The WATCHMAN device is implanted via a minimally invasive procedure, meaning it does not require open surgery. A cardiologist - usually an interventional cardiologist or electrophysiologist - uses tiny tubes called catheters to deliver the device to the left atrial appendage (LAA). It is carefully placed to block blood flow into the LAA, where blood clots can form and contribute to a stroke. Media provided courtesy of Boston Scientific. © 2015 Boston Scientific Corporation or its affiliates. All rights reserved.

If you have atrial fibrillation and are unable to take anticoagulant medications, it is possible your doctor will recommend a procedure known as left atrial appendage closure (LAAC or LAA closure). This procedure helps reduce the risk of stroke. There are different types of LAA closure techniques. One of these includes use of the WATCHMAN device.

WATCHMAN is a new method of left atrial appendage closure for stroke prevention that was approved by the U.S. Food and Drug Administration (FDA) in 2015. The FDA approved this device for patients who have atrial fibrillation and need an alternative to blood-thinning medications, such as warfarin (Coumadin).

The WATCHMAN device works through a process known as occlusion. To “occlude” means to obstruct or block. The WATCHMAN blocks off the left atrial appendage (LAA) and prevents any blood from entering it. The LAA is a small pouch that sits on the top-left part of the heart. In people with atrial fibrillation, blood tends to pool and form clots in the LAA. The clots can then move through the bloodstream to the brain, where they can block blood flow and cause an ischemic stroke.  Blocking the LAA so blood cannot flow into it greatly reduces the chance of an ischemic stroke.

What Is the WATCHMAN?

The WATCHMAN is a device approximately the size of a quarter that is shaped like an umbrella or parachute. It is made of a surgical fabric with small metal barbs that hold it in place against the walls of the heart and the LAA.

Once a WATCHMAN device is implanted, it remains permanently in the heart. Initially it stops blood from entering the LAA. Over time, heart tissue forms over and around the device, permanently sealing off the opening to the LAA and completely preventing blood from getting in and forming a clot.

A WATCHMAN device only needs to be placed one time, since once it is in position and working, you will not have to undergo the procedure again, barring any complications.

How the WATCHMAN Is Implanted

The WATCHMAN procedure is performed a specially trained cardiologist who has experience using tiny tubes (catheters) to treat problems in the blood vessels and the heart. The WATCHMAN device is delivered from a blood vessel in the upper leg into the heart. Once in place in the heart, the device blocks blood flow into the left atrial appendage, where many stroke-related blood clots tend to originate. © 2015 Boston Scientific Corporation or its affiliates. All rights reserved.

The WATCHMAN left atrial appendage closure procedure is minimally invasive. This means that it is not necessary to make an incision in the chest. WATCHMAN procedures are typically performed in a cardiac cathetherization laboratory (where angioplasty is performed) or in an electrophysiology laboratory (where pacemakers are implanted).

During the procedure, you will be under general anesthesia for the whole procedure, which typically takes about an hour. This means that you will be asleep through the procedure and will wake up when it is over.

At the beginning of the procedure, your cardiologist will perform a transesophageal echocardiogram to ensure that there are no blood clots in your heart. After the test, your cardiologist will continue with the procedure.

While you are asleep, your doctor will create a very small incision in your upper leg. Your doctor will guide thin, flexible tubes (catheters) into a blood vessel in your leg and up to the heart’s left atrial appendage. The catheter in the vein in your leg will be used to perform a transseptal puncture, to push the tip from your heart’s right upper chamber (right atrium) to its left upper chamber (left atrium). Once the catheters are in place, the WATCHMAN device will be guided through a catheter. The device will remain collapsed until it reaches the LAA sac. Once the WATCHMAN is in place at the entrance to the LAA, the doctor will open the WATCHMAN and carefully position it so that it completely blocks the LAA. Once the device is in place, the catheters will be backed out of the body and the WATCHMAN will remain in place, where it will do its job of keeping blood from entering the LAA.

Complications May Occur During LAA Procedures

Throughout the procedure, your doctor will use imaging tools to carefully track the movement and placement of the device in your blood vessels and heart. Nevertheless, like all procedures, there are risks associated with left atrial appendage closure. For example, once the transseptal puncture is performed, it is possible for a blood clot to form in the catheter or for air to get into the catheter and be injected into the heart. If a blood clot or air travels to the brain, it could cause a stroke. Physicians are aware that these complications can occur and so they take steps, such as flushing out the catheter, to minimize these risks.  

Another possible complication is rupture of the left atrial appendage. This complication may occur because the left atrial appendage is a relatively thin-walled structure devices and the device may apply some pressure on the LAA while it is being implanted. This is a potentially disastrous complication that requires emergency heart surgery.

To learn more about the risks and benefits associated with LAA procedures, click here.

Before & After Your LAAC WATCHMAN Procedure

If you are having an LAAC procedure, your medical team will provide detailed information about what you need to do before the procedure to prepare and what you can expect to happen after the procedure is concluded. For more general information, check out these SecondsCount resources:

To watch a video that shows how left atrial appendage closure may be used to help prevent stroke in people with atrial fibrillation, click here.

What to Expect Before LAA Closure Using Occlustion and the WATCHMAN Device

What Happens After LAA Closure Using Occlusion and the WATCHMAN Device