Author + information
- Magnus Settergren, MD, PhD⁎,
- Magnus Bäck, MD, PhD⁎,
- Kambiz Shahgaldi, PhD†,
- Per Jacobsen, MD⁎ and
- Reidar Winter, MD, PhD†,⁎ ()
- ↵⁎Address for correspondence:
Dr. Reidar Winter, Department of Cardiology, Karolinska University Hospital, 141 86 Stockholm, Sweden
three-dimensional (3d) transesophageal echocardiography (tee) has rapidly moved into clinical routine, and is increasingly useful in different percutaneous catheter based interventions, especially the transcatheter mitral valve repair (TMVR) procedure (MitraClip) (1,2). However, in commercially available systems today, the online image presentation is lacking the true depth sense. Depth vision can be obtained in different ways, where the red-green coding and use of red-green glasses is an accessible way to enable depth vision in online 3D TEE images. We illustrate the incremental value of 3D TEE with stereovision in a 75-year-old woman with heart failure and functional mitral regurgitation grade 3/3 who was denied conventional surgery due to comorbidities and therefore underwent TMVR.
The additional value of 3D TEE lies mainly in the possibility of seeing the valve and the device in an anatomical context. The most valuable additional information provided by 3D TEE is the guidance for adjusting the clip perpendicular to the line of coaptation in an “en face” view as illustrated in Figure 1. However, for guiding the clip from the septum towards the mitral valve there is a “blind spot” in echo guidance from the transseptal puncture and moving the device down toward the valve where both 2-dimensional (2D) TEE and “conventional” 3D TEE has shortcomings. Using 2D, it is difficult to keep the tip of the device in the image plane when moving from the septum towards the valve plane. Although 3D permits keeping the device within the image plane throughout this movement, the lack of stereo vision in the conventional image presentation prevents a correct assessment of the distance between structures, due to lack depth coding. Both 2D and 3D thus carry some uncertainty during maneuvering towards the valve and, consequently, some potential risk for complications when not seeing the exact location of the repair device. The novel stereo vision modality with red-blue/cyan color coding (GE Vivid E9, Horten, Norway) makes it possible for the operator using red-blue/cyan glasses to actually see the distance in stereo depth coding between the device and intracardiac structures, i.e., the coumadin ridge, the atrial wall, and the mitral valve. Figures 2 to 5⇓⇓⇓ and the associated Online Videos (Online Videos 1, 2, 3, 4, 5, 6, 7, and 8) illustrate the different phases of maneuvering during the movement in the left atrium from the transseptal puncture towards the mitral valve.
The most important potential gain of using stereovision is: 1) increased safety, due to the continuous visualization of the device which enables a safer translation of the device from the atrial septum to the correct positioning above the mitral valve due to the visualization of the distance to intracardiac structures, making it easier for the operator to avoid unnecessary contact with the LA wall; and 2) a shorter procedural time due to the possibility of continuous visualization for the operator without waiting for the repositioning of image planes and/or changing imaging modalities between 2D and 3D images. However, the limitation of the present approach is the necessity for the operator and TEE examiner to use red-blue/cyan glasses. An improvement to the existing system could be a 3D screen to overcome this inconvenience for the operator.
Dr. Settergren is a proctor and is on the advisory board for Abbott Vascular. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation