Transcatheter fenestration of hemi-Fontan baffles after completion of Fontan physiology using balloon dilatation and stent placement.

De novo transcatheter fenestration of hemi-Fontan baffles has not been previously described. The purpose of this report is to present our experience in such de novo transcatheter fenestration in two consecutive patients with absent fenestration in whom the hemi-Fontan baffle was the only direct access to the pulmonary venous atrium.