Different LAA occluder device types. Common criteria are transcatheter transseptal delivery via femoral venous access, self-expanding nitinol-made cage or mesh, designed to be permanently implanted at or slightly distal to the LAA ostium to trap potential emboli before they exit the LAA. A (left panel) shows the historically first LAA device named PLAATO (Appriva Medical Inc.) with a nitinol-made cage covered with an polytetrafluoroethylene membrane with small anchors along the struts; range of diameters 15-32 mm. Faced to the apex of left atrial appendage the cover is opened for the filling of blood and a later thrombosis inside the device. B (middle panel) shows the Watchmen device (Atritech Inc.) with a polyethylene membrane on the atrial-faced surface of a nitinol-made cage and a row of fixation barbs; range of diameters 21-33 mm. C (right panel) ACP device (AGA Medical Inc.) is constructed from a nitinol mesh and polyester patch, consists of a lobe and a disc connected by a central waist; range of diameters 16-30 mm.