Overlay of 3D Scans on Live Fluoroscopy for Endovascular Procedures in the Hybrid OR

Endovascular treatment is performed under the guidance of an X-ray angiography system. Fluoroscopy and conventional 2D digital subtraction angiography (DSA) are used to navigate the interventional device (and implant) across the lesion to achieve a correct bridging of the diseased region of the vessel, while excluding the involvement of patent vessels. Drawbacks of these peripheral interventions include the radiation dose, use of contrast, and need for a clinician with excellent wire-handling skills. The use of 2D imaging alone may not be enough to describe the three-dimensional(3D) relationship between interventional devices (and implants) and the complex vascular anatomy, often making positioning, deployment and evaluation suboptimal. In addition, the endovascular approach can lead to complications such as in-stent thrombosis and type II endoleak (in the case of aortic aneurysms) for which 2D imaging along is again sub-optimal for re-intervention planning and guidance. As endovascular procedures become more complex, there is a growing need for 3D image overlay to assist with device guidance and placement. Currently, a 3D image is typically created intra-operatively using 3D rotational angiography (3D-RA) or cone-beam CT (XperCT). This 3D image may then be overlaid on live fluoroscopy to provide 3D guidance information (Dynamic 3D Roadmapping). 3D navigation can also be acquired by registration of a pre-acquired MR/CT or 3D rotational image to live fluoroscopy.