Anatomical variations of patent foramen ovale

Failure of the atrial septum primum and secundum to fuse after birth results in the persistence of foramen ovale (Patent Foramen Ovale). Variations in the atrial septal morphology of the PFO are frequent and have important technical implications on the success of transcatheter PFO closure. Patients should be carefully selected on the basis of morphology and location of the interatrial defect to minimize the rate of complications of percutaneous closure of PFO and to avoid residual shunts that can result in recurrence of symptoms. To achieve a successful, complete closure of the PFO, a detailed understanding of PFO anatomy is required. In this chapter we will review the different anatomical variations of PFO and their clinical implications.