Patent foramen ovale and atrial septal defect closure is a routine procedure to close holes in the upper chambers of the heart. A patent foramen ovale, or PFO, is a special type of hole between the upper chambers of the heart.Patent foramen ovale (PFO) is a congenital cardiac lesion which is generally asymptomatic and affects up to a quarter of the population. The foramen ovale is a hole in the wall between the left and right atria of every human fetus. This hole allows blood to bypass the fetal lungs. Percutaneous closure of a patent foramen ovale (PFO) reduces the risk of recurrent cryptogenic stroke specifically in younger patients.