Using virtual reality for difficult airway management planning

Introduction

Computerised tomography (CT) and magnetic resonance imaging (MRI) are used throughout medicine, with images typically viewed in sagittal, coronal and axial planes as two‐dimensional (2D), greyscale representations of the subject matter. New breakthroughs in virtual reality (VR) technology offer the ability to interactively view scans as three‐dimensional (3D) images, with the potential to enhance interpretation for clinical planning [1]. We are interested in the feasibility of using VR software to support decision‐making in patients with potentially difficult airways.

Process and application

The CT digital imaging and communications in medicine (DICOM) file from an anonymised patient with a known head and neck pathology (supra‐glottic/glottic lesion) was entered into 3D modelling software (D2P; 3D Systems, Inc., South Carolina, USA). The subsequent 3D image was then viewed using a VR system (VIVE Cosmos Elite; HTC Corporation, Taoyuan City, Taiwan) which included a VR headset and two hand controllers linked to a number of room sensors. The software allowed variations in structures viewed based on density, enabling differentiation between bone and various levels of soft tissue. The controller was able to determine the plane being viewed (including but not limited to sagittal, coronal and axial), view more than one plane simultaneously, and move the model in order to obtain the desired view. This dynamic visualisation and ability to change or combine views appears to be novel.

Of interest to clinicians who are involved in airway management, airspaces in the CT head were maintained (Fig. 1), allowing the ability to track and assess the airway in a method that closely resembles virtual endoscopy. The immediate availability of the scans for review, adjacent soft tissue visualisation and unlimited plane views available potentially offer advantages when compared to virtual endoscopy. The measurement function available could also support tracheal tube sizing (see also Supporting Information, Video S1).

Figure 1.

Virtual reality screenshot, showing 3D airspaces.

Discussion

The fourth National Audit Project by the Royal College of Anaesthetists and the Difficult Airway Society reported inadequate planning as a contributor to poor airway outcomes [2]. Advances in technology such as the system we describe, offer a way to enhance airway planning through greater understanding of an individual's anatomy prior to intervention. While it is unlikely to replace CT and MRI as a diagnostic tools, there appear to be clear benefits supporting its utilisation for difficult airway management planning.

In our experience, it was easier to analyse the airway using VR than with a standard CT series, as the views through the airway more closely resembled those seen with direct or video‐laryngoscopy and flexible bronchoscopy. Additionally, the 3D reconstruction and the view seen by the individual wearing the VR headset are available simultaneously on another screen, so they can be shared during navigation of the model, supporting multidisciplinary team discussion, planning and work‐up.

We note the 3D VR reconstruction is limited in similar ways to CT scans. The CT scans from which the 3D models are constructed are taken with the patient in the supine position and are not dynamic images of the airway, key considerations if using this as a tool to support difficult airway management planning.

Capital investment is needed to due to the specific equipment and software requirements; however, the use of this technology could be extended to other specialities and for educational purposes [3]. There is also the potential to combine this technology with other modalities such as 3D printing to further support difficult airway management planning [4].

Supporting information

Video S1. Airway evaluation of reconstructed CT head and neck using virtual reality software.