Incomplete cor triatriatum dexter and percutaneous closure of atrial septal defects, a single-centre experience

Cor Triatriatum Dexter (CTD) is a rare congenital heart malformation, with an estimated incidence of 0.025%, characterised by a membrane dividing the right atrium (RA) into two chambers. A variant, incomplete CTD (CTDi), occurs when the right membrane extends partially into the interatrial septum without fully dividing the RA. CTDi can be associated with interatrial septal defects, found in 5% of patients with atrial septal defects or a patent foramen ovale (PFO). The study reports three adult patients (46-53 years old) with CTDi and a PFO, all presenting cryptogenic stroke and referred for PFO closure. Two cases underwent percutaneous closure with guidance from fluoroscopy and 2D/3D transesophageal echocardiography (TEE), and the last one utilised intracardiac echocardiography (ICE) for device placement. In patients referred for PFO closure, CTDi is common and can complicate visualisation, prolong procedure times, and reduce success rates. Difficulties in device deployment and the risk of residual shunt or embolisation have been reported. The authors highlight that using oversizing techniques, traction manoeuvres during device deployment, and preoperative planning with advanced imaging (such as ICE or 3D TEE) are crucial for successful percutaneous closure in cases with CTDi and PFO.