Failure of the GORE HELEX atrial septal defect occluder to treat membranous VSDs in swine

Abstract

We tested the suitability of the GORE HELEX septal occluder for closure of membranous ventricular septal defect in three Yucatan minipigs that had naturally-occurring membranous ventricular septal defects. The animals were studied in the Gore Science Center Laboratory in Flagstaff, Arizona. In all of the device implantations, seating of the right disk along the right ventricular septum was problematic with resultant entanglement of one device in the chordae tendinae during attempted removal, implantation of one device onto the tricuspid valve papillary muscle and unlocking of one device occurring after implantation. A new occluder design appears to be needed to minimize the risk of disk entanglement with cardiac structures, particularly within the right ventricle. These studies did establish that the Yucatan mini swine are an acceptable and appropriate model for evaluating occluders intended for closure of membranous ventricular septal defects.