Atrial Septal Defect Closure with Occlutech(®) ASD Fenestrated Device in a Child with Severe Pulmonary Hypertension

A North American, single-center experience implanting fenestrated atrial devices and atrial flow regulators into a heterogeneous group of pediatric pulmonary hypertension patients

INTRODUCTION

The clinical deterioration commonly experienced by pediatric patients with pulmonary arterial hypertension (PAH) has motivated a shift in the treatment of pulmonary hypertension (PH) through innovations in surgical salvage interventions. The Occlutech fenestrated atrial septal defect (FASD) Occluder and the atrial flow regulator (AFR), which provides a protective, atrial-level shunt during hypertensive crises, have found an important role in treating pediatric patients with PAH. Other groups of pediatric patients with PH may also benefit from a similar protective physiology. The primary aim of this work is to present a single center's experience with AFR and FASD devices for managing a heterogeneous group of pediatric PH patients. A secondary goal is to identify hemodynamic changes and complications following device implantation.

MATERIALS AND METHODS

We performed a retrospective review of all pediatric PH patients who, after being found suitable, either successfully or unsuccessfully received an FASD or AFR device between January 2015 and December 2021 at the Stollery Children's Hospital in Edmonton, Canada.

RESULTS

Fourteen patients (eight female) with a median age of 4.6 (range 0.3-17.9) years and a median body mass index of 15.1 (Q₁ = 13.8, Q₃ = 16.8) kg/m² underwent device implantation: five received FASDs, eight received AFRs, and one was ultimately unable to receive an implant due to thrombosed iliac vessels and required surgical intervention. Of the fourteen patients, seven were in group 1 (PAH), one was in group 3 (lung disease), and six were in group 5 (primarily pulmonary hypertension vascular disease) under the World Symposium PH classification. All patients were on mono-, dual-, or triple-drug PH therapy. Device stabilization was not possible for two patients, who then required a repeat catheterization. Of the group 1 patients, three AFR and three FASD implants were successful, while one FASD implant was unsuccessful due to thrombosed vessels. At a six-month clinical assessment, all group 1 patients had patent devices and improved WHO FCs.

CONCLUSION

This work presents a single center's experience with AFR and FASD implants in a heterogeneous group of fourteen pediatric patients with severe PH. This treatment strategy is novel in the pediatric population and so this work provides momentum for future studies of interventional cardiac catheterization procedures for pediatric patients with PH. Further collaborations are required to develop criteria to identify ideal pediatric candidates and optimally time interventions in order to maximize the benefits of this treatment.

Transcatheter Closure of Atrial and Ventricular Septal Defects: JACC Focus Seminar

The field of congenital interventional cardiology has experienced tremendous growth in recent years. Beginning with the development of early devices for transcatheter closure of septal defects in the 1970s and 1980s, such technologies have evolved to become a mainstay of treatment for many atrial septal defects (ASDs) and ventricular septal defects (VSDs). Percutaneous device closure is now the preferred approach for the majority of secundum ASDs. It is also a viable treatment option for selected VSDs, though limitations still exist. In this review, the authors describe the current state of transcatheter closure of ASDs and VSDs in children and adults, including patient selection, procedural approach, and outcomes. Potential areas for future evolution and innovation are also discussed.

Unconventional combination of left atrial appendage device occlusion in patients with atrial fibrillation who needed concomitant catheter interventions for underlying structural heart disease

Objectives

Left atrial appendage occlusion (LAAO) in non-valvar atrial fibrillation (AF) reduces cardioembolic strokes. Despite increased risk, trials exclude valvar AF in structural heart diseases where clots extend beyond appendage.

Methods

Patients with AF and relative risks for oral anticoagulation (OAC) needing structural interventions underwent concomitant LAAO. After six months of OAC, aspirin was continued. Transesophageal echocardiogram was done three monthly till one year and yearly thereafter. The patient demographics, procedural details, post-procedural follow-up were analyzed.

Results

Nine patients aged 51.5 ± 6.3 years with AF underwent LAAO concomitantly with balloon mitral valvotomy in four patients, atrial septal defect device closure in four and periprosthetic mitral leak closure in one patient. Six patients had heart failure, four had prior embolic events, and two had documented LAA thrombus. The mean CHADS₂VASc score was 2.44 ± 0.8 and mean HASBLED score was 3.0 ± 0.8. Devices included Amplatzer Cardiac Plug™ in six patients, LAmbre™ Lifetech device in two and Watchman™ device in one. All procedures were successful without acute complications. A patient developed pericardial effusion at six months requiring pericardiocentesis. Early device-associated thrombus in one patient resolved after OAC for six months. No embolic events occurred on follow-up.

Conclusion

On a detailed literature search, this largest LAAO experience in structural heart diseases indicates its utility. OAC for six months followed by aspirin seems to prevent thrombus formation in these patients. The only incidence of early thrombus formation indicates immunity from clot formation after device endothelialisation. Larger multicenter trials combining LAAO with structural interventions in valvular AF are warranted in developing nations.

Hemodynamic assessment of atrial septal defects

Atrial septal defect (ASD) is one of the most common congenital cardiac anomalies. ASD can present as an isolated lesion in an otherwise normal heart or in association with other congenital heart conditions. Regardless of the type of ASD, the direction and degree of shunting across the communication is mainly determined by the difference in compliance between the right and left ventricle. Hemodynamics in children is characterized by left-to-right shunting, dilated right heart structures and normal pulmonary artery pressures (PAP). Patients diagnosed at adult age often present with complications related to long-standing volume overload such as pulmonary artery hypertension and right and left ventricular dysfunction. Diagnostic catheterization is usually not indicated unless there is suggestion of pulmonary hypertension on echocardiography. In older patients and/or in those with ventricular dysfunction, measurement of left heart pressures during temporary balloon occlusion is recommended prior to device closure as it may not be tolerated. In ASD associated with other congenital malformations, shunting degree and direction will depend upon underlying condition. Restrictive ASD can result in significant hemodynamic compromise in neonates with conditions such as hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA). In most cases, hemodynamics can be estimated with echocardiography only.

Atrial septal defect closure: indications and contra-indications

Transcatheter closure has become an accepted alternative to surgical repair for ostium secundum atrial septal defects (ASD). However, large ASDs (>38 mm) and defects with deficient rims are usually not offered transcatheter closure but are referred for surgical closure. Transcatheter closure also remains controversial for other complicated ASDs with comorbidities, additional cardiac features and in small children. This article not only provides a comprehensive, up-to-date description of the current indications and contra-indications for ASD device closure, but also further explores the current limits for transcatheter closure in controversial cases. With the devices and technology currently available, several cohort studies have reported successful percutaneous closure in the above-mentioned complex cases. However the feasibility and safety of transcatheter technique needs to be confirmed through larger studies and longer follow-up.

Percutaneous closure of residual shunting in a patient with a fenestrated atrial septal defect occluder: A case report

RATIONALE

Fenestrated atrial septal defect (ASD) occlusion has been performed in patients complicated with severe pulmonary hypertension (PH). Nevertheless, the persistent interatrial residual shunting in the fenestration might increase the risk of paradoxical embolism. Percutaneous closure of fenestrated ASD occluder (ASO) has not yet been reported.

PATIENT CONCERNS

A 26-year-old patient with a 25-mm ASD and severe PH underwent ASD closure using a Memory ASO with a waist of 32 and 6-mm custom-made fenestration. Echocardiography revealed the fenestration remained 6 mm and the pulmonary artery pressure decreased to the normal range at the 6-month follow-up.

DIAGNOSES

Persistent interatrial residual shunting in ASO.

INTERVENTIONS

Percutaneous closure of residual interatrial shunting was performed using a waist of 8-mm ASO under guidance of TEE.

OUTCOMES

The fenestration was successfully closed. Neither thromboembolism nor infection events were noted during the 12-month follow-up after the procedure.

LESSONS

This case illustrates that percutaneous closure of the residual shunting in fenestrated ASO was feasible and safe for short- and long-term.

The Medical Devices Special Access Program in Canada: A Scoping Study

New health technologies enter Canadian healthcare organizations in various ways, and understanding them is essential to the development of a pan-Canadian Health Technology Management (HTM) Strategy, now a priority of governments across Canada. One way is through Health Canada's Medical Devices Special Access Program (MDSAP), which permits unlicensed devices to be obtained by healthcare professionals. However, the circumstances around and implications of the current use of this program are not clear. A scoping literature review was conducted to clarify these and identify important roles and issues related to the MDSAP. Limited information was found on the MDSAP. Nevertheless, three themes demonstrating the roles of the MDSAP in HTM emerged: arbiter in technology selection, a route to technology procurement and facilitator of health technology innovation. No information suggesting that MDSAP is used to circumvent licensing was found. Rather, it enables desired patient outcomes and product commercialization.