-Square tests were used for categorical variables, with Fisher's Exact being used when expected cell counts were small.

RESULTS

In this study, warfarin was held for an average of 5.43 days, clopidogrel was held for an average of 6.60 days, aspirin was held for an average of 7.65 days, and direct oral anticoagulants (DOACs) were held for an average of 4.00 days. There was no significant difference in hemoglobin (Hb) change, rate of intraoperative transfusion, postoperative transfusion, bleeding complication, pseudoaneurysm rate, or additional bleeding processes between patients on prior anticoagulation therapy and those not on therapy. There was no significant difference in intraoperative or postoperative outcomes based on history of aspirin use and continuation of aspirin through the surgery. While estimated blood loss appeared statistically significant initially, this difference was accounted for by the covariates of comorbidities, RENAL score, surgical approach, and type of renorrhaphy. Overall, there was no difference in complication rate based solely on aspirin use or continuation of aspirin through surgery.

CONCLUSIONS

No difference in complication rate of partial nephrectomy was determined to be solely due to prior use of anticoagulation or aspirin use alone with appropriate cessation of anticoagulation preoperatively. Overall, patients on anticoagulation are not at a higher risk of intraoperative or postoperative bleeding complications when undergoing partial nephrectomy.

An Adaptive Human-Robotic Interaction Architecture for Augmenting Surgery Performance Using Real-Time Workload Sensing-Demonstration of a Semi-autonomous Suction Tool

OBJECTIVE

This study developed and evaluated a mental workload-based adaptive automation (MWL-AA) that monitors surgeon cognitive load and assist during cognitively demanding tasks and assists surgeons in robotic-assisted surgery (RAS).

BACKGROUND

The introduction of RAS makes operators overwhelmed. The need for precise, continuous assessment of human mental workload (MWL) states is important to identify when the interventions should be delivered to moderate operators' MWL.

METHOD

The MWL-AA presented in this study was a semi-autonomous suction tool. The first experiment recruited ten participants to perform surgical tasks under different MWL levels. The physiological responses were captured and used to develop a real-time multi-sensing model for MWL detection. The second experiment evaluated the effectiveness of the MWL-AA, where nine brand-new surgical trainees performed the surgical task with and without the MWL-AA. Mixed effect models were used to compare task performance, objective- and subjective-measured MWL.

RESULTS

The proposed system predicted high MWL hemorrhage conditions with an accuracy of 77.9%. For the MWL-AA evaluation, the surgeons' gaze behaviors and brain activities suggested lower perceived MWL with MWL-AA than without. This was further supported by lower self-reported MWL and better task performance in the task condition with MWL-AA.

CONCLUSION

A MWL-AA systems can reduce surgeons' workload and improve performance in a high-stress hemorrhaging scenario. Findings highlight the potential of utilizing MWL-AA to enhance the collaboration between the autonomous system and surgeons. Developing a robust and personalized MWL-AA is the first step that can be used do develop additional use cases in future studies.

APPLICATION

The proposed framework can be expanded and applied to more complex environments to improve human-robot collaboration.

Impact of Variant Histology on Oncological Outcomes in Upper Tract Urothelial Carcinoma: Results From the ROBUUST Collaborative Group

INTRODUCTION

Oncologic implications of variant histology (VH) have been extensively studied in bladder cancer; however, further investigation is needed in upper tract urothelial carcinoma (UTUC). Our study aims to evaluate the impact of VH on oncological outcomes in UTUC patients treated with radical nephroureterectomy (RNU).

METHODS

A retrospective analysis was performed on patients who underwent a robotic or laparoscopic RNU for UTUC using the ROBUUST database, a multi-institutional collaborative including 17 centers worldwide. Logistic regression was used to assess the effect of VH on urothelial recurrence (bladder, contralateral upper tract), metastasis, and survival following RNU.

RESULTS

A total of 687 patients were included in this study. Median (IQR) age was 71 (64-78) years and 470 (68%) had organ confined disease. VH was present in 70 (10.2%) patients. In a median follow-up of 16 months, the incidence of urothelial recurrence, metastasis, and mortality was 26.8%, 15.3%, and 11.8%, respectively. VH was associated with increased risk of metastasis (HR 4.3, P <.0001) and death (HR 2.0, P =.046). In multivariable analysis, VH was noted to be an independent risk factor for metastasis (HR 1.8, P =.03) but not for urothelial recurrence (HR 0.99, P =.97) or death (HR 1.4, P =.2).

CONCLUSION

Variant histology can be found in 10% of patients with UTUC and is an independent risk factor for metastasis following RNU. Overall survival rates and the risk of urothelial recurrence in the bladder or contralateral kidney are not affected by the presence of VH.

Physiological Metrics of Surgical Difficulty and Multi-Task Requirement during Robotic Surgery Skills

Previous studies in robotic-assisted surgery (RAS) have studied cognitive workload by modulating surgical task difficulty, and many of these studies have relied on self-reported workload measurements. However, contributors to and their effects on cognitive workload are complex and may not be sufficiently summarized by changes in task difficulty alone. This study aims to understand how multi-task requirement contributes to the prediction of cognitive load in RAS under different task difficulties. Multimodal physiological signals (EEG, eye-tracking, HRV) were collected as university students performed simulated RAS tasks consisting of two types of surgical task difficulty under three different multi-task requirement levels. EEG spectral analysis was sensitive enough to distinguish the degree of cognitive workload under both surgical conditions (surgical task difficulty/multi-task requirement). In addition, eye-tracking measurements showed differences under both conditions, but significant differences of HRV were observed in only multi-task requirement conditions. Multimodal-based neural network models have achieved up to 79% accuracy for both surgical conditions.

Outcomes of Robot-Assisted Laparoscopic Pyeloplasty Based on Degree of Obstruction on Preoperative Tc-99 MAG-3 Renal Scintigraphy

Objective: Management of symptomatic ureteropelvic junction (UPJ) obstruction with hydronephrosis and discordant Tc-99 mercaptoacetyltriglycine (MAG-3) renal scintigraphy is challenging. In this study we describe long-term outcomes of patients who underwent robot-assisted laparoscopic pyeloplasty for the correction of symptomatic UPJ obstruction with discordant preoperative Tc-99m MAG-3 renal scintigraphy. Methods: Patients undergoing robot-assisted laparoscopic pyeloplasty for symptomatic UPJ obstruction at a single academic center from 2009 to 2021 were retrospectively reviewed. Patients were categorized into three groups with varying degrees of obstruction based on preoperative MAG-3 imaging: Group 1: no obstruction (Lasix T1/2 clearance <10 minutes), Group 2: equivocal obstruction (Lasix T1/2 clearance 10-20 minutes), and Group 3: obstruction (Lasix T1/2 clearance >20 minutes. Pyeloplasty success was defined as resolution of symptoms and improvement/stable computed tomography (CT) imaging or MAG-3 scintigraphy. Failure was defined as persistence of symptoms with either obstruction on functional imaging, worsening hydronephrosis, or subsequent intervention. Results: A total of 125 cases were identified, with a median patient age of 35 years. Dismembered pyeloplasty technique was performed in 98.4% of cases. Median preoperative split renal function on MAG-3 scintigraphy was the only statistically significant (p = 0.003) difference in preoperative characteristics between the three groups. There were 15 postoperative complications, with a rate of Clavien-Dindo grade 3 or higher complications of 4.8%. Overall pyeloplasty success was 92.8%, with success rates of 100% (15/15) and 97% (32/33) in the no obstruction and equivocal obstruction groups, respectively. Median time to pyeloplasty failure was 20.4 months. Conclusion: Robot-assisted laparoscopic pyeloplasty is a safe and effective surgical intervention for correcting UPJ obstruction. Patients with symptoms of UPJ obstruction and discordant functional imaging studies demonstrate similar or improved success rates after pyeloplasty compared with patients with documented high-grade obstruction. Based on these findings preoperative renal scan may not be reliable in appropriate selection of candidacy for pyeloplasty.

On-Clamp vs. Off-Clamp Robot-Assisted Partial Nephrectomy for cT2 Renal Tumors: Retrospective Propensity-Score-Matched Multicenter Outcome Analysis

We compared perioperative outcomes after on-clamp versus off-clamp robot-assisted partial nephrectomy (RAPN) for >7 cm renal masses. A multicenter dataset was queried for patients who had undergone RAPN for a cT2cN0cM0 kidney tumor from July 2007 to February 2022. The Trifecta achievement (negative surgical margins, no severe complications, and ≤ 30% postoperative estimated glomerular filtration rate (eGFR) reduction) was considered a surrogate of surgical quality. Overall, 316 cases were included in the analysis, and 58% achieved the Trifecta. A propensity-score-matched analysis generated two cohorts of 89 patients homogeneous for age, ASA score, preoperative eGFR, and RENAL score (all p > 0.21). Compared to the on-clamp approach, OT was significantly shorter in the off-clamp group (80 vs. 190 min; p < 0.001), the incidence of sRFD was lower (22% vs. 40%; p = 0.01), and the Trifecta rate higher (66% vs. 46%; p = 0.01). In a crude analysis, >20 min of hilar clamping was associated with a significantly higher risk of sRFD (OR: 2.30; 95%CI: 1.13−4.64; p = 0.02) and with reduced probabilities of achieving the Trifecta (OR: 0.46; 95%CI: 0.27−0.79; p = 0.004). Purely off-clamp RAPN seems to be a safe and viable option to treat cT2 renal masses and may outperform the on-clamp approach regarding perioperative surgical outcomes.

Temporal Study of Renal Volume Losses in Patients with Robotic Partial Nephrectomies

Purpose: Robotic partial nephrectomies (RPNs) by their nature are associated with renal volume loss. Our goal of this study is to examine renal volume loss over time post partial nephrectomy. Materials and Methods: Fifty patients were followed for 1-year post-RPN with two-layer renorrhaphy and the sliding clip technique. This was done with a preoperative CT scan to assess renal mass and location. Patients post-RPN were imaged at time points 3 days, 6 months, and 12 months. Results: Patient demographics were 82% men with a median (interquartile range [IQR]) age of 57 (45-67) years and all were of Japanese descent. The medians (IQR) for warm ischemia time were 18 minutes (14-22), total operative time was 181.5 minutes (169.3-218.5), and estimated blood loss was 20 mL (10-50). The tumor characteristics had a median (IQR) diameter of 2.8 cm (2.5-3.4) with a RENAL score of 7 (6-8). The renal CT showed median (IQR) volume losses at 3 days of -1% (-7.1, 1.8), at 6 months of -15.3% (-20.6, -11.2), and at 12 months of -16.3% (-19.0, -12.8). Significance was seen at the 3 days to 6 months comparison for volume loss (p < 0.0001). Mean (standard deviation) estimated glomerular filtration rate (GFR) losses were as follows: at discharge 0.5% (12.9), 1 month -6.4% (11.8), 6 months -4.6% (9.8), and 12 months -3.6% (11.9). Statistical analysis showed significance for GFR loss at the comparison between discharge to 1 and 6 months (p = 0.01, p = 0.04). Conclusion: The initial volume loss seen postsurgery from resected healthy tissue was not significant and only became relevant at longer time points, suggesting that loss could be from atrophy. Volume loss over time supports the hypothesis that suture renorrhaphy is a primary cause of volume loss when warm ischemia time is <25 minutes.

Robotic vs laparoscopic nephroureterectomy for upper tract urothelial carcinoma: a multicenter propensity-score matched pair "tetrafecta" analysis (ROBUUST collaborative group)

PURPOSE

To compare the outcomes of robotic radical nephroureterectomy (RRNU) and laparoscopic radical nephroureterectomy (LRNU) within a large multi-institutional worldwide dataset.

MATERIAL AND METHODS

The ROBotic surgery for Upper tract Urothelial cancer STudy (ROBUUST) includes data from 17 centers worldwide regarding 877 RRNU and LRNU performed between 2015 and 2019. Baseline features, perioperative and oncological outcomes, were included. A 2:1 nearest-neighbor propensity-score matching with a 0.001 caliper was performed. An univariable and a multivariable logistic regression model were built to evaluate the predictors of a composite "tetrafecta" outcome defined as occurrence of bladder cuff excision + LND + no complications + negative surgical margins.

RESULTS

After matching, 185 RRNU and 91 LRNU were assessed. Patients in the RRNU group were more likely to undergo bladder cuff excision (81.9% vs 63.7%; p<0.001) compared to the LRNU group. A statistically significant difference was found in terms of overall postoperative complications (p=0.003) and length of stay (p<0.001) in favor of RRNU. Multivariable analysis demonstrated that LRNU was an independent predictor negatively associated with achievement of "tetrafecta" (OR: 0.09; p=0.003).

CONCLUSIONS

In general, RRNU and LRNU offer comparable outcomes. While the rate of overall complications is higher for LRNU in this study population, this is mostly related to low grade complications, and therefore with more limited clinical relevance. RRNU seems to offer shorter hospital stay but this might also be related to the different geographical location of participating centers. Overall, the implementation of robotics might facilitate achievement of a "tetrafecta" outcome as defined in the present study.

A Preoperative Nomogram to Predict Renal Function Insufficiency for Cisplatin-based Adjuvant Chemotherapy Following Minimally Invasive Radical Nephroureterectomy (ROBUUST Collaborative Group)

BACKGROUND

Postoperative renal function impairment represents a main limitation for delivering adjuvant chemotherapy after radical nephroureterectomy (RNU).

OBJECTIVE

To create a model predicting renal function decline after minimally invasive RNU.

DESIGN, SETTING, AND PARTICIPANTS

A total of 490 patients with nonmetastatic UTUC who underwent minimally invasive RNU were identified from a collaborative database including 17 institutions worldwide (February 2006 to March 2020). Renal function insufficiency for cisplatin-based regimen was defined as estimated glomerular filtration rate (eGFR) <50 ml/min/1.73 m² at 3 mo after RNU. Patients with baseline eGFR >50 ml/min/1.73 m² (n = 361) were geographically divided into a training set (n = 226) and an independent external validation set (n = 135) for further analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Using transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) guidelines, a nomogram to predict postoperative eGFR <50 ml/min/1.73 m² was built based on the coefficients of the least absolute shrinkage and selection operation (LASSO) logistic regression. The discrimination, calibration, and clinical use of the nomogram were investigated.

RESULTS AND LIMITATIONS

The model that incorporated age, body mass index, preoperative eGFR, and hydroureteronephrosis was developed with an area under the curve of 0.771, which was confirmed to be 0.773 in the external validation set. The calibration curve demonstrated good agreement. Besides, the model was converted into a risk score with a cutoff value of 0.583, and the difference between the low- and high-risk groups both in overall death risk (hazard ratio [HR]: 4.59, p < 0.001) and cancer-specific death risk (HR: 5.19, p < 0.001) was statistically significant. The limitation mainly lies in its retrospective design.

CONCLUSIONS

A nomogram incorporating immediately available clinical variables can accurately predict renal insufficiency for cisplatin-based adjuvant chemotherapy after minimally invasive RNU and may serve as a tool facilitating patient selection.

PATIENT SUMMARY

We have developed a model for the prediction of renal function loss after radical nephroureterectomy to facilitate patient selection for perioperative chemotherapy.

Identifying Preoperative Predictors of Operative Time and Their Impact on Outcomes in Robot-Assisted Partial Nephrectomy

Objective: To identify preoperative characteristics in patients with renal masses that influence operative time during robot-assisted partial nephrectomy (RAPN) and evaluate the relationship between operative time and length of stay (LOS), complication rates, and overall outcome. Materials and Methods: We queried our institutional database to identify a cohort of patients who underwent RAPN by two experienced robotic surgeons between 2012 and 2019. A multivariable regression model was developed to analyze operative time, LOS, and any grade complication within 30 days postoperatively using the bootstrap resampling technique. Results: A total of 392 patients were included. On multivariable analyses, prior abdominal surgery (p = 0.001) was associated with 22 minutes of increase in operating room time, as well as adhesive perirenal fat (22 minutes, p = 0.001). For each one unit increase in nephrometry score, there was a 4-minute increase in operating room time (p = 0.028), and for each one-cm increase in tumor size, there was an associated 12-minute increase in operating room time (p < 0.001). For each 1 year increase in age, there was an associated 0.024-day increase in LOS [odds ratio (OR) (0.013-0.035)]; in addition, for every one-cm increase in tumor size there was a 0.18-day associated increase in LOS [OR (0.070-0.28)]. Each 1-hour increase in operating room time was associated with a 0.25-day increased LOS [OR (0.092-0.41)]. Only tumor size was found to be associated with any grade complication. Conclusions: Patients with a history of abdominal surgery, larger complex tumors, and significant Gerota's fat undergoing robotic partial nephrectomy should anticipate longer operative times. Older patients with larger tumors and longer operative times can anticipate a longer LOS. Tumor size appears to be the common determinant of all three outcomes: operative time, LOS, and any grade Clavien complication.

Procedure: Laparoscopic Donor Nephrectomy

Minimally invasive approaches for laparoscopic donor nephrectomy are necessary to limit surgical morbidity, and technical challenges differ from those encountered during other laparoscopic renal surgeries. Presented here is a step-by-step guide for laparoscopic donor nephrectomy-focusing on pure laparoscopic and hand-assisted techniques. Both straight laparoscopic and hand-assisted nephrectomies were performed in healthy donors who met transplantation criteria in terms of global health and psychologic well-being. Patient positioning, trocar placement, surgical steps, incision closure, and postoperative care are reviewed. Standard equipment used to complete this procedure is itemized. This guide outlines indications, preoperative preparation, and procedural steps for laparoscopic donor nephrectomy. The techniques and the evolution thereof represent our experience since 2002 for 510 cases. The attached videos demonstrate a high-volume surgeon's typical approach while factoring in anatomical variation. In both cases, the donor nephrectomies were without incident and the patient's postoperative courses were without complication. A basic framework for donor nephrectomy is presented highlighting surgical steps we believe to be essential for graft preservation and ultimately effective transplantation. Although no two cases are the same, systematic approaches will allow for timely case completion, fewer complications, and better donor/recipient outcomes.

Folate-targeted intraoperative fluorescence, OTL38, in robotic-assisted laparoscopic partial nephrectomy

OBJECTIVE

To investigate the safety and efficacy of OTL38, a folate-targeted, intraoperative fluorescence agent, in patients undergoing robotic-assisted laparoscopic partial nephrectomy.

METHODS

Patients with proven or suspected localized renal cell carcinoma at a single academic institution were selected from 2016 to 2018. Patients received one dose of OTL38 at 0.025 mg/kg prior to robotic-assisted laparoscopic partial nephrectomy. The da Vinci Fluorescence Imaging Vision System was used to identify the tumor and inspect for residual disease after resection. Immunohistochemistry was performed to quantify folate receptor alpha in both the tumor and surrounding normal parenchyma. Patient follow-up was 1 month. Outcome data included descriptive statistics of the patient cohort and surgeon and pathologist surveys.

RESULTS

Ten cases were performed. Mean patient age was 62.9 years (range = 50-70). Mean tumor size was 2.45 cm. Pathologic tumor stages ranged from T1a-T3a. Histologic tumor types included clear cell, chromophobe, type 1 papillary renal cell carcinoma and oncocytoma. The tumors did not fluoresce, while the surrounding normal parenchyma did show fluorescence. No adverse reactions were seen. Staining for folate receptor alpha was localized to the proximal renal tubules. Average staining in normal surrounding renal parenchyma was significantly greater than staining observed in tumor tissue (0.2086 vs 0.0467; p = 0.002). The mean difference in staining between tumor tissue and surrounding normal renal parenchyma was 0.1619 (95% CI = 0.0796-0.2442).

CONCLUSIONS

Based on our initial experience, OTL38 shows potential as a safe, effective and easy to use tool to improve visualization and resection of renal tumors.

Single stage Xi® robotic radical nephroureterectomy for upper tract urothelial carcinoma: surgical technique and outcomes

BACKGROUND

Radical nephroureterectomy (RNU) represents the standard of care for high grade upper tract urothelial carcinoma (UTUC). Open and laparoscopic approaches are well-established treatments, but evidence regarding robotic RANU is growing. The introduction of the Xi® system facilitates the implementation of this multi-quadrant procedure. The aim of this video-article is to describe the surgical steps and the outcomes of Xi® robotic RNU.

METHODS

Single stage Xi® robotic RNU without patients repositioning and robot re-docking were done between 2015 and 2019 and collected in a large worldwide multi-institutional study, the ROBotic surgery for Upper tract Urothelial cancer STudy (ROBUUST). Institutional review board approval and data share agreement were obtained at each center. Surgical technique is described in detail in the accompanying video. Descriptive statistics of baseline characteristics and surgical, pathological, and oncological outcomes were analyzed. RESULTSː Overall, 148 patients were included in the analysis; 14% had an ECOG >1 and 68.2% ASA ≥3. Median tumor dimension was 3.0 (IQR:2.0-4.2) cm and 34.5% showed hydronephrosis at diagnosis. Forty-eight% were cT1 tumors. Bladder cuff excision and lymph node dissection were performed in 96% and 38.1% of the procedures, respectively. Median operative time and estimated blood loss were 215.5 (IQR:160.5-290.0) minutes and 100.0 (IQR: 50.0-150.0) mL, respectively. Approximately 56% of patients took opioids during hospital stay for a total morphine equivalent dose of 22.9 (IQR:16.0-60.0) milligrams equivalent. Postoperative complications were 26 (17.7%), with 4 major (15.4%). Seven patients underwent adjuvant chemotherapy, with median number of cycles of 4.0 (IQR:3.0-6.0).

CONCLUSIONS

Single stage Xi® RNU is a reproducible and safe minimally invasive procedure for treatment of UTUC. Additional potential advantages of the robot might be a wider implementation of LND with a minimally invasive approach.

Clear cell papillary renal cell carcinoma: Characteristics and survival outcomes from a large single institutional series

OBJECTIVES

To investigate the clinical characteristics and survival outcomes of a large clear cell papillary renal cell carcinoma cohort.

METHODS AND MATERIALS

A retrospective review of patients with clear cell papillary renal cell carcinoma at a single academic center was performed after Institutional Review Board approval. Patients underwent either partial or radical nephrectomy from September 2009 to July 2019. Demographic and clinical characteristics, recurrence, and cancer specific and overall survival were reported.

RESULTS

A total of 90 patients were included in the study. Median follow up was 26.5 months. Median age was 61 (range 27 to 87). 47.8% of patients were African American. 26.7% of patients had end stage renal disease. 37.8% had multifocal renal tumors. 48.9% underwent partial nephrectomy, while the remainder underwent radical nephrectomy. 43.3% underwent an open surgical approach, 40.0% a robotic approach, and 16.7% a laparoscopic approach. Pathologic stage included T1a (90.0%), T1b (1.1%), and T2b (8.9%). Fuhrman grades 1-3 were present in 18.9%, 77.8%, and 3.3% of patients, respectively. There were no cancer specific deaths. There was one local recurrence and no metastases. The overall survival at a median follow up of 26.5 months was 92.1% (95% confidence interval 83.1%-96.4%).

CONCLUSIONS

Clear cell papillary renal cell carcinoma typically presents at a low stage and grade and has favorable survival outcomes. A nephron-sparing approach to treatment should be considered when feasible due to the tumor's indolent nature and propensity towards multifocality.

Folate Receptor Beta Designates Immunosuppressive Tumor-Associated Myeloid Cells That Can Be Reprogrammed with Folate-Targeted Drugs

Although immunotherapies of tumors have demonstrated promise for altering the progression of malignancies, immunotherapies have been limited by an immunosuppressive tumor microenvironment (TME) that prevents infiltrating immune cells from performing their anticancer functions. Prominent among immunosuppressive cells are myeloid-derived suppressor cells (MDSC) and tumor-associated macrophages (TAM) that inhibit T cells via release of immunosuppressive cytokines and engagement of checkpoint receptors. Here, we explore the properties of MDSCs and TAMs from freshly isolated mouse and human tumors and find that an immunosuppressive subset of these cells can be distinguished from the nonimmunosuppressive population by its upregulation of folate receptor beta (FRβ) within the TME and its restriction to the TME. This FRβ+ subpopulation could be selectively targeted with folate-linked drugs. Delivery of a folate-targeted TLR7 agonist to these cells (i) reduced their immunosuppressive function, (ii) increased CD8+ T-cell infiltration, (iii) enhanced M1/M2 macrophage ratios, (iv) inhibited tumor growth, (v) blocked tumor metastasis, and (vi) improved overall survival without demonstrable toxicity. These data reveal a broadly applicable strategy across tumor types for reprogramming MDSCs and TAMs into antitumorigenic immune cells using a drug that would otherwise be too toxic to administer systemically. The data also establish FRβ as the first marker that distinguishes immunosuppressive from nonimmunosuppressive subsets of MDSCs and TAMs. Because all solid tumors accumulate MDSCs and TAMs, a general strategy to both identify and reprogram these cells should be broadly applied in the characterization and treatment of multiple tumors. SIGNIFICANCE: FRβ serves as both a means to identify and target MDSCs and TAMs within the tumor, allowing for delivery of immunomodulatory compounds to tumor myeloid cells in a variety of cancers.

Nephron-sparing management of upper tract urothelial carcinoma

Urothelial carcinoma of the upper urinary tract is uncommon and presents unique challenges for diagnosis and management. Nephroureterectomy has been the preferred management option, but it is associated with significant morbidity. Nephron-sparing treatments are a valuable alternative and provide similar efficacy in select cases. A PubMed literature review was performed in English language publications using the following search terms: urothelial carcinoma, upper tract, nephron-sparing, intraluminal and systemic therapy. Contemporary papers published within the last 10 years were primarily included. Where encountered, systematic reviews and meta-analyses were given priority, as were randomized controlled trials for newer treatments. Core guidelines were referenced and citations reviewed for inclusion. A summary of epidemiological data, clinical diagnosis, staging, and treatments focusing on nephron-sparing approaches to upper tract urothelial carcinoma (UTUC) are outlined. Nephron-sparing management strategies are viable options to consider in patients with favorable features of UTUC. Adjunctive therapies are being investigated but the data remains mixed. Protocol variability and dosage differences limit statistical interpretation. New mechanisms to improve treatment dwell times in the upper tracts are being designed with promising preliminary results. Studies investigating systemic therapies are ongoing but implications for nephron-sparing management are uncertain. Nephron-sparing management is an acceptable treatment modality best suited for favorable disease. More work is needed to determine if intraluminal and/or systemic therapies can further optimize treatment outcomes beyond resection alone.

Sensor-based indicators of performance changes between sessions during robotic surgery training

Training of surgeons is essential for safe and effective use of robotic surgery, yet current assessment tools for learning progression are limited. The objective of this study was to measure changes in trainees' cognitive and behavioral states as they progressed in a robotic surgeon training curriculum at a medical institution. Seven surgical trainees in urology who had no formal robotic training experience participated in the simulation curriculum. They performed 12 robotic skills exercises with varying levels of difficulty repetitively in separate sessions. EEG (electroencephalogram) activity and eye movements were measured throughout to calculate three metrics: engagement index (indicator of task engagement), pupil diameter (indicator of mental workload) and gaze entropy (indicator of randomness in gaze pattern). Performance scores (completion of task goals) and mental workload ratings (NASA-Task Load Index) were collected after each exercise. Changes in performance scores between training sessions were calculated. Analysis of variance, repeated measures correlation, and machine learning classification were used to diagnose how cognitive and behavioral states associate with performance increases or decreases between sessions. The changes in performance were correlated with changes in engagement index (rrm=-.25,p<.001) and gaze entropy (rrm=-.37,p<.001). Changes in cognitive and behavioral states were able to predict training outcomes with 72.5% accuracy. Findings suggest that cognitive and behavioral metrics correlate with changes in performance between sessions. These measures can complement current feedback tools used by medical educators and learners for skills assessment in robotic surgery training.

Eye-Tracking Metrics Predict Perceived Workload in Robotic Surgical Skills Training

OBJECTIVE

The aim of this study is to assess the relationship between eye-tracking measures and perceived workload in robotic surgical tasks.

BACKGROUND

Robotic techniques provide improved dexterity, stereoscopic vision, and ergonomic control system over laparoscopic surgery, but the complexity of the interfaces and operations may pose new challenges to surgeons and compromise patient safety. Limited studies have objectively quantified workload and its impact on performance in robotic surgery. Although not yet implemented in robotic surgery, minimally intrusive and continuous eye-tracking metrics have been shown to be sensitive to changes in workload in other domains.

METHODS

Eight surgical trainees participated in 15 robotic skills simulation sessions. In each session, participants performed up to 12 simulated exercises. Correlation and mixed-effects analyses were conducted to explore the relationships between eye-tracking metrics and perceived workload. Machine learning classifiers were used to determine the sensitivity of differentiating between low and high workload with eye-tracking features.

RESULTS

Gaze entropy increased as perceived workload increased, with a correlation of .51. Pupil diameter and gaze entropy distinguished differences in workload between task difficulty levels, and both metrics increased as task level difficulty increased. The classification model using eye-tracking features achieved an accuracy of 84.7% in predicting workload levels.

CONCLUSION

Eye-tracking measures can detect perceived workload during robotic tasks. They can potentially be used to identify task contributors to high workload and provide measures for robotic surgery training.

APPLICATION

Workload assessment can be used for real-time monitoring of workload in robotic surgical training and provide assessments for performance and learning.

Outcomes of Robot-assisted Partial Nephrectomy for Clinical T3a Renal Masses: A Multicenter Analysis

BACKGROUND

Use of partial nephrectomy (PN) in T3 renal cell carcinoma (RCC) is controversial.

OBJECTIVE

To evaluate quality outcomes of robot-assisted PN (RAPN) for clinical T3a renal masses (cT3aRM).

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective multicenter analysis of patients with cT3aN0M0 RCC who underwent RAPN.

INTERVENTION

RAPN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was a trifecta composite outcome of negative surgical margins, warm ischemia time (WIT) ≤25 min, and no perioperative complications. The optimal outcome was defined as achieving this trifecta and ≥90% preservation of the estimated glomerular filtration rate (eGFR) and no stage upgrading of chronic kidney disease. Multivariable analysis (MVA) identified risk factors associated with lack of the optimal outcome. Kaplan-Meier analysis was conducted for survival outcomes.

RESULTS AND LIMITATIONS

Analysis was conducted for 157 patients (median follow-up 26 mo). The median tumor size was 7.0 cm (interquartile range [IQR] 5.0-7.8) and the median RENAL score was 9 (IQR 8-10). Median estimated blood loss (EBL) was 242 ml (IQR 121-354) and the median WIT was 19 min (IQR 15-25). A total of 150 patients (95.5%) had negative margins. Complications were noted in 25 patients (15.9%), with 4.5% having Clavien grade 3-5 complications. The median change in eGFR was 7 ml/min/1.72 m², with ≥90% eGFR preservation in 55.4%. The trifecta outcome was achieved for 64.3% and the optimal outcome for 37.6% of the patients. MVA revealed that greater age (odds ratio [OR] 1.06; p = 0.002), increasing RENAL score (OR 1.30; p = 0.035), and EBL >300 ml (OR 5.96, p = 0.006) were predictive of failure to achieve optimal outcome. The 5-yr recurrence-free survival, cancer-specific survival, and overall survival, were 82.1%, 93.3%, and 91.3%, respectively. Limitations include the retrospective design.

CONCLUSIONS

RAPN for select cT3a renal masses is feasible and safe, with acceptable quality outcomes. Further investigation is requisite to delineate the role of RAPN in cT3a RCC.

PATIENT SUMMARY

Robot-assisted partial nephrectomy in patients with stage 3a kidney cancer provided acceptable survival, functional, and morbidity outcomes in the hands of experienced surgeons, and may be considered as an option when clinically indicated.

Robotic and open partial nephrectomy for tumors in a solitary kidney

Introduction and objective:

Traditionally, patients with renal masses in solitary kidneys were managed with an open partial nephrectomy. With improving techniques, robotic-assisted partial nephrectomy in the setting of a solitary kidney is increasingly utilized. The objective of this study was to compare open partial nephrectomy and robotic-assisted partial nephrectomy outcomes in solitary kidney patients.

Methods:

A retrospective study of 536 total patients who underwent partial nephrectomy between 2004–2016 was performed. Of these patients, 23 had a renal mass in a solitary kidney. Patient demographics, perioperative values, and surgical outcomes were analyzed using descriptive statistics to compare open partial nephrectomy to robotic-assisted partial nephrectomy.

Results:

Of the 23 patients in the cohort, 52% ( n=12) underwent open partial nephrectomy and 48% ( n=11) underwent robotic-assisted partial nephrectomy. Patient characteristics were not significantly different. The mean (standard deviation) nephrometry score was 6.9 (1.8) for open partial nephrectomy and 6.1 (1.9) for robotic-assisted partial nephrectomy ( p=0.290). The mean (standard deviation) pre-operative creatinine was 1.2 (0.3) in open partial nephrectomy and 1.5 (0.4) in robotic-assisted partial nephrectomy, which did not reach statistical significance ( p=0.110). No difference in postoperative kidney function, Clavien grade 3 or higher complication rate, blood loss, or hospitalization length was noted.

Conclusion:

Although traditionally patients with a tumor in a solitary kidney are counseled to undergo open partial nephrectomy, robotic-assisted partial nephrectomy is a safe alternative with no decrease in postoperative renal function when compared with a similar cohort of patients undergoing open partial nephrectomy in a solitary kidney.

Level of evidence:

Level II

Machine Learning and Artificial Intelligence in Surgical Fields

Artificial intelligence (AI) and machine learning (ML) have the potential to improve multiple facets of medical practice, including diagnosis of disease, surgical training, clinical outcomes, and access to healthcare. There have been various applications of this technology to surgical fields. AI and ML have been used to evaluate a surgeon's technical skill. These technologies can detect instrument motion, recognize patterns in video recordings, and track the physical motion, eye movements, and cognitive function of the surgeon. These modalities also aid in the advancement of robotic surgical training. The da Vinci Standard Surgical System developed a recording and playback system to help trainees receive tactical feedback to acquire more precision when operating. ML has shown promise in recognizing and classifying complex patterns on diagnostic images and within pathologic tissue analysis. This allows for more accurate and efficient diagnosis and treatment. Artificial neural networks are able to analyze sets of symptoms in conjunction with labs, imaging, and exam findings to determine the likelihood of a diagnosis or outcome. Telemedicine is another use of ML and AI that uses technology such as voice recognition to deliver health care remotely. Limitations include the need for large data sets to program computers to create the algorithms. There is also the potential for misclassification of data points that do not follow the typical patterns learned by the machine. As more applications of AI and ML are developed for the surgical field, further studies are needed to determine feasibility, efficacy, and cost.

Urologic Surgery and COVID-19: How the Pandemic Is Changing the Way We Operate

The coronavirus disease 2019 (COVID-19) pandemic has had a global impact on all aspects of health care, including surgical procedures. For urologists, it has affected and will continue to influence how we approach the care of patients preoperatively, intraoperatively, and postoperatively. A risk-benefit assessment of each patient undergoing surgery should be performed during the COVID-19 pandemic based on the urgency of the surgery and the risk of viral illness and transmission. Patients with advanced age and comorbidities have a higher incidence of mortality. Routine preoperative testing and symptom screening is recommended to identify those with COVID-19. Adequate personal protective equipment (PPE) for the surgical team is essential to protect health care workers and ensure an adequate workforce. For COVID-19 positive or suspected patients, the use of N95 respirators is recommended if available. The anesthesia method chosen should attempt to minimize aerosolization of the virus. Negative pressure rooms are strongly preferred for intubation/extubation and other aerosolizing procedures for COVID-19 positive patients or when COVID status is unknown. Although transmission has not yet been shown during laparoscopic and robotic procedures, efforts should be made to minimize the risk of aerosolization. Ultra-low particulate air filters are recommended for use during minimally invasive procedures to decrease the risk of viral transmission. Thorough cleaning and sterilization should be performed postoperatively with adequate time allowed for the operating room air to be cycled after procedures. COVID-19 patients should be separated from noninfected patients at all levels of care, including recovery, to decrease the risk of infection. Future directions will be guided by outcomes and infection rates as social distancing guidelines are relaxed and more surgical procedures are reintroduced. Recommendations should be adapted to the local environment and will continue to evolve as more data become available, the shortage of testing and PPE is resolved, and a vaccine and therapeutics for COVID-19 are developed.

Renal Volume Loss During Partial Nephrectomy Due to Resected Healthy Parenchyma: A Tool for Quick Estimation

Purpose: Our objective is to evaluate a technique for estimating the amount of healthy margin resected during partial nephrectomy (PN). Materials and Methods: The resected healthy margin volume was determined by planimetry (gold standard), which was performed in a prospective manner on 30 freshly resected renal masses by cross-sectional slicing every ∼5 mm. A single cross-sectional slice containing the largest tumor diameter (bivalved tumor) was chosen to build a model for estimating the amount of healthy kidney removed. This single-slice technique was then applied to a second series of patients (n = 39) status post PN. Three-dimensional models were created using pre- and postoperative CT scans to determine the overall volume loss following PN. Results: The median (range) for tumor diameter and tumor volume was 3.2 cm (1-6.1) and 10.7 cm³ (0.5-101.9), respectively, for the 30 PN specimens used to build the single-slice estimation equation. The median (range) healthy margin volume calculated by planimetry and single slice technique was 9.0 cm³ (1.0-22.1) and 7.8 cm³ (1.0-31.0), respectively (p = 0.37). The Pearson correlation was 0.84, and the median (range) percent difference between the planimetry and single slice techniques was -0.5% (-39% to 57%). For the 39 PN patients, the median (range) total renal volume loss, 25.8 cm³ (3-79), was significantly greater than the volume of healthy margin removed during resection, 5.7 cm³ (1-22), p < 0.001. Conclusions: The healthy margin resected during PN differs widely and can be estimated from a single cross-section. The healthy margin resected accounted for <50% of the total volume loss seen during PN.

Robotic and open partial nephrectomy for intermediate and high complexity tumors: a matched-pairs comparison of surgical outcomes at a single institution

Objective: To compare peri-operative factors and renal function following open partial nephrectomy (OPN) and robotic partial nephrectomy (RPN) for intermediate and high complexity tumors when controlling for tumor and patient complexity.Methods: A retrospective review of 222 patients undergoing partial nephrectomy was performed. Patients with intermediate (nephrometry score NS 7-9) or high (NS 10-12) complexity tumors were matched 2:1 for RPN:OPN using NS, Charlson Comorbidity Index (CCI), and BMI. Patient demographics, peri-operative values, renal function, and complication rates were analyzed and compared.Results: Seventy-four OPN patients were matched to 148 RPN patients with no difference in patient demographics. Estimated blood loss in OPN patients was significantly higher (368.5 vs 210.5 mL, p < 0.001) as was transfusion rate (17% vs 1.6%, p < 0.001). Warm ischemia time was longer in OPN (25.5 vs 19.7 min, p = 0.001) while operative time was reduced (200.5 vs 226.5 min, p = 0.010). RPN patients had significantly shorter hospitalizations (5.3 vs 3.0 days, p < 0.001). GFR decrease after one month was not statistically significant (12.9 vs 6.6 ml/min, p = 0.130). Clavien III-V complications incidence was higher for OPN compared to RPN although not significantly (20.3% vs 10.8%, p = 0.055).Conclusion: When matching for tumor and patient complexity, RPN patients had fewer high grade post-operative complications, decreased blood loss, and shorter hospitalizations. RPN is a safe option for patients with intermediate and high complexity tumors.

Multimodal Physiological Signals for Workload Prediction in Robot-assisted Surgery

Monitoring surgeon workload during robot-assisted surgery can guide allocation of task demands, adapt system interfaces, and assess the robotic system's usability. Current practices for measuring cognitive load primarily rely on questionnaires that are subjective and disrupt surgical workflow. To address this limitation, a computational framework is demonstrated to predict user workload during telerobotic surgery. This framework leverages wireless sensors to monitor surgeons’ cognitive load and predict their cognitive states. Continuous data across multiple physiological modalities (e.g., heart rate variability, electrodermal, and electroencephalogram activity) were simultaneously recorded for twelve surgeons performing surgical skills tasks on the validated da Vinci Skills Simulator. These surgical tasks varied in difficulty levels, e.g., requiring varying visual processing demand and degree of fine motor control. Collected multimodal physiological signals were fused using independent component analysis, and the predicted results were compared to the ground-truth workload level. Results compared performance of different classifiers, sensor fusion schemes, and physiological modality (i.e., prediction with single vs. multiple modalities). It was found that our multisensor approach outperformed individual signals and can correctly predict cognitive workload levels 83.2% of the time during basic and complex surgical skills tasks.

Renorrhaphy techniques and effect on renal function with robotic partial nephrectomy

PURPOSE

The role of robotic partial nephrectomy (RPN) is becoming increasingly prevalent in managing small renal masses. Renal functional outcomes have been reported with relation to the amount of healthy renal parenchyma resected and ischemia time; however, there is limited data on the effect of renorrhaphy on long-term renal function. Our aim is to evaluate the impact of renorrhaphy technique on renal functional outcomes.

METHODS

A nonsystematic literature review was performed to retrieve articles assessing renorrhaphy techniques and renal function outcomes, specifically focusing on single-layer vs. traditional two-layer renorrhaphy.

RESULTS

Performing single-layer renorrhaphy while omitting cortical renorrhaphy appears to improve renal function postoperatively, based on very limited studies in the literature that were evaluated.

CONCLUSION

Single-layer renorrhaphy may be associated with improved postoperative renal function and could prove to be useful in patients with chronic renal insufficiency or solitary kidney. The ongoing clinical trial NCT02131376 may provide further information on the impact of renorrhaphy technique on long-term renal function.

Correlation and Prediction of Living-Donor Remaining Function by Using Predonation Computed Tomography-Based Volumetric Measurements: Role of Remaining Kidney Volume

OBJECTIVES

Kidney volume in healthy living donors may serve as a surrogate marker of renal function. Here, we evaluated whether preserved kidney volume correlated with and could predict donor renal function at 2 years postdonation using the CKD-EPI estimated glomerular filtration rate equation.

MATERIALS AND METHODS

Healthy living donors (n = 208) with computed tomography volume measurements were evaluated for renal function before and after donation. Preserved kidney volume was adjusted to body surface area. Demographic characteristics (including race/ethnicity and sex) and renal function variables of donors were analyzed for postdonation renal function.

RESULTS

Donor mean age was 39.4 ± 10.7 years (36.2% males, 91.9% white). Median adjusted preserved kidney volume was 180.6 mL. At 2 years postdonation, median estimated glomerular filtration rate was 62.4 mL/min (interquartile range, 54.8-73.2 mL/min). Predonation estimated glomerular filtration rate, age, and adjusted preserved kidney volume were found to be inde-pendent predictors of 2-year estimated glomerular filtration rate (P < .001). We further analyzed data by stratifying preserved kidney volumes into tertiles. Mean 2-year estimated glomerular filtration rates were 57.9 ± 12, 65 ± 16, and 73 ± 17 mL/min for lowest to highest tertile groups, respectively (P < .05). The odds ratio of having a 2-year postdonation estimated glomerular filtration rate of < 60 mL/min for donors in the lowest tertile group was 3.51 (95% confidence interval, 1.9-6.4; P < .001), whereas the risk for donors in the highest tertile group was 0.23 (95% confidence interval, 0.12-0.44; P< .001). Sensitivity analysis result was 0.764 (95% confidence interval, 0.69-0.82; P = .005) for adjusted preserved kidney volume and estimated glomerular filtration rate of < 60 mL/min.

CONCLUSIONS

Remaining kidney volume before donation correlated with and predicted estimated glomerular filtration rate after donation. Remaining kidney volume should be assessed when selecting kidneys from healthy donors.

Commentary on "Prognostic effect of carcinoma in situ in muscle-invasive urothelial carcinoma patients receiving neoadjuvant chemotherapy."

BACKGROUND

Carcinoma in situ (CIS) is a poor prognostic finding in urothelial carcinoma. However, its significance in muscle-invasive urothelial carcinoma (MIUC) treated with neoadjuvant chemotherapy (NAC) is uncertain. We assessed the effect of CIS found in pretreatment transurethral resection of bladder tumor (TURBT) biopsies on the pathologic and clinical outcomes.

MATERIALS AND METHODS

Subjects with MIUC treated with NAC before cystectomy were identified. The pathologic complete response (pCR) rates stratified by TURBT CIS status were compared. The secondary analyses included tumor response, progression-free survival (PFS), overall survival (OS), and an exploratory post hoc analysis of patients with pathologic CIS only (pTisN0) at cystectomy.

RESULTS

A total of 137 patients with MIUC were identified. TURBT CIS was noted in 30.7% of the patients. The absence of TURBT CIS was associated with a significantly increased pCR rate (23.2% vs. 9.5%; odds ratio = 4.08; 95% CI: 1.19-13.98; P = 0.025). Stage pTisN0 disease was observed in 19.0% of the TURBT CIS patients. TURBT CIS status did not significantly affect the PFS or OS outcomes. Post hoc analysis of the pTisN0 patients revealed prolonged median PFS (104.5 vs. 139.9 months; P = 0.055) and OS (104.5 vs. 152.3 months; P = 0.091) outcomes similar to those for the pCR patients.

CONCLUSION

The absence of CIS on pretreatment TURBT in patients with MIUC undergoing NAC was associated with increased pCR rates, with no observed differences in PFS or OS. Isolated CIS at cystectomy was frequently observed, with lengthy PFS and OS durations similar to those for pCR patients. Further studies aimed at understanding the biology and clinical effect of CIS in MIUC are warranted.

Robotic Partial Nephrectomy for a Peripheral Renal Tumor

Partial nephrectomy (PN) is the preferred surgical treatment for T1 renal tumors whenever technically feasible. When properly performed, it allows preservation of nephron mass without compromising oncologic outcomes. This reduces the postoperative risk of renal insufficiency, which translates into better overall survival for the patients. PN can be technically challenging, because it requires the surgeon to complete the tasks of tumor excision, hemostasis and renorrhaphy, all within an ischemic time of preferably below 30 minutes. The surgeon needs to avoid violating the tumor margins while leaving behind the maximal parenchymal volume at the same time. Variations such as zero ischemia, early unclamping, and selective clamping have been developed in an attempt to reduce the negative impact of renal ischemia, but inevitably add to the steep learning curves for any surgeon. Being able to appreciate the fine details of each surgical step in PN is the fundamental basis to the success of this surgery. The use of the robotic assistance allows a good combination of the minimally invasive nature of laparoscopic surgery and the surgical exposure and dexterity of open surgery. It also allows the use of adjuncts such as concurrent ultrasound assessment of the renal mass and intraoperative fluorescence to aid the identification of tumor margins, all with a simple hand switch at the console. Robot-assisted laparoscopic PN is now the most commonly performed type of PN in the United States and is gaining acceptance on the global scale. In this video, we illustrate the steps of robot-assisted laparoscopic PN and highlight the technical key points for success.

Preoperative Nomograms for Predicting Renal Function at 1 Year After Partial Nephrectomy

INTRODUCTION

Partial nephrectomy (PN) reduces the risk of postoperative chronic renal insufficiency (CRI). However, some patients still develop CRI after PN, and may eventually require dialysis. Being able to predict renal function before PN helps in counseling patients and managing expectations. We aimed to construct nomograms that predict estimated glomerular filtration rates (eGFRs), defined by the modification of diet in renal disease (MDRD) and the chronic kidney disease epidemiology collaboration (CKD-EPI) formulae, at 1 year after PN, using only preoperative covariates as predictors.

PATIENTS AND METHODS

We identified patients who underwent PN in our institution between 2004 and 2016, with known postoperative serum creatinine levels at 1 year. The preoperative covariates included patients' demographics, chronic comorbid conditions, tumor characteristics, and preoperative renal status. The endpoints were eGFRs at 1 year after PN, calculated using the MDRD and the CKD-EPI formulae. We first identified preoperative covariates with significant associations with the endpoints by Pearson correlation and independent samples t-test. Suitable covariates were then included in two multivariate linear regression models, for constructing and internally validating two nomograms.

RESULTS

461 patients were eligible for analysis. The percentage of patients with eGFR below 60 mL/min/1.73 m² increased from 25% before PN to 35% at 1 year after PN. We included age, gender, African American race, body mass index, preoperative creatinine level, ipsilateral renal volume, solitary kidney status, tumor diameter, hypertension, diabetes, ischemic heart disease, and previous stroke in the multivariate linear regression models for nomogram construction. Internal validation showed bootstrap-corrected coefficients of determination of 0.61 and 0.70, for predicting eGFRs defined by the MDRD and CKD-EPI formulae, respectively.

CONCLUSIONS

We constructed and internally validated two nomograms to predict eGFRs at 1 year after PN, using only preoperative covariates as predictors.

Training the next generation of surgeons in robotic surgery

Context

Robotic surgery has been used with rapidly increasing frequency within urology and across many other surgical specialties. A standardized curriculum for the training and credentialing of robotic surgeons has unfortunately trailed far behind the adoption of this surgical technology.

Objective

To review the current available surgical skills training models, assessments, and curricula for the purpose of training resident, fellow, and practicing surgeons in an effort to promote surgical skill proficiency and mastery and to minimize the risk of patient harm.

Evidence acquisition

We performed a thorough review of available literature through a PubMed database search in February 2015.

Evidence synthesis

In this article, we compiled and scrutinized the available relevant literature regarding past and present robotic surgical training techniques and credentialing criteria. This review details the basic surgical skills (both technical and nontechnical) that are necessary for individuals and teams to be successful in the operative setting. We go on to discuss the role of current robotic surgical training techniques including dry lab and virtual simulators. Finally, we offer current validated training curricula, the Global Evaluative Assessment of Robotic Skills and Fundamentals of Robotic Surgery models, which have laid the groundwork for a future standardized model that could be applied on a national and international level and across several surgical subspecialties. The ultimate goal of the review is to provide a foundation from which a future standardized training and credentialing curriculum could be based.

Conclusion

There is currently a great need for a standardized curriculum to be developed and employed for the use of training and credentialing future and current robotic surgeons.