This leaflet aims to give you an overview of a procedure called Patent Foramen Ovale closure in adults.
What is a PFO?
The foramen ovale is a “flap” of tissue which is part of the wall separating the two small collecting chambers (the atria) of the heart.
In the fetus, the flap is pushed wide open, allowing blood in the right atrium to cross to the left atrium – a normal part of the circulation before birth. After birth the pressure in the left atrium increases and the flap is pushed closed, although often it is not quite “watertight”, so that in small babies it is frequently possible to detect a little blood flowing across it on an ultrasound scan of the heart. When blood flow across the foramen (in either direction) is detectable this is known as a patent foramen ovale (PFO).
Many adults have a PFO
Perhaps as many as 20% of the general population, and the PFO in itself is harmless.
Stroke and PFO
With increasing age, it is possible that small blood clots form in the veins in the legs, even in people who are otherwise completely well.
If a blood clot in the leg breaks away and floats along the bloodstream it reaches the heart, and in most people, it would then usually get pumped to the lungs. This may cause very little in the way of symptoms unless the blood clot is big.
However, in a patient with a PFO there is a chance that the blood clot might reach the heart and cross the PFO to reach the left side of the heart, where the clot can get pumped to the body instead of to the lungs.
If the clot then happens to be carried to the arteries which feed blood to the brain, it can block a small artery in the brain itself, stopping blood getting to that part of the brain. If the artery remains blocked, the area of the brain which is fed by that artery will die. This is known as a stroke and can cause symptoms such as weakness down one side of the body or difficulty with speech.
Most strokes are caused by disease in the arteries (“atherosclerosis”) causing the arteries to become narrow and sometimes to block completely, or by heart disease causing blood clots to form inside the heart.
Patients who have had a stroke usually have tests to look for narrow arteries and heart disease but, particularly in young adults, sometimes no cause can be found but a PFO is detected. It is often very difficult in such cases to know whether the PFO has played a part in causing the stroke or not – although we know that it is possible for blood clots to pass through a PFO to cause a stroke, we also know that many normal adults who have not had strokes also have a PFO.
Having a stroke is very frightening and is potentially serious, so when no cause can be found except for a PFO, then doctors may think about closing the PFO in the hope of reducing the chances of the patient having further strokes in the future.
There is now very good research evidence that if patients are correctly selected closing the PFO is beneficial in terms of prevention of further stroke compared with treatment with medicines only.
Treatment for PFO closure
PFOs can be closed by a keyhole technique where a specially designed “button” is placed in the PFO through a long tube inserted into the vein at the top of the leg. The button used to close the PFO is guided into place using Xray pictures and a “transoesophageal” ultrasound scan (a “TOE”- a probe down the patient’s throat). This is usually done with a general anaesthetic. If you decide you want us to close your PFO it is important that you understand that, although PFO closure may reduce the risk of another stroke, it does not guarantee that another stroke will not occur.
Keyhole treatment carries a very small risk of death or stroke. There is also a very small chance (probably around 1 in 400) of other complications occurring, such as the device moving out of place after it has been put into the PFO. Usually this can be managed with another keyhole procedure.
Aftercare
After keyhole treatment most patients need only one night in hospital and are usually completely back to normal activities within a few days. You may have a bruise at the top of the leg, where the tube has been inserted, so we recommend a few days off work, not to drive and no heavy lifting for a couple of days.
Medicines to reduce the chances of blood clots forming on the device such as aspirin, are usually given for around 3-6 months after the procedure, by which time the device will be covered by a smooth layer of scar tissue as part of the normal healing process. We usually recommend that low dose aspirin should be continued for the rest of the patient’s life, even after successful PFO closure, as a secondary prevention of stroke.
You will be reviewed in the outpatient’s department 2-3 months after the procedure, when an echocardiogram will be performed.
Other information
If you decide to proceed, you will be placed on the waiting list. You will receive a letter through the post with your procedure date. We try to give you around 4 weeks’ notice but it’s often not possible for us to give you more than a week or two notice of the date.
Please contact the secretary
As soon as you receive your letter to confirm either by telephone or email.
This is very important
If you do not confirm in good time your slot will be offered to someone else.
Most people who are attending for a PFO closure do not need to attend a pre-assessment clinic.
If you are taking an anticoagulant drug (blood thinner) this should be stopped in advance (usually around 3 days). You will receive a telephone preassessment call approximately 2 weeks prior to the date of the procedure”.
Please make sure you have had a recent dental check-up and all outstanding dental treatment has been completed before the procedure due to the small risk of endocarditis (infection in the heart).
If you receive the date for your procedure and become unwell, or something has changed since your clinic appointment, please contact the specialist nursing team who will advise whether any further tests are necessary.
We appreciate it can be quite a wait between your clinic appointment and your procedure so, if in the time waiting for your procedure you have any questions or concerns, then please contact the specialist nursing team who will be happy to assist you.
You can watch a video about a PFO patient consultation here:
PFO (Patient Foramen Ovale) Patient Consultation
My name is Dr. Jamie Benham, and I’m one of the interventional cardiologists here in Leeds. Thank you for taking the trouble to watch this video. We’re going to meet a patient that’s had a stroke and be referred through to us by one of the stroke doctors, but this video may also apply if you’ve had a blood clot to other parts of the body. We will tell you if we think that it’s useful for you to have watched this video. If you do have questions, please write them down. There’ll be an opportunity by telephone or if meeting us personally for you to ask those questions.
We’re about to meet Adele. She’s had a stroke unfortunately and has been referred through to see us by one of the stroke physicians outside of Leeds. Okay, we’ll go through everything with her, and then if you could meet with her as well and go through any further questions she’d have, sure that would be good. That’s great. Welcome, Adele. Thank you for coming in to see us today, Adele, and this is Bianca, one of the specialist nurses that works with us here in Leeds.
Hi Adele, Nice to meet you. Do you know why you’ve come to see us? I had a stroke, and then they said I had a hole in my heart. Yes, that’s right. So your stroke doctor has written to me and in fact sent me a list and a copy of all the investigations that you’ve had following your stroke, and they’ve not found another cause other than a hole in your heart. So you came up to see them, and you had a bubble contrast echocardiogram, where they injected some bubbles into your arm and found that they were able to cross to the left side of the circulation, which suggests that there’s a hole in the heart, and that’s why they’ve asked me to see you, okay?
I’m just going to explain to you about that and about how that can potentially be a cause of your stroke, and then we can look at treatment options and think about what your choices are going forward. So holes in the heart actually are very common; one in four to one in five adults will have a PFO, or a small flat valve that is able to open in certain circumstances, and a PFO is normal. Before you’re born, it’s part of the unborn baby’s circulation, but after you’re born, the flap of tissue should come together and close so that anything that’s going on the right side of the circulation can’t get access to the left side of the circulation, where the blood vessels to the brain come off.
So this is a model of the heart that I’ve got here, and this is the vein from which the blood vessel comes from the lower body. Now you can see, if you form blood clots in your legs or in your pelvis or abdomen, these come up into the heart, and we form those from time to time quite normally, but they should go through the lung pump into the lungs and be absorbed by the body, and that’s a normal process.
If clots form, however, and come into this chamber and are able to get through a hole in the heart through a PFO, they’re able to then access the left side of the circulation, go up the main body artery, and can then get to the brain and cause a stroke, and that’s one of the potential mechanisms for stroke in your case, because we’ve not found another reason. Unfortunately, there’s no way of proving it, so we won’t be absolutely sure that the PFO is the cause of your stroke, but it’s a likely mechanism. We would want you to stay on your anticoagulation, which your straight physician has started, even if we decide to close the hole in your heart for that reason, and we know that medical treatment is very effective at preventing a further stroke, which will be what will worry you in the future to answer the question about whether closing the PFO would prevent further stroke.
There’s been lots of really good clinical trials. I’ve got a few copies of those studies here; they were published in 2017 in the New England Journal of Medicine. I’m happy for you to have a copy of them to read. So what they did was they, for sake of illustration, took a hundred people and left them on their anticoagulation clopidogrel aspirin warfarin apixaban for example, and took a hundred people left them on their medical therapy, but also closed the hole in the heart, and then they followed those patients for between two and five years to see what would happen and count the amount of recurrent strokes that occurred, and what happened was that those were treated, that were treated medically with anticoagulation, had more recurrent strokes than those that had medical treatment and closure of PFO, so PFO closure was found to be an effective treatment to prevent recurrent stroke and that’s really why you’ve come to talk to me about the procedure today.
So the procedure itself requires you to come into hospital under our care usually as an overnight stay, but sometimes we can let you home the same day and what we do once you’re asleep or under local anaesthetic sometimes is we access the blood vessel at the top of your leg and remember that blood vessel allows us then to come up into the heart and that’s exactly where the hole is okay and what we do is we bring up a special plastic tube which we call a catheter up into the and across the hole, and we put a device in that has a disc on one side on the left atrial side pull the hole closed and then the disc on the right side comes so a double disc device to fully close off the hole and then the device is left behind and the catheter’s taken out.
Here’s an example of the device how as it would be left in your heart the body then heals over it over the course of around six months we would follow you up uh six weeks and a year after the procedure just to check that all is well, and the device would stay behind in the heart lifelong.
The procedure takes around 30 minutes or thereabouts it’s quite straightforward, but it still has risks attached to it like any medical procedure and those lists we would go through on the consent form and sign together, but they would include infection bleeding damage to the heart or blood vessel need for emergency surgery is not likely and would be a very, very low risk but not zero risk and stroke and death very very very low risk but again not zero risk and that’s why we have to weigh up the benefits and the risks and those clinical trials have done that for us and found in favour of PFO closure to prevent recurrent stroke in patients like you at a young age okay what are your thoughts on having the procedure I think I would like to proceed with the procedure.
Okay, you can decide today, or you can go away and think about it. You can phone us at any time. The specialist nurses are happy to take your questions. However simple, what would happen now? The answer is that I’ll ask my secretary to put your name on the waiting list, and then when an opportunity for you to come in arises, we’ll write to you and ask you to telephone us to confirm that it’s okay for you to attend.
Once you’ve had the procedure, you’ll stay in overnight. We’d then hope that you would go home the next day, have a day or two off work, or the rest of the week depending on how you’re feeling. You’re able to drive once you feel fit and able to do so, and I’d want you up and about as soon as possible. You might have a bruise at the top of the leg where we’ve done the procedure, but no cuts or stitches, so I wouldn’t expect you to be anything other than a little saw, just like a typical bruise. Any other questions you can help with today? Not at the moment. Thank you. Well, thank you for coming in, and we’ll be in touch soon. Thank you.
Thank you for taking the trouble to watch this video. There’s more material available in the links below the video that is very useful at reading material. We’ve put them in order of the easiest to read through to some of the more difficult material that has quite a lot of medical information within it, but you’re welcome to read as much or as little as you wish.