Application of Balloon-Expandable Transcatheter Heart Valve in Bicuspid Aortic Valve

Figure 1. Reconstruction Principle in Type-0 Bicuspid Aortic Valve Schematic representation of the type-0 bicuspid aortic root. After reconstruction using 2 hinge points, a series of measurements are made through different angulations of the transverse plane. The optimal plane is defined as the plane with the smallest annulus dimension. The optimal projection is defined to obtain the farthest distance between the 2 hinge points.

Figure 2. Semiautomatic Approach to Obtain Optimal Annular Plane (A) Place the yellow central line in the aortic root manually. (B) Select the type-0 bicuspid aortic valve model and determine the 2 hinge points of the cups. (C) Rotate the crosshairs to obtain the shortest dimension in the transverse plane. (D) Centralize the yellow line in the sagittal plane to obtain a perpendicular plane with the shortest dimension. (E and F) The smallest annular area is obtained compared with the other larger oblique plane.

Figure 3. Balloon Sizing (A) In all aortic valve types, the anatomical relationship between the sinus hinge points and the balloon serves as the major criterion to decide the THV size, whereas contrast backflow and the movement of the balloon serve as the minor criteria. (B) In BAV, balloon sizing serves as a THV simulator. In cases with a heavily calcified annulus, the balloon could shift to the less-calcified side. Excessive THV shift during placement could result in coronary artery occlusion (especially in shallow sinus width and longer leaflet length), PVL, and aortic root injury. BAV = bicuspid aortic valve; THV = transcatheter heart valve; PVL = paravalvular leak

Figure 4. “Double Coplanar View” in Type-0 BAV Schematic illustration of the “Double coplanar view” with the alignment of both the native valve and the prosthetic valve. Coaxiality of BEV with the left ventricular outflow tract, annulus, and aortic root should be obtained when the guidewire is placed in the apex (right anterior oblique 30° view). The parallax of the inflow end and the outflow end should be eliminated (red lines). BAV = bicuspid aortic valve; BEV = balloon-expandable valve.

Figure 5. “Follow the Right Cusp Rule” Schematic illustration of the “follow the right cusp” to optimize the ODP in type-1 BAV. C-arm rotation direction is consistent with the position of the RCC based on the other hinge points (purple arrows). CAU = caudal; CRA = cranial; L = left coronary cusp; LAO = left anterior oblique; N = noncoronary cusp; R = right coronary cusp; RAO = right anterior oblique.

Figure 6. Valve-Crossing Basic Technique (Top) Schematic illustration of the valve crossing starting cusp. AL-1 with wire starts in the NCC, whereas AL-1 without wire starts in the LCC. (Bottom) Schematic illustration of the rotation course. Clockwise rotation of AL-1 goes from NCC to LCC/RCC, whereas counterclockwise rotation of AL-1 goes from LCC to NCC/RCC. AL-1 = Amplatz 1; LCC = left coronary cusp; NCC = noncoronary cusp; RCC = right coronary cusp; other abbreviations as in Figure 5.

Figure 7. Valve-Crossing Course and Prediction Point (Top) Schematic illustration of the valve crossing course (red arrows) in type-0 and -1 BAVs. (Bottom) Schematic illustration of the predicted crossing point (red arrows) with maximum likelihood. BAV = bicuspid aortic valve; CCF = coronary cusp fusion; LR = left-right coronary fused cusp; MCF = mixed cusp fusion; RN = right-noncoronary fused cusp; other abbreviations as in Figure 5.

Figure 8. Anatomy-Base Prediction for Valve-Crossing Point Type 0 CCF (A to C) and type-1 L-R (D to I) are illustrated separately. (A) Fused right and noncoronary cusp was determined in pre-TAVR CT. (B) The pigtail was placed in the fused cusp and the predicted crossing point was on the right side of the pigtail. (C) The straight wire went across the valve at the predicted point. (D) A raphe between RCC and NCC was determined in pre-TAVR CT. (E) The pigtail was placed in the RCC and the prediction point was on the right side of the pigtail. (F) Tried to cross the valve at the predicted crossing point. (G) Pigtail jumped out of the small RCC. (H) The pigtail was placed in NCC with stableness and the predicted point changed to the right side of the pigtail. (I) The straight wire crossed the valve at the predicted point. BAV = bicuspid aortic valve; RN = right-noncoronary fused cusp; TAVR = transcatheter aortic valve replacement; other abbreviations as in Figures 5, 6 and 7.

Figure 9. High Deployment Schematic illustration of high deployment in BAV. A “high,” 90% aortic deployment can be achieved by placing the middle marker of the deployment balloon slightly (one-half to 1 length of the 3-mm long marker) above the annulus. BAV = bicuspid aortic valve.

Figure 10. “Flare the Inflow” and “Flare the Outflow” Techniques (A) Schematic illustration of the “flare the inflow” technique: place the middle marker and open the deployment balloon toward the ventricular end of the BEV frame (red line). A better sealing of the BEV skirt prevents PVL without increasing the risk of annular rupture. (B) Schematic illustration of the “flare the outflow” technique by aligning the middle marker of the deployment balloon at the height of BEV outflow (red line). A better anchoring of the valve to avoid migration/embolization can be achieved. BAV = bicuspid aortic valve; BEV = balloon expandable valve; PVL = paravalvular leak; THV = transcatheter heart valve.

Figure 11. “Flare the Inflow” and “Flare the Outflow” Techniques: Angiographic Examples Examples of “flare the inflow” (A) and “flare the outflow” techniques (B).

Figure 12. Workflow in Heavily Calcified BAVs Schematic illustration of workflow in heavily calcified BAVs in the “gray zone” annular dimension of 23.5 mm. With different strategies after balloon sizing, smaller (23 mm) THV or bigger THV (26 mm) could be chosen. (Left) A 23-mm Sapien 3 is deployed with intentional overexpansion. Place the marker of deployment balloon directly on top of the annulus line (red line) and deploy the BEV with nominal filling volume. In case of PVL, “flare the inflow” with additional 2 mL for postdilatation to achieve overexpansion without giving additional pressure on the annulus. (Right) A 26-mm Sapien 3 is deployed with intentional underexpansion. Place the marker of deployment balloon 3 mm above the annulus line (red line). Intentional underfilling of the deployment-balloon with 2 mL less than nominal volume. Post-dilate—“flare the inflow”—with nominal volume to prevent PVL without giving additional pressure on the annulus. In contrast, a dashed black rectangle shows the standard deployment and standard post-dilatation. BAV = bicuspid aortic valve; PVL = paravalvular leak.