Patients who do need treatment may take medicines or have a percutaneous coronary intervention to close the PFO. In more serious cases, surgery may be needed.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. A patent foramen ovale (PFO) is a hole in the heart that didn't close the way it should after birth. In this heart surgery, the surgeon uses stitches to close the PFO . Note: This policy does not apply to individuals < 18 years of age and does not apply to atrial septal defect closure. Probabilities for freedom from reintervention are depicted at 5- and 10-year follow-up. If you have a PFO and low blood oxygen levels or an unexplained stroke, you may need a procedure to close the hole. A PFO closure fills an opening between your heart's two upper chambers.