from all my reading I understand they can just sew it closed. there is also another device that will just clip it closed and just recently I was reading about a new process called "the lariat" which is just inserting a loop around the LAA and simply closing it off tight....interesting......there was some discussion years ago that the LAA actually has some influence on body temp...hmmmm....

What is an atrial clip?
The Procedure

The AtriClip, which is applied to the outside surface of the left atrial appendage, permanently closes the left atrial appendage at its base, preventing blood from entering the pouch. This procedure is performed by a cardiac surgeon using minimally invasive surgical techniques.

LARIAT Device
The Procedure
The second catheter-based procedure uses a device called LARIAT to place a loop stitch around the base of the left atrial appendage, permanently sealing it off from the rest of the heart and blocking stroke-causing blood clots from entering the brain. Johns Hopkins is currently the only center in the mid-Atlantic region offering LARIAT as an option. Patients who have had prior cardiac surgery are not candidates for this procedure. A CT scan will need to be performed to make certain that the left atrial appendage is not too large or has an unusual location that precludes placement of this device.

What are the risks?
The use of the suture delivery device does not require the use of immediate use of blood thinners. As with any invasive procedure, there are risks to placement of this type of device. Your doctor can go over these risks in detail.

What happens after the procedure?
You will have a follow-up appointment 45 days after the procedure.

Once the left atrial appendage is blocked, you will be followed on a routine basis by your referring physician.

https://www.ctsnet.org/article/thoracoscopic-left-atrial-appendage-closure-atriclip