Research Article Safety of Occlutech Septal Occluder ACCELL Flex II for Transcatheter Closure of Secundum Atrial Septal Defects in Children: A Long-Term Follow-Up AmalM.El-Sisi , 1 Sonia A. El-Saiedi , 1 Rasha Ammar, 1 Asmaa Abdelhameed, 2 ZiyadM.Hijazi , 3 andMohammedM.Soliman 1 1 Cairo University-Pediatric Department-Cardiology Division, Cairo, Egypt 2 Ministry of Health Hospitals, Cairo, Egypt 3 Sidra Heart Center, Sidra Medicine& Weill Cornell Medical College, Doha, Qatar Correspondence should be addressed to Mohammed M. Soliman; mohamed.soliman@kasralainy.edu.eg Received 8 September 2020; Revised 28 October 2021; Accepted 3 November 2021; Published 4 January 2022 Academic Editor: ach N. Nguyen Copyright © 2022 Amal M. El-Sisi et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objectives. To assess the long-term safety and efficacy of the Occlutech ® ACCELL ® Flex II device used for atrial septal defect (ASD) closure. is device differs from the regular device by having two very thin patches that are made of polyethylene terephthalate (PET). ese patches enhance faster sealing of the defect. Background. Transcatheter closure has become the method of choice to manage most patients with secundum ASDs. ere are different types of devices. e regular Occlutech device used to close an ASD is called the Occlutech Figulla Flex II. A newer modification of this device (Occlutech ® ACCELL ® Flex II) has been designed to eliminate/reduce thrombus formation and to enhance faster sealing. Methods. irty patients were followed up after occlusion of secundum ASD using the Occlutech ® ACCELL ® Flex II Device. e follow-up period ranged from 5.2–5.5 years with median of 5.3 years. Detailed history and full clinical examination, twelve-lead electrocardiogram (ECG), plain chest radiograph, and full 2D transthoracic echocardiography (TTE) were performed at discharge, at one month, six months, and yearly thereafter. Results. e mean age of the study group at the last follow-up was 10.4 ± 4.6 years, with 63.3% (nineteen patients) females. ere were no residual shunts or complications encountered immediately after the procedure and at the latest follow-up. Conclusion. is study confirmed the transcatheter closure (TCC) of secundum ASDs using the Occlutech ® ACCELL ® Flex II device to be safe and effective with no complications detected in children and adolescents. 1.Introduction Atrial septal defects (ASDs) are common and account for about 6–10% of all congenital heart lesions [1]. Due to its efficacy and reliability, transcatheter device closure of a secundum ASDs had emerged to be the principal choice for management of secundum ASDs. It results in less complications and reduced hospitalization, as compared to open surgical ASD closure [2–4]. e inherent advantages of transcatheter closure (TCC) of ASDs include the absence of a thoracotomy incision, no intensive care unit admission, less psychological impact, shorter hospital stay, and less need for blood transfusion. e absence of a myocardial scar may decrease the incidence of incisional dysrhythmias [1]. e ideal device should be repositionable, retrievable prior to release, and should facilitate complete closure with minimal risk of embolization. Additionally, it should fa- cilitate rapid endothelialization and be biocompatible and suitable for treating a wide range of defect characteristics. e standard Occlutech Figulla ® Flex II device (FSO; Occlutech GmbH, Jena, Germany) is a nitinol double-disk occluder that possesses these characteristics and is used frequently for closure of secundum ASDs [5–9]. Hindawi Journal of Interventional Cardiology Volume 2022, Article ID 8886813, 6 pages https://doi.org/10.1155/2022/8886813