Transcatheter Closure of Atrial Septal Defects using the GORE(®) Septal Occluder in Children Less Than 10 kg of Body Weight

Biodegradable polymeric occluder with controllable locking structure for closure of atrial septal defect via interventional treatment

Atrial septal defect (ASD) is one of the major congenital heart diseases, and transcatheter closure with a cardiac occluder is a modern method to treat ASD with the advantage of mini-invasiveness over traditional surgical closure. While current occlusion devices are mainly made of non-degradable nitinol with superelasticity, the permanent existence of a metal in vivo may trigger potential complications and especially has an adverse effect on the heart development for children. However, it is challenging to invent a superelasticity-free occluder that can be delivered through a catheter but firmly locked after being opened at the target site; it is also much desired for research and development to quickly assess the feasibility of a superelasticity-free occluder in vitro. Herein, a biodegradable poly(L-lactide) (PLLA) occluder composed of a braided PLLA frame as the skeleton and a nonwoven PLLA fabric as the flow-blocking membrane is developed, and a controllable locking structure is designed to enable firm closure for a device even without superelasticity. We also suggest and justify a series of in vitro methods to assess the efficacy of the biodegradable occluder, and the results confirm the reliability of locking, water-blocking, mechanical strength and degradability. It is found that the PLLA fabric with moderate fiber density is optimal for surface endothelialization. We also carry out biological assessments; significant endothelialization and alleviated inflammation response are observed after 6 months of subcutaneous implantation into rabbits. The porcine model illustrates that the biodegradable polymeric occluder can be successfully implanted into the atrial septum via transcatheter intervention; the follow-ups have confirmed the safety and efficacy of this biodegradable polymeric occluder with the controllable locking structure.

Mid-term follow-up by speckle tracking and cardiac MRI of children post-transcatheter closure of large atrial septal defects

This is a case-control study of our experience of mid-term follow-up of 40 children who had a transcatheter closure of very large atrial septal defects group (1). All cases had an atrial septal defect device size more than 1.5 times their weight, a ratio considered a contraindication for trans catheter closure (TCC) in some previous reports. The aim of this study is to report the outcomes and mid-term follow-up of transcatheter closure of large atrial septal defects using two-dimensional conventional echocardiography, tissue Doppler imaging, and four-dimensional speckle tracking imaging, and as such to compare results of same echocardiographic examination of age-matched control group of 40 healthy children group (2). Cardiac MRI was performed on cases group (1) only to detect right ventricle and left ventricle volumes and function and early signs of complications. There was no difference between cases and matched healthy controls in terms of the assessment of left ventricle and right ventricle by two-dimensional echocardiography, tissue Doppler imaging, and four-dimensional speckle tracking imaging. Similarly, there was no statistically significant difference between four-dimensional echocardiography and cardiac MRI in their respective assessment of both left ventricle and right ventricle volumes and function. We also detected no complications by echo or by cardiac MRI after a median follow-up period of 2 years and recorded a complete remodelling of right ventricle volumes in all children studied. This points to the safety and efficiency of transcatheter closure of large atrial septal defects in children on mid-term follow-up.

Assessment of Transcatheter or Surgical Closure of Atrial Septal Defect using Interpretable Deep Keypoint Stadiometry

Automated echocardiogram interpretation with artificial intelligence (AI) has the potential to facilitate the serial diagnosis of heart defects by primary clinician. However, the fully automated and interpretable analysis pipeline for suggesting a treatment plan is largely underexplored. The present study targets to build an automatic and interpretable assistant for the transthoracic echocardiogram- (TTE-) based assessment of atrial septal defect (ASD) with deep learning (DL). We developed a novel deep keypoint stadiometry (DKS) model, which learns to precisely localize the keypoints, i.e., the endpoints of defects and followed by the absolute distance measurement with the scale. The closure plan and the size of the ASD occluder for transcatheter closure are derived based on the explicit clinical decision rules. A total of 3,474 2D and Doppler TTE from 579 patients were retrospectively collected from two clinical groups. The accuracy of closure classification using DKS (0.9425 ± 0.0052) outperforms the "black-box" model (0.7646 ± 0.0068; p < 0.0001) for within-center evaluation. The results in cross-center cases or using the quadratic weighted kappa as an evaluation metric are consistent. The fine-grained keypoint label provides more explicit supervision for network training. While DKS can be fully automated, clinicians can intervene and edit at different steps of the process as well. Our deep learning keypoint localization can provide an automatic and transparent way for assessing size-sensitive congenital heart defects, which has huge potential value for application in primary medical institutions in China. Also, more size-sensitive treatment planning tasks may be explored in the future.

Update on shunt closure in neonates and infants

Introduction: Cardiac defects that result in shunting are the most common types of congenital heart anomalies. Although these lesions can be simple, they can cause significant hemodynamic changes and can be challenging to manage in neonates and infants. Over the recent decades, the development of new transcatheter techniques and devices has made it safe and feasible to manage such defects when indicated, even in the smallest of patients. Understanding these interventional procedures is essential in order to manage those patients.Areas covered: In this article, we review the techniques and experience for closure of atrial septal defects, ventricular septal defects, patent ductus aarteriosus,as well as coronary arteriovenous malformations and fistulas in neonates and infants. Literature review of PubMed articles was performed through January 2021, with focus on the latest data and results of the usage of interventional techniques in treating these lesions specifically in this age-group.Expert opinion: Significant shunting lesions can be particularly challenging to manage in neonates and infants. Newer lower profile devices will likely continue to be developed in the future, allowing their use for transcatheter interventions in even smaller patients and those with more complex anatomy.

Open heart surgery or echocardiographic transthoracic or percutaneous closure in secundum atrial septal defect: a developing approach in one Chinese hospital

Background

To study the clinical manifestations and advantages of open-heart surgery and echocardiographic transthoracic or percutaneous closure with secundum atrial septal defect (ASD). The surgeon’s learning curve was also analyzed.

Methods

In all, 115 consecutive patients with ASD from May 2013 to May 2019 were enrolled. According to the operative procedure, patients were divided into three groups: group one (open repair group) (n = 24), where patients underwent ASD repair (ASDR) under cardiopulmonary bypass (CPB); group two (closed surgical device closure group) (n = 69), where patients (six patients ≤1 y and sixteen ≤10 kg) underwent transthoracic ASD occlusion under transesophageal echocardiographic (TEE) guidance; and group three (transcatheter occlusion group) (n = 22), where patients underwent percutaneous ASD occlusion under echocardiography. The clinical features and results of each group were analyzed. All patients were telephonically followed-up after 3 months.

Results

All the three methods treating ASD were successfully performed in our hospital. It was also a typical developing history of congenital heart disease (CHD) surgery in China. One patient in the group two was transferred to emergency surgery for occluder retrieval and CPB-ASDR. Eight patients experienced failed transthoracic or percutaneous occlusion, two of whom underwent unsuccessful percutaneous closure at another hospital. Two patients each in the groups two and three were intraoperatively converted to CPB-ASDR. Two patient in the group three was converted to transthoracic occlusion surgery. All patients were discharged without any residual shunt. The three-month follow-up also did not show any residual shunt and occluder displacement.

Conclusion

In low-weight, infants, or huge ASDs with suitable rim for device occlusion, transthoracic ASD closure was successfully performed. Based on knowledge of ASD anatomy and skilled transthoracic occlusion of ASD, surgeons can perform percutaneous occlusion of ASD under echocardiographic guidance.

Transcatheter closure of a residual shunt with posteroinferior deficient rim after surgical closure of an ASD: a case report

BACKGROUND

There are few reports in the literature of device closure of residual shunts following initial surgical closure of an atrial septal defect (ASD). This case study reports one such case. We describe here a case of secundum type ASD that was initially closed surgically, followed by device closure of a residual shunt with a posteroinferior deficient rim.

CASE PRESENTATION

A 7-month-old boy was admitted to our hospital for elective surgery to surgically correct a secundum type ASD. Unfortunately, a residual shunt 3.5 mm in diameter appeared before discharge and was enlarged at1-year follow-up. The cause of this residual shunt was dehiscence at the posteroinferior aspect, and the posteroinferior rim was 3.7 mm. After careful discussion and preparation, we proceeded with an interventional procedure. A 16 mm ASD occluder (AGA Medical Corp, Plymouth, Minnesota) was deployed successfully with no residual shunt. In some cases of ASD, interventional therapy is not considered due to the size and position of the defect, but we show here, a successful case of interventional therapy for a residual shunt with a deficient rim.

CONCLUSION

We have presented a case in which a postoperative residual shunt with a deficient rim was successfully closed with interventional therapy.

Here today, gone tomorrow: Outcomes of residual leak following secundum atrial septal defect closure with the GORE CARDIOFORM Septal Occluder

OBJECTIVE

To assess the outcomes and potential predictors of residual leak after implantation of the GORE CARDIOFORM Septal Occluder (GSO) in secundum atrial septal defects (ASDs).

BACKGROUND

The non-self-centering design of the GSO could lead to residual leak at the edge of the device. Outcomes of residual leak are poorly understood.

METHODS

Retrospective, multicenter review of patients treated with the GSO for the pivotal and continued access study. Procedural, echocardiographic, and follow up data were reviewed. Multivariate analysis was performed to determine predictors of leak at implant and outcomes of these leaks.

RESULTS

There were 370 total ASD device closures with the GSO, 65 (17.56%) of which were found to have residual leak at implantation. Patients with residual leak had larger defects (10.33 ± 3.05 mm vs. 9.13 ± 2.89 mm, p = .006) and smaller aortic rims (4.87 ± 3.33 mm vs. 6.17 ± 3.78 mm, p = .019), as compared to those without leak. Larger devices were implanted (p = .008) and more devices per case (p = .007) were utilized in the residual leak cohort as compared to those without leak. Overall, among patients with residual leak, there was a significant decrease in leak size over 1 year, from 1.55 ± 0.75 mm to 0.25 ± 0.74 mm (p < .001), with the majority (87.6%) disappearing by 12-month follow-up.

CONCLUSIONS

Residual leak at implantation can be seen after ASD device closure with the GSO, more commonly in larger defects with smaller retroaortic rims. The vast majority of these leaks completely resolve by 1 year follow up.

Biodegradable atrial septal defect occluders: A current review

Atrial septal defect (ASD) is a common structural congenital heart disease. With the development of interventional closure devices and transcatheter techniques, interventional closure therapy has become the most well-accepted therapeutic alternative worldwide, as it offers a number of advantages over conventional therapies such as improved safety, easier operation, lower complication rates and invasiveness, and shorter anesthetic time and hospitalizations. During the past decades, various types of occluders based on nondegradable shape memory alloys have been used in clinical applications. Considering that the permanent existence of foreign nondegradable materials in vivo can cause many potential complications in the long term, the research and development of biodegradable occluders has emerged as a crucial issue for interventional treatment of ASD. This review aims to summarize partially or fully biodegradable occlusion devices currently reported in the literature from the aspects of design, construction, and evaluation of animal experiments. Furthermore, a comparison is made on the advantages and disadvantages of the materials used in biodegradable ASD occlusion devices, followed by an analysis of the problems and limitations of the occlusion devices. Finally, several strategies are proposed for future development of biodegradable cardiac septal defect occlusion devices. STATEMENT OF SIGNIFICANCE: Although occlusion devices based on nondegradable alloys have been widely used in clinical applications and saved numerouspatients, biodegradable occlusion devices may offer some advantages such as fewer complications, acceptable biocompatibility, and particularly temporary existence, thereby leaving "native" tissue behind, which will certainly become the development trend in the long term. This review summarizes almost all partially or fully biodegradable occlusion devices currently reported in the literature from the aspects of design, construction, and evaluation of animal experiments. Furthermore, a comparison is made on the advantages and disadvantages of the materials used in biodegradable ASD occlusion devices, followed by an analysis of the problems and limitations of the occlusion devices. Finally, several strategies are proposed for future development of biodegradable cardiac septal defect occlusion devices.

State-of-the-Art Atrial Septal Defect Closure Devices for Congenital Heart

This article describes current devices and indications for transcatheter device closure of atrial septal defect (TC-ASD) and patent foramen ovale in children and young adults. TC-ASD has a proven record of efficacy and safety, but device erosion raises questions about the relative safety of TC-ASD versus operative open heart surgical ASD closure. New devices for ASD closure with properties to reduce risk of erosion are being developed. Recent studies demonstrating superiority of patent foramen ovale device closure over medical therapy for cryptogenic stroke may lead to changes in practice for structural/interventional cardiologists. Care should be taken in extrapolating data to children and younger adults.

Transcatheter device closure of atrial septal defects: more to think about than just closing the hole

PURPOSE OF REVIEW

To review current controversies in the transcatheter device closure of ostium secundum atrial septal defects (ASD).

RECENT FINDINGS

Transcatheter device closure of ASD (TC-ASD) has well established efficacy and safety. For most individual patients with suitable anatomy, TC-ASD is the preferred method for treating ASD. The availability of large multicenter data sets has made it possible to study practice patterns at a range of hospitals across the United States. These studies have revealed differences in practice that were not previously appreciated. Interpretation of the indications for TC-ASD, specifically the definition of right ventricular volume overload varies between hospitals. In response to concern about device erosion, an increasing proportion of patients are being referred for operative ASD closure. Over the last decade, the average age at which ASD closure occurs has decreased. These trends demonstrate previously underappreciated differences in opinion between cardiologists across the country and suggest that further research is necessary to address knowledge gaps limiting consistency of practice.

SUMMARY

As TC-ASD and congenital interventional cardiology mature as a field, studies of real-world practice provide increasingly valuable information about aspects of care in which there are disagreements about best practices and in which further research is necessary.

Transcatheter atrial septal defect closure in an infant (body weight 6.4 kg) using the GORE CARDIOFORM septal occluder (GCSO)

Introduction

Transcatheter closure has become the treatment of choice for secundum atrial septal defects (ASD II), but particularly in small children, there is concern regarding procedure-related complications.

Case description

We report on a 10-month-old infant, body weight of 6.4 kg, with a large ASD who was referred for failure to thrive and dyspnea on exertion. Echocardiography showed two neighboring ASDs centrally located within an atrial septum with a length of 27 mm resulting in significant left-to-right shunting. During cardiac catheterization, hemodynamic significance of the defect as well as normal pulmonary vascular resistance was demonstrated. Balloon sizing of the central ASD showed a stretched defect diameter of 12 × 11 mm. A 20-mm GORE CARDIOFORM septal occluder (GCSO; Goremedical, W. L. Gore & Associates, Inc., Newark, DE, USA) was implanted without any complications. Initial trivial residual shunting resolved during 4 months of follow-up. Right ventricular dimensions declined significantly, and the boy gained body weight properly.

Discussion, evaluation and conclusion

As demonstrated in our report, even large ASDs can be closed safely by catheter intervention in small infants. Selection of implant device and optimal sizing is of paramount importance. The size of the delivery sheath (11 French in our patient) is a potential limitation for the GCSO in smaller infants.