Most PFOs don't need to be closed. Most PFOs cause no symptoms or complications. Larger PFOs may cause stroke. People with symptomatic or large PFOs may benefit from a procedure to close the hole.
Ing to this model, PFOs smaller than 8 mm should be closed with a 25 mm device, PFOs 8 mm to 11 mm with a 35 mm device, and PFOs larger than 11 mm with an Amplatzer septal occluder.
Most PFOs require no treatment. People who have no risk factors for stroke or any history of traveling blood clots usually do not get treatment. Your healthcare provider may want to treat your PFO if you have had problems from these traveling blood clots, like stroke.
Now the oxygen-rich blood comes from the lungs and enters the left upper heart chamber. The pressure of the blood pumping through the heart usually forces the flap opening of the foramen ovale to close. In most people, the opening closes sometime during infancy.