Technology & Innovations
The Watchman Device
An important recent innovation for patients is the Watchman Device. The theory behind the Watchman Device is most A-Fib clots originate in the Left Atrial Appendage (LAA). The Watchman Device closes off the LAA where 90-95% of A-Fib strokes come from. It’s a relatively low risk procedure compared to open heart surgery. It takes only a short time to install. Then you would usually not need to be on blood thinners.
Here’s how it works:
Once a patient’s Left Atrial Appendage is measured, a wide-sheathed catheter with a spline is used to insert the Watchman device which has a self-expanding Nitinol (a special metal) open-ended circular frame. The atrial surface of this frame is covered with a thin, permeable 160 μm (micron) pore filter made of polyester material (Polyethylene Terephthalate known as Dacron or PET). This filter allows blood to pass through while stopping clots. Little hooks or anchors called fixation barbs at the middle of the device make sure it is attached firmly to the LAA wall. The Watchman device comes in multiple sizes from 21mm to 33mm to accommodate the different sizes of LAAs.
Before the catheter is removed (which fixes the Watchman device in place), contrast agents are used to make sure the Watchman device is stable and entirely closes off the LAA opening. Over time heart tissue grows over the polyester (PET) material so that it completely closes off the LAA with mooth heart tissue similar to other heart surfaces. In this Occlusion slide, heart tissue has completely covered the Watchman device after only nine months.
Some doctors are inserting the Watchman device in as little as 20 minutes. There is no surgery or ablation involved.
Patients on Coumadin continue to take it for six weeks after the Watchman device is inserted. They are then examined using a TEE (Transesophageal Echocardiogram) to make sure there is complete closure of the LAA. At that time they are taken off of Coumadin.
VIDEO: A 3 minute animation of how the Watchman device is deployed (or watch at https://www.youtube.com/watch?v=1GWXBs-ly2k)
Coumadin reduces but does not totally eliminate the risk of stroke. Even with the proper INR levels of Coumadin, a small number of people with A-Fib have had strokes. The Watchman device also reduces but does not totally eliminate the risk of stroke. Like Coumadin, the Watchman is not an absolute guarantee one will never have a stroke. It basically reduces the risk of stroke similar to that of a person with a normal heart.
Those of us who hate having to take Coumadin or blood thinners will be able to go in for a procedure that takes as little as 20 minutes, and replace Coumadin and blood thinners with the Watchman. This is incredibly good news for many of us.
Even while we are waiting for or trying to decide on having a Pulmonary Vein Ablation, we can have the Watchman inserted and reduce our risk of stroke similar to that of a person with a normal heart.
The Watchman device may become part of most catheter ablation procedures. If the catheter ablation procedure were unsuccessful or in case of silent A-Fib attacks after ablation, patients would still be protected from an A-Fib stroke by the closing off of the Left Atrial Appendage. The Watchman Device may become standard therapy not just for people with A-Fib, but also for anyone at risk of a stroke.
Return to Index of Articles: Research and Innovations
Last updated: Sunday, March 29, 2015