Enlargement of the Excluded Left Atrial Appendage With Thrombus

Abstract

SummaryWe report progressive enlargement of the excluded left atrial appendage (LAA) with a thrombus in a patient who had undergone valve surgery and endocardial suture closure of the LAA previously. Echocardiography and CT detected no communication between the LAA and the left atrium. Magnetic resonance imaging showed the LAA was filled with fresh and old thrombi. Coronary arteriography demonstrated small left coronary artery-LAA fistulae. At surgery, successful exclusion of the LAA was confirmed after removal of the thrombi. Persistent inflow of blood through the coronary artery fistulae to the excluded LAA may be the primary mechanism of this pathology. (Int Heart J 2017; 58: 144-146) Key words: Atrial fibrillation, Embolism, Exclusion of the left atrial appendage, Left atrium I n patients with atrial fibrillation (AF), exclusion of the left atrial appendage (LAA) is recommended to prevent thromboembolic events, [1][2][3] and it can be accomplished with various techniques such as suture ligation or stapling devices. 4) Generally, the successfully excluded LAA is filled with a thrombus and the thrombus eventually organizes late after exclusion. 5)In this paper, we report progressive enlargement of a successfully excluded LAA that was filled with a thrombus in a patient who had undergone valve surgery and endocardial suture closure of the LAA previously, and discuss a pathophysiologic mechanism of enlargement of an LAA with a thrombus.The current study was approved by our Institutional Research Ethics Board at St. Mary's Hospital, and patient consent was waived. Case ReportA 79-year-old woman with persistent AF was admitted for an abnormality on cardiac silhouette. The patient had a history of valve surgery for rheumatic valve disease and endocardial suture exclusion of the LAA 13 years before. On admission, she was asymptomatic and on anticoagulant therapy with warfarin. Chest X-rays showed moderate cardiomegaly with progressive local protrusion of the left border of the cardiac silhouette. Transthoracic echocardiography (TTE) revealed a dilated left atrium (LA) and normally functioning aortic and mitral prosthetic valves. A solid mass, 45 × 51 mm in size, which was just adjacent to the body of the LA and was clearly demarcated from the enlarged LA, was also delineated on both TTE and chest CT, but contrast enhancement of the mass was not observed on CT ( Figure 1A, 1B). Magnetic resonance imaging demonstrated that the mass contained fresh and old thrombi ( Figure 1C, 1D). Coronary arteriography revealed normal arteries, however, small fistulae from the left coronary artery to the LAA were observed (Figure 2). Based on these findings, enlargement of the successfully excluded LAA filled with a thrombus was suspected. Surgical removal of the LAA was planned because of its expanding nature. Intraoperative transesophageal echocardiography (TEE) showed no communication between the LA and the LAA. After dissection of the pericardium through a median sternotomy, the solidified and enlarged LAA was found and was ...