Near-infrared fluorescence imaging to facilitate super-selective arterial clamping during zero-ischaemia robotic partial nephrectomy

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.