Patent foramen ovale closure is a medical procedure performed to close a patent foramen ovale (PFO), which is a small, flap-like opening in the wall between the right and left atria of the heart. This opening is present in all individuals before birth but usually closes shortly after birth. In some cases, it remains open, potentially leading to complications such as stroke or heart failure. The closure procedure involves using a device to seal the opening, preventing blood from flowing between the atria.