Double-umbrella device for transvenous closure of patent ductus arteriosus and atrial septal defect: first experience

Outcomes of Device Closure of Atrial Septal Defects

Several devices have been designed and tried over the years to percutaneously close atrial septal defects (ASDs). Most of the devices were first experimented in animal models with subsequent clinical testing in human subjects. Some devices were discontinued or withdrawn from further clinical use for varied reasons and other devices received Food and Drug Administration (FDA) approval with consequent continued usage. The outcomes of both discontinued and currently used devices was presented in some detail. The results of device implantation are generally good when appropriate care and precautions are undertaken. At this time, Amplatzer Septal Occluder is most frequently utilized device for occlusion of secundum ASD around the world.

Transcatheter closure of atrial septal defects

Transcatheter closure of atrial septal defects has evolved significantly over the last 20 years. Transcatheter closure has replaced surgical closure for the treatment of most secundum atrial septal defectsat the current time. A major reason for this is the lower morbidity of transcatheter closure procedures. Several closure devices have come into clinical use. The Amplatzer septal occluder (AGA Medical Co.) currently has the largest reported experience and subsequently the best-established safety and efficacy features. Clinically challenging situations, such as larger atrial septal defects, atrial septal defects with deficient rims and multiple atrial septal defects, are increasingly being addressed using the transcatheter approach, with improved results. The incidence of most complications has significantly reduced over time, and serious side effects are relatively uncommon. In this review, the literature is summarized regarding the current role of transcatheter closure, the evolution of the different available devices for clinical use and the complications that occur with their use. A comparison is also made with surgical closure techniques.

Exclusion of patients with arteriosclerosis reduces long-term recurrence rate of presumed arterial embolism after PFO closure

BACKGROUND

Percutaneous transcatheter closure of patent interatrial communications after presumed paradoxical embolism is used as an alternative to surgery or long-term anticoagulation for the treatment of patients who are at risk for recurrent thromboembolism. To avoid atherosclerotic events to be judged as recurrent paradoxical embolism, we prospectively excluded all patients with detectable arteriosclerosis from our series and investigated long-term results.

METHODS AND RESULTS

We report the outcome of 180 patients who underwent percutaneous transcatheter closure of patent foramen ovale (PFO), PFO like atrial septal defect (ASD), or an ASD because of paradoxical embolism. One hundred four patients had cerebral embolism, 57 had transient ischemic attacks, 16 coronary embolism, and 3 had peripheral embolism. Twenty-three patients experienced multilocal arterial embolism. One hundred twenty-five patients had a PFO, 63 of them with an atrial septal aneurysm (ASA), 24 a PFO-like ASD (7 of them with an ASA), and 31 had an ASD. After 18 months, only 5 patients (2.8%) showed a trivial residual shunt. At a mean follow-up of 40 months (range 4 to 88), resulting in 602 observed patient-years, only 1 patient experienced a presumed paradoxical (coronary) embolism (calculated annual risk to suffer a recurrent thromboembolic event: 0.16%).

CONCLUSIONS

Percutaneous transcatheter closure of PFO/ASD is a safe and effective therapeutic option for the secondary prevention of presumed paradoxical embolism. It is associated with a high success rate, low incidence of hospital complications, and very low frequency of recurrent systemic embolic events.

Dysfunction of an Atrial Septal Defect Occluder 8 Years after Implantation

Catheter interventional treatment of atrial septal defect (ASD) is widely accepted. The ASD occluder system (ASDOS) is no longer a widely used device nowadays. However, it is implanted in a substantial number of patients. We report a case of severe left-to-right shunt 8 years after catheter interventional closure of an ASD with an ASDOS device. The shunt was due to a membrane perforation, while the arms of the device were not dislocated. Microscopy, microbiology, and histology could not establish a proper explanation for the dysfunction; so long-term follow-up investigation may be required in patients with an implanted ASDOS device.

Patent foramen ovale closure: historical perspective

The work of the pioneers in PFO closure finally may evolve into a front-line therapy for secondary prevention of stroke in selected patients who have PFO and embolic events. Current implants, although new to most of interventional cardiology and neurology, are the result of years of steady, progressive work. It seems that PFOclosure is here to stay and will become a key element in a collaborative approach between cardiology and neurology in the treatment of embolic stroke. The advances in device technology may make PFO closure sufficiently safe, effective,and durable that it may become one of the most frequent catheter laboratory procedures to be performed.

Contemporary management of children with atrial septal defects: a focus on transcatheter closure

Atrial septal defects that result in right atrial and ventricular volume overload should be closed if diagnosed in children and adolescents. With closure of the atrial septal defect, the left-to-right shunt is eliminated e.g. the volume loading of the right heart, the excessive pulmonary blood flow and the total cardiac work load are reduced. The possibility of future arrhythmic events is lessened and paradoxical emboli across the septum eliminated. The first intracardiac surgical repair of a congenital lesion was a defect in the atrial septum nearly 50 years ago. Surgical closure remains a valuable, although viable technique. Recently percutaneous transcatheter techniques are now available. The conventional approach is via a median sternotomy incision but is associated with pain, risk of wound infection, postoperative immobilization and a permanent scar. It has been suggested that alternative approaches such as surgical repair using mini-sternotomy or lateral thoracotomy incisions yield similar results to the conventional surgical technique and are associated with fewer adverse effects. Transcatheter closure has developed over the last two decades and has evolved into a well tolerated, efficient and cost effective method with minimal discomfort for the patients. Complete closure rates are high and this approach has become a viable option for ASD management.

Catheter Closure of Secundum ASD Using “Other” Devices

The first nonoperative ASD closure was performed by Noel L. Mills and Terry D. King in a 17-year old female patient on April 8, 1975. In the following years there was little interest in this clinical field after trials with the "Clamshell Device" had been discontinued because of arm fractures. From the late 1980s until the mid 1990s E. B. Sideris ("Buttoned Device") and U.U. Babic ("ASDOS") kept the ideas of King & Mills alive while G.S. Das developed the first self-centering device ("AngelWings"). Clinical trials with ASDOS and AngelWings have been stopped because of complicated technology and risk of perforation. The Buttoned Device and its modifications are still used with high success rates even in defects > 20 mm and low long-term risk of perforation. Since the pioneering works of King & Mills marked improvements in devices and delivery systems have been achieved. After almost three decades of ongoing research and development, transcatheter ASD closure has become a clinical routine procedure.

ASD Closure with the Amplatzer Device

We report the safety and efficacy of the Amplatzer device for transcatheter closure of ASD and fenestrated Fontan in children and adults. One hundred and two patients underwent transcatheter occlusion of the defect. The median age of the patients was 18.2 years, the median size of the ASDs by TEE was 17.6 mm, the median balloon-stretched diameter was 19.9 mm, and the median size of the device implanted was 20 mm. Immediately after the release of the device, color Doppler echocardiography revealed no residual shunt in 92 (90.19%) of 102 patients. At 24 hours all the patients 101/101 (100%) had complete closure. The minor complications encountered after the procedure were atrial arrhythmias in 4 patients. The only major complication we had was a baby who died. In conclusion, the ASO device is a safe and effective device for catheter closure of most secundum ASDs and fenestrated Fontan.

Amplatzer Device closure of Atrial Septal Defects and Patent Ductus Arteriosus: Initial Experience

Surgical closure of Atrial Septal Defects (ASD) and Patent Ductus Arteriosus (PDA) can be performed successfully with low mortality. However, the morbidity associated with general anaesthesia, thoracotomy, cardiopulmonary bypass, postoperative monitoring in the intensive care unit, several days of hospital stay and the requirement of blood products is considerable. The expense associated with this morbidity, operative scar and the psychologic trauma to the patient and parents are additional disadvantages of surgery. Hence, the closure of these defects by transcatheter methods with various devices has been evaluated worldwide. We report the initial experience at our centre with closure of secundum ASDs and large PDAs with the Amplatzer Septal Occluder and Amplatzer Duct Occluder.

Transcatheter closure of atrial septal defects with the Amplatzer septal occluder--a Japanese clinical trial

This study reports the results of a Japanese clinical trial of transcatheter closure of atrial septal defects (ASD) using the Amplatzer septal occluder (ASO). Thirty-five patients with secundum ASD underwent transcatheter closure using the ASO at a median age of 12.9 years (range, 3.2-29.2 years) and a median weight of 39.2kg (range, 11.6-65.1 kg). The ASO was successfully implanted in 34 patients. The mean ASD diameter of the 34 patients measured by transesophageal echocardiography was 11.7 +/- 4.2mm (range, 5.0-20.8mm) and the mean balloon stretched diameter was 16.8 +/- 4.2 mm (range, 9-25 mm). The mean ASO size was 16.9 +/- 4.3 mm (range, 9-26mm). Complete closure rate at 1 day and 1 year after closure was 91% and 97%, respectively. One patient developed a transient second-degree atrioventricular block during the implantation procedure. No other complications occurred. Transcatheter closure of ASD using the ASO is effective and safe.

Transcatheter closure of interatrial communications for secondary prevention of paradoxical embolism: single-center experience

BACKGROUND

Patients with a patent foramen ovale (PFO) after cerebral, coronary, or systemic embolic events of presumed paradoxical origin are at risk for recurrent thromboembolism. We report our single-center experience of interventional closure of interatrial communications for secondary prevention of presumed paradoxical embolism. Methods and Results- Since 1997, percutaneous closure of interatrial communications was performed at our institution in 66 patients (mean age 47.8+/-12.7 years; 31 males) with a PFO or an atrial septal defect and at least 1 documented presumed paradoxical thromboembolic event. Fifty-eight patients had cerebral embolism, 10 had coronary embolism, and 3 had peripheral embolism. Several patients experienced multilocal arterial embolism. Fifty-four patients had a PFO, 33 of them with an atrial septal aneurysm, and 12 had an atrial septal defect. The implantation procedure was successful and without complication in all patients. After 3 months, only 2 patients showed a residual shunt, which disappeared in both cases after 12 months. In 112.2 patient-years of follow-up (range, 5 weeks to 3.5 years), we have not seen any recurrent thromboembolic event.

CONCLUSIONS

Interventional closure of interatrial communications is a safe and effective therapeutic option for the secondary prevention of presumed paradoxical embolism. To further evaluate this strategy, randomized trials comparing interventional closure with anticoagulation have been initiated by us and others.

Natural history of growth of secundum atrial septal defects and implications for transcatheter closure

OBJECTIVE

To investigate the natural history of secundum atrial septal defects (ASDs) over several years using serial echocardiographic studies.

METHODS

All patients with isolated secundum ASDs who had serial transthoracic echocardiograms at Texas Children's Hospital, Houston, Texas, from January 1991 to December 1998 were identified. Patients with fenestrated or multiple ASDs, other congenital heart defects, or less than a six month interval between echocardiograms were excluded. There were 104 patients eligible for inclusion in the study. Studies were reviewed by two echocardiographers (blinded) and the maximal diameter was recorded. Defects were defined as small (> 3 mm to < 6 mm), moderate (> or = 6 mm to < 12 mm), or large (> or = 12 mm). ASDs that grew > or = 20 mm were defined as having outgrown transcatheter closure with the device available to the authors' institution.

RESULTS

ASD diameter increased in 68 of 104 patients (65%), including 31 patients (30%) with a > 50% increase in diameter. Spontaneous closure occurred in four patients (4%). Thirteen defects (12%) increased to > or = 20 mm. One fifth of the patients studied had an insufficient atrial rim by transthoracic echocardiogram to hold an atrial septal occluder. The only factor associated with significant growth of ASDs was initial size of the defect. ASD growth was independent both of age at diagnosis and when indexed to body surface area.

CONCLUSIONS

Two thirds of secundum ASDs may enlarge with time and there is the potential for secundum ASDs to outgrow transcatheter closure with specific devices. Further development in devices and general availability of devices capable of closing larger ASDs should circumvent this problem.

Non-surgical closure of atrial septal defect

BACKGROUND

Recently many devices for the transcatheter closure of atrial septal defect (ASD) were developed in the world. Several ASD closing devices, such as Clamshell device, buttoned device, ASD occluder system (ASDOS), Angel Wings, are not fully acceptable from a practical point of view. We reported the clinical trials of transcatheter closure of ASD for Clamshell double umbrella device and Amplatzer septal occluder (ASO) in Japan.

METHODS

Clamshell devices were implanted in 11 patients. Clinical trials for ASO device were carried out in 34 patients in Japan. We reported the results of 17 patients in National Children's Hospital.

RESULTS

Clamshell devices were implanted in all of the patients successfully. Minimal residual shunt was present in four patients (36%), 1 year after the procedure by Doppler color flow imaging. Nine of 11 umbrellas demonstrated fracture of the stainless steel arm. Arm fracture occurred between 1 week and 12 months after implantation. The implantations of ASO device were successful in all of the 17 patients. Sixteen out of 17 (94.1%) had complete closure in the average observation period of 5.5 months. Complications were minimal and transient.

CONCLUSIONS

With respect to complete closure rate, easy manipulation, and complication rate, ASO is the best transcatheter ASD closure device among all the devices at the present time.

Occlusion of interatrial communications with the Amplatzer device: experience in 48 consecutive patients

Both secundum atrial septal defect (ASD) and patent foramen ovale (PFO) have been closed interventionally using several different occluding devices. At a single institution we strived for interventional occlusion of interatrial communications using the Amplatzer device exclusively. During a study period of 22 months, we studied 48 patients ranging in age from 1 to 48 years with an ASD (n = 45) or a PFO (n = 3). Successful implantation of an Amplatzer device was possible in 92% of the patients, and 95% of these patients had a complete early closure of their defect. There were no complications related to the procedure. We conclude that interventional closure of interatrial communications with the Amplatzer device is feasible and safe for selected patients.

Transcatheter closure of atrial septal defects in children & adults using the Amplatzer Septal Occluder

We are reporting the worldwide experience in closing atrial septal defects (ASDs) in children and adults using the Amplatzer Septal Occluder (ASO) as of July 2000. The outcome measures were safety and efficacy with special emphasis on: (1) immediate success of the ASD closure as measured by transesophageal echocardiography (TEE), (2) short- and medium-term follow-up at 24 hours and 1 and 3 months and long-term follow-up at 1, 2, and 3 years as assessed by transthoracic echocardiography (TTE); and (3) the incidence of complications. In all, 3580 procedures were performed in 3535 patients. In 75 patients, the device was not implanted for variety of reasons; 3460 patients received a single ASO device and 45 received two devices for multiple ASDs. The median age of the patients was 12.1 year, (range, 10 days-88 years, the median weight was 41.0 kg (range, 2.4-137 kg) and the median Qp/Qs ratio was 2 (range, 0.3-10). The median size of ASD by TEE was 14 mm (range, 1-38 mm) and the median stretched diameter was 18 mm (range, 4-44 mm). The median size of device implanted was 18 mm (range, 4-40 mm). The median fluoroscopy time was 17.1 minutes (range, 0.0-194.0 minutes). The immediate success rate including those patients with complete closure, trivial residual shunt, or with small residual shunt was 97.4%. This increased to 99.2% and 100% at 3 months and 3 years, respectively. Minor complications were encountered in 2.8% of procedures, while serious complications occurred in less than 0.3% of the cases. There were no device related deaths. We conclude that the ASO is a safe and effective device for catheter closure of small to large ASDs up to a stretched diameter of 40 mm in children and adults with very high short-, medium, and long-term success rates.

Results of transvenous occlusion of secundum atrial septal defects with the fourth generation buttoned device: comparison with first, second and third generation devices. International Buttoned Device Trial Group

OBJECTIVES

The purpose of this study was to assess safety and effectiveness of the fourth generation buttoned device in dosing atrial septal defects (ASDs) and to test the hypothesis that introduction of double button reduces unbuttoning rate without reducing effectiveness.

BACKGROUND

Because of the high unbuttoning rate (7.2%) with first, second and third generation buttoned devices, the device was modified (fourth generation) so that there were two radiopaque spring buttons 4 mm apart on the button loop attached to the occluder.

METHODS

During a four-year period ending in September 1997, 423 patients, ages 1.5 to 80 years (median 16 years), underwent closure of ASD at 40 medical centers around the world.

RESULTS

The ASD size varied between 5 and 30 mm (median 17 mm). The device size varied between 25 and 60 mm. Unbuttoning occurred in 4 (0.9%) of 423 patients. Effective occlusion, defined as no (n = 343) or trivial (n = 34) residual shunt on echo-Doppler studies performed within 24 h of the procedure, was demonstrated in 377 patients (90%). Thus, the unbuttoning rate (0.9 vs. 7.2%) decreased (p<0.01) while effective occlusion rate (90 vs. 92%) remained unchanged (p>0.1) with this device, compared with earlier generation devices. During follow-up from one month to five years (23+/-15 months), 21 (5%) of 417 patients required surgical (n = 12) or transcatheter (n = 9) reintervention, mostly to treat significant residual shunt. In the remaining patients there was gradual reduction and disappearance of the residual shunt. No wire integrity problems were observed.

CONCLUSIONS

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.

Interventional procedures for congenital heart disease

Interventional techniques available for use in treating congenital heart disease include balloon dilation of valves and vessels, stent placement and coil embolization of collaterals, patent ducts and other arterial fistulae. In addition, a variety of devices for closure of atrial and ventricular septal defects and patent ducts currently are under investigation. Radiofrequency ablation of arrhythmias also is applicable to the pediatric population.

Transcatheter closure of atrial septal defect and patent foramen ovale with ASDOS device (a multi-institutional European trial)

A clinical trial was conducted to assess the feasibility, safety, and efficacy of the atrial septal defect (ASD) occlusion system for transcatheter closure of secundum ASD and patent foramen ovale (PFO) after episodes of cerebral embolism. Occlusion was attempted in 200 patients aged 1 to 74 years (mean 32). The procedure failed in 26 patients (13%); the device was retrieved through a catheter in 20 and through surgery in 6 patients. Procedure-related complications necessitating surgical removal of the device included device embolization in 2, device entrapment within the Chiari network in 1, frame fracture in 1, and perforation of atrial wall in 2. All 6 patients experienced an uneventful postoperative course. An additional 11 patients (6%) underwent surgical removal of the device during follow-up. There were 163 patients (81%) with an implanted ASD occlusion system at follow-up of from 6 to 36 months (mean 17). Thrombus formation around the device was detected by transesophageal echocardiography in 9 patients 1 to 4 weeks after implantation. One of these patients (who had a coagulation factor XII deficiency) suffered a cerebral thromboembolism. Late atrial wall perforation (5, 6, and 8 months after implantation) occurred in 3 adult patients. Infectious endocarditis developed in 2 adult patients (1%). No late device embolization and no atrioventricular valve injury occurred. An asymptomatic device frame fracture was found in 14% and frame deformity in 4% of all patients during the follow-up period of >230 patient-years. Immediately after closure, a moderate/large residual shunt remained in 8% and a small shunt in 29% of patients. After 1 year, a moderate/large shunt was present in 2% and a small one in 26% of patients. During a total follow-up of 49 patient-years, only 1 of 46 patients with PFO had a transient neurologic event after the closure. The study indicates that patients with centrally situated secundum ASD and those with PFO after cerebral embolism can be treated with this system with a high success rate and an acceptable morbidity.

Transcatheter closure of atrial septal defects within the oval fossa: medium-term results in children using the 'ASDOS'-technique

OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of the ASDOS-technique (Sulzer-Osypka GmbH, Germany) for transcatheter closure of atrial septal defects within the oval fossa.

BACKGROUND

Although several attempts have been made to occlude defects within the oval fossa by transcatheter techniques, none of these has gained general acceptance.

METHODS

Patients with a defect in the oval fossa measuring equal to or less than 20 mm diameter, with a residual septal rim of 5 mm or greater, body weight greater than 10 kg, with clinical indications for surgical closure were considered for transcatheter closure. Follow-up investigations were performed at discharge, after 1, 3, 6 and 9 months, as well as after 1 and 2 years.

RESULTS

Of 78 patients considered for closure, a device was inserted in 41 patients (53%), with success being achieved in 40 patients (98%). The ages ranged from 1.1 to 15 years (7.8 +/- 1.92 years), the 'stretched' diameter of the defect from 10 to 20 mm (14.7 +/- 2.60 mm), and the diameters of the inserted devices from 25 to 45 mm (33.2 +/- 5.43 mm). Transient impairment of atrioventricular conduction occured in 4 patients. During the follow-up of 23.0 +/- 5.6 months elective surgical closure of a residual shunt was performed 26 months after insertion of the device in one patient. None of the other patients required surgery, hospitalisation or medical treatment, and none is requiring further treatment of the defect within the oval fossa. Fracture of one arm of the device occurred in 4 patients, but the fractured arms are in an unchanged and stable position after a period of at least 19 months.

CONCLUSIONS

Our medium-term data show that transcatheter closure in children of defects within the oval fossa can be performed with a high efficacy and safety using the ASDOS-device.

Closure of atrial septal defects with the Amplatzer occlusion device: preliminary results

OBJECTIVES

This study reports our clinical experience with transcatheter closure of secundum atrial septal defects (ASDs) in children, using the Amplatzer, a new occlusion device.

BACKGROUND

None of the devices previously used for transcatheter closure of interatrial communications has gained wide acceptance.

METHODS

We examined the efficacy and safety of the Amplatzer, a new self-centering septal occluder that consists of two round disks made of Nitinol wire mesh and linked together by a short connecting waist. Sixteen patients with secundum ASD met established two- and three-dimensional echocardiographic and cardiac catheterization criteria for transcatheter closure. The Amplatzer's size was chosen to be equal to or 1 mm less than the stretched diameter. The device was advanced transvenously into a 7F long guiding sheath and deployed under fluoroscopic and ultrasound guidance. Once its position was optimal, it was released.

RESULTS

The mean ASD diameter by transesophageal echocardiography was 14.1+/-2.3 mm and was significantly smaller (p < 0.001) than the stretched diameter of the ASD (16.8+/-2.4 mm). The mean device diameter was 16.6+/-2.3 mm. No complications were observed. After deployment of the prosthesis, there was no residual shunt in 13 (81.3%) of 16 patients. In three patients there was trivial residual shunt immediately after the procedure that had disappeared in two of them at the 3-month follow-up.

CONCLUSIONS

The Amplatzer is an efficient prosthesis that can be safely applied in children with secundum ASD. However, a study including a large number of patients and a longer follow-up period are required before this technique can be widely used.

Transcatheter closure of secundum atrial septal defects with the atrial septal defect occlusion system (ASDOS): initial experience in children

OBJECTIVE

To report initial experiences with transcatheter occlusion of atrial septal defects using a new occlusion device.

SUBJECTS

10 children aged 1.1 to 14.9 years.

INCLUSION CRITERIA

Patients with a body weight above 10 kg, normal pulmonary resistance and an indication for surgical closure of a secundum atrial septal defect, a residual tissue rim of interatrial septum surrounding the defect of more than 5 mm, and a maximum defect diameter of 20 mm.

METHODS

The defects were closed by a transcatheter device (ASDOS) consisting of two umbrellas which are introduced over a guidewire loop. Both umbrellas consist of a central body and five arms formed from preshaped nitinol wire covered with a thin polyurethane patch. The central body of the distal umbrella contains a thread, the proximal umbrella contains a bolt. The two umbrellas are connected by screwing the bolt on the thread using a screwdriver catheter.

RESULTS

The implantation was performed under echocardiographic guidance; in six of 10 patients, transoesophageal echocardiography was necessary. The "stretched" diameter of the defect evaluated during balloon sizing ranged from 10 to 20 mm, and the pulmonary to systemic blood flow ratio from 1.5:1 to 2.8:1. Transcatheter closure was successfully performed in 9/10 patients using devices with a diameter of 25 mm to 40 mm. No severe complications occurred. However, in one patient with a pre-existing prolonged PR interval brief periods of second and third degree atrioventricular block occurred after the implantation but normalised within 3 d. During a follow up period of 21 to 29 weeks no device embolisation, thromboembolic complications, fractures of the implanted device, atrial perforations, pericardial effusions, obstructions of systemic or pulmonary veins, atrioventricular valve dysfunction, or other complications occurred.

CONCLUSIONS

The new device is a promising transcatheter approach for the occlusion of secundum atrial septal defects in children. However, further evaluation and long term data are needed before this transcatheter technique can be recommended.

Transcatheter closure of large atrial septal defects with the Babic system

An improved 10 Fr version of the atrial septal defect (ASD) occlusion system consisting of two umbrellas for transvenous introduction over the long veno-arterial guide-wire was used to attempt closure in five adult patients with large defects (26-35 mm). The umbrellas are made of nitinol wire frame and a thin membrane of microporous polyurethane. Supported by the metal cannula and guided by selective left atriography, the umbrellas of 45-60 mm were placed individually into the atria and screwed together at the septum level by means of a torquer catheter. Positioning and screwing on, unscrewing, separating, and repositioning the umbrellas up to 17 times were needed to anchor the prosthesis correctly in a patient. The prosthesis could be implanted primarily in all patients (in one at second session). Dislodgement of a 60 mm prosthesis and left atrial perforation with a 55 mm prosthesis required surgery in two patients 8 hours and 2 weeks post procedure, respectively. A single umbrella-arm fracture was noticed in one patient 4 months after the implantation. All five patients were free of symptoms at follow-up after 7-10 months. Transcatheter closure of large ASDs is technically feasible with this system. The morbidity is mainly associated with the implantation of very large umbrellas.