Left Atrial Appendage Exclusion

The left atrial appendage (LAA) is a small, finger-shaped pouch off the left atrium. In atrial fibrillation (AF) blood pools in it, and up to 90% of the clots that cause AF-related strokes start there. Closing it off during heart surgery lowers the stroke risk for patients with AF, and it is now a standard add-on to valve, bypass and Maze operations in these patients. The appendage must be closed right at its base, leaving a stump of less than about 1 cm, and with no leak, because an incomplete closure may raise the risk of clots and stroke. There are four common ways to do it, and the surgeon picks one for each patient: an epicardial clip (such as the AtriCure AtriClip) placed around the base from the outside, which also suits minimally invasive approaches; surgical excision (amputation) of the appendage with the opening sewn closed with pledgeted polypropylene; excision with a vascular stapler; or closure from inside the left atrium with a purse-string or layered suture after the atrium is opened for mitral or Maze surgery. Excision and clip methods close the appendage completely more often than inside sutures, which leak more often. If there is clot in the appendage, it is cut out rather than clipped or sewn shut from inside. The scrub person's job depends on the method: the clip must be sized and handled exactly as its maker directs and cannot be repositioned once released; stapler cartridges must be ready in the size the surgeon wants; and pledgeted sutures must be loaded for the stump. TEE is used before and after to look for clot and to check for leaks into the appendage. The main risks are bleeding or tearing at the base, injury to the nearby circumflex coronary artery, and an incomplete closure.