Role of inverted buttoned device in transcatheter occlusion of atrial septal defects or patent foramen ovale with right-to-left shunting associated with previously operated complex congenital cardiac anomalies

Feasibility, safety, and effectiveness of transcatheter occlusion of atrial septal defect (ASD) with the buttoned device has been demonstrated. Despite its effectiveness in occluding secundum ASD with left-to-right shunt and patent foramina ovalia, presumably responsible for paradoxic embolism, it has limitations in effectively occluding ASD with evident right-to-left shunts. Therefore, the device was modified so that the square-shaped occluder component of the device is on the right atrial side, the inverted buttoned device. This study determines the feasibility, safety, and effectiveness of inverted buttoned device occlusion of atrial defects with right-to-left shunts. During a 17-month period ending August 1996, 12 patients, aged 1.6 to 39.0 years, underwent occlusion of residual ASD after repair of pulmonary atresia/stenosis with intact ventricular septum (n = 5), modified or fenestrated Fontan for tricuspid or pulmonary atresia (n = 5), and double-inlet left ventricle (n = 2). The systemic arterial oxygen saturation increased (p <0.001) from 82 +/- 7% (range 72% to 90%) to 94 +/- 3% (range 88% to 98%). There was no change in heart rate or cardiac index measured by Fick. Right atrial pressure increased by 1 to 4 mm in 5 of 12 patients (42%). There was trivial (n = 5) or no (n = 7) residual shunt by color Doppler study. Six- to 18-month (median 12) follow-up in all 12 patients revealed stable oxygen saturations (92 +/- 3%) by pulse oximetry. Color Doppler studies revealed small (n = 1), trivial (n = 1), or no (n = 10) residual shunt at follow-up. Based on these data, it is concluded that transcatheter occlusion of ASD with right-to-left shunts with inverted buttoned device is feasible in relieving arterial hypoxemia. Further clinical trials in a larger number of patients and careful evaluation of follow-up results are indicated to examine its safety and longer term effectiveness.