Introduction: Technologies to help improve surgical outcomes of robot-assisted partial nephrectomy (RAPN) such as intravenous dye: indocyanine green (ICG). When viewed under near-infrared (NIR) light it signals green for kidney perfusion. It is utilized in complex vascular anatomy cases of RAPN, to delineate surgical margins for tumorectomy and in selective or whole arterial clamping. ActivSight laser speckle contrast imaging (LSCI) uses coherent light to detect perfusion by tissue intensity based on motion in real-time laparoscopic visceral surgery. Our objective is to compare ActivSight to ICG in displaying renal perfusion in an animal model.
Methods: ActivSight, is FDA approved imaging sensor adapter, inserted between a Stryker 1288 HD system camera head and laparoscope. A standard white light is attached to the laparoscope and a coherent laser source is attached to ActivSight. An anesthetized porcine model was used, the left kidney was mobilized and renal hilar vessels were isolated. ActivSight’s ‘perfusion mode’ and ‘quantification mode’ displays blood flow as a heatmap and numerical signal intensity respectively. All procedures performed in accordance with the Animal Welfare Act and hospital ethics regulation for the study.
Results: Figure 1 below shows the kidney after ICG administered and upper segmental artery clamped.
? ICG in lower pole on left picture after 40 seconds.
? ActivSight quantification mode on right picture shows low (dark color) perfusion in upper pole.
Figure 2 below shows the kidney after the upper segmental artery clamp is removed.
? ICG is retained in the lower pole on left picture.
? ActivSight perfusion demonstrated in the entire kidney on right picture.
No intraoperative adverse events were noted.
Conclusions: We demonstrate that ActivSight LSCI is a dye free, repeatable, real-time adjunct of renal parenchymal perfusion. Applicability in robotic renal surgery is hypothesised to complement the technology of ICG guidance, increasing digitally active surgery. Further follow-up utility and clinical trial assessment of ActivSight should follow.