Clinical value of plane computed tomography and three-dimensional segmented CT reconstruction for the guidance of left atrial appendage closure: a comparative study of Watchman device selection

Abstract

Objective To explore the clinical value of plane computed tomography (CT-P) and three-dimensional segmented CT reconstruction (CT-3D) before the left atrial appendage closure (LAAC) procedure by comparing the measurement of LAA and the size of Watchman device. Methods Seventy-seven atrial fibrillation patients before LAAC procedure were taken a LAA CTA examination, and the data of the LAA ostium inner diameter and depth of horizontal, coronal and digital plane by CT-P were acquired, and the maximal and the minimal dimensions of LAA landing zone on CT-3D views were measured. The measurements by CT-P and CT-3D were compared and the difference and correlation were evaluated. Then the maximum diameters of CT-P and CT-3D were compared with LAA angiography (LAA-A) diameter and the sized Watchman device. Results Seventy-three(73/77) atrial fibrillation patients achieved successful LAA occlusion with Watchman device and 4(4/77) cases failed. LAA landing zone inner diameters of horizontal, coronal and sagittal plane by CT-P were (21.1±4.8) mm, (20.7±4.4) mm and (18.4±4.5) mm respectively. The maximal LAA landing zone dimension of CT-P was (22.5±4.3) mm. The depth was (28.3±7.9) mm. The maximal dimension of CT-3D was (25.6±4.7) mm and the maximal depth was (32.5±7.5) mm. LAA landing zone diameter of LAA-A and the size of closure were (22.4±3.9) mm and (27.6±3.2) mm. Pearson correlation analysis showed that the correlation of LAA landing zone diameters between CT-P and CT-3D (r=0.748) were better than that of depth (r=0.564). Correlation between the LAA landing zone maximum diameters by CT-P to LAA-A and the sized device were 0.476 and 0.492 (P=0.000). Correlation between the LAA landing zone maximum diameter by CT-P to LAA-Aand the size of device were 0.600 and 0.632 (P=0.000). Correlation between LAA-A and the size of device was most relative(r=0.750, P=0.000). The maximal dimension of CT-3D was bigger than the measurements of CT-P maximum and LAA-A (P<0.01). Conclusions LAA landing zone maximal dimension of CT-3D was bigger than the measurements of CT-P maximum and LAA-A. Compared to CT-P, CT-3D had better correlation to the measurements of LAA-A and the size of device. Therefore, the guidance of CT-3D maybe be more accurate before LAAC for proper selection of watchman device. Key words: Computed tomography; Left atrial appendage; Atrial fibrillation