Left Atrial Appendage Closure Device (WATCHMAN device): Indications and Risks

Your heart is made up of four chambers; the upper left and right atria and the lower left and right ventricle. These chambers contract rhythmically to pump blood to the rest of the body. Conditions like atrial fibrillation increase the risk of formation of a clot in the atria. 90% of the stroke causing clots in these patients come from a pouch in the left atrium called the left atrial appendage (LAA). Closing off this part of the left atrium from the circulation will hence reduce the risk of stroke dramatically.

Left atrial appendage closure device, the WATCHMAN device is the first of its kind to be approved by the FDA. The WATCHMAN is a parachute shaped device that comes in various sizes. It is used to cut off the left auricle from the blood flowing through the heart hence preventing it from releasing clots that might cause stroke. This device has been shown to non-inferior to anti coagulation therapy in reducing the risk of stroke. The devise consists of a semi spherical frame made from nitinol and covered by a specialized coating to prevent the formation of clot on it.

WATCHMAN Device Procedure 

This procedure is done under general anaesthesia. Your doctor will administer anaesthetic through an intra venous line in your arm. After the anaesthesia takes effect your doctor will gain access to the vein in your groin by standard percutaneous technique. A guide wire and a vessel dilator are introduced into the heart via this vein. The progression of the wire is monitored with the help of x-ray while the heart in monitored by a trans esophageal echocardiogram (TEE,a device producing and receiving ultrasound is introduced into your food pipe to monitor and visualise the chambers of the heart on a screen). After reaching the right atrium through the vein, the guide wire crosses over to the left atrium by piercing the septa separating both the atrium. An access sheet is then advanced over this guide wire into the left atrium. The sheet is navigated to the left atrial appendage. The size and shape of the left atrial appendage are examined with the help of the TEE and an appropriate WATCHMAN device is selected, employed and released over the left atrial appendage. After checking for proper placement of the device the access sheet and the guide wire are withdrawn from the heart and the vein. The wound site in the groin is closed.

Indications for WATCHMAN device

The WATCHMAN is indicated for individuals with non valvular atrial fibrillation who cannot be on blood thinners due to high risk of bleeding, provided they can tolerate short term anti coagulation treatment.

Preparation

To prepare for this surgery your doctor will request for a trans esophageal echography (TEE) to check for presence of blood clots in the left atrial appendage. Your doctor might also order other tests to evaluate the health of your heart like an electro cardiogram and a holter monitoting. The doctor would like to know about all the medications that you’ve been taking and might make some changes in them. You will be asked to stop eating and drinking eight hours before the surgery.

Complications of WATCHMAN device

As with all medical procedure this surgery has a set of risks associated with it, they are:

• Infection
• Bruising and bleeding
• Arrhythmia
• Damage to structures of the heart
• Formation of blood clot on the device
• Dislodging of the device
• Improper placement of the device
• Stroke .

Recovery after WATCHMAN device

Following the procedure you will be monitored overnight in the hospital and will be allowed to go home the next day. It is advisable to arrange for someone to drive you home. Your doctor will ask you to take warfarin and aspirin for atleast the first 45 days after the surgery. This will be followed by a regimen of clopidogrel and aspirin followed by only low dose aspirin. You will have a follow up visit scheduled with your doctor to check if the left atrial appendage has been sealed off appropriately by the surgery.

Resources

• https://www.watchman.com/en-us-hcp/laac-nvaf-patients/watchman-laac-device-procedure.html
• www.heart.org
• www.hrsonline.org