Left Atrial Appendage Closure

Figures

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  Figure 1. Relevant Anatomic landmarks for LAA Closure (A and B) Endocardial left atrial wall showing the orifice of the LAA in 2 human specimens. Note in B the extra-appendicular posterior pectinate muscles extending inferiorly from the left appendage toward the vestibule of the MV (white arrows) and the close anatomic relationship with the LCx (red arrows) to the LAA neck. (C) Endoscopic computed tomography view of the left posterolateral wall shows the prominent left lateral ridge between the LSPV and the ostium of the LAA. (D) Cross-histologic section of the LAA (longitudinal section) stained with Masson’s trichrome. Note the myocardium of the lateral ridge, the landing zone of the LAA, and the LCx close to the vestibule of the MV. The arrows show the variable thickness of myocardium that forms the walls of the LAA. (E) Leftward extension of the Bachmann’s bundle (white broken lines) on either side of the neck of the LAA to run in parallel fashion to the lateral aspect of the left atrium. (F) Dissection of the subendocardial fibers and the fiber arrangement of the septoatrial bundle and its 3 major fascicles (white dotted lines). Note the circular arrangement of the endocardial fibers…