Background: Closure of the fibrillating left atrial appendage (LAA) has been recommended during valve surgery to decrease the risk of arterial embolism. However, patients undergoing surgical LAA closure have not systematically been reevaluated for complete LAA obliteration.
Methods and results: During a 12-month period, we studied 6 consecutive patients with paroxysmal (n = 3) or permanent (n = 3) atrial fibrillation who underwent surgical LAA closure at the time of valve surgery. Transesophageal echocardiography (TEE) performed 23-159 days (mean 51) postoperatively demonstrated complete LAA closure in only 1 patient. In 5 patients, incomplete LAA closure was found due to disruption of the closure line. The size of the residual LAA orifice ranged from 3 to 20 mm. There was a high flow velocity at the LAA orifice (0.33-2.2 m/s), whereas flow in the LAA body was low (<0.2 m/s). Spontaneous echocardiographic contrast (SEC) in the LAA had newly developed (n = 3) or was much more intense than preoperatively (n = 2). Despite therapeutic anticoagulation 2 patients showed a LAA thrombus which had not been present on the preoperative TEE, and 1 patient with SEC suffered a stroke 4 weeks after attempted LAA closure.
Conclusion: Surgical LAA closure was incomplete in most patients, resulting in blood stagnation and an increased likelihood of clot formation. Incomplete surgical LAA closure, therefore, may promote rather than reduce the risk of stroke. Intraoperative TEE is mandatory to verify complete LAA obliteration.
Copyright 2005 S. Karger AG, Basel.