Percutaneous closure of the left atrial appendage: The value of real time 3D transesophageal echocardiography and the intraoperative change in the size of the left atrial appendage.

OBJECTIVE: The aim of this study was to investigate the value of real time three-dimensional transesophageal echocardiography (RT3DTEE) in percutaneous closure of the left atrial appendage (LAAC). In addition, this study also explored the change in the size of the left atrial appendage (LAA) from 24 hours before the operation to just before implantation during the operation.

METHODS AND RESULTS: In a retrospective study, 32 patients underwent two-dimensional transesophageal echocardiography (2DTEE) and RT3DTEE 24 hours prior to operation and during operation. The maximal LAA orifice diameter (by 2DTEE, 22.7 ± 2.7 vs 24.6 ± 2.2 mm, P < 0.01; by RT3DTEE, 24.2 ± 2.9 vs 25.8 ± 2.7 mm, P < 0.01), the maximal landing zone diameter (by 2DTEE, 19.0 ± 2.8 vs 20.4 ± 2.8 mm, P < 0.01; by RT3DTEE, 20.4 ± 2.7 vs 22.6 ± 3.0 mm, P < 0.01), and the maximal depth diameter (by 2DTEE, 25.2 ± 3.2 vs 26.5 ± 3.0 mm, P < 0.01; by RT3DTEE, 26.4 ± 3.2 vs 27.5 ± 3.7 mm, P < 0.01) all increased significantly during the operation. The highest correlation (R) between the maximal landing zone diameter and the compressed occluder diameter was determined for RT3DTEE measurements during the operation (R = 0.90), whereas the landing zone diameter (R = 0.80) measured by 2DTEE was less correlated. In addition, our study showed that RT3DTEE was of great value in discriminating the LAA orifice shape, allowing differentiation of the LAA morphology and identification of the number of LAA lobes.

CONCLUSIONS: A certain amount of intravenous rehydration just before and during operation increased the LAA size significantly. The measurements by RT3DTEE showed a closer correlation to LAA occluder size than those by 2DTEE. The LAA displayed by RT3DTEE was more visible than that by 2DTEE.