Several devices are available for transcatheter occlusion of atrial septal defect. This report describes the international experience with the buttoned device. During a 4.5-year period ending in February 1993, 180 transcatheter atrial septal defect occlusions were performed with the buttoned device. Patient age varied between 0.6 and 76 years and stretched atrial defect diameter between 5 and 25 mm. The defects were closed with 25 to 50 mm devices delivered through 8F (148 patients) or 9F (32 patients) sheaths. Twelve patients were adults whose defects were closed to prevent recurrence of cerebrovascular accidents caused by presumed paradoxic embolism. In the remaining patients the atrial defect was closed to treat the left-to-right shunt. The atrial septal defects were effectively occluded as demonstrated by (1) decrease in pulmonary-to-systemic flow ratio from 2.1 +/- 0.6 (mean +/- SD) to 1.05 +/- 0.1 (p < 0.01) by oximetry; (2) normalized S2 and disappearance of the diastolic murmur by auscultation; and (3) improvement in right ventricular volume overloading by echocardiogram. However, trivial to small shunts could be detected by color Doppler studies in 76 (45%) of 168 patients in whom such data are available. Complications included unbuttoning in 13 and whole-device embolization in 1. All patients remained stable, and retrieval of the device and surgical closure of the atrial septal defect were accomplished in 10 patients. Transcatheter retrieval was used in the remaining 4 patients. The incidence of unbuttoning, a major complication of the procedure, appeared to decrease with the increasing experience of the investigators and with device modification (third-generation). The follow-up duration varied between 1 month and 4 years. Six patients required surgery during the follow-up period. In the remaining patients (n = 160), clinical examination did not reveal signs of atrial shunts. Color Doppler studies revealed either complete disappearance of the previously demonstrated shunts or further diminution of their size. The results indicate that transcatheter occlusion of the atrial septal defects with buttoned devices is feasible, relatively safe, and effective, and it appears to be a viable alternative to surgery for some patients with secundum atrial septal defect. Complications are infrequent and should improve with experience.

on behalf of the "Buttoned device" clinical trials international register Abstract Objectives-To study the feasibility of congenital ventricular septal defect occlusion by the buttoned device and to establish guidelines for its safe and effective application.

The feasibility and safety of transvenous closure of atrial septal defects by a new device was tested in 20 piglets, in which atrial septal defects were created by foramen ovale dilatation with angioplasty balloons. The device was small enough to be introduced in a 7F or 8F sheath, and it measured 20-25 mm. It has no hooks and consists of a foam occluder from the left atrium and a counter-occluder from the right atrium, buttoned independently. The animals were observed by angiography and color flow mapping, and they were electively killed at various intervals up to 2 months after occlusion. The device was not thrombogenic and had endothelialized by 2-3 weeks. All atrial defects were found to be completely occluded. Complications occurred only with the first three prototype devices, including counter-occluder detachment, right atrial perforation, and need for double occlusion and pulmonary artery embolization. No such complications occurred in the last 17 experiments because of modifications of the device and operator experience. These observations showed the feasibility of occlusion of moderate-size atrial septal defects in piglets by a new device introduced through a small sheath. The method appears promising for potential human application. (Circulation 1990;81:312-318 tages over existing devices by relatively easy insertion and fewer associated complications. Methods ProtocolAtrial septal defects were created by foramen ovale dilatation with angioplasty balloon catheters in 20 piglets weighing 7-29 kg. The animals were heavily sedated by an initial dose of 10-20 mg/kg i.v. ketamine (100 mg/ml, Vetalar, Fort Dodge Laboratories, Fort Dodge, Iowa). The experiments were performed under sterile conditions. A femoral vein cutdown was performed under local anesthesia with 2% xylocaine, and the animals were heparinized (100 units/kg). A multipurpose marker catheter (Cordis, Hialeah, Florida) was introduced into the right atrium under fluoroscopy and was used to probe the foramen ovale. The marker catheter was used both for wire exchanges and dimension measurements after angiography. An angioplasty catheter (Olbert) with a balloon diameter of 10-12 mm was introduced over a 0.035 -in. exchange wire into the left atrium, through the foramen ovale. Three dilatations were performed with dilute contrast material for inflation periods up to 30 seconds. The angioplasty catheter was subsequently replaced by a marker angiographic catheter,

Stretched diameter of the atrial septal defect (ASD), determined by balloon sizing at cardiac catheterization, is commonly used to select the sizes of the devices used for transcatheter closure of the secundum ASD. We have previously evaluated the utility of pulmonary/systemic flow ratio and angiographic and echocardiographic (echo) sizes of the ASD in estimating stretched ASD diameter in a group of 16 patients and determined that echo diameter had the best correlation with stretched diameter (r = 0.82; p less than 0.001). The stretched diameter can be estimated: 1.05 x echo diameter in millimeters + 5.49. In this study we have prospectively evaluated this formula in estimating the stretched ASD diameter by two-dimensional echo measurements obtained in two (long and short-axis) subcostal views in another group of 21 patients aged 2.5 to 29 years (median 4.5 years). The echo size of the ASD was 9.7 +/- 3.0 mm, whereas the measured stretched diameter was 15.3 +/- 4.0 mm. The predicted stretched ASD diameter was calculated according to the above formula and was 15.7 +/- 3.1 mm, not significantly different (p greater than 0.1) from the measured stretched diameter. The correlation between predicted and measured stretched ASD sizes was excellent (r = 0.9; p less than 0.001). The mean squared error was 2.4. The differences between measured and predicted values were within 2 mm in all but three patients. It is concluded that stretched ASD diameter can be estimated accurately by two-dimensional subcostal echo measurements, which in turn could be used for selection of device size for occlusion of the ASD.

A clinical trial was conducted of the buttoned device for transcatheter closure of ostium secundum atrial septal defect. Occlusion was attempted in 57 patients aged 1 to 62 years (median 5). The procedure was abandoned in 7 patients after 1 or more unsuccessful attempts, and devices were released in 50 patients. Urgent surgical retrieval was necessary in 4 patients because of unstable device position: 3 devices "unbuttoned," with migration of the counteroccluder to the pulmonary artery or inferior vena cava, and 1 intact device embolized to the main pulmonary artery. All patients remained stable and underwent successful operation. Successful device implantation was therefore achieved in 46 patients, with immediate reduction in Qp/Qs from 1.8 +/- 0.6 to 1.1 +/- 0.2 (mean +/- SD, p < 0.0001). At most recent follow-up (1 to 20 months), 45 of 46 patients (98%) have no shunt or a trivial residual shunt. The prevalence of residual shunts declined from 65% at 1 month to 19% at 12 months after the occlusion procedure (p < 0.0001). Complications included unbuttoning of a fourth device, transient tricuspid regurgitation in 2 patients, and transient mitral regurgitation in 2 patients. An episode of asymptomatic atrial flutter was noted in a 46-year-old patient which may have been related to device implantation, but which has not recurred. There have been no cases of endocarditis or thromboembolism in 350 patient-months of follow-up. The buttoned device provided effective closure of the atrial septal defect in 45 of 57 patients (79%) in whom implantation was attempted and in 45 of 46 patients (98%) in whom device implantation was successfully accomplished.(ABSTRACT TRUNCATED AT 250 WORDS)

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These data suggest that the fourth generation buttoned device is as effective as earlier generation devices, but without significant unbuttoning. Follow-up results remained good, with a reintervention-free rate of 89% at five years.

It is concluded that transcatheter closure of patent ductus arteriosus with the adjustable buttoned device is feasible and effective and can be accomplished via small 7F sheaths; a 7F sheath is adequate for all ductal sizes; and the adjustable length of the loop accommodated all types of patent ductus arteriosus. Clinical trials on a larger number of patients are warranted.