A Patent Foramen Ovale (PFO) closure is a minimally invasive medical procedure designed to seal a small, flap-like opening between the two upper chambers of the heart, the right and left atria. This opening, the foramen ovale, is a remnant of the circulatory system present before birth. While most people are unaware they have a PFO, it can sometimes be linked to serious medical events. The procedure uses a specialized device delivered through a catheter to permanently block the opening, typically reducing the risk of certain complications.
What is a Patent Foramen Ovale
A Patent Foramen Ovale is an anatomical variation found in approximately one in four adults, where the foramen ovale, a flap-like opening in the atrial septum, does not completely close after birth. This opening is a necessary structure in fetal circulation, allowing blood to bypass the inactive lungs. Since a fetus receives oxygenated blood from the mother, the foramen ovale shunts blood directly from the right atrium to the left atrium.
At birth, the baby’s lungs inflate and begin to function, causing a drop in pressure on the right side of the heart and an increase in pressure on the left side. This pressure change pushes the flap, called the septum primum, against the atrial septum, sealing the opening. In most cases, this flap fuses permanently within the first few months or years of life, forming the fossa ovalis.
The term “patent” signifies that the opening remains structurally open, allowing a connection between the two atria. This persistent opening may permit a small amount of blood to shunt from the right side of the heart to the left side, particularly during moments of increased pressure, such as coughing or straining. While the presence of a PFO is generally benign, it creates a potential pathway for blood clots to cross from the venous system directly into the arterial circulation.
When PFO Closure Becomes Necessary
The primary reason doctors consider PFO closure is for patients who have experienced a cryptogenic stroke (a stroke of unknown cause). In these cases, a blood clot may form in the venous system, travel to the right side of the heart, and pass through the PFO into the left side. This allows the clot to move to the brain and cause a stroke, a process known as a paradoxical embolism.
Clinical trials have demonstrated that PFO closure, when combined with antiplatelet therapy, is superior to antiplatelet therapy alone in preventing recurrent strokes in selected patients, particularly those under the age of 60. The decision often involves identifying high-risk PFO features, such as a large size or an associated atrial septal aneurysm (an excessive bulging of the tissue flap). A multi-specialty team, including a neurologist and a cardiologist, evaluates the patient to rule out other causes of stroke and determine if the PFO was the source.
PFO closure may also be considered for other conditions where the right-to-left shunt causes problems. It is sometimes recommended for deep-sea divers who have experienced decompression sickness, often called “the bends.” This occurs when nitrogen bubbles in the blood pass through the PFO and enter the arterial circulation. A PFO has also been linked to certain types of migraine headaches, particularly those with aura, and closure may be explored in patients with severe symptoms.
Details of the Transcatheter Closure Procedure
The PFO closure procedure is a minimally invasive, transcatheter intervention performed by an interventional cardiologist in a cardiac catheterization laboratory. The patient receives conscious sedation or general anesthesia for comfort during the procedure, which typically takes one to two hours. Access to the heart is gained by making a small incision, usually in the groin, to insert a catheter into the femoral vein.
The catheter is threaded through the vein, guided by imaging technologies like fluoroscopy (a form of X-ray) and echocardiography, until it reaches the right atrium. Once positioned, the catheter is maneuvered across the PFO and into the left atrium. A specialized closure device, often resembling a double-disc or double-umbrella shape made of a nickel-titanium alloy mesh, is delivered through the catheter.
The device is deployed so that one disc opens on the left atrial side of the septum and the other opens on the right atrial side, effectively sandwiching the PFO shut. The cardiologist confirms the precise position and stability of the device using imaging before releasing it permanently. Once secured, the catheter is withdrawn, and pressure is applied to the groin insertion site to stop bleeding.
Life After PFO Closure
Patients typically experience a short recovery period, often spending one night in the hospital for observation before discharge. Common post-procedure sensations include mild chest discomfort or a bruise at the groin insertion site, which are temporary. Patients are advised to limit strenuous activities, such as heavy lifting or vigorous exercise, for a short time to allow the access site to fully heal.
Antithrombotic medication is an important part of post-procedure care to prevent blood clots from forming on the newly placed device. Dual antiplatelet therapy, commonly involving aspirin and a drug like clopidogrel, is prescribed for a specific duration, typically ranging from one to six months. This regimen is maintained until the heart tissue naturally grows over and integrates the closure device, a process called endothelialization.
After the initial dual therapy period, patients are transitioned to a single antiplatelet medication, such as aspirin, which may be continued for several years or longer depending on their individual stroke risk factors. Follow-up imaging, typically an echocardiogram, is scheduled around six months after the procedure. This confirms that the device is securely in place and that the PFO remains successfully closed, ensuring the treatment is effective.