A tiny device implanted in the heart can be a lifesaver for some patients with atrial fibrillation (AFib). If placed correctly, the device prevents clots from forming in the heart and causing a stroke. If not, then blood can leak behind the device and clot - actually raising the patient's risk of stroke rather than lowering it.
The bad news: Standard practice allows leaks to occur in 50% of cases.
The good news: We found a better way.
WellSpan is the first-in-the-US to anchor an in-lab 4D-CT imaging modality to ensure devices are positioned properly. CT gives us a detailed view of the device at every angle - revealing gaps around the edge that you can't see otherwise. Our approach pays off for patients, with a leak rate of only 9%.
Stewart M. Benton Jr., MD, FACC
Below I break down why these devices are necessary and how exactly 4D-CT compares to standard imaging during and after surgery.
AFib Is Common - and So Are Clots
Atrial fibrillation affects about 1 in 22 adults in the U.S. Without a strong beat to pump blood out of the heart, blood can pool and form clots in the left atrial appendage. These clots are so common that they are responsible for 9 in 10 strokes suffered by people with AFib.
Blood Thinners Can Work But Come With Risks
We typically prevent clots with blood thinners, but they aren't ideal for every patient. They have to be taken for life, and they increase the risk of internal and external bleeding. For elderly patients on blood thinners, this risk can be quite serious. Falling and hitting their head is often a life-ending injury.
That's why left atrial appendage closure devices are so valuable. They wall off the appendage so that blood can't collect there, and they do this without the risks associated with blood thinners.
But for the devices to be effective, you need to have a perfect seal. And for that you need CT.
CT Scans Show What TEEs Can't
Standard practice is to use transesophageal echocardiogram (TEE) to confirm placement of these devices during surgery and view them in follow-up appointments. But TEE doesn't show you all the angles and detail you need. A gap could be hidden along an edge you weren't able to capture. Or it could be right there in front of you, but the image is too poor to reveal it.
When CT shows me a gap, I reposition the device by a few millimeters and view it again. In our clinic, about 1 in 5 surgeries require this extra adjustment - that's 1 in 5 patients who would have a leak and never know it without 4D-CT.
Same Device, Different Story
No gaps or leaks are visible around the device. Any surgeon viewing these images would see a "perfect result" for device placement.
lntraoperative CT
4D-CT of the same device shows a different story. The dotted white line is the outline of the device. The wedge of light gray along the device's right edge, indicated by the arrow, is a gap where blood can leak behind the device and clot.
CT at 90 Days Postop
I repositioned the device to close the gap. At 90 days we see it hugging the wall of the left atria perfectly. The dark gray color inside the device proves no blood is getting behind it.
Who's a Candidate for Closure Devices
Today, left atrial appendage closure devices are a good option for people who:
- Have AFib
- Qualify for a blood thinner
- Are at risk of bleeding due to falling or medications
- Can't afford their blood thinner medication
But eligibility may expand soon. We recently participated in the CHAMPION-AF clinical trial, which compared the incidence of stroke among patients with a closure device versus that of patients taking blood thinners. When the data comes out, we should see that closure devices are equally effective at preventing stroke. And instead of saving these devices for people who shouldn't take blood thinners, we may be offering them to anyone with AFib.
For more information about this technique, please contact Dr. Benton directly at sbenton@wellspan.org or call 717-812-4605 to refer a patient.