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Fixing broken hearts with an umbrella
Improved imaging equipment in the new Wellington Regional Hospital has enabled cardiologists to introduce a new procedure which will save some stroke patients from a further stroke and enable them to avoid using potent blood thinners with the lifetime risk of major bleeds.
The procedure fixes a type of “hole in the heart” called a Patent Foramen Ovale (or PFO) – in which a small hole allows blood to flow from the right atrium into the left atrium.
In the foetus this is normal – with blood passing through a small channel between the two atria of the heart. In most people that channel closes off completely in the first few months of life, but around 20% of adults have a weak area where the channel used to be – and in a small minority of cases that weakness opens up to create a hole between the left and right atria.
“Sometimes that weakened area will open up, creating a hole in the heart, due to physical stress,” Wellington Hospital cardiologist Dr Alexander Sasse says.
“Divers are a particularly high risk group - a hole can open up if they have this congenital weakness and then develop air bubbles as a result of decompression,”
“PFO is often related to stroke in patients under the age of 55 – often in their 20s or 30s at an age when you would not expect people to suffer from a stroke,” Dr Sasse adds.
Until recently the only way to close that hole was open heart surgery – a step which was rarely taken due to the risk of the operation. Most patients instead needed to take the blood thinner Warfarin for the rest of their lives.
“The problem with Warfarin or other blood thinners is that if you take it regularly - and some of these patients who are young will need to take it for 50 years or more - then each year there is a 1-to-2 percent risk of a major bleed,” Dr Sasse says.
In recent years there has been growing use internationally of less-invasive approaches to treating this condition – using catheters to insert devices which block the hole.
In New Zealand this has only been possible at Auckland Hospital. Any patients from elsewhere in the country – including Wellington and the central region – have had to travel to Auckland for the procedure.
Then, earlier this month Dr Phillip Matsis and Dr Sasse began using this approach at Wellington Hospital.
“The improved xray imaging equipment we have in the new Cath Labs at Wellington Regional Hospital - along with updated echo equipment - has made it easier to diagnose this condition, and has also opened up the way for us to offer this new procedure,” Dr Phillip Matsis says.
The new procedure which he and Dr Sasse have now used on two patients, uses a small device called an Amplatzer Occluder, which is fed up through a tube into the heart, and opens up to seal the hole off.
“The best way to describe it is as being like two tiny umbrellas,” Dr Matsis says.
“We insert a catheter into the femoral vein, which is in the groin area, and feed that tube up through the veins into the patient’s heart. Our way is guided by the new imaging equipment – which gives us a clear picture every step of the way.
“Once inside the heart we thread the catheter through the existing hole between the left and right atria. At that point we pull the catheter back slightly – which allows the front half of the device to deploy – it opens up like a tiny umbrella. We then pull that open umbrella up tight against the wall between the two atria.
“We then open up a second umbrella – 25 millimetres across – on the other side of the wall where the hole is, so that it creates a physical barrier on both sides of the hole.
“In time new tissue grows across where the device is implanted, completely closing off the hole,” Dr Matsis says.
This approach – blocking the hole with a small implantable device – can be done under local anaesthetic, with the patient sedated but not requiring a general anaesthetic. They are discharged home the following morning to return back to work within 48 hours.
“The old equipment we had just didn’t have the precise imaging detail that’s needed for this sort of precise positioning of a device inside the heart,” Dr Matsis says.
Dr Sasse agrees. “This new procedure, made possible by the new imaging equipment, will make a real positive difference for these patients. It can free them from not only a lifetime of Warfarin, but also with significant reduction in the risk of bleeds and stroke.”