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How is a PFO closed using a catheter-based procedure?
Catheter-based procedures are commonly used to diagnose and treat
heart-related problems. For example, catheter-based procedures are used to
diagnose and treat clogged arteries and heart attacks. A catheter can also be
used to guide the placement of a patent foramen ovale closure device - which
becomes a permanent implant - that will close the hole (prevent the flaps from
opening) in the heart wall.
To further briefly explain what happens in a PFO catheter-based procedure, a
cardiac catheterization involves slowly moving a catheter (a long, thin,
flexible, hollow tube) into the heart. The catheter is initially inserted into a
large vein through a small incision 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 better visualize the heart. An ultrasound imaging
technique, to see the defect better and also to determine the size of the
closure device needed, may be used. One technique, intracardiac echo (ICE),
involves passing an imaging device up to the heart through the vein in the
patient’s other leg. Another technique uses an ultrasound probe passed down
the esophagus (transesophageal echo, or TEE) to allow your doctor to see the
heart structures and blood flow as the device is being placed. In addition, a
special balloon on a catheter is moved to the area of the hole and inflated
across the hole in order to measure the size of the hole when it is gently
stretched.
A PFO closure device is moved through the catheter to the heart and
specifically to the location of the heart wall defect. Once in the correct
location, the PFO closure device is allowed to expand its shape to straddle each
side of the hole. The device will remain in the heart permanently to stop the
abnormal flow of blood between the two atria chambers of the heart. The catheter
is then removed and the procedure is complete.
How long does the procedure take?
The cardiac catheterization procedure for a PFO closure typically takes 2 to
4 hours to complete. A local anesthetic is used to numb the groin area where the
catheter was inserted. Use of general anesthesia or sedation by IV is situation
dependent -- depending on doctor preference and particular patient needs.
What types of PFO closure devices are there?
Two major types of PFO closure devices are currently being used at the
Cleveland Clinic - the CardioSEAL® Occluder and the StarFlex® Occluder.
The
CardioSEAL® Occluder is available for use under humanitarian device
regulations. For more information on use of the CardioSEAL® Occluder under
humanitarian device regulations, see the document, "Humanitarian Device
Exemption (HDE)."
The CardioSEAL® Occluder consists of a two wire frameworks to which two
small pieces of polyester fabric are attached. The metal in the framework and
the fabric are the same that is used in implants in other open-heart and other
surgeries. The implant looks like two opened square umbrellas, with the two
opened sides directly against each other. Special spring coils in the framework
help hold the device in place, with one "umbrella" positioned on each
side of the defect. Pressure from the blood in the heart also helps to keep the
device in place. 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 fabric and metal framework.
The StarFlex® Occluder is a newer version of the CardioSEAL®
Occluder and is an investigational device in the United States. It is approved
for use in countries outside the United States, but is only currently available
to US patients who are enrolled in a clinical trial. To learn more about
participating in the StarFlex® Device clinical trial, see the document,
"The StarFlex® Septal Occluder of Patent Foramen Ovale (PFO): The CLOSURE
I Trial."
How does the body react to a permanent implant?
The materials used in the closure device products have a proven long-term
safety history and have been widely used in heart surgery procedures. It’s not
likely that the body will have a negative reaction to these devices. Within a
few days, the body’s own tissue will begin to grow over the device. By 3 to 6
months, the device is completely covered by heart tissue and at that point
becomes a part of the wall of the patient’s heart.
The patient will not be able to feel the device. The implant will not be
affected by airport or other security sensors, or by any household appliances,
or medical imaging methods. However, the clarity of medical images may be
slightly reduced because of the wire frame on the occluder devices. For this
reason, be sure to inform the imaging technician that you or your child has such
a device in your heart. You will receive an identification card that should be
carried with you/or by your child to show to medical personnel if necessary.
Can a catheter-based PFO closure procedure be used in all cases?
No. At the present time, the FDA has approved the use of the CardioSEAL®
Occluder for a very specific indication. The StarFlex® Occluder is available in
the United States only to patients enrolled in the CLOSURE I trial, a trial
being conducted at the Cleveland Clinic.
The desire to close PFOs through a nonsurgical, catheter-based procedure
(such as with the CardioSEAL® Occluder) is gaining doctors’ interest. These
methods may avoid the long-term need for powerful blood-thinning medications
(the most often used current method of treatment) and still reduce the risk of
recurrent stroke or TIA.
How does the catheter-based PFO closure procedure compare with the use of
medication?
The catheter-based procedure has not been compared with medical therapy (the
blood-thinning drugs aspirin, warfarin) for PFO closure in the "gold
standard" format for comparison, a clinical trial. One of the goals of a
trial at the Cleveland Clinic, the CLOSURE I trial, will be to determine how
these two approaches to PFO closure compare in this scientific format. To learn
more about this clinical trial, see the document, "Participating in the
CLOSURE I Trial for the StarFlex® Septal Occluder System."
Doctors who are using or studying the CardioSEAL® or the StarFlex®
Occluders believe the primary advantage of these catheter-based approaches is
that they permanently seal the defect, making the long-term use of
blood-thinning medications unnecessary in some patients. They also believe this
approach may reduce the risk of a recurrent stroke or transient ischemic attack
as much as medications have been shown to do. Although this has not been proven
yet in a scientific clinical trial, such a trial is currently underway.
Your doctor will discuss these two treatment alternatives with you in order
to make the best decision for you or your child.
What follow-up tests and home care instructions are typically given following
a catheter-based procedure for PFO closure?
Within 24 hours after the procedure, a chest x-ray, electrocardiogram, and
echocardiogram are conducted to make sure that the device is positioned
correctly. Bed rest in the hospital for 6 hours after device placement is
required. The patient may go home the evening of the procedure or possibly the
following morning. The patient may experience minor pain at the catheter
incision site and a slight sore throat for a few days if an ultrasound probe was
used to check device placement. The patient will be instructed not to lift
anything greater than 10 pounds for 1 week after the procedure. Your doctor will
discuss when you or your child can return to regular activity (usually within a
week).
Your doctor will prescribe medications that will need to be taken at home.
Aspirin or other blood-thinning drug will need to be taken daily for 6 months or
longer to prevent blood clots from forming. Antibiotics will also need to be
taken 1 hour before certain medical procedures (for example, dental
cleaning/dental surgical procedures as well as certain surgeries) for up to 1
year post device placement. Your doctor will provide information on which
procedures will require antibiotic pre-treatment.
As with all medications, take them only as directed by your doctor, never
stop taking the medication without talking with your doctor first, and call your
doctor if you experience unpleasant reactions or have any concerns about the
medication.
Finally, a few follow-up return trips to the hospital will be necessary over
the next year to monitor the patient’s heart and device placement. Each visit
-- at 1 month, 6 months, and 1 year -- will include a chest x-ray,
electrocardiogram, and echocardiogram.
If you have any questions regarding this procedure, contact:
Kim Brown, RN, BSN
216/444-5380
800/223-2273 ext. 45380
brownk@ccf.org
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