Safety and feasibility of left atrial appendage inversion in swine: A proof-of-concept study for potential therapy to prevent embolic stroke

Figures

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  FIGURE 1. Diagram of LAA inversion procedure. (A) Shape of LAA before inversion. (B) Using surgical tools and glue to invert the LAA apex. (C). Procedure details: An auricle clamp gently grabbed the LAA apex and put it inward, while tissue glue was applied around the tip of clamp. The purse-string suture was knotted to secure the inversion. (D) Shape of inverted LAA. The procedure reduced the dead space in the LAA chamber.

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  FIGURE 2. Echocardiogram images. (A) TEE before the procedure. (B) ICE before the procedure. (C) An example of LAA measurement before the procedure (blue: orifice diameter; green: depth). (D) TEE at 8 weeks after the procedure. (E) ICE at 8 weeks after the procedure. (F) An example of LAA measurement at termination (white ring: area). The inversion significantly reduced or eliminated the LAA space.

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  FIGURE 3. Morphology of LAA inversion (termination at 8 weeks after surgery). (A) View from the outside (epicardium). (B) View from the inside (endocardium). Yellow rings show the inverted LAA.

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  FIGURE 4. HE and MT staining (×4 objective). (A) HE for inverted LAA. Tissue remodeling and fibrosis are shown between myocardia. (B) MT for inverted LAA. Collagen expresses in blue, and myocardium expresses in red. (C) HE for right atrial appendage as control. (D) MT for right atrial appendage as control.

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  FIGURE 5. Immunofluorescence staining (×10 objective). Green: Wheat Germ Agglutinin; Blue: Nuclear. Red: Anti-bodies. (A) Anti-fibronectin. (B) Anti-collagen (I) (C) Anti-macrophage. (D) Anti-caspase 3. The anti-fibronectin and anti-collagen I were positive (red stain was evident), while the anti-macrophage and anti-caspase were negative (red stain was not present).