What's known on the subject? and What does the study add?• There is concern that warm ischaemia time during partial nephrectomy may have an adverse impact on postoperative renal function. As a result, there is increased interest in developing a safe and effective method for performing non-ischaemic partial nephrectomy. Several novel approaches have recently been described.• We present our initial experience performing zero-ischaemia partial nephrectomy using near-infrared fluorescence imaging to facilitate super-selective arterial clamping. We report the operative and early postoperative outcomes from such cases as compared with a matched cohort of patients undergoing traditional partial nephrectomy with clamping of the main renal artery. We show that this technique is both safe and effective and may lead to improved renal preservation at short-term follow-up. Objective• To describe a novel technique of eliminating renal ischaemia during robotic partial nephrectomy (RPN) using near-infrared fluorescence (NIRF) imaging. Patients and Methods• Over an 8-month period (March 2011 to November 2011), 34 patients were considered for zero-ischaemia RPN using the da Vinci NIRF system. • Targeted tertiary/higher-order tumour-specific branches were controlled with robotic bulldog(s) or neurosurgical aneurysm micro-bulldog(s). Indocyanine green dye was given, and NIRF imaging used to confirm super-selective ischaemia, defined as darkened tumour/peri-tumour area with green fluorescence of remaining kidney.• Matched pair analysis was performed by matching each patient undergoing zero-ischaemia RPN (n = 27) to a previous conventional RPN (n = 27) performed by the same surgeon. Results• Of 34 patients, 27 (79.4%) underwent successful zero-ischaemia RPN; seven (20.6%) required conversion to main renal artery clamping (ischaemia time <30 min) for the following reasons: persistent tumour fluorescence after clamping indicating inadequate tumoral devascularization (n = 5), and parenchymal bleeding during RPN (n = 2).• Matched-pair analysis showed comparable outcomes between cohorts, except for longer operating time (256 vs 212 min, P = 0.02) and superior kidney function (reduction of estimated glomerular filtration rate (-1.8% vs -14.9%, P = 0.03) in the zero-ischaemia cohort. All surgical margins were negative. Conclusions• In this pilot study, we show that zero-ischaemia RPN with NIRF is a safe alternative to conventional RPN with main renal artery clamping.• Eliminating global ischaemia may improve functional outcomes at short-term follow-up.

In an independent cohort, GEARS was able to differentiate between different robotic skill levels, demonstrating excellent construct validity. As a standardized assessment tool, GEARS maintained consistency and reliability for an in vivo robotic surgical task and may be applied for skills evaluation in a broad range of robotic procedures.

Objectives• To evaluate three standardized robotic surgery training methods, inanimate, virtual reality and in vivo, for their construct validity.• To explore the concept of cross-method validity, where the relative performance of each method is compared. Materials and Methods• Robotic surgical skills were prospectively assessed in 49 participating surgeons who were classified as follows: 'novice/trainee': urology residents, previous experience <30 cases (n = 38) and 'experts': faculty surgeons, previous experience Ն30 cases (n = 11).• Three standardized, validated training methods were used:(i) structured inanimate tasks; (ii) virtual reality exercises on the da Vinci Skills Simulator (Intuitive Surgical, Sunnyvale, CA, USA); and (iii) a standardized robotic surgical task in a live porcine model with performance graded by the Global Evaluative Assessment of Robotic Skills (GEARS) tool.• A Kruskal-Wallis test was used to evaluate performance differences between novices and experts (construct validity). • Spearman's correlation coefficient (r) was used to measure the association of performance across inanimate, simulation and in vivo methods (cross-method validity). Results• Novice and expert surgeons had previously performed a median (range) of 0 (0-20) and 300 (30-2000) robotic cases, respectively (P < 0.001).• Construct validity: experts consistently outperformed residents with all three methods (P < 0.001).• Cross-method validity: overall performance of inanimate tasks significantly correlated with virtual reality robotic performance (r = -0.7, P < 0.001) and in vivo robotic performance based on GEARS (r = -0.8, P < 0.0001).• Virtual reality performance and in vivo tissue performance were also found to be strongly correlated (r = 0.6, P < 0.001). Conclusions• We propose the novel concept of cross-method validity, which may provide a method of evaluating the relative value of various forms of skills education and assessment.• We externally confirmed the construct validity of each featured training tool.

Epithelial-to-mesenchymal transition (EMT) has been implicated in the progression of bladder cancer. To study its contribution to bladder cancer metastasis, we established new xenograft models derived from human bladder cancer cell lines utilizing an orthotopic “recycling” technique that allowed us to isolate and examine the primary tumor and its corresponding circulating tumor cells (CTC’s) and metastatic lesions. Using whole genome mRNA expression profiling, we found that a reversible epithelial-to-mesenchymal transition (EMT) characterized by TGFβ pathway activation and SNAIL expression was associated with the accumulation of CTCs. Finally, we observed that conditional silencing of SNAIL completely blocked CTC production and regional/distant metastasis. Using this unique bladder cancer xenograft model, we conclude that metastasis is dependent on a reversible EMT mediated by SNAIL.

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