Navigation and visualisation with HoloLens in endovascular aortic repair

Abstract

IntroductionEndovascular aortic repair (EVAR) is a minimal-invasive technique that prevents life-threatening rupture in patients with aortic pathologies by implantation of an endoluminal stent graft. During the endovascular procedure, device navigation is currently performed by fluoroscopy in combination with digital subtraction angiography. This study presents the current iterative process of biomedical engineering within the disruptive interdisciplinary project Nav EVAR, which includes advanced navigation, image techniques and augmented reality with the aim of reducing side effects (namely radiation exposure and contrast agent administration) and optimising visualisation during EVAR procedures. This article describes the current prototype developed in this project and the experiments conducted to evaluate it.MethodsThe current approach of the Nav EVAR project is guiding EVAR interventions in real-time with an electromagnetic tracking system after attaching a sensor on the catheter tip and displaying this information on Microsoft HoloLens glasses. This augmented reality technology enables the visualisation of virtual objects superimposed on the real environment. These virtual objects include three-dimensional (3D) objects (namely 3D models of the skin and vascular structures) and two-dimensional (2D) objects [namely orthogonal views of computed tomography (CT) angiograms, 2D images of 3D vascular models, and 2D images of a new virtual angioscopy whose appearance of the vessel wall follows that shown in ex vivo and in vivo angioscopies]. Specific external markers were designed to be used as landmarks in the registration process to map the tracking data and radiological data into a common space. In addition, the use of real-time 3D ultrasound (US) is also under evaluation in the Nav EVAR project for guiding endovascular tools and updating navigation with intraoperative imaging. US volumes are streamed from the US system to HoloLens and visualised at a certain distance from the probe by tracking augmented reality markers. A human model torso that includes a 3D printed patient-specific aortic model was built to provide a realistic test environment for evaluation of technical components in the Nav EVAR project. The solutions presented in this study were tested by using an US training model and the aortic-aneurysm phantom.ResultsDuring the navigation of the catheter tip in the US training model, the 3D models of the phantom surface and vessels were visualised on HoloLens. In addition, a virtual angioscopy was also built from a CT scan of the aortic-aneurysm phantom. The external markers designed for this study were visible in the CT scan and the electromagnetically tracked pointer fitted in each marker hole. US volumes of the US training model were sent from the US system to HoloLens in order to display them, showing a latency of 259±86 ms (mean±standard deviation).ConclusionThe Nav EVAR project tackles the problem of radiation exposure and contrast agent administration during EVAR interventions by using a multidisciplinary approach to guide the endovascular tools. Its current state presents several limitations such as the rigid alignment between preoperative data and the simulated patient. Nevertheless, the techniques shown in this study in combination with fibre Bragg gratings and optical coherence tomography are a promising approach to overcome the problems of EVAR interventions.

A Smart Factory in a Smart City: Virtual and Augmented Reality in a Smart Assembly Line

“…These and other shortcomings are described also e.g. in [35] and [36]. Therefore, we currently recommend using AR rather for maintenance as described e.g.…”

Experimental Setup Employed in the Operating Room Based on Virtual and Mixed Reality: Analysis of Pros and Cons in Open Abdomen Surgery

“…In [12], anatomy training has been proposed using a HoloLens-based augmented reality system. Referring to navigation, in [13], Microsoft HoloLens has been used for navigation in endovascular aortic repair, with the aim of reducing side effects such as radiation exposure and contrast agent administration. In [13], a novel multicriteria evaluation model for HoloLens-based mixed reality surgical navigation system is illustrated.…”

“…Referring to navigation, in [ 13 ], Microsoft HoloLens has been used for navigation in endovascular aortic repair, with the aim of reducing side effects such as radiation exposure and contrast agent administration. In [ 13 ], a novel multicriteria evaluation model for HoloLens-based mixed reality surgical navigation system is illustrated. The model, which includes factors such as comfort and safety, is performed in an actual clinical application [ 13 ].…”

“…In [ 13 ], a novel multicriteria evaluation model for HoloLens-based mixed reality surgical navigation system is illustrated. The model, which includes factors such as comfort and safety, is performed in an actual clinical application [ 13 ]. Referring to visualization, in [ 14 ], a framework for 3D holographic visualization of myocardial scar (imaged using late gadolinium enhancement) has been developed based on Microsoft HoloLens.…”

Catheter pose-dependent virtual angioscopy images visualized on augmented reality glasses

“…An approach to overcome the current disadvantages of guiding EVAR procedures is based on displaying the pose of an electromagnetically (EM) tracked catheter tip in a three-dimensional (3D) preoperative computed tomography (CT) volume [1]. Augmented reality (AR) technology, specifically Microsoft HoloLens, can be used to provide a more intuitive visualization of the EM tracked catheter tip inside the 3D aortic model [2,3]. For supplementary guidance in this setup, we propose to display virtual angioscopy images based on the current pose of the tracked catheter tip on a virtual 2D canvas using HoloLens.…”