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.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. In this heart surgery, the surgeon uses stitches to close the PFO . If you have a PFO and low blood oxygen levels or an unexplained stroke, you may need a procedure to close the hole. In this case, the word patent means open. 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. Patent foramen ovale (PFO) is a hole between your heart's upper chambers.