ABSTRACT
INTRODUCTION Devices able to close atrial septal defects percutaneously were developed in the 1980s, and these devices have been used subsequently to close PFOs as well.1 As they were originally developed to close true atrial septal defects, devices currently used to close PFOs have certain characteristics in common, such as right and left atrial anchor arms that are rigidly connected to each other at a fixed distance, and a means to physically close tissue defects (‘umbrella’ fabric design or extensive metal strutwork to encourage tissue overgrowth).
