Experimental atrial septal defect closure with a new, transcatheter, self-centering device

Antiplatelet and Antithrombotic Therapy After Patent Foramen Oval and Atrial Septal Defect Closure

Pathologies of the atrial septum include different interatrial communications varying from patent foramen ovale (PFO) to actual defects. Atrial septal defects (ASDs) may be localized within the fossa ovalis such as the secundum type ASD or outside the region of fossa ovalis, such as the ostium primum defect and sinus venosus defect. Over the last decades, the percutaneous closure of interatrial shunts has become a feasible and safe method. During these procedures, the delicate balance between thrombotic risk, device sealing process and bleeding risk is crucial. In this review, we sought to describe current available data on the antiplatelet and antithrombotic management of patients after percutaneous ASD or PFO closure.

Key Regulatory Differentially Expressed Genes in the Blood of Atrial Septal Defect Children Treated With Occlusion Devices

Atrial septal defects (ASDs) are the most common types of cardiac septal defects in congenital heart defects. In addition to traditional therapy, interventional closure has become the main treatment method. However, the molecular events and mechanisms underlying the repair progress by occlusion device remain unknown. In this study, we aimed to characterize differentially expressed genes (DEGs) in the blood of patients treated with occlusion devices (metal or poly-L-lactic acid devices) using RNA-sequencing, and further validated them by qRT-PCR analysis to finally determine the expression of key mediating genes after closure of ASD treatment. The result showed that total 1,045 genes and 1,523 genes were expressed differently with significance in metal and poly-L-lactic acid devices treatment, respectively. The 115 overlap genes from the different sub-analyses are illustrated. The similarities and differences in gene expression reflect that the body response process involved after interventional therapy for ASDs has both different parts that do not overlap and the same part that crosses. The same portion of body response regulatory genes are key regulatory genes expressed in the blood of patients with ASDs treated with closure devices. The gene ontology enrichment analysis showed that biological processes affected in metal device therapy are immune response with CXCR4 genes and poly-L-lactic acid device treatment, and the key pathways are nuclear-transcribed mRNA catabolic process and proteins targeting endoplasmic reticulum process with ribosomal proteins (such as RPS26). We confirmed that CXCR4, TOB1, and DDIT4 gene expression are significantly downregulated toward the pre-therapy level after the post-treatment in both therapy groups by qRT-PCR. Our study suggests that the potential role of CXCR4, DDIT4, and TOB1 may be key regulatory genes in the process of endothelialization in the repair progress of ASDs, providing molecular insights into this progress for future studies.

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.

Role of animal models for percutaneous atrial septal defect closure

As for any preclinical development of new implantable device, bench testing has been followed by experimental studies on large animal models for the development of atrial septal defect closure devices. Various models have been used according to studied species (porcine, ovine or canine model) and whether the septal defect was percutaneously or surgically created. Animal models of percutaneous atrial septal defect closure aim to assess the healing process and device endothelialisation, as well as the development of magnetic resonance imaging guided procedures, the short-term effects of volume overload on right ventricular contractility through haemodynamic studies and the understanding of other complications such as nickel hypersensitivity. Each technique has its own advantages and drawbacks, and leads to different punch-related, acute septal injuries that could have an effect on the healing process after device implantation. It has been suggested that some long-term, major device-related complications such as thrombosis or infective endocarditis may be associated with an inappropriate healing process or insufficient endothelialisation of the device, leading industrial companies to pay a great deal of attention to the healing process. Tissue reactions in animal models were shown to adequately reproduce the healing response after device implantation in humans, with an endothelial device coverage observed as early as 30 days after implantation and complete after 3 to 6 months. Research perspectives may evaluate both animal models and in-vitro studies in parallel with a view to clarify the endothelialisation process using human endothelial cells through in-vitro experiments. Self-sensing device for detecting the presence of endothelial cells on the surface of intracardiac occluders and high-resolution imaging techniques that could non-invasively assess the complete endothelialisation of a device would also be promising tools which would need large animal models studies before their clinical application.

Outcomes of Totally Endoscopic Atrial Septal Defect Closure Using a Glutaraldehyde-Treated Autologous Pericardial Patch

BACKGROUND

We evaluated the outcomes of totally endoscopic minimally invasive surgery for atrial septal defect (ASD) using a glutaraldehyde-treated autologous pericardial patch in the transcatheter interventional era.Methods and Results:We retrospectively reviewed 37 consecutive patients who underwent totally endoscopic ASD closure with a glutaraldehyde-treated autologous pericardial patch between June 2011 and April 2015. All patients had been deferred from catheter-based intervention for clinical or anatomical reasons. We analyzed operative outcomes and postoperative echocardiographic data. The mean age was 45.7±16.5 years, and 25 patients (67.6%) were women. The mean ratio of pulmonary to systemic flow was 2.4±0.7. Six patients (16.2%) underwent concomitant tricuspid valve repair, and 3 patients (8.1%) underwent concomitant atrial fibrillation surgery. There were no operative deaths, and the median length of hospital stay was 5 days. Postoperative echocardiography revealed trivial residual shunt in 1 patient. During the follow-up period, there were no re-interventions for ASD or readmission for heart failure. Follow-up echocardiography revealed no recurrent shunt or calcification of the autologous pericardial patch.

CONCLUSIONS

Totally endoscopic ASD closure with a glutaraldehyde-treated autologous pericardial patch demonstrated excellent outcomes. It is a useful option for patients with unfavorable anatomy or other reasons excluding transcatheter intervention.

Historical developments of atrial septal defect closure devices: what we learn from the past

INTRODUCTION

Since King and Mills' pioneering work in percutaneous closure devices of secundum atrial septal defects (ASD) four decades ago, developments in device shape, material and implantation technique led to adoption of percutaneous ASD closure as current treatment of choice. Not only was the feasibility of such a percutaneous procedure tested altogether, but pursuing the ideal device in terms of safety and efficacy became priority.

AREAS COVERED

In this review we present the historical development of ASD devices in design, material and technique with clinical data, and provide the future perspectives in percutaneous ASD closures.

EXPERT OPINION

An 'ideal device' requires complete defect closure with negligible risk of complications using a safe, straightforward delivery technique with repositioning and retrieving properties. Some of the devices currently at hand come close to fulfilling these criteria, however none seem to provide those prerequisites completely. By understanding how challenges in device development were overcome in the past, new insights into future improvements are given.

[Percutaneous closure of atrial septal defects with the Amplatzer® device: 15 years of experience]

INTRODUCTION

Percutaneous closure of atrial septal defects is an alternative to surgical treatment.

OBJECTIVES

We report the results of percutaneous closure of atrial septal defects with the Amplatzer(®) device.

METHOD

We include patients taken to the catheterization laboratory from September 1997 to December 2011.

RESULTS

We proceeded with defect closure in 721 patients and in 85 the defect was considered not suitable for closure. The stretched diameter of the defect was 23±6.7mm (limits, 5-42). All devices were positioned successfully. In 15 cases (2.1%) the device was changed due to instability and in 6 (0.8%) the device embolized within the first 24h, 4 were retrieved and repositioned (final success with intention to treat 719/806-89.2%). Immediate control showed complete closure in 247 patients (34.3%), leak through the device in 395 (54.9%), mild residual leak in 75 (10.4%) and moderate in 2 (0.3%). We have follow-up in 626 patients (87.1%) for 33±27.5 months, with headache in 54 (8.6%), new supraventricular arrhythmia in 10 (1.6%), puncture site complications in 4 (0.6%), and stroke in one (0.1%).

CONCLUSION

The design of the Amplatzer(®) device allows effective closure of atrial septal defects with a simple technique and patient safety.

Biomaterials and design in occlusion devices for cardiac defects: a review

This review examines the biomaterials used in occlusion devices for cardiac defects, and how the choice of these materials is dictated by design. Specifically, the devices used in three major applications, the atrial septal defect, the ventricular septal defect and the patent ductus arteriosus, are examined critically. A number of different devices are available, with varied performance in deployment and sealing. There is no device in any of the three categories that satisfies fully the range of requirements, and all have associated complications. The type and rate of complications are different among different devices. The short-term (immediate) complications are addressed by immediate retrieval. For longer-term complications, most of which can be fatal, currently only surgical retrieval and replacement are possible. Most of these longer-term complications can be alleviated by the use of fully degradable devices, which will eliminate concerns regarding the use of metals inside the heart, and if fully endothelialized, also minimize migration concerns. On the other hand, the lower moduli of currently available biodegradable materials need to be augmented. Improvements in the stiffness required for deployment can be accomplished with the use of fillers, nano- or micro-sized, and an example of this are radiopaque fillers.

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.

Surgical intervention for embolization of atrial septal defect closure devices: case report

Atrial septal defect (ASD) closure using a percutaneous transcatheter device is used as an alternative to surgery. Various devices are increasingly used in clinical practice, and various types and models of septal occluder devices are available. The Amplatzer device (Amplatzer Medical, Golden Valley, MN, USA) is one with increasing popularity.We report a case of attempted percutaneous transcatheter closure of a large ASD in a 14-year-old girl, complicated by total device embolization to the right ventricle necessitating emergency surgery.

Amplatzer occluder versus CardioSEAL/STARFlex occluder: a meta-analysis of the efficacy and safety of transcatheter occlusion for patent foramen ovale and atrial septal defect

OBJECTIVE

Percutaneous transcatheter occlusion has benefited thousands of patients suffering from patent foramen ovale and atrial septal defect. However, no general agreement has been reached on the superiority among occluders. Thus, a meta-analysis between the two most commonly adopted types of occluders was conducted.

METHODS

The literature review has identified relevant studies up to May, 2011 in the databases of PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, and World Health Organization clinical trials registry centre. Meta-analysis was performed in a fixed/random effects model using Revman 5.1.1. Information on complications and outcomes was extracted.

RESULTS

Analysis from included studies reports an outcome in favour of the Amplatzer. The Amplatzer has proven its superiority in efficacy with a significantly lower risk of early (95% confidence interval = 0.09-0.34) and long-term (95% confidence interval = 0.14-0.97) residual shunt rate for atrial septal defect occlusion, although no significant difference in performance has been reported for patent foramen ovale. In addition, the Amplatzer has also remarkably reduced the risk of embolisation by the device (95% confidence interval = 0.07-0.45) for atrial septal defect and new-set atrial fibrillation (95% confidence interval = 0.18-0.48) for patent foramen ovale. On evaluation of recurrent thrombotic events, it was found that the Amplatzer greatly lowered the rate of thrombus formation on the device (95% confidence interval = 0.02-0.21) for patent foramen ovale; however, no statistical difference was found on atrial septal defect evaluation. However, the result indicated no statistically significant difference between the two kinds of occluders in stroke and transient ischaemic attack of patent foramen ovale.

CONCLUSION

The meta-analysis has proven the Amplatzer to be the superior occluder, serving better prognosis with more fluent procedure and less complications.

Rheumatic fever pathogenesis: Approach in research needs change

Despite identifying that rheumatic fever (RF) is the result of an immunological reaction following group-A beta-hemolytic streptococcal infection, the pathogenesis remains elusive. RF has been incorrectly designated as causing pancarditis, since it does not cause myocarditis. Research directed toward myocarditis, targeting myosin to unravel the pathogenesis has not succeeded in more than 60 years. RF causes permanent damage to cardiac valves. The mitral valve (MV), derived from the wall of the left ventricle, is composed of a central core of connective tissue, covered on both sides by endothelium. The left ventricle does not have either myocardial or intermyocardial connective tissue involvement in RF. By exclusion, therefore, the primary site of RF damage appears to be the endothelium. Evaluation of the histopathology and immunopathology indicates that RF is a disease of the valvular and vascular endothelium. It is not a connective tissue disorder. Research to identify pathogenesis needs to be focused toward valvular endothelium.

Atrial septum defect closure device in a beating heart, from the perspective of a researcher in artificial organs

Transcatheter closure of atrial septum defect (ASD) with a closure device is increasing, but the history of clinical use of this procedure is still short, and the efficacy and long-term safety remain unproved. The total number of closure devices implanted throughout the world has not been counted accurately. Therefore, the probability of complications occurring after implantation is uncertain. Device-related complications that occur suddenly late after implantation are life-threatening, and quite often necessitate emergency surgical intervention. In Japanese medical journals, authors reporting closure devices have mentioned no complications and problems in their facilities. Detailed studies of device-related complications and device removal have not been reported in Japan. In fact, this literature search found an unexpectedly large number of reports of various adverse events from many overseas countries. When follow-up duration is short and the number of patients is small, the incidence of complications cannot be determined. Rare complications may emerge in a large series with a long observation period. Consequently, the actual number of incidents related to ASD closure devices is possibly several times higher than the number reported. Guidelines for long-term patient management for patients with an implanted closure device are necessary and post-marketing surveillance is appropriate. Development of a national database, a worldwide registration system, and continuous information disclosure will improve the quality of treatment. The devices currently available are not ideal in view of reports of late complications requiring urgent surgery and the need for life-long follow-up. An ideal device should be free from complications during life, and reliability is indispensable.

Randomized clinical trial comparing percutaneous closure of patent foramen ovale (PFO) using the Amplatzer PFO Occluder with medical treatment in patients with cryptogenic embolism (PC-Trial): rationale and design

Background

Several studies have shown an association of cryptogenic stroke and embolism with patent foramen ovale (PFO), but the question how to prevent further events in such patients is unresolved. Options include antithrombotic treatment with warfarin or antiplatelet agents or surgical or endovascular closure of the PFO. The PC-Trial was set up to compare endovascular closure and best medical treatment for prevention of recurrent events.

Methods

The PC-Trial is a randomized clinical trial comparing the efficacy of percutaneous closure of the PFO using the Amplatzer PFO occluder with best medical treatment in patients with cryptogenic embolism, i.e. mostly cryptogenic stroke. Warfarin for 6 months followed by antiplatelet agents is recommended as medical treatment. Randomization is stratified according to patients age (<45 versus ≥45 years), presence of atrial septal aneurysm (ASA yes or no) and number of embolic events before randomization (one versus more than one event). Primary endpoints are death, nonfatal stroke and peripheral embolism.

Discussion

patients were randomized in 29 centers of Europe, Canada, and Australia. Randomization started February 2000. Enrollment of 414 patients was completed in February 2009. All patients will be followed-up longitudinally. Follow-up is maintained until the last enrolled patient is beyond 2.5 years of follow-up (expected in 2011).

Trial Registration

Trial listed in ClinicalTrials.gov as NCT00166257 and sponsored by AGA Medical, Plymouth, MN, USA

Community use of the amplatzer atrial septal defect occluder: results of the multicenter MAGIC atrial septal defect study

The objective of this study was to determine the initial safety and results of unrestricted multi-institution routine community use of the Amplatzer Septal Occluder (ASO) for atrial septal defect (ASD) closure. A multicenter, nonrandomized prospective study was performed in 13 pediatric cardiology centers from November 2004 to September 2007. Data were collected at the time of cardiac catheterization and 1 day postimplant. Four hundred seventy-eight patients underwent cardiac catheterization for ASO device closure of an ASD. The median age was 6 years (range, <1-83 years), and the mean weight was 37.2 kg (range, 2.6-148 kg). Procedural success was 96% (458/478 patients), with deficient rims being the major single reason for failed implantation (9/20). Major and minor complication rates were 1.1% and 4.8%, respectively, and were not different between simple and complex ASD groups. Success at 24 h was 99.4% (333/335) in the simple ASD group and 100% (120/120) in the complex ASD group. The presence of large defects, the presence of multiple defects, the use of multiple devices, and a weight <8 kg were significantly associated with a residual shunt (small to moderate) at 24 h. In conclusion, the ASO device in routine clinical practice for simple and complex ASD closure has an immediate safety and effectiveness profile equal to that reported in the initial pivotal FDA trial for simple ASDs. Based on the evolution in care posed by the ASO and the lack of consensus on patient selection in complex ASDs, this study points out the need to redefine the optimal patient and possibly broaden the indications for device closure of ASDs.

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.

A comparison between the early and mid-term results of surgical as opposed to percutaneous closure of defects in the oval fossa in children aged less than 6 years

OBJECTIVES

To compare surgical as opposed to percutaneous interventional closure of isolated atrial septal defects in the oval fossa in terms of hospital stay, efficacy, and complications, and to study the respective role of the two techniques in current practice.

METHODS

Between January 1998 and April 2004, 126 out of 1210 patients treated at our institution for closure of an isolated defect in the oval fossa were aged less than 6 years. The mean age of these 126 patients at procedure was 4.2 plus or minus 1 year. The ratio of females to males was 74 to 52.

RESULTS

Of the patients, 62% were treated successfully using a percutaneous approach. The groups treated surgically or percutaneously did not differ for age, gender, or indications for treatment. No deaths occurred. The rates of total and major complications were higher in the group undergoing surgical closure, at 34% versus 9%, p less than 0.0001, and 10.5% versus 1%, p equal to 0.01, respectively. Embolisation of the device requiring subsequent surgery occurred in 1% of patients. The stay in hospital was shorter in those closed percutaneously, at 3.2 plus or minus 0.9 days versus 6.8 plus or minus 2.8 days, p equal to 0.0001. During a mean follow-up of 3.4 plus or minus 1.9 years, no major complications occurred in either group, and symptoms improved significantly in both groups. Additional sequels occurred in 2 patients who had major complications subsequent to surgical closure.

CONCLUSIONS

Even in young children, it is both feasible and safe to close defects in the oval fossa percutaneously. Compared to surgical closure, the transcatheter approach allows a shorter stay in hospital, and has a lower rate of complications. Early and mid-term follow-up has confirmed the safety and efficacy of both techniques.

Biocompatibility of septal defect closure devices

OBJECTIVE

Despite their clinical introduction 10 years ago, no human series on the healing response to Amplatzer and Starflex devices in humans have been reported yet. We sought to investigate the biocompatibility of Amplatzer and Cardioseal/Starflex septal occluder devices in humans and compare the findings to results in experimental animals.

METHODS

The healing response of Amplatzer and Cardioseal/Starflex septal occluder devices in humans (n = 12, follow-up periods from 5 days to 4 years) and in experimental animals (n = 32, follow-up periods from 4 days to 1 year) was studied using a uniform work up protocol. Histological sections of paraffin-wax-embedded or methacrylate-embedded specimen and scanning electron microscopy were used for biocompatibility screening.

RESULTS

Neoendothelialisation of all examined devices was complete after 3 months in vivo. Protruding metal frame parts, like screw threads and spring arms, were covered last. The initial deposition of fibrin and blood cells on the polyester fabric was subsequently organised by ingrown fibroblastic cells. Loosely arranged and poorly vascularised young granulation tissue was transformed time-dependently into quiescent fibre-rich connective repair tissue poor of cellular and capillary vessel components. Consistently, a mild chronic inflammatory response directed against textile fibres of both types of implants characterised by lymphocytic infiltration and multinucleated foreign body giant cells was observed equally in human and animal explants.

CONCLUSIONS

Systematic biocompatibility screening in a series of explanted human septal occluder devices showed results corresponding to findings in animal studies with regard to neoendothelialisation, cellular organisation of initial thrombus and persisting immune response.

Interventional Atrial Septal Defect Closure Using a Totally Bioresorbable Occluder Matrix

OBJECTIVES

We sought to test the hypothesis that interventional atrial septal defect (ASD) closure can be performed safely and effectively using a bioresorbable occluder matrix.

BACKGROUND

The ideal septal occluder scaffold should promote the healthiest and most complete healing response while eventually facilitating the full resorption of the material and leaving "native" tissue behind, thus minimizing the potential for future complications from chronic foreign body and maintaining the possibility for later unobstructed transseptal access to the left atrium.

METHODS

The STARFlex occluders (NMT Medical Inc., Boston, Massachusetts) were modified by substituting the conventional polyester fabric for a bioengineered, acellular type-I collagen matrix derived from porcine submucosa with a heparin-coated surface (BioSTAR occluder, NMT Medical Inc.). Comparative transcatheter closure of ASDs was performed in young sheep (n = 36). Gross pathology and histopathology were obtained after follow-up periods ranging from 7 days to 2 years.

RESULTS

The STARFlex (control) devices were encapsulated time-dependently by ingrown fibrous tissue. Histology showed a mild but chronically persisting foreign body reaction. By contrast, BioSTAR devices exhibited a mild-to-moderate transient cellular immune response. Heparin coating of the BioSTAR surface improved the biocompatibility of the device by reducing surface thrombogencity. A remodeling process of the collagen scaffold, starting after 30 days in vivo, resulted in the full replacement of the matrix by host tissue after 2 years of follow-up.

CONCLUSIONS

The BioSTAR device is the first septal occluder with a totally bioresorbable matrix that is fully replaced by host tissue during the healing process. The promising results of this study support testing of the BioSTAR device in clinical trials.

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.

Percutaneous versus surgical closure of secundum atrial septal defect: comparison of early results and complications

BACKGROUND

Surgical closure of atrial septal defect (ASD) provides excellent results. Given the increasing popularity of percutaneous techniques, a comparison between the 2 methods is needed.

METHODS

Between December 1988 and June 2003, we performed 1284 procedures in 1268 consecutive patients with isolated secundum ASD. Five hundred and thirty-three patients underwent surgical repair of ostium secundum ASD (group A). Seven hundred and fifty-one consecutive patients underwent percutaneous ASD closure (group B). The following outcomes were studied: mortality, morbidity, hospital stay, and efficacy.

RESULTS

There were no postoperative deaths. The overall rate of complications was higher in group A than in group B: 44% (95% CI 39.8%-48.2%) versus 6.9 % (95% CI 5%-8.7%) (P < .0001). Major complications were also more frequent in group A: 16% (95% CI 13%-19%) versus 3.6% (95% CI 2.2%-5.0%) (P = .002). Multiple logistic regression analysis showed that surgery was independently strongly related to the occurrence of total complication (odds ratio [OR] 8.13, 95% CI 5.75-12.20) and of major complications (OR 4.03, 95% CI 2.38-7.35). The occurrence of minor complications was independently related to surgery (OR 7.33, 95% CI 4.75-11.02), childhood (OR 1.52, 95% CI 1.01-2.34), and presence of systemic hypertension (OR 1.35, 95% CI 1.01-4.41). Hospital stay was shorter in group B (3.2 +/- 0.9 vs 8.0 +/- 2.8 days, P < .0001).

CONCLUSIONS

Percutaneous ASD closure provides, in experienced hands and in highly specialized centers, excellent results with a lower complication rate and requires a shorter stay in hospital.

Patent foramen ovale and left atrial appendage: new devices and methods for closure

Transcatheter closure of atrial septal defects (ASDs) has become a routine procedure in many countries of the world. It spares many patients cardiac surgery and has proven efficacy in long-term studies. Device improvements have resulted in a continuous reduction of complications and of residual shunt frequency. ASD closure devices are also used for transcatheter closure of patent foramen ovale (PFO) for prevention of paradoxical embolism. In the past few years, there has been increasing interest in developing devices specifically designed for PFO closure. Although transcatheter closure of ASDs is well established, interventional closure of the left atrial appendage is in its development stage. Closure of the left atrial appendage is designed to reduce the risk of stroke in patients with atrial fibrillation in whom anticoagulation with Warfarin-type drugs is contraindicated. This article describes the latest developments in catheter closure of PFO and the left atrial appendage.

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.

CardioSEAL/STARflex versus Amplatzer devices for percutaneous closure of small to moderate (up to 18 mm) atrial septal defects

BACKGROUND

The Amplatzer septal occluder (ASO) allows the percutaneous closure of small to very large atrial septal defects (ASDs). The CardioSEAL/STARflex (CS/SF) can be used only for closure of small to moderate ASDs (stretch size up to 18 mm). These 2 devices are widely used in clinical practice. Therefore, a comparison of their use in the closure of small to moderate ASDs is needed.

METHODS

From December 1996 to September 2002, 274 consecutive patients (mean age 20.3 +/- 17 years) underwent percutaneous closure of small to moderate ostium secundum ASDs. The CS/SF device was used in 121 patients, and the ASO was used in 153.

RESULTS

There were no differences in age, sex ratio, or pulmonary/systemic flow ratio. Stretch size of the defect was higher in the ASO group (13.6 +/- 3.5 mm vs 15.5 +/- 3.2 mm, P <.001). Procedure time and fluoroscopy time were shorter in patients treated with the ASO (61 +/- 21 vs 75 +/- 32 min, P <.0003, and 11.6 +/- 9 vs 23.8 +/- 17.4 min, P <.0001, respectively). Residual shunt at procedure and discharge was significantly more frequent in the CS/SF group (P <.0001). There were no differences in the complication rate for the 2 groups (CS/SF 4/121 vs ASO 6/153). Length of follow-up was longer in the CS/SF group (24 +/- 14 vs 16 +/- 9 months, P =.0001). Residual shunting was significantly more frequent in the CS/SF group during follow-up, while closure rate reached 100% after 1 month in ASO group.

CONCLUSIONS

The 2 devices are clinically safe and effective in ASD closure. However, percutaneous closure of small to moderate ASDs with ASO is quicker and provides an higher rate of complete occlusion.

New echocardiographic diameter for Amplatzer sizing in adult patients with secundum atrial septal defect: Preliminary results

Anatomical atrial septal defect (ASD) diameter measured by transesophageal echocardiography (TEE) underestimates the Amplatzer septal occluder (ASO) size for ASD closure. The aim of this study is to investigate whether a new echocardiographic diameter (procedural ASD diameter) may enable precise measurements of ASO device size. Fifty adult patients with secundum ASD were evaluated by TEE for percutaneous closure. The procedural ASD diameter was measured using the steadier rim borders where thickness was 2.5 mm. Out of the 50 patients, 12 were considered unsuitable for Amplatzer device closure. The other 38 patients underwent percutaneous closure. The mean anatomical ASD diameter was 14.8 +/- 7.0 mm, the mean procedural ASD diameter measured 19.5 +/- 8.1 mm, and the mean stretched balloon diameter (SBD) was 20.0 +/- 8.0 mm. ASO device size was 20.1 +/- 8.0 mm. At linear regression analysis, a high correlation (r = 0.99) was found between procedural ASD diameter and SBD. Procedural ASD diameter correlates with SBD and may allow reliable prediction of Amplatzer device in an adult population undergoing percutaneous ASD closure.

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.

Five-year clinical and echocardiographic evaluation of the Das AngelWings atrial septal occluder

BACKGROUND

The late outcome of patients treated with atrial septal occluder devices remains incompletely defined. The purpose of this study was to assess the late outcome (range 4-7 years postprocedure) of patients in whom the Das AngelWings septal occluder device was implanted in the atrial septum. We report the clinical and echocardiographic outcome, at an average of 5 years following the procedure, of patients treated with the Das AngelWings device used to close either a secundum atrial septal defect (ASD) or a patent foramen ovale (PFO).

METHODS

Thirty-two patients underwent successful percutaneous closure of an atrial septal closure, patent foramen ovale, or fenestration in the lateral tunnel of their Fontan with the Das AngelWings device between June 1995 and March 1998 at Duke University Medical Center. Two of the 32 patients were lost to follow-up. The remaining 30 patients were divided into 3 groups based on indication for device implantation. Group 1 consisted of 14 patients with a secundum ASD and predominantly left-to-right atrial shunting. Group 2 consisted of 8 patients who had a PFO and who suffered a thromboembolic event. Group 3 (compassionate use) consisted of 10 patients with multiple comorbid medical problems with predominantly right-to-left shunting at the atrial level causing hypoxemia. Eight of the patients in group 3 were severely ill at the time of device implantation. The 2 remaining patients in group 3 underwent AngelWings implantation for closure of right-to-left shunting through a Fontan fenestration. Mean follow-up was 59 months.

RESULTS

There was no device embolization. No patient in the ASD or PFO/stroke group had a clinical complication. By radiographic examination, 2 of 27 patients had evidence of fracture of the nitinol framework at 2-year follow-up. Residual shunting was present in 44% at 24 hours, 20% at 1 year, and 18.8% at 2 years by use of Doppler color flow imaging and/or microcavitation echocardiographic studies. Mild mitral regurgitation caused by the AngelWings device occurred in 1 patient. One patient in the compassionate use group had a subsequent neurologic event. Five of the 10 patients in the compassionate use group died of comorbid illnesses in follow-up, none directly related to device complications.

CONCLUSION

The late clinical outcome of secundum ASD and PFO/stroke patients in this study demonstrates that Das AngelWings closure of the atrial septum is effective and safe. These data are encouraging with respect to the expanding use of other percutaneously implanted ASD occlusion devices, although late clinical safety and efficacy data are needed for the specific devices being implanted.

Indication and Techniques of Transcatheter Closure of Patent Foramen Ovale

A potential causal relationship of a patent foramen ovale (PFO) and a stroke was first suggested by Cohnheim in 1877.1 Today, this correlation is generally accepted. However, there is still no "gold standard" for the treatment of patients with presumed paradoxical embolism. This article reviews the epidemiology of and the diagnostic methods for PFO, the clinical relationship between PFO and cerebral ischemia, as well as indications and techniques for transcatheter closure of PFO. In the author's opinion, transcatheter PFO closure represents an elegant management for selected patients at risk.

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.

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.

Cardiac troponin I is increased after interventional closure of atrial septal defects

This study was designed to assess possible myocardial injury caused by interventional closure of atrial septal defects (ASDs) compared to diagnostic catheterization by measuring cardiac troponin I (cTn-I). Forty patients were enrolled; in 33 ASDs were successfully closed, while in 7 a diagnostic balloon sizing of the defect was performed only. Total cTn-I increased significantly from 0.1 to 1.9 microg/l at the end of the intervention and 2.23 at 4 hr and decreased to 1.35 at 15 hr. No significant increase could be detected in patients with diagnostic balloon sizing only or of CK/CK-MB levels either. Following interventional closure of ASDs with Amplatzer septum/PFO occluders, increased cTn-I levels for several hours indicate some transient, reversible myocardial membrane instability due to the device. Discrimination of ventricular myocardial infarction might be possible by estimating less sensitive CK and CK-MB levels only.

Transcatheter patch occlusion of experimental atrial septal defects

The effectiveness and safety of transcatheter patch atrial septal defect (ASD) occlusion were studied in 20 piglets. Experimental atrial septal defects were created by foramen ovale dilation. ASDs were corrected by polyurethane patches of two types (flat and sleeve). Specially made balloon catheters supported the patches for periods varying from 1 to 6 days; after this period, the supporting catheters were withdrawn and the patches were released. All transcatheter patches were safely embedded in the atrial septum 48 hr or more after implantation. All defects were fully occluded. One patch became infected. The transcatheter patch experimental ASD occlusion method was found effective and safe, potentially applicable in the occlusion of human ASDs.

Comparison of transcatheter closure of secundum atrial septal defect using the Amplatzer septal occluder associated with deficient versus sufficient rims

To evaluate the feasibility of transcatheter closure of secundum atrial septal defects (ASDs) associated with deficient rims (<5 mm) using the Amplatzer septal occluder (ASO), 23 patients (median age 10.7 years) underwent an attempted transcatheter closure. The patients had a deficient anterior rim of 0 to 4 mm (n = 20), an inferior rim of 2 mm (n = 2), or a posterior rim of 4 mm (n = 1) as assessed by transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE). Forty-eight patients with sufficient rims (>5 mm) who underwent closure served as controls. There were no differences between the 2 groups in ASD stretched diameter and device size (p >0.05). Of 23 patients with deficient rims, 17 (74%) had immediate complete closure compared with 44 of 48 patients (92%) with sufficient rims (p <0.05). At 24-hour and 6-month follow-up, the complete closure rates were not significantly different between the 2 groups (91% for patients with deficient rims vs 94% for patients with sufficient rims at 24 hours and 100% vs 93% at 6 months, respectively). The fluoroscopic time and procedure time were longer in patients with deficient rims (13 +/- 7 and 72 +/- 26 minutes, respectively) compared with those with sufficient rims (10 +/- 4 and 61 +/- 22 minutes, respectively). No major complications were encountered either during or after the closure procedure in both groups. Thus, transcatheter closure of ASDs associated with small anterior, inferior, or posterior rims is feasible using an ASO. Long-term follow-up data are still needed to assess long-term safety and efficacy.

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.

Choice of device size and results of transcatheter closure of atrial septal defect using the amplatzer septal occluder

The impact of device size choice on closure results was analyzed in 138 (101 females, 37 males; age 0.5-84.0 years) consecutive patients who underwent transcatheter closure of the secundum atrial septal defect (ASD) using the Amplatzer septal occluder (ASO). The balloon stretched diameter (SD) of ASD was 19.5 +/- 7.2 mm in 123 patients with single defects, and 20.4 +/- 6.6 mm for the largest defects in 15 patients with multiple ASDs. The difference (delta) between ASO size chosen for closure and the stretched diameter of the defect was calculated and divided into groups: A (delta < -2 mm); B (delta -2.0 to -0.1 mm); C (delta = 0); D (delta 0.1-2.0 mm) and E (delta > 2 mm). The results demonstrated that immediate and 24-hour complete closure rates were significantly higher in patients in groups C and D (P < 0.001). However, at 6-month follow-up, the complete closure rates were similar in patients of groups A-D, while patients of group E had a lower closure rate of 75%. The complication rates were similar in all groups. In conclusion, a choice of a device size identical to or within 2 mm larger than the SD of the defect should be used to maximize the closure rates of ASD using the ASO.

Comparison between transcatheter and surgical closure of secundum atrial septal defect in children and adults: results of a multicenter nonrandomized trial

OBJECTIVES

This study sought to compare the safety, efficacy and clinical utility of the Amplatzer septal occluder (ASO) for closure of secundum atrial septal defect (ASD) with surgical closure.

BACKGROUND

The clinical utility of a device such as the ASO can only be judged against the results of contemporaneous surgery.

METHODS

A multicenter, nonrandomized concurrent study was performed in 29 pediatric cardiology centers from March 1998 to March 2000. The patients were assigned to either the device or surgical closure group according to the patients' option. Baseline physical exams and echocardiography were performed preprocedure and at follow-up (6 and 12 months for device group, 12 months for surgical group).

RESULTS

A total of 442 patients were in the group undergoing device closure, whereas 154 patients were in the surgical group. The median age was 9.8 years for the device group and 4.1 years for the surgical group (p < 0.001). In the device group, 395 (89.4%) patients had a single ASD; in the surgical group, 124 (80.5%) (p = 0.008) had a single ASD. The size of the primary ASD was 13.3 +/- 5.4 mm for the device group and 14.2 +/- 6.3 mm for the surgery group (p = 0.099). The procedural attempt success rate was 95.7% for the device group and 100% for the surgical group (p = 0.006).

CONCLUSIONS

The early, primary and secondary efficacy success rates were 94.8%, 98.5% and 91.6%, respectively, for the device group, and 96.1%, 100% and 89.0% for the surgical group (all p > 0.05). The complication rate was 7.2% for the device group and 24.0% for the surgical group (p < 0.001). The mean length of hospital stay was 1.0 +/- 0.3 day for the device group and 3.4 +/- 1.2 days for the surgical group (p < 0.001). Mortality was 0% for both groups. The early, primary and secondary efficacy success rates for surgical versus. device closure of ASD were not statistically different; however, the complication rate was lower and the length of hospital stay was shorter for device closure than for surgical repair. Appropriate patient selection is an important factor for successful device closure. Transcatheter closure of secundum ASD using the ASO is a safe and effective alternative to surgical repair.

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.

Cost implications of closure of atrial septal defect

We sought to evaluate the relative cost of surgical and device closure of atrial septal defect. Device closure for atrial septal defects is becoming an alternative to surgical closure. We examined the hospital-generated cost data in 13 patients who underwent surgical repair and 15 patients who underwent device closure of an atrial septal defects (ASD) or patent foramen ovale (PFO) during a prospective clinical trial of the device. The cost of device closure of ASD was 7,837 dollars less on average than surgical closure when the cost of the occlusion device was excluded (device closure cost 7,397 dollars +/- 2,822 dollars, surgical closure cost 15,234 dollars +/- 3,851 dollars; P < 0.001). When adjusted for a 5% failure rate of device closure, the cost savings was 7,076 dollars. Device closure of ASD results in substantial hospital-related cost savings that will be an important consideration once new devices are approved for clinical use.

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.

[Percutaneous closure of atrial septal defect with the Amplatz device: initial result and mid-term follow-up]

OBJECTIVES

Percutaneous device occlusion of atrial septal defects (ASD) is, although with some limitations, an alternative to surgical closure. The aim of this study was to evaluate the efficacy and safety of percutaneous ASD closure using the Amplatz device.

PATIENTS AND METHODS

From October 1999 to March 2000, 25 children underwent transcatheter closure of ASD at a mean +/- SD age of 8.7 +/- 3.1 years (range 3-15 years) and a mean weight of 31.8 +/- 16.7 kg (range 11-84 kg). Device selection was based on the stretched diameter of the ASD using the PTA OS balloon. The device was implanted under ultrasonographic and radiological guidance. All patients showed signs of volume-overload of the right ventricle. The ASD was single (n = 21), with two separate holes (n = 2), or cribiform (n = 2).

RESULTS

The median +/- SD size of the device used was 21.7 +/- 5.4 mm (range 15-36 mm). In twenty-two patients (88%) the device was successfully implanted. A repeat echocardiogram was performed the next day before discharge. Two patients underwent surgery after deployment of the device due to mitral valve dysfunction (n = 1) or residual leak (n = 1). In a patient with a two-hole ASD, another device was percutaneously withdrawn, while still attached to the delivery cable due to incomplete occlusion.

CONCLUSION

a) Transcatheter occlusion with the Amplatzer device is an effective treatment for ostium secundum atrial septal defects; b) the low complication rate and the short hospitalization period makes this procedure the treatment of choice in these patients, and c) ASD which are too large, cribiform or with deficient rims may require a different approach.