Evolution of left atrial appendage exclusion

Atrial fibrillation is independently associated with an increased risk of thromboembolic stroke. While anticoagulants decrease this risk, they also carry a substantial risk of bleeding. Most left atrial thrombi arise from the left atrial appendage (LAA), which has led to several investigations into surgical and percutaneous methods of LAA exclusion for stroke reduction. The PubMed database was queried, and over 400 articles were considered for inclusion in this review. Of the surgical methods of LAA exclusion, complete excision is the most effective. Other methods, including ligation and stapling, may be incomplete and associated with left atrial thrombus formation. Surgical LAA exclusion has been commonly performed during mitral valve surgery although it has not been shown to prevent stroke in many retrospective studies. In patients unable to take warfarin, several percutaneous LAA exclusion devices have been studied, including the PLAATO system, Amplatzer Cardiac Plug (ACP), Watchman device, and Lariat. Both the ACP and Watchman have shown a significant stroke reduction and improved procedural safety with greater experience. The Lariat ligates the LAA using a combined endocardial and epicardial approach but is currently associated with substantial procedural risks. With better patient selection for the different options of LAA exclusion, thromboembolic stroke protection can be maximized with fewer complication risks.