Patient Screening for Self-Expanding Percutaneous Pulmonary Valves Using Virtual Reality

Abstract

Background: In recent years, self-expanding technology to treat pulmonary regurgitation in the native right ventricular outflow tract became Food and Drug Administration approved in the United States and is now routinely used. The current practice for selection of patients who are candidates for these devices includes screening for "anatomic fit," performed by each of the manufacturing companies. Our study aims to validate the use of virtual reality (VR) as a tool for local physician-led screening of patients.

Methods and results: This retrospective study from Children's Hospital Colorado included patients who underwent pulmonary valve replacement and had screening for a Harmony TPV or Alterra Prestent performed between September 2020 and January 2022. The data from the commercial companies' dedicated analysis for self-expanding transcatheter pulmonary valve frames evaluation with perimeter analysis were collected. VR simulation was performed blinded by 2 congenital interventional cardiologists using Elucis VR software and an Oculus Quest 2 headset. Among the 27 evaluated cases, the use of a self-expandable valve was recommended by companies' dedicated analysis in 23 cases (85.2%), by VR assessment in 26 cases (96.3), and finally implanted in 25 cases (92.6%). Regarding the level of agreement, both modalities (manufacturer and VR) were good at screening-in patients who received a self-expanding valve (100% versus 96.1%). When it came to screening-out the patients, VR presented good capacity to accurately classify nonsuitable patients (50% versus 100%).

Conclusions: Our institutional experience with VR transcatheter pulmonary valve implantation planning accurately predicted clinical outcomes. This paves the way for routine use of VR in patient selection for self-expanding valve technologies.

Keywords: Alterra Prestent; anatomic fit; harmony TPV; self‐expanding technology; transcatheter pulmonary valve implantation; virtual reality.

Figure 1. Steps of creating a 3D model of the RVOT using Elucis (Realize Medical Inc., Canada).

(A) DICOM file of a dynamic computed tomography angiography (CTA) is loaded into the 3D environment of Elucis. The CT images can be viewed in 2D as in any DICOM viewer and then using thresholding, the area of interest is selected. A 3D model is then created in a 2D view (panel B) or in a 3D view (panel C).This 3D model is now dynamic and will show the MPA characteristics during the cardiac cycle. The models of the different valves evaluated are imported and placed in the area of interest to simulate the implantation position (panel D–G). The views include internal aspects of the stent and outflow tract to assess anatomical interaction between the two. CT indicates computed tomography; DICOM, digital imaging and communications in medicine; MPA, main pulmonary artery; and RVOT, right ventricular outflow tract.

Figure 2. 3D models created by our team utilizing 3D rotational angiography of the devices at scale.

The resulting STL files were used to simulate valve implantation within Elucis. STL indicates stereolithography.