Retrospective Evaluation of Transcatheter Edge-To-Edge Mitral Valve Repair in Dogs With Myxomatous Mitral Valve Disease

Figures

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  FIGURE 1. Summary of pre‐procedure assessment factors for evaluating risks and outcomes in 20 dogs undergoing transcatheter edge‐to‐edge mitral valve repair. AML, anterior mitral leaflet length; BW, body weight; MR, mitral regurgitation; PML, posterior mitral leaflet length; TEER, Transcatheter edge‐to‐edge repair; VC, vena contracta.

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  FIGURE 2. Illustration of the Canine Mitral V‐Clamp delivery system. Arm diameter and clamp length are depicted. The system is available in four sizes, each tailored to accommodate varying anatomical requirements. The clamp length and arm diameter measure 14 and 6.7 mm for Size 2, 16 and 7.7 mm for Size 3, 18 and 8.7 mm for Size 4, and 20 and 9.5 mm for Size 5 (the largest), respectively.

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  FIGURE 3. Representative transesophageal echocardiographic and 3D reconstructed imaging of the transcatheter edge‐to‐edge mitral valve repair procedure. (A) An apex puncture was made with a guide wire. (B) Following the guidewire, a 14‐Fr sheath dilator set was inserted into the left ventricle. (C) The sheath was advanced into the left atrium with careful maneuvering. (D) The V‐clamp was deployed, starting with the front clamp in the left atrium, followed by the rear clamp. (E) The position of the clamp was adjusted to ensure centering and proper alignment with the mitral valve. (F–G) Alignment of the clamp was confirmed using 2D and 4D echocardiography, ensuring it was perpendicular to the valve. (H) The clamp was hard closed after a soft closure check. (I–J) After measuring captured lengths of leaflets and mitral pressure, the clamp was released.

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  FIGURE 4. Transesophageal echocardiography (TEE) images before and after transcatheter edge‐to‐edge repair therapy. Mitral regurgitation was significantly reduced immediately following the TEER procedure. (A) 2D TEE images prior to clamping; (B) 2D TEE images post‐clamping; (C) 3D TEE images prior to clamping; (D) 3D TEE images post‐clamping. Simultaneous biplane 2D images show mid‐esophageal mitral commissural (on the left in each panel) and long axis (on the right in each panel) views. 3D color flow Doppler images illustrate the mitral valve with the aorta at its 12 o’ clock position.

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  FIGURE 5. Scatter plot of the pre‐ and post‐transcatheter edge‐to‐edge mitral valve repair vertebral heart size (VHS) and vertebral left atrial size (VLAS) measurements.

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  FIGURE 6. Radiographic and echocardiographic variables of dogs undergoing TEER, including changes observed over a 3‐month period. Thoracic radiography and echocardiographic variables were available for nine of the 13 dogs owing to the lack of standardized monitoring protocols. Mitral regurgitation severity and quantification were feasible in six dogs, excluding three that had been initially evaluated using a different ultrasound machine. ARJ/LAA, maximal ratio of the regurgitation jet area signal to LA area; E‐vel, early transmitral inflow peak velocity; LA:AO, left atrium‐to‐aorta ratio; LVIDdN, left ventricular internal dimension in diastole normalized to body weight; RF, regurgitant fraction; TEER, Transcatheter edge‐to‐edge repair.