LAUSR

During cardiogenesis, the sinus venosus is closed by the left and right venous valves. The left venous valve becomes incorporated into the septum secundum. The more prominent right venous valve directs oxygenated blood from the left side through the foramen ovale. It subsequently involutes during development to form the eustachian and thebesian valves. Disruption of this process is believed to be responsible for a wide variety of abnormalities: prominent eustachian valve, Chiari network (2%-15%) and, in the most extreme case, cor triatriatum dexter (CTD), in which the right atrium is completely divided into 2 compartments by a membrane that restricts flow toward the right ventricle. CTD can be associated with right ventricular hypoplasia, pulmonary atresia, and Ebstein abnormality. The redundant eustachian valve combined with septal defect can lead to paradoxical embolism or platypnea-orthodeoxia syndrome. One variant is incomplete CTD (iCTD), in which the valve remnant, without completely dividing the right atrium, is prolonged with the anterior border of the atrial septum, thus generating septal misalignment with atrial septal defect (ASD) (Figure 1). We describe 7 patients in whom this finding was associated with complications or the impossibility of percutaneous ASD closure: 6 pediatric patients (2-13 years) and 1 adult patient aged 63 years, all diagnosed with moderate-large ASD, with hemodynamic repercussions and anatomic features considered amenable to percutaneous closure. In 6 patients, transesophageal echocardiography (TEE) pointed to a common anatomy consisting of a membrane that extended from the anterior border of the inferior vena cava to the atrioventricular border of the ASD, and, in some cases, as far as the retroaortic margin, which pulled this structure, leading to misalignment with the rest of the septum secundum. In 4 patients, percutaneous closure was attempted; in 2, initial closure was achieved, with a 10.5-mm device in 1 patient and a 15 mm device in the other. In both patients, the device was embolized early to the ascending aorta, then recaptured with a loop, and, finally, a new oversized device (14 and 22 mm) was placed to achieve stable and successful closure. In the other 2 patients, closure was not achieved because it was not possible to trap the anterior border of the defect, not even with oversized devices. In view of prior experience and after confirmation of a less favorable anatomy by TEE, 2 patients were not considered suitable for percutaneous closure. One of these was a 63-year old woman who was referred from another center for persistent right ventricular dilatation and pulmonary hypertension after percutaneous closure of an ostium secundum atrial septal defect. With TEE and surgery, the device Rev Esp Cardiol. 2019;72(7):582–596