Transcatheter closure of a quadriform atrial septal defect with a custom double-fenestrated occluder: A case report.

Background: Quadriform atrial septal defect (ASD) is a rare anatomical and functional variant of ASD. Its rarity and complex morphology pose significant diagnostic and therapeutic challenges, distinguishing it from more common forms of ASD. Although surgical closure has traditionally been the standard treatment, this case demonstrates the feasibility and efficacy of a minimally invasive transcatheter approach. Case Report: A 71-year-old woman presented with shortness of breath. Physical examination and transthoracic echocardiography revealed an interatrial septal defect. Right heart catheterization combined with transesophageal echocardiography confirmed a complex ostium secundum ASD with a cribriform morphology resembling a quadriform ASD and associated high-flow, low-resistance pulmonary hypertension. Device deployment required additional manual modification and manipulation by the operators. Successful ASD closure was achieved using a single 40-mm occluder with double fenestrations. The patient remained asymptomatic at the 3-month follow-up. Conclusion: Transcatheter device closure may be an effective treatment option for quadriform ASD, although close follow-up is required to ensure proper device positioning. The increasing complexity of ASD presentations, particularly secundum defects, underscores the importance of continued discussion and experience sharing within the cardiovascular community.