Comparison of imaging techniques to assess appendage anatomy and measurements for left atrial appendage closure device selection.

BACKGROUND: The adequate device size selection for left atrial appendage closure is crucial to ensuring adequate implantation and for avoiding the need for multiple attempts that increase the risk of complications. Our aim was to evaluate the information obtained using different imaging techniques to select the size of the closure device in a clinical environment. METHODS: Thirty-seven patients who consecutively underwent implantation of Amplatzer cardiac plug (ACP) devices were studied. All patients were examined using computed tomography (CT) prior to intervention. Measurements were compared to those obtained using intraoperative transesophageal echocardiography (IOTEE) and angiography. Size was determined by the longest axis of the appendage ostium. The influence of all techniques on the correct selection of final size was assessed. RESULTS: The measurements taken using the three techniques agreed in only 21.6% of the cases, leading to accurate selection of device size. Two techniques coincided as follows: IOTEE-CT in 45.9%, angiography-CT in 35.13%, and angiography-IOTEE in 24.3%. Measurements using CT were definitive for ACP selection in 75.7% of cases, angiography in 48.6%, and echocardiography in 51.4%. Device size was undermeasured with angiography in 35.1% of cases, and with IOTEE in 24.3%; CT overmeasured 21.6% of cases. The combination of angiography-CT was the most accurate for selection of device size. CONCLUSION: CT most often predicts the appropriate device size. If it fails, it usually overestimates the size. Agreement of measurements with all three techniques is the most accurate situation; when two agree, the most accurate combination is angiography and CT.

Anatomical classification of left atrial appendages in specimens applicable to CT imaging techniques for implantation of amplatzer cardiac plug.

BACKGROUND: Certain anatomical characteristics of the left atrial appendage (LAA) are associated with complexity in the implantation of occluder devices. OBJECTIVE: The aim was to define characteristics measurable by three-dimensional imaging that would predict complexities both in the implantation procedure and the selection of the appropriate device size. METHODS: An anatomical study was performed of 50 postmortem hearts, of which 15 had a history of atrial fibrillation, and of 30 consecutive patients undergoing LAA occlusion with the Amplatzer cardiac plug (ACP). The specimens were classified according to variables that can be visualized using computerized tomography (CT). The CT scans of 30 consecutive patients were classified according to the level of the LAA ostium, the left lateral ridge (LLR), the LAA limbus and distance from LAA to the mitral annulus before undergoing LAA occlusion, and the results were correlated. RESULTS: Three types of LAA orifice were defined: type I, with a usually higher, anterior LAA ostium, a short, flattened and wide LLR and almost nonexistent limbus; type II, presenting a long, pointed and narrow LLR, and a longer, more defined limbus; type III, with a lower LAA ostium, close to the left atrium floor and the mitral annulus, a marked separation from the left pulmonary vein orifices and a limbus of intermediate length. CONCLUSION: LAA with lower ostia are more difficult to occlude. Types II and III have very prominent LLRs with longer limbi, which may increase the difficulty of inserting the guide and making measurements for selection of the right ACP size.