The aim of this review is to discuss the management of atrial septal defects (ASD) in the adult patient paying special attention to the elderly population and the most recent transcatheter advancements. ASDs are characterized by the following categories: ostium secundum, ostium primum, sinus venosus, and coronary sinus defects; though multiple defects may exist concurrently. Intervention for closure of ASDs are indicated with the development of right ventricular volume overload, or in the clinical context of paradoxical embolic stroke. Previously, there was significant disagreement regarding the timing of ASD closure in adult patients, but there is now general consensus that adult patients with clinical evidence of right ventricular overload should undergo closure of ASDs at the time of presentation. The present review describes the typical presentation of patients with symptomatic ASD's, medical management, and whether surgical or percutaneous approach should be pursued. We will also discuss other important considerations for patient selection and potential early and late complications of transcatheter ASD closure such as congestive heart failure, device embolization, and tissue erosion. At the time of this writing, there are currently three FDA-approved devices for percutaneous VSD closure including the Amplatzer TM Septal Occluder (ASO, St. Jude Medical, St. Paul, MN), Gore HELEX TM Septal Occluder (W.L. Gore and Associates, Newark, NJ), and Gore CARDIOFORM TM Septal occluder (GCSO, W.L. Gore and Associates, Newark, NJ) devices. Many premarket approvals were granted for devices that never went to market due to poor investigational study performance. Likewise, the HELEX device has since been discontinued upon bringing the GCSO device to market. We will focus primarily on the ASO device with a brief review of current investigations into the GCSO device, both of which carry an indication for closure small to medium sized ASDs in the ostium secundum position. Additionally, this review covers the safety of transcatheter closure of ASDs with currently available devices, review studies associated with devices available outside the United States, and perioperative considerations for transcatheter Page 2 of 18 Zimmermann et al. Vessel Plus 2019;3:31 I http://dx.intervention. Obstacles to device employment and countermeasures to overcome operational challenges will also be discussed. To this end, variations or similarities of currently approved devices will be emphasized throughout this discussion where possible. Lastly, we will offer insights into device evolution trends with the expectation of new device developments on the horizon. We will briefly discuss up and coming areas of active research, including the emerging fields of novel biomaterials and gene therapy.
MORPHOLOGY AND CLINICAL FEATURES OF ASDS
Location, Morphology, and suitability for surgery vs. transcatheter interventionIt is important to note that morphological variations of different types of ASDs, which determines whether a particular defect is amenabl...