Left Atrial Appendage Closure (LAAC)
Left atrial appendage closure (LAAC) is a minimally invasive procedure that’s used to reduce the risk of stroke that comes with atrial fibrillation (Afib). Afib is a common form of arrhythmia, a condition in which the heart beats out of rhythm. By itself, Afib is usually not life-threatening. There are a number of ways to treat this common condition. For most patients, the most dangerous aspect of Afib is its link to stroke. During an Afib episode, blood can collect inside the small portion of the heart known as the left atrial appendage (LAA). If a blood clot forms and then escapes from the LAA, it can travel to the brain and cause a stroke. This is why most people who have Afib take blood-thinning medications that prevent blood clots. For patients who have trouble with these medications, LAAC procedures are a newer treatment option that prevents blood from traveling into and therefore preventing any blood clots from exiting the LAA causing a stroke.
How LAAC works
LAAC actually refers to different techniques that close or seal off the LAA of the heart. The LAA is a hollow sac located just off the top chamber of the heart. The LAA serves no known purpose, much like the appendix. In fact, doctors have found that in people with Afib, the LAA is the primary location for possible blood clot formation due to the low flow into this sac. When a blood clot comes out of the LAA it then can be sent to the main pumping chamber of the heart (left ventricle) and then be sent out to the body which can cause a myriad of problems including a stroke when it travels to the brain. Closing off the LAA reduces the risk of blood clots that can lead to stroke, and fortunately, it doesn’t seem to prevent the heart from functioning normally.
Types of LAAC procedures
LAAC can be performed using a technique that sews the LAA sac closed (ligation, often with a tool called Lariat) or with a device that plugs the LAA closed (occlusion, with a device called WATCHMAN or with the Amplatzer Cardiac Plug). In both techniques, the goal is to close off the LAA so blood can’t enter the sac and collect there. This strategy eliminates the opportunity for blood to pool and form dangerous clots that could eventually escape the heart and cause a stroke or other dangerous conditions.
- LARIAT – The LARIAT procedure involves guiding catheters through the blood vessels to the heart's LAA. The catheters are used to tighten a loop around the mouth of the LAA, tying it off from the rest of the heart.
- WATCHMAN or AMPLATZER Cardiac Plug – The WATCHMAN is a tiny, umbrella-shaped device that’s delivered to the heart through a catheter. Once the catheter is in place at the opening to the LAA, the WATCHMAN is implanted in the LAA so that it blocks blood from entering the LAA. The AMPLATZER Cardiac Plug, while shaped differently, is implanted much like the WATCHMAN, and also to prevent blood flow into the LAA.
- Surgical clamping – In some cases, your medical team may recommend that the LAA be clamped shut. This requires open-heart surgery and is usually performed during another operation such as coronary bypass surgery or valve surgery.
If you undergo a LAAC procedure with the LARIAT or WATCHMAN device, you’ll have a test called a transesophageal echocardiogram (TEE), which checks to make sure the closure is complete and also rules out the presence of any remaining blood clots. You’ll need to take blood-thinner medications for a period of time following the procedure. This permits the body to heal over the site of the closure effectively sealing off the LAA permanently. Your team will also recommend taking aspirin indefinitely to reduce the risk of blood clots forming anywhere else in your heart and blood vessels.