Use of Amplatzer fenestrated atrial septal defect device in a child with familial pulmonary hypertension

Feasibility, safety, and efficacy of Atrial Flow Regulator in children under 10 kg

INTRODUCTION

The Atrial Flow Regulator (AFR) is a new self-expandable percutaneous-delivered fenestrated device providing an interatrial shunt. Its use in pediatric population has been reported in failing Fontan, pulmonary hypertension, or in patients with cardiomyopathy and venoarterial extracorporeal membrane oxygenator (ECMO) support. Its use in small children under 10 kg has not been reported.

METHODS

We report the initial single center experience of the AFR implantation in children below 10 kg.

RESULTS

Four children underwent AFR implantation. Patients' age and weight ranged between 9 and 22 months and 5-8.7 kgs. Indications were to unload the left atrium during ECMO support for end-stage cardiomyopathy and to enlarge a restrictive interatrial shunt in two other patients with complex congenital heart diseases. Devices implanted were AFR-6 and AFR-8. Delivery sheaths used via venous femoral access were undersized and ranged from 9 to 11 Fr. Devices were successfully implanted and provided unrestrictive interatrial shunt in all cases. One child developed a nonocclusive thrombus in the inferior vena cava which resolved within 1 month. Clinical improvement and femoral vein patency were observed in all cases.

CONCLUSION

AFR implantation is feasible in selected children under 10 kg. The AFR can be safely deployed through sheaths that are 1-2 Fr smaller than the recommended manufacturer size. More studies are needed to confirm safety and efficacy of the device in selected pediatric patients.

Interventionelle Behandlungsverfahren der pulmonalen Hypertension im Kindesalter

Die pulmonale Hypertension (PH) ist eine progressive Gefäßerkrankung und führt über eine Widerstands- und/oder Druckerhöhung im kleinen Kreislauf zu einem fortschreitenden Rechtsherzversagen. Auch wenn mithilfe aktueller medikamentöser Therapien eine deutliche Verbesserung der Lebensqualität und des Überlebens der Betroffenen erreicht werden konnte, bleibt die PH eine zumeist nichtheilbare Erkrankung, die im fortgeschrittenen Stadium eine Lungentransplantation notwendig macht. Interventionelle Verfahren, wie die Anlage eines interatrialen Shunts (z. B. durch atriale Septostomie oder den Atrial Flow Regulator) oder eines Reversed Potts Shunt, verbessern die RV-Funktion und die ventrikuläre Interaktion durch Schaffung einer prä- oder posttrikuspidalen „Eisenmenger-Physiologie“ und stellen eine Überbrückung oder sogar Alternative zur Lungentransplantation dar. Bei Patienten mit segmentaler PH oder chronisch thrombembolischer pulmonaler Hypertension (CTEPH) stellt die Ballonangioplastie eine bereits etablierte Intervention zur Verbesserung der pulmonalen Perfusion und damit rechtsventrikulären (RV-)Funktion dar. Dagegen ist die pulmonalarterielle Denervation ein neuartiges Verfahren, mit dem Ziel, die neurohumorale Dysregulation bei PH positiv zu beeinflussen. Der individuelle Einsatz solcher Interventionen, additiv zu den bereits etablierten medikamentösen Therapien, erweitert die Behandlungsmöglichkeiten und kann die Prognose betroffener Patienten noch weiter verbessern.

Implantation of an Atrial Flow Regulator in a Child on Venoarterial Extracorporeal Membrane Oxygenator as a Bridge to Heart Transplant: A Case Report

BACKGROUND

Balloon dilation and stenting of the atrial septum are techniques used to unload left heart cavities in acute or end-stage heart failure in children. However, they carry significant risks such as tamponade or device embolization.

CASE PRESENTATION

We report the first case of a child with an end-stage mitochondrial cardiomyopathy on a venoarterial extracorporeal membrane oxygenator as a bridge to heart transplant where an atrial flow regulator device has been implanted.

CONCLUSIONS

This case illustrates the feasibility and safety of atrial flow regulator implantation in this setting. This procedure allowed to wean inotropic support while awaiting heart transplantation.

Interventional Therapies in Pulmonary Hypertension

Despite advances in drug therapy, pulmonary hypertension-particularly arterial hypertension (PAH)-remains a fatal disease. Untreatable right heart failure (RHF) from PAH eventually ensues and remains a significant cause of death in these patients. Lowering pulmonary input impedance with different PAH-specific drugs is the obvious therapeutic target in RHF due to chronically increased afterload. However, potential clinical gain can also be expected from attempts to unload the right heart and increase systemic output. Atrial septostomy, Potts anastomosis, and pulmonary artery denervation are interventional procedures serving this purpose. Percutaneous balloon pulmonary angioplasty, another interventional therapy, has re-emerged in the last few years as a clear alternative for the management of patients with distal, inoperable, chronic thromboembolic pulmonary hypertension. The current review discusses the physiological background, experimental evidence, and potential clinical and hemodynamic benefits of all these interventional therapies regarding their use in the setting of RHF due to severe pulmonary hypertension.

Interventional and surgical therapeutic strategies for pulmonary arterial hypertension: Beyond palliative treatments

Despite significant advances in pharmacological treatments, pulmonary arterial hypertension remains an incurable disease with an unreasonably high morbidity and mortality. Although specific pharmacotherapies have shifted the survival curves of patients and improved exercise endurance as well as quality of life, it is also true that these pharmacological interventions are not always accessible (particularly in developing countries) and, perhaps most importantly, not all patients respond similarly to these drugs. Furthermore, many patients will continue to deteriorate and will eventually require an additional, non-pharmacological, intervention. In this review we analyze the role of atrial septostomy and Potts anastomosis in the management of patients with pulmonary arterial hypertension, we summarize the current worldwide clinical experience (case reports and case series), and discuss why these interventional/surgical strategies might have a therapeutic role beyond that of a "bridge" to transplantation.

Atrial septostomy in patients with pulmonary hypertension: should it be recommended?

Treatment options for patients with advanced pulmonary hypertension (PH) are limited. Iatrogenic creation of an interatrial communication (i.e., atrial septostomy [AS]) has been suggested as a possible treatment option or as a bridge to transplantation in selected patients and has been incorporated into current PH guidelines. Uptake of the procedure has been slow and the worldwide experience with AS is limited to approximately 280 published cases, over a period of more than 25 years. The rationale for creating an AS has been provided by the observation that patients with congenital heart disease, shunt lesions and PH have a better survival compared with patients with idiopathic PH. We review pathophysiologic data and the published clinical experience and discuss the rationale, indication and potential pitfalls of AS in patients with severe PH.