Intraoperative 3-dimensional Projection of Blood Vessels on Body Surface Using an Augmented Reality System.

Preoperative understanding of the running pattern of blood vessels is an important factor to approach surgical fields safely. In 2 cases where the vascular abnormalities were estimated, we projected the blood vessels onto the surgical field using an augmented reality device HoloLens. A splint was made to allow the patient to be fixed while undergoing computed tomographic angiography. Three-dimensional (3D) data on the blood vessels, skin surfaces, bones, and the 3 chosen points for alignment were segmented and then projected onto the body surfaces as holograms using the HoloLens. Two types of projection for holograms were used: projection type 1-where the body contours were projected as a line, and projection type 2-where the body surface was projected as meshed skin type. By projecting projection type 2 rather than projection type 1, we gained a better understanding of the 3D anatomic findings and deformation characteristics, including the anatomic blood vessel variation and positional relationships between the organs and body surfaces. To some extent, we could make sure that the depth perception can be obtained by recognizing the bone, vessels, or tumor inside the meshed skin surface. Our new method allows the 3D visualization of blood vessels from the body surface, and helps understand the 3D anatomic variation of the blood vessels to be applied as long as the blood vessels can be visualized.