PFO treatment closes the Patent Foramen Ovale (PFO) through blood thinning medicines or a catheter-based procedure to close the hole. PFO closure may be achieved through open heart surgery or through a transcatheter procedure using an occlusion device.However, it may cause serious complications under certain circumstances. 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. Most people with a patent foramen ovale don't need treatment. However, it may cause serious complications under certain circumstances. Objective. Randomization and Trial Treatment. It requires no treatment or followup. Congenital lesion resulting in a defect in the fossa ovalis smaller than an atrial septal defect.