Indocyanine green angiography visualized by augmented reality in aneurysm surgery.

Objective We prospectively investigated how to integrate indocyanine green (ICG) angiography in an augmented reality (AR) setting for aneurysm surgery. Methods In 20 patients with a total of 22 aneurysms the head-up display (HUD) of the operating microscope (Kinevo900) was used for AR. ICG-AR was established directly by the HUD superimposing the ICG angiography as green live video overlay. Additionally, the reconstructed outline of the 3-dimensional (3D) vessel architecture was visualized by AR applying intraoperative low-dose computed tomography (iCT) (vessel-AR). Results In all patients ICG-AR and vessel-AR were successfully implemented. The flow in the vessels could be observed directly in the white light view of the microscope oculars without being distracted from the surgical site by looking on separate screens. This enabled also surgical manipulation during ICG angiography. In parallel, AR additionally visualized the 3D vessel architecture enhancing the understanding of the 3D anatomy (target registration error: 0.71±0.21mm; iCT effective dose: 42.7μSv). Linear (n=28, range: 1mm to 8.5mm) and rotational (n=3, range: 2.9° to 14.4°) navigation adjustments performed in 18 of 20 patients resulted in a close matching of the vessel-AR outline with the real vessel situation after preparation, compensating for shifting. Conclusions ICG-AR could be successfully implemented. It facilitated surgical manipulation and flow interpretation during ICG angiography since it could be observed directly while looking through the microscope oculars in white light instead of being distracted from the surgical site while looking on separate screens. Additional AR visualizing the vessel architecture improved understanding 3D anatomy for preparation and clipping.