Patent Foramen Ovale (PFO) & Catheter-based Procedures
What is a patent foramen ovale (PFO) closure device placement procedure?
Catheter-based procedures are commonly used to diagnose and treat heart-related problems, such as clogged arteries and heart attacks. A catheter can also be used to guide the placement of a patent foramen ovale (PFO) closure device - which becomes a permanent implant - that will close the hole (prevent the flap from opening) in the heart wall.
A cardiac catheterization is a procedure in which a catheter (a long, thin, flexible, hollow tube) is slowly moved into the heart. The catheter is inserted into a large vein through a small incision (cut), made usually in the inner thigh (groin area), and then is advanced into the heart. One or more tests will be done to measure the PFO and to be sure there are no other defects.
An imaging test called angiography (an injection of a certain type of dye followed by an X-ray motion picture) may be used to get a better view of the heart. An ultrasound imaging technique known as an intracardiac echo (ICE) will also be used to see the defect better and also to determine the size of the closure device needed.
The ultrasound imaging device is also advanced up to the heart through the vein. In addition, a special balloon on a catheter may be moved to the area of the hole and inflated to measure the size of the hole when it is gently stretched to be sure the correct device size is chosen. The ICE allows your doctor to see the heart structures and blood flow as the hole is being gently stretched by the balloon, and also as the device is being placed to close the defect.
A PFO closure device is moved through the vein to the heart, and specifically to the location of the heart wall defect. Once in the correct location, the PFO closure device is formed so that it straddles each side of the hole. The device will remain in the heart permanently to stop the abnormal flow of blood between the two atrial chambers of the heart. The catheter is then removed and the procedure is complete.
How long does the PFO closure procedure take?
The cardiac catheterization procedure for a PFO closure typically takes one to two hours to complete. A local anesthetic is used to numb the groin area where the catheter was inserted. Use of general anesthesia or intravenous (IV) sedation depends on the situation (doctor preference and the patient’s needs).
What types of PFO closure devices are available?
There is currently one device (the Amplatzer® PFO occluder) approved by the FDA specifically for PFO closure. Devices approved to close other types of holes (atrial septal defect or ventricular septal defect) can also be used to close a PFO. PFO closure devices currently being used at Cleveland Clinic include the GORE® CARDIOFORM Septal Occluder and the Amplatzer® PFO occluder.
The GORE® CARDIOFORM Septal Occluder consists of a wire frame made of a nickel-titanium metal alloy covered with a thin membrane made of Gore-Tex, a material that has been used in open heart surgery for more than 20 years. Once the device is passed through the catheter, it opens up to form one circular disk that covers the hole on the left side and one disc on the right side of the septum. Your doctor will choose an occluder device that is slightly larger than the size of the defect. Over time, the patient's own tissue grows into and around the device.
The Amplatzer® PFO occluder consists of two expandable discs with a connecting waist, all made of a nickel-titanium metal alloy. The discs have a polyester mesh inside to enhance elimination of flow across the hole. This is a slightly bulkier device than the GORE® CARDIOFORM Septal Occluder. Your doctor will select the device that best fits the anatomy of your hole.
How does the catheter-based PFO closure procedure compare with the use of medication?
Three clinical trials comparing the catheter-based procedure for PFO closure with medical therapy (the blood-thinning drugs aspirin or warfarin) have been completed. Two did not show a clear difference between PFO closure and medical therapy. One trial suggested that while the rate of new strokes in both treatment groups was very low, patients who underwent PFO closure and were treated with blood-thinning drugs (most often aspirin) had a lower rate of new strokes than patients treated with blood-thinning drugs alone.
A study analyzing data pooled from all three trials also suggested that PFO closure decreased the rate of recurrent (repeated) stroke in comparison to medical therapy. Other clinical trials are underway to further evaluate this question.