Planned reduction in Fontan fenestration size using the Atrial Flow Regulator.

Fontan fenestration allows right-to-left shunting increasing cardiac output and oxygen delivery. Increased shunting occurs as cardiac function and ventricular end-diastolic pressures improve, potentially decreasing oxygen saturation. Complete closure may result in impaired Fontan haemodynamics and low cardiac output; however, there are no dedicated devices to reduce fenestration size. We describe Fontan fenestration size reduction using the Atrial Flow Regulator.