Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 0 0 2024 06 22 Closure of Sinus Venous Atrial Septal Defects with Transcatheter Balloon Expanding Stent: A Case Series from Single Center Experience 2023 2023 Hojjat Mortezaeian Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran MohamamdHossein MozafaryBazargany Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Alireza Salmanipour Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Amir Banazade Dardashty Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran 2024 02 19 2024 09 22 Background: A sinus venous atrial septal defect (SVASD) is a type of congenital heart defect that predominantly involves an opening between the Superior Vena Cava (SVC) and the Right Upper Pulmonary Vein (RUPV). Surgical closure of SVASD has been the standard treatment; however, the surgical closure of SVASD is far more complex than mere ASD secundum reconstruction, and complications are more likely. Transcatheter closure of SVASD is an emerging alternative for surgical repair. Methods: We report five cases of successful transcatheter closure of SVASD and one case of failure that required surgical intervention. All patients underwent pre-procedure Computed Tomography Angiography (CTA) to determine the size and location of the defect and the optimal stent size and position. The SVC stenting was performed using balloon-expandable stents, followed by RUPV angioplasty if needed. Results:  Final angiograms and pressure measurements in the SVC, RUPV, and Right Atrium (RA) confirmed the absence of residual shunt and pulmonary venous obstruction. One patient experienced stent migration to the pulmonary artery, which necessitated surgical retrieval and defect closure. Conclusion: The balloon expansion test is not mandatory before stent implantation, as in the case of RUPV obstruction, its flow could be reestablished by ballooning and/or stent implantation within the RUPV with a mild residual shunt which might resolve spontaneously. https://rhythm.tums.ac.ir/index.php/jthc/article/view/2023