Percutaneous left atrial appendage occlusion, sometimes abbreviated as LAAO, is a keyhole procedure developed to close a small part of the heart called the appendage.

The left atrial appendage is responsible for causing the majority of strokes in patients that have atrial fibrillation.

During normal heart rhythm the heart contracts in an organised and controlled way resulting in regular blood flow through the heart. Atrial fibrillation is an irregular and chaotic heart rhythm that occurs in the upper chambers (atria) of the heart.

This abnormal heart rhythm disturbs the organised heart contraction and produces irregular blood flow through the heart.

The sac-like shape of the left atrial appendge facilitates the pooling of blood within it during atrial fibrillation. The clots form in the appendage and then break off, resulting in strokes.

The most effective treatment to prevent strokes is to take oral anticoagulant tablets such as warfarin, apixaban, dabigatran or rivaroxaban.

Unfortunately some patients are unable to tolerate these tablets or choose not to because of their higher risk of bleeding.

The alternative treatment is to close off the left atrial appendage so that no blood can flow into it and thus no clots will form.

Percutaneous left atrial appendage occlusion is an operation that uses a medical device, very similar to a plug or cover, to seal off the left atrial appendage.

The procedure takes about 1 to 2 hours and is done under general anaesthesia or deep sedation.

Recent research trials have shown that this procedure is as good as taking warfarin to reduce the risk of stroke in patients with atrial fibrillation.  Left atrial appendage occlusion offers considerable advantages such as reducing the risk of bleeding associated with oral anticoagulants, taking fewer tablets every day and eliminates the regular blood tests required for warfarin treatment.

The Atrial Fibrillation Association has more information here.

See the guidance on left atrial appendage occlusion from NICE here.