Initial Experience using 2 novel Occlutech devices in pediatric patients – the atrial flow regulator and the fenestrated atrial septal defect occluder

Background
Of the many transcatheter implantable devices used for the treatment of congenital heart defects there have been none designed specifically to reduce the size of an existing defect (i.e. decrease the size of a Fontan fenestration) or close a secundum atrial septal defect [ASD] whilst preserving a fenestration in the setting of pulmonary arterial hypertension [PAH]. Two novel Occlutech devices (fenestrated ASD occluder [fASD] and the atrial flow regulator [AFR]) have direct application to the pediatric population but data on procedural and short to medium term outcomes are limited.

Methods
Retrospective review of pediatric patients who underwent implantation of the fASD and AFR at a single referral center from 2016-2018.

Results
Four patients (75% male, mean 8.6 ± 3.0 years old) underwent successful device implant (3 fASD, 1 AFR). Three fASD patients had large secundum ASDs - 2 with PAH and 1 diastolic dysfunction. The patients with PAH had elevated pulmonary vascular resistance (4.2 and 11.5 iWu) with inducible left to right shunts (Qp:Qs 1:1 and 1.2:1 increased to 1.7 and 1.6:1 with vasodilator testing). They were able to escalate vasodilator therapy post-implant and had improved results on a 6-minute walk test (428 m to 533.5 m). One AFR patient had significant cyanosis (72%) after Fontan palliation related to an oversized fenestration and had improved saturations after device implant (87%). Patients were maintained on warfarin alone or in conjunction with aspirin for at least 6 months and all 4 fenestrations were patent by echocardiography up to 6 months post-implant. The only procedural complication was 1 fASD embolization which was retrieved without complication. This patient underwent a successful implant of a larger device at a subsequent catheterization.

Conclusions
AFR and fASD implantation is safe and feasible in a variety of clinical settings in pediatric patients with congenital heart disease. Patients experienced improvement in subjective and objective measures of clinical well-being after device implant. Device fenestrations remain patent in the short-medium term without any device related complications. These devices could have other applications with creating small ASDs for right or left atrial decompression.