Left atrial appendage closure (also known as LAAC or LAA closure) is a minimally invasive procedure that seals off a small part of the heart where blood clots can form. People with atrial fibrillation – an irregular heartbeat that causes the upper chambers of the heart to quiver – are at increased risk for forming blood clots that can travel to the brain and cause a stroke. To understand how LAA closure can help prevent stroke, it helps to learn why and how a stroke occurs.

A Stroke Is a Life-Threatening Medical Emergency

There are two main types of stroke. In an ischemic stroke (left), a blood clot blocks the flow of blood to the brain. In a hemorrhagic stroke (right), a blood vessel in the brain breaks or ruptures, causing bleeding in the brain, which damages brain cells. People with atrial fibrillation are five times greater risk for stroke than people who do not have atrial fibrillation.

According to the American Heart Association and the American Stroke Association, strokes are the fifth leading cause of death and the leading cause of long-term disability in the United States. Every year, about 800,000 people suffer a stroke.

Ischemic stroke and hemorrhagic stroke are the two main types of stroke. In an ischemic stroke, a blood clot blocks the flow of blood to the brain. In a hemorrhagic stroke, a blood vessel in the brain breaks or ruptures, causing bleeding in the brain, which damages brain cells. Ischemic strokes are far more common than hemorrhagic strokes. You can learn more about stroke, including the symptoms to watch for, here.

There are a number of risk factors that increase the chances of having a stroke. One of the most significant risk factors is atrial fibrillation, which affects about 2.7 million people. To learn what happens to the heart during atrial fibrillation and how it is diagnosed and can be treated, visit the SecondsCount Atrial Fibrillation Center here.

Preventing Stroke

Fortunately, there are a number of strategies used to prevent stroke. Most involve an individualized plan for reducing your stroke risk factors. If you have atrial fibrillation, your medical team may recommend that you take several medications, including anticoagulants that thin the blood and help prevent it from clotting.

Some people struggle with taking anticoagulants, especially warfarin (Coumadin), because it requires regular blood tests to confirm that it is working as it should. Your medical team will probably try to find an anticoagulant medication that works for you but, if you are unable to take anticoagulant medications, your doctor may recommend trying a procedure that stops the heart from misfiring the electrical signals that cause Afib. These procedures include electrical cardioversion, ablation and surgical maze.

Left atrial appendage closure (also known as LAA closure or LAAC) is another treatment option. LAA closure is a relatively new procedure that can be used to prevent stroke in some people who have atrial fibrillation. LAAC works by sealing off the small part of the heart known as the left atrial appendage, or LAA. This prevents blood from flowing into the LAA, where it can clot. There are different approaches to closing off the LAA. Each approach uses a different device, but the goal is the same:  to prevent blood clots from forming in the LAA and then traveling through the blood vessels to the brain, where they could cause a life-threatening stroke.

How Left Atrial Appendage Closure Procedures Work

There are two main techniques used for sealing off the left atrial appendage. One, called ligation, involves tying the LAA sac closed. The other, called occlusion, implants a small device in the heart to close off the opening of the LAA sac. In both cases, the goal is to make it impossible for blood to get into the LAA where it could clot. By eliminating a major location where blood clots may form, the procedure decreases the chances that a blood clot will travel to the brain and cause a stroke. For both the ligation and occlusion techniques, patients are given general anesthesia so they are not awake for the procedure. Let’s take a look at how each technique works.

LAAC with Ligation

The goal of left atrial appendage closure with ligation procedures is to close off the entrance to the left atrial appendage and prevent blood from collecting there. As the word “ligation” suggests, the doctor or surgeon who performs LAAC with ligation will tie a small loop around the entrance to the left atrial appendage sac and then tighten it until the sac is closed. There are two LAAC ligation methods:

• Transpericardial Ligation with LARIAT: Transpericardial ligation is a minimally invasive procedure. This means that the patient’s chest does not have to be surgically opened and recovery tends to be shorter than after open-heart surgery. After the general anesthesia has taken effect and the patient is asleep, the specially trained cardiologist – usually an interventional cardiologist or electrophysiologist -- will guide small, slender tubes (catheters) through a tiny opening in the patient’s upper leg. Another is placed under the ribcage. These are the “access points” for inserting the catheters into the major vein that goes directly from the leg to the heart. The catheters will be advanced through the blood vessel to the heart. The catheter is then pushed through the heart wall (the septum), which divides the right and left upper chambers of the heart (the atria). The catheters will be pointed toward the opening of the left atrial appendage sac. A small balloon catheter with a wire inside will be placed at the tip of the left atrial appendage sac. A second wire will then be inserted through the catheter under the ribcage. The LARIAT device will be advanced over the second wire to the left atrial appendage. Once the LARIAT has been delivered to the heart, the doctor will loop it around the left atrial appendage sac and tighten it until the LAA cannot receive blood when the heart pumps.
• Surgical Ligation: Surgical ligation takes place during open-heart surgery. It is a procedure that is performed as part of another operation on or near the heart. While the heart surgeon is creating a bypass around blocked arteries or repairing a faulty heart valve, he or she may also tie (ligate) a loop around the LAA sac and tighten it to permanently seal it closed, so that blood cannot enter. Or the surgeon may remove the appendage completely. It takes about six weeks to recover from open-heart surgery, although most patients spend only a few days in the hospital.

You can learn more about how left atrial appendage closure with ligation works by clicking here.

LAAC with Occlusion

“To occlude” means to obstruct or block. In left atrial appendage occlusion procedures, a tiny device is used to block the left atrial appendage sac so that blood cannot flow into it. There are two methods for LAA closure occlusion. Both are minimally invasive, so the patient does not have to undergo open-heart surgery.

• Left atrial appendage closure with WATCHMAN: After the general anesthesia has been administered and the patient is asleep, a specially trained cardiologist will make a tiny incision into a vein that leads to the patient’s heart. The cardiologist – usually an interventional cardiologist or an electrophysiologist – will advance a long thin tube (a catheter) through the vein to the heart. The catheter will then be pushed through the heart wall (the septum) that divides the right and left upper heart chambers (the atria). The catheter will be pointed toward the opening of the left atrial appendage sac. The tiny WATCHMAN device is shaped like an umbrella. It will be delivered through one of the catheters and snugly implanted in the opening to the LAA. The WATCHMAN closes off the LAA so blood cannot get in and form clots. Over time, heart tissue grows around the WATCHMAN. You can watch a video showing how a WATCHMAN device is implanted here or click here to read more details about the procedure.
  
• Left atrial appendage closure with AMPLATZER Cardiac Plug: The AMPLATZER Cardiac Plug is another device that can be guided into the body through a blood vessel in much the same way the WATCHMAN device is delivered to the left atrial appendage. It has a different shape from the WATCHMAN device, but also will be positioned near the entrance to the left atrial appendage, so the LAA is blocked and blood cannot enter the LAA sac.

If your doctor is concerned about blood clots forming in your LAA but you are not a candidate for either type of LAA closure procedure, another approach may be considered, especially if you are scheduled to have open-heart surgery for blocked arteries (coronary bypass surgery) or a faulty heart valve. During your open-heart operation, your surgeon may remove the left atrial appendage.

Learn More

To learn more about atrial fibrillation, visit the SecondsCount Atrial Fibrillation information center.

For more information about stroke, you can go to the SecondsCount Stroke Center.

SecondsCount also includes an in-depth information center on LAA closure. Click here to visit.