A Patent Foramen Ovale (PFO) is a common heart condition where a small opening exists between the two upper chambers of the heart, the atria. While often harmless and asymptomatic, a PFO can sometimes require a medical intervention known as PFO closure. This procedure seals the opening, typically to prevent certain health complications.
Understanding a Patent Foramen Ovale
A PFO is a small, flap-like opening situated in the wall, or septum, that separates the heart’s two upper chambers, the right and left atria. This opening, called the foramen ovale, is a normal and necessary part of a baby’s circulation before birth, allowing blood to bypass the non-functional lungs and directing oxygenated blood from the placenta directly to the rest of the fetal body.
After birth, when a baby takes its first breath and the lungs begin to function, pressure changes in the heart typically cause this flap to close naturally. The tissue usually grows together, sealing the hole permanently. However, in approximately 1 in 4 adults, this opening does not fully close, remaining “patent”.
A PFO is often discovered incidentally during medical examinations for other conditions, as most individuals with a PFO experience no symptoms. The presence of a PFO itself usually does not cause problems or require treatment unless specific complications arise.
Reasons for PFO Closure
One of the most common reasons for PFO closure is to reduce the risk of cryptogenic stroke. In individuals with a PFO, a blood clot, often from the legs, can travel to the right side of the heart. Instead of being filtered by the lungs, this clot can pass through the PFO into the left side of the heart and then travel to the brain, causing a stroke.
PFO closure may also be considered for certain cases of migraine with aura. Some studies suggest a higher prevalence of PFO in people with migraine with aura. The mechanism might involve tiny clots or certain chemicals bypassing the lungs and reaching the brain to trigger migraine attacks.
Another indication for PFO closure is decompression sickness, commonly known as “the bends,” particularly in divers. Nitrogen bubbles that form in the blood during diving can bypass the lungs through a PFO and enter the arterial circulation, potentially leading to decompression sickness. PFO closure may reduce the risk of recurrent events in divers who have experienced severe decompression sickness.
The PFO Closure Procedure
A PFO closure is a percutaneous, catheter-based procedure, avoiding open-heart surgery. The process typically begins with local anesthesia in the groin, often with conscious sedation or general anesthesia for comfort. Patients may need to fast and temporarily stop certain medications, such as blood thinners.
A small incision is made to access a large vein. A catheter is then inserted and guided through the blood vessels to the heart. Imaging techniques, such as X-ray (fluoroscopy) and echocardiography, are used to visualize the heart and guide the catheter precisely to the PFO.
Once the catheter reaches the PFO, a specialized closure device is threaded through it. These devices are typically umbrella-like or disc-shaped, designed to straddle the opening and seal it. The device is deployed to cover the hole, and its position is confirmed with imaging before the catheter is removed. The entire procedure typically takes about 30 minutes to an hour.
Recovery and Outlook After PFO Closure
Following a PFO closure, patients are usually monitored in a recovery area and may have a short hospital stay. There might be some minor discomfort or bruising at the groin incision site. Patients are typically advised to keep the leg straight for a few hours and limit strenuous activities, heavy lifting, and bathing for about a week or more.
Medications are commonly prescribed after the procedure to prevent blood clots. This often includes a combination of antiplatelet drugs, such as aspirin and clopidogrel, for several months, followed by aspirin alone for an extended period. Regular follow-up appointments are scheduled, including imaging tests like echocardiograms, usually at around 6 months, to confirm the device’s proper placement and ensure the PFO is fully sealed.
Over time, the body’s natural tissue grows over and around the implanted device, integrating it into the heart wall and sealing the PFO. PFO closure has high success rates in sealing the opening and can significantly reduce the risk of recurrent strokes in selected patients. The long-term outlook is generally positive, with low rates of complications.