In this heart surgery, the surgeon uses stitches to close the PFO . A PFO closure fills an opening between your heart's two upper chambers.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. 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. Int J Cardiol 2010;14–10. The foramen ovale usually closes 6 months to a year after the baby's birth. PFOs, on the other hand, are normal before birth but may fail to close after birth. A patent foramen ovale (PFO) is a hole in the heart that didn't close the way it should after birth.