State-of-the-Art Review: Anatomical and Imaging Considerations During Transcatheter Tricuspid Valve Repair Using an Annuloplasty Approach

Figures

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  Figure 1. Anatomy of the tricuspid valve complex. (A) Main panel shows a heart cut in a plane simulating transesophageal view with the superior vena cava (SVC) at 11 O'clock position. The circles mark the leaflet commissures and the white lines trace the segments of the hinge line. Note the smooth wall vestibule of atrial wall leading to the valve orifice. The smaller panels taken from random specimens demonstrate the thinness of the vestibular wall and variations in relationship of the hinge line (arrows), depth of fat-filled atrioventricular groove, and location of right coronary artery(*) at the numbered segments. (B) The tricuspid valve shown in closed position with chordal insertions in the rough zone. The vestibule separates the leaflet hinge (arrow) from the pectinated part of the atrium. The right coronary artery (RCA) runs in the tissues of the atrioventricular groove (yellowish area). The inset is a histologic section cut in the same plane showing separation of atrial and ventricular myocardium (red stain). There is no robust fibrous annulus at the hinge line (arrow). Instead, fibrous tissues (green stain) from the leaflet integrate with tissues of the atrioventricular (AV)…

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  Figure 2. The Cardioband (CB) implant. The CB is implanted along the tricuspid annulus from the antero-septal commissural (ASC) area to the postero-septal commissural (PSC) region (left image). The specific implant features are seen on the right image. The system consists of polyester sleeve containing a pre-mounted contraction wire that is connected to an adjusting spool. On the polyester sleeve radiopaque markers are applied at a distance of 8 mm. In this example 17 anchors are present (F-band size). Note that the first anchor is at an almost 90° angle to the other anchors. Images with permission from Edwards Lifesciences, Irvine, CA, USA.

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  Figure 3. Main transesophageal echocardiographic (TEE) imaging planes for the assessment of the tricuspid valve (TV): the mid- esophageal 4-chamber view (0–10°). (A) The main imaging planes for assessing a TV using TEE are shown in an anatomical image of a TV with 3 leaflets. (B) The specific imaging plane for the mid-esophageal 4-chamber view is shown. (C) By using commercial simulation software (Mentice Healthy Simulation; version VIST G5; Gothenburg, Sweden) TEE and fluoroscopic views can be generated simultaneously based on MDCT data sets. The upper picture shows the necessary positioning of the TEE probe in fluoroscopy (35° RAO, 6° CRANIAL) to create a mid-esophageal 4-chamber view at 0° (see image below). (D) A standard 2D TEE view at 0° is shown. RA, right atrium; RV, right ventricle; RAA, right atrial appendage; RCA, right coronary artery; LA, left atrium; LV, left ventricle; MV, mitral valve; SL, septal leaflet; AL, anterior leaflet; PL, posterior leaflet; MDCT, multi-detector computed tomography; Abbreviations are also used for Figures 4–7.

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  Figure 4. Deep esophageal view at 0–10°. (A) The specific imaging plane for the deep esophageal view is shown (see also Figure 3A). Starting from the mid-esophageal 4-chamber view at 0–10°, the probe is advanced deeper until the CS becomes visible. This maneuver allows for an easy evaluation of the septal leaflet. The evaluation of the posterior region of the septal and the posterior leaflets is of particular importance since the main axis of tricuspid annular dilation is in anterior-posterior direction and leaflet retraction is often pronounced in the posterior part. (B) The upper picture shows the necessary positioning of the TEE probe in fluoroscopy (35° RAO, 6° CRANIAL) to create the deep esophageal view at 0° (see image below). (C) The corresponding 2D TEE view without (left) and with (right) color Doppler is shown. CS, coronary sinus; other abbreviations see Figure 3.

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  Figure 5. Right ventricular (RV) inflow-outflow tract view (50–70°) as seen in mid- to deep esophageal views. (A) The imaging plane for the RV inflow-outflow tract is found here in a deeper transesophageal view at 60° (see also Figure 3A). (B) The upper picture shows the positioning of the TEE probe in fluoroscopy (35° RAO, 6° CRANIAL). (C) A 2D TEE RV inflow-tract view is shown (slightly higher mid-esophageal position of the TEE probe). Ao, aorta; RVOT, right ventricular outflow tract; PV, pulmonary valve; other abbreviations see Figure 3.

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  Figure 6. Anteriorly rotated mid- to deep- esophageal view (50–70°). (A) This view is achieved by rotating the probe anteriorly from the mid-esophageal or a deeper esophageal RV inflow-outflow tract view toward the anterior tricuspid annulus as shown here. (B) The image on the top left shows the necessary positioning of the TEE probe in fluoroscopy (35° RAO, 6° CRANIAL) to create this anteriorly rotated RV inflow-outflow tract view at 60° (image on the top right). The images below show the orthogonal long axis view (right) using x-plane imaging. During the procedure, x-plane imaging in this view can be used to identify the tip of the IC at the anterior annulus (bottom left), while in the long axis plane (right) the distance to both the RCA and the hinge point of the tricuspid leaflet can be judged. Note the course of the RCA and the proximity to annulus in this case. In (C) a 2D TEE view is shown. Ao, aorta; ant., anterior; IAS, interatrial septum; other abbreviations see Figure 3.

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  Figure 7. Transgastric and 3D enface views. Trans-gastric short axis views are particularly helpful, as all leaflets are usually visible. In most cases, adequate short axis views can be generated between 30 and 60°, so that the probe can be easily advanced trans-gastrally from the mid-esophageal RV inflow-outflow tract view. Additively an anterior flexion is then necessary. It should be attempted to display all commissures. (A) The image on the left shows the necessary positioning of the TEE probe in fluoroscopy (35° RAO, 6° CRANIAL) to create this trans-gastric short axis view at 60°. (B) A zoomed 2D TEE trans-gastric view obtained at 60° is shown. On the left the coaptation gap is traced (yellow line), on the right color Doppler is used to assess the origination and extension of the TR jet. (C,D) X-plane imaging along the anterior leaflet (images on the left) allows the evaluation of the anterior and posterior leaflet in relation to each other in long axis views (images on the right). (E) A three-dimensional (3D) enface view of the TV is acquired from a 60 degree view. It should be ensured, that part of the aortic valve/aortic root (Ao) and the coronary sinus (CS) is included in the 3D…

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  Figure 8. Multi-detector computed tomography (MDCT) based pre-procedural planning by using specific software (3mensio, Pie Medical Imaging BV, Bilthoven, the Netherlands). (A) MDCT is used to provide measurements of tricuspid annular (red circle) dimension and the distances of the anticipated anchor positions to the right coronary artery (RCA; light green line). Anchors with insufficient distance to the RCA are shown in red, the others in blue. Furthermore, the band size is determined, and the position of the first anchor point is defined as the distance from the antero-septal tricuspid annulus to the center of the aortic valve (yellow circle), which serves as a largely stable landmark. (B) In addition, optimal left anterior oblique (LAO; left) and right anterior oblique (RAO; right) projections for the procedure are pre-defined. (C) For each anticipated anchor position, the distance to the RCA and the hinge point of the leaflet is measured. Here the first anchor (A1) position is exemplarily shown.

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  Figure 9. Measurement of tricuspid annular dimensions in 3D transesophageal echocardiography (TEE) by using real-time multi-planar reconstruction (RT-MPR). (A) The 3D data set is acquired from a mid-esophageal 60? RV inflow-outflow tract view. RT-MPR is used to measure the annular circumference (yellow circle; bottom right) after the green cropping line is adapted to the annular plane in the orthogonal views (top right and bottom left). (B) Measurements for band sizing should be made in diastole, when annular dimensions are largest (51). The green cropping lines are adapted to the annular plane in the same way as shown in (A) (top right and bottom left). In the z-plane (bottom right), the white line is then positioned at the end of the coronary sinus (CS) whereas the yellow line is positioned at the antero-septal annulus by sparing out the aorta (Ao). The hinge line (curved yellow line) is then traced in between the white and yellow line. A second line (light green) is drawn at about 4 mm away, where anchors can realistically be placed in tissue. This measurement is used to confirm the pre-selected band size which was obtained from multi-detector computed tomography imaging measurements.

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  Figure 10. Procedural steps. (A) The introduction of delivery system via the IVC is seen. The tip disappears in the SVC, which is not visible. This 3D view is generated from a wide angle bi-caval view at 105°. IAS, SVC, and IVC should be integrated in the image. The image is then rotated and rotated so that the IAS is located on the left (medial) side. (B) The individual catheter components as seen in fluoroscopy. (C) In this schematic the catheter components, the implant and the first three implanted anchors (1,2,3) in the antero-septal commissural area are shown. (D) The navigation of the delivery system toward the first anchor position is seen in a 3D TEE enface view. (E) The measurement from the IC tip at the anterior annulus to the middle of the aorta which confirms a correct 1st anchor position is seen on the left side. X-plane imaging is used to evaluate the distance to the hinge point of the leaflet (right). Lateral positioning of the spool must be avoided, otherwise the contraction wire may be damaged during anchoring. (F) The use of real-time multi-planar reconstruction to confirm adequate distance from the IC tip to the hinge point of the leaflet is demonstrated for an anchor in…

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  Figure 11. Monitoring during step-wise contraction of the implant. (A) Evaluation of the reduction of tricuspid regurgitation (TR) under gradual increasing contraction (2.5, 3.5, and 5.5 cm) are shown in x-plane imaging with color Doppler (TEE 60? left/150? right). Under maximum contraction (5.5 cm; bottom right) only trivial residual TR is visible. (B) The implant size and shape is seen in fluoroscopy before (upper image) and after (lower image) contraction. SAT, size adjustment tool.