PMC9871352_01
Case 1: Volumetric and multiplanar 3D-TEE images of PFO. (A) Three-dimensional rendering of bicaval view (90 ) depicting PFO tunnel length (horizontal dotted white arrow) and tunnel height (vertical dotted white arrow). (B) En face 3D rendering of PFO (orthogonal to bicaval view) as seen from LA depicting tunnel width (dotted white arrow) at LA opening. (C) En face 3D rendering of PFO as seen from RA (orthogonal to bicaval view) demonstrating tunnel width (dotted white arrow) at RA opening. (D) Bicaval 3D multiplanar image (90 ) of PFO with transverse imaging plane (dotted red line) used to create orthogonal multiplanar view (E) for measurement of PFO tunnel width (white arrow) at RA opening. (F) Bicaval 3D multiplanar image (90 ) of PFO with transverse imaging plane (red dotted line) advanced superiorly to create orthogonal multiplanar view (G) for measurement of PFO tunnel width (white arrow) at LA opening. (H) Bicaval 3D multiplanar image (90 ) of PFO with further advancement of transverse imaging plane along apparent tunnel length demonstrates in orthogonal view (I) that the roof of the tunnel is no longer intact (white arrow) due to crescentic LA opening. Ao, Aorta; LA, Left atrium; RA, right atrium; SVC, superior vena cava.
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Transcatheter PFO closure was performed with intraprocedural 3D-TEE, which demonstrated a 10-mm PFO tunnel length and a 7-mm tunnel height or separation between the septum primum and secundum (Figure 1A). However, the PFO tunnel width, that is, the size of the opening as seen with en face 3D volumetric and multiplanar imaging at both the left (LA) and right atrial (RA) openings, was much larger at 22 mm (Figure 1B-I, Videos 1 and 2).
Case 1: 2D- and 3D-TEE images after transcatheter PFO closure. (A) Midesophageal 45  short-axis view showing deployment of PFO occluder device along interatrial septum. (B) En face 3D rendering of LA disk of PFO occluder device in the anterosuperior portion of the interatrial septum. (C) En face 3D multiplanar view of LA disk with red arrows approximating location of PFO tunnel widths at RA and LA openings and blue arrow demonstrating tunnel length. (D) Bicaval 3D multiplanar view demonstrating PFO tunnel length (blue arrow) relative to PFO occluder device. The device is "centered" at the RA opening. (E) Three-dimensional multiplanar view (orthogonal to bicaval view) demonstrating PFO tunnel width at RA opening (red arrow) relative to PFO occluder device. The tunnel width has been adequately "sandwiched" by both RA and LA disks. Ao, Aorta; LA, left atrium; RA, right atrium; SVC, superior vena cava.
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However, the PFO tunnel width, that is, the size of the opening as seen with en face 3D volumetric and multiplanar imaging at both the left (LA) and right atrial (RA) openings, was much larger at 22 mm (Figure 1B-I, Videos 1 and 2). After deployment, the device appeared well seated along the interatrial septum with no impingement on surrounding structures (Figure 2A-E, Video 3) or evidence of shunting by color Doppler or with agitated saline injection.
Case 2: Volumetric and multiplanar 3D-TEE images of PFO. Three-dimensional rendering of bicaval (A) and en face (B) view of PFO from the left atrium (LA) demonstrating ASA with septum primum displaced toward the right atrium precluding visualization of PFO tunnel and measurement of tunnel width in corresponding 3D multiplanar image (C). Three-dimensional rendering of bicaval (D) and en face (E) view of PFO from the LA with septum primum lifted 2-3 mm off septum secundum due to transient increase in RA pressure. Three-dimensional bicaval view demonstrates very short tunnel length (2 mm, dotted white arrow). Three-dimensional en face view depicts crescentic opening of PFO into the LA and PFO tunnel width. In the corresponding 3D multiplanar image (F), the PFO tunnel width (dotted white arrow) measures 15 mm. Three-dimensional rendering of bicaval (G) and en face (H) view of wire (*) through PFO ("wire sizing") allowing for easier measurement of PFO tunnel width (20 mm) by multiplanar 3D imaging (I) as shown with the larger dotted white arrow. Three-dimensional multiplanar views optimized to visualize PFO tunnel width (panels C, F, and I) are obtained from the plane orthogonal to the bicaval view (dotted red lines). Ao, Aorta; FO, fossa ovalis; RA, right atrium; SVC, superior vena cava.
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Initial 3D-TEE imaging demonstrated a rightward displaced interatrial septum (Figure 3A-C, Video 4). With separation of the septum primum and secundum during a transient increase in RA pressure, the tunnel length was 2 mm, tunnel height was 2 to 3 mm, and tunnel width was 15 mm by 3D multiplanar imaging (Figure 3D-F). With the wire tenting open in the tunnel, the PFO tunnel width was remeasured at 20 mm (Figure 3G-I, Video 5), while tunnel length was unchanged.
PMC9871352_02
Case 2: Volumetric and multiplanar 3D-TEE images of PFO. Three-dimensional rendering of bicaval (A) and en face (B) view of PFO from the left atrium (LA) demonstrating ASA with septum primum displaced toward the right atrium precluding visualization of PFO tunnel and measurement of tunnel width in corresponding 3D multiplanar image (C). Three-dimensional rendering of bicaval (D) and en face (E) view of PFO from the LA with septum primum lifted 2-3 mm off septum secundum due to transient increase in RA pressure. Three-dimensional bicaval view demonstrates very short tunnel length (2 mm, dotted white arrow). Three-dimensional en face view depicts crescentic opening of PFO into the LA and PFO tunnel width. In the corresponding 3D multiplanar image (F), the PFO tunnel width (dotted white arrow) measures 15 mm. Three-dimensional rendering of bicaval (G) and en face (H) view of wire (*) through PFO ("wire sizing") allowing for easier measurement of PFO tunnel width (20 mm) by multiplanar 3D imaging (I) as shown with the larger dotted white arrow. Three-dimensional multiplanar views optimized to visualize PFO tunnel width (panels C, F, and I) are obtained from the plane orthogonal to the bicaval view (dotted red lines). Ao, Aorta; FO, fossa ovalis; RA, right atrium; SVC, superior vena cava.
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Initial 3D-TEE imaging demonstrated a rightward displaced interatrial septum (Figure 3A-C, Video 4). With separation of the septum primum and secundum during a transient increase in RA pressure, the tunnel length was 2 mm, tunnel height was 2 to 3 mm, and tunnel width was 15 mm by 3D multiplanar imaging (Figure 3D-F). With the wire tenting open in the tunnel, the PFO tunnel width was remeasured at 20 mm (Figure 3G-I, Video 5), while tunnel length was unchanged.
Case 2: 2D- and 3D-TEE images after transcatheter PFO closure. Midesophageal 45  view (A) demonstrating suboptimal deployment of 25-mm occluder. Due to its smaller size relative to the PFO width, the device did not capture the PFO (white arrow) at tunnel opening and easily recoiled posteriorly in the atria. Midesophageal 45  view (B), bicaval view (C), and en face 3D rendering (D) from LA demonstrating improved seating of larger 35-mm PFO occluder device along interatrial septum. Ao, Aorta; LA, left atrium; RA, right atrium; SVC, superior vena cava.
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Initial 3D-TEE imaging demonstrated a rightward displaced interatrial septum (Figure 3A-C, Video 4). The 25-mm occluder device, however, failed to seat well along the interatrial septum (Figure 4A, Video 6) after initial deployment, and the device was recaptured and removed. After deployment, the device appeared well seated along the interatrial septum with no impingement on surrounding structures (Figure 4B-D, Video 7) or evidence of shunting by color Doppler or with agitated saline injection.
PFO sizing and device size selection schematic based on tunnel width for transcatheter PFO closure. When the PFO tunnel width at the RA opening is adequately oversized by the RA disk, the PFO tunnel will be sufficiently closed and prevent passage of thrombi from the right to left atrium. The blue arrow depicts PFO width at RA opening and the multicolor arrow depicts RA disk diameter with the red portion showing degree of PFO tunnel width oversizing. LA, Left atrium; RA, right atrium.
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With the wire tenting open in the tunnel, the PFO tunnel width was remeasured at 20 mm (Figure 3G-I, Video 5), while tunnel length was unchanged.