Abstract
Outcomes for children with hypoplastic left heart syndrome have improved over the years, but there remains a subgroup for which the mortality rate remains extremely high: those with an intact/restrictive atrial septum. Fetal surgical approaches for this group involve balloon septoplasty or stenting (off-label use of adult coronary stents) of the atrial septum to relieve left atrial hypertension. However, significant challenges exist with these approaches on account of atrial recoil and the lack of devices engineered for this application. We present two device concepts that demonstrate potential to address these challenges. The first is a self-expanding flanged stent that eases positioning challenges and reduces the risk of stent migration. The second is a balloon with an electrode array that uses radiofrequency electrical energy to denature the atrial septal tissue following a balloon septoplasty to reduce the degree of tissue recoil. The two device concepts were tested for first-order feasibility on an atrial septum analogue. The stent device was fabricated from a commercially available self-expanding carotid stent and the balloon device was simulated using an electrode array bonded to a dilating mandrel. Both devices successfully created a channel in the atrial septum analogue, demonstrating the feasibility of these device concepts.
