Patent foramen ovale (PFO) is a hole between your heart's upper chambers. 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. The healthcare provider inserts the catheter through a blood vessel in the groin and guides it to the PFO. Most people with a patent foramen ovale don't need treatment. Patent foramen ovale closure is a procedure to close a hole in the heart. We use minimally invasive approaches to treat PFO without open-chest surgery. Most PFOs need no treatment. People who have no risk factors for stroke or any history of traveling blood clots often don't get treatment. Your healthcare provider may want to treat your PFO if you have had problems from these traveling blood clots, like stroke.