Left Atrial Appendage Occlusion (LAAO)

Overview

Left atrial appendage occlusion (LAAO), also called left atrial appendage closure (LAAC), is a minimally invasive procedure to reduce the risk of stroke associated with atrial fibrillation (AFib). AFib is a common abnormal heart rhythm or arrhythmia. By itself, AFib is usually not life-threatening, but for most people, the most dangerous aspect of AFib is its risk of stroke.

During an AFib episode, blood sits still inside the small portion of the heart known as the left atrial appendage (LAA). Sitting still can cause blood to clot. If a blood clot forms in the LAA, it can travel with the bloodstream to the brain and cause a stroke. Most people who have AFib take oral anticoagulants (OAC) - blood-thinning medications that prevent blood clots. For people who have trouble with these medications, LAAO procedures are an alternative treatment option to prevent blood clots from forming in the LAA and causing a stroke.

How LAAO works

The LAA is a blind-ending pocket attached to the upper left chamber of the heart. It serves no purpose, similar to the appendix, and is a leftover from embryonic development. In people with AFib, the LAA is the main site for blood clot formation due to blood pooling in this pocket. When a blood clot forms there and travels out, it can be pumped by the heart's main chamber (left ventricle) to any part of the body, potentially causing serious problems like a stroke if it reaches the brain. Closing the LAA lowers the risk of blood clots that can lead to stroke and generally does not affect the heart's normal function.

Types of LAAO procedures

LAAO is performed using a device that plugs the opening of the LAA (occlusion, with a device called WATCHMAN or Amulet). Both devices close off the LAA so blood can’t enter and exit there. This strategy eliminates the opportunity for blood to form dangerous clots that could leave the heart and cause a stroke or other dangerous conditions.

Alternatively, a cardiac surgeon can perform LAA closure with a clamp (AtriClip) or a suture during a cardiac surgery. This procedure is typically performed for people undergoing cardiac surgery for another reason (i.e. bypass or valve surgery).

During the LAAO Procedure

The physician performing the procedure, a specialized cardiologist called an interventional cardiologist or cardiac electrophysiologist, will use real-time imaging from an ultrasound probe to guide them to successfully implant the LAAO device. Ultrasound (echocardiography) imaging is performed either via transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE). Both approaches have their pros and cons, and patients should discuss the tradeoffs with their physicians.

Comparison of ICE vs. TEE

Characteristics	ICE (Ultrasound via catheter in the heart)	TEE (Ultrasound via catheter in the esophagus)
Invasiveness	Minimally-invasive – 1/8-inch catheter placed under local anesthesia and sedation through a leg vein.	Semi-invasive – involves insertion of a 1/2-inch tube through the mouth and into the esophagus for ~45 minutes. No skin is broken.
Sedation	Moderate sedation – patient is sleepy but breathing independently and may be aware of operator speaking and touching	General anesthesia – patient is asleep and paralyzed with a breathing machine
Preparation	Patients typically asked to fast	Patients always asked to fast
Procedure Time	Lower	Higher
Risk of Complications	Low (<5%)	Low (<5%)
Types of Potential Complications	Puncture to walls of heart Bleeding in space around the heart (a risk inherent with any procedure involving a catheter in the heart Infection at point of incision	Gastrointestinal bleeding Trauma to the gastrointestinal tract Aspiration
Recovery Time	Faster	Longer
Availability	Lower	Higher
Contraindications		Gastrointestinal bleeding Trauma to the gastrointestinal tract
Other Considerations	Learning curve for the operator