Entering the LAA
Entering the LAA is difficult in these cases because of the small size of the residual communications. After confirming no residual thrombus in LAA, in 4 of 5 cases, a 4mm ablation catheter (Biosense Webster, Irvine, CA) was used to enter the LAA through the residual communication under TEE guidance. Once the catheter tip was advanced into the LAA, it provided the necessary support to advance the requisite delivery sheath into the LAA through the narrow neck of the communication (Figures 1A, 2A, 3E ). In the patients with prior surgical closure, the neck was small and either the ablation catheter or the sheath were occlusive of the communication as noted by contrast injection (Figure 1A, Figure 2B ). For Amplatzer placement, an Agilis sheath (Abbott, St Paul MN) was used for device delivery (n=3, large curl Agilis in 2 cases). For placement of a WATCHMAN device, the Boston Scientific WATCHMAN sheath (Boston Scientific, St Paul MN) was advanced into the LAA over the ablation catheter (Table 2 ). In all cases, when the sheath tip was visualized in the LAA, the ablation catheter was withdrawn.