A preserved transseptal puncture zone in a novel PFO occluder enables safe repeat left atrial interventions: preclinical validation in a porcine model

Figure 1. Experimental devices employed in the study. (A) Displays the PFO occluder with a retained puncture area; (B) illustrates the novel PFO occluder attached to the delivery system; (C) depicts the bottle-shaped left atrial appendage occluder utilized in the experiment; and (D) presents the atrial septal puncture system employed during the study.

Figure 2. (A) Illustrates optimal positioning of the occluder without any observable shunting, as confirmed by a follow-up transesophageal echocardiogram 3 months after transcatheter PFO closure; the occluder is highlighted by the yellow arrow. In (B), emphasis is placed on measuring the dimensions (width and depth) of the left atrial appendage orifice, with its location indicated by the yellow arrow. (C) Demonstrates successful puncturing of the atrial septum through the PFO occluder under TEE guidance. Highlighted by the yellow arrow is the puncture needle. Lastly, in (D), TEE-guided LAAC is depicted with a focus on highlighting using a yellow arrow. (E–H) Shows the surgical procedure of percutaneous left atrial appendage occlusion using a new occluder under DSA fluoroscopy.

Figure 3. Specimens of occluders implanted in experimental animals. (A) The left atrial appendage is occluded by puncturing the PFO occluder and subsequently dissected from the heart post-euthanasia. The yellow arrow on the left indicates the implantation of the left atrial appendage occluder in the experimental animal, while the arrow on the right points to the retained puncture site of the PFO occluder after 3 months of implantation. (B) Shows that the puncturable PFO occluder was removed and separated after a 3-month period following implantation. The left atrial disc retains a PLLA membrane covered with a nickel-free titanium alloy mesh to facilitate needle penetration, while the right atrial disc features apertures aligned with the left atrial membrane. The yellow arrow indicates the residual puncture hole following LAAC. (C) H-E stained specimen obtained through diamond knife sectioning of the puncturable occluder at a post-implantation duration of 3 months, with emphasis on its puncturable area indicated by blue arrow. The histological findings at 3 and 6 months further confirmed complete endothelialization. (D) Electron microscope specimen obtained through diamond knife sectioning…