Interventional closure of atrial septal defects larger than 20 mm in diameter

Over the last few years, various devices for the interventional closure of atrial septal defects (ASD) up to a diameter of 20 mm have been developed. We report our clinical experience in closing ASD with a diameter larger tha n 20 mm diameter with the Amplatzer Septal Occluder (ASO). Method: The stretched diameter of the ASD was measured by inflating a sizin g balloon within the defect until an indentation in the circumference in th e balloon could be observed. An ASO with a stent diameter 2-1 mm larger tha n the indentation in the circumference of the balloon was chosen and implan ted via 9-12 French sheaths. In contrast to the closure of smaller defects, pullback of the device onto the atrial septum was only performed when the connecting stent of the ASO was completely deployed in order to achieve max imal centering characteristics and optimal support of the retention skirt o f the left atrial disc on the edges of the defect. Only then was the right atrial disc deployed and actively configured by advancing the sheath and th e delivery cable against the atrial septum. Implantation was only attempted if the atrial septal rims (except the anterior rim around the aorta) measu red more than 7 mm by echocardiography to avoid injury or disturbance of se nsitive intracardiac structures. After placement, the fixation of the devic e and the mechanical stability was proven by an extensive "Minnesota wiggle ". The ASO was released only when TEE showed no or a trivial residual color flow through the connecting stent; otherwise repositioning was performed. Results: Out of 352 patients (P) with successful closure of interatrial def ects, 70 P (age: 1.1-77.3 years) had stretched defects larger than 20 mm di ameter (median 22 mm diameter (20-36), 25/75% quartiles = 20/26 mm). Mean s hunt size was Qp:Qs 2.1:1 (0.7-3.9:1), mean fluoroscopy time 10.9 min (0-63 ). Complete closure could be achieved in 85.7/93.1/100% after 3 months, 1 a nd 2 years, respectively. Besides 3 P with persistent atrial fibrillation, only 5 P showed transient atrial tachyarrhythmias, 2 only periprocedural an d 3 within the first 3 months after implantation were treated with beta -bl ocker. In one patient, an acute embolization of the device occurred because a diminished posterior rim was not visualized by a monoplane TEE probe nec essitating surgical explantation and defect occlusion. Despite oversizing t he device, no "mushrooming" misconfiguration were observed. Conclusion: Transcatheter closure of large atrial septal defects with the A mplatzer Septal Occluder is feasible, safe and effective.. Risk of complica tions do not seem to occur more frequently than after closure of smaller de fects if one adheres to certain sizing and implantation measures. The incid ence of transient atrial tachyarrhythmias seems to be low.