Percutaneous Closure of Atrial Septal Defects with the MemoPart Atrial Septal Occluder: The Early-Term Results of a Multicenter Study

Atrial septal defect (ASD) is a common congenital heart disease with left-to-right shunt that may lead to pulmonary hypertension over time. Secundum ASD closure with transcatheter technique is currently the preferred method. The aim of this study was to evaluate the clinical experience and early-term outcomes of patients treated with a MemoPart ASD occluder device between June 2013 and June 2019. Fifty-six patients (35 females) with a mean age of 9.4 ± 6.6 years (range: 2-44 years) were included in the study. The diameters of the devices used to close the ASDs were 7-28 mm. The ratio of the device/defect diameter was 1.14:1. Atrial septal defect closure was applied successfully in all patients. The MemoPart septal occluder is a safe and effective device for ASD closure. In wide ASDs and cases with more than one deficient rim, weak rims, or wide and complicated cases, it can be used carefully with sufficient experience.

Recent developments in next-generation occlusion devices

Transcatheter closure has been widely accepted as a highly effective way to treat abnormal blood flows and/or embolization of thrombus in the heart. It allows the closure of four types of congenital heart defects (CHDs) and stroke-associated left atrial appendage (LAA). The four types of CHDs include atrial septal defect (ASD), patent foramen ovale (PFO), patent ductus arteriosus (PDA), and ventricular septal defect (VSD). Advancements in the materials and configurations of occlusion devices have spurred the transition from open-heart surgery with high complexity and morbidity, or lifelong medication with a high risk of bleeding, to minimally invasive deployment. A variety of occlusion devices have been developed over the past few decades, particularly novel ones represented by biodegradable and 3D-printed occlusion devices, which are considered as next-generation alternatives to conventional Nitinol-based occlusion devices due to biodegradability, customization, and improved biocompatibility. The aim here is to comprehensively review the next-generation occlusion devices in terms of materials, configurations, manufacturing methods, deployment strategies, and (if available) experimental results or clinical data. The current challenges and the direction of future work are also proposed. STATEMENT OF SIGNIFICANCE: Implantation of occlusion devices has become a widely accepted and highly effective treatment for occluding abnormal blood/thrombus flow within the heart. Due to the serious complications such as erosion and displacement of conventional Nitinol-based occluders, next-generation occluders with reduced risk of complications and improved biocompatibility has emerged. Here, we comprehensively review the next-generation occluders developed for atrial septal defect (ASD), patent foramen ovale (PFO), patent ductus arteriosus (PDA), ventricular septal defect (VSD), and left atrial appendage (LAA), with special emphasis on biodegradable occluders. Besides, intelligent materials (e.g., automatically deployable shape memory polymers) and rapid customized manufacturing methods (3D/4D printing) for the fabrication of occluders are also introduced. Lastly, the directions of future work are highlighted.